Study on the CO2 electric driven fixed swash plate type compressor for eco-friendly vehicles

NASA Astrophysics Data System (ADS)

Nam, Donglim; Kim, Kitae; Lee, Jehie; Kwon, Yunki; Lee, Geonho

2017-08-01

The purpose of this study is to experiment and to performance analysis about the electric-driven fixed swash plate compressor using alternate refrigerant(R744). Comprehensive simulation model for an electric driven compressor using CO2 for eco-friendly vehicle is presented. This model consists of compression model and dynamic model. The compression model included valve dynamics, leakage, and heat transfer models. And the dynamic model included frictional loss between piston ring and cylinder wall, frictional loss between shoe and swash plate, frictional loss of bearings, and electric efficiency. Especially, because the efficiency of an electric parts(motor and inverter) in the compressor affects the loss of the compressor, the dynamo test was performed. We made the designed compressor, and tested the performance of the compressor about the variety pressure conditions. Also we compared the performance analysis result and performance test result.

Electric Energy Management in the Smart Home: Perspectives on Enabling Technologies and Consumer Behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zipperer, Adam; Aloise-Young, Patricia A.; Suryanarayanan, Siddharth

2013-11-01

Smart homes hold the potential for increasing energy efficiency, decreasing costs of energy use, decreasing the carbon footprint by including renewable resources, and transforming the role of the occupant. At the crux of the smart home is an efficient electric energy management system that is enabled by emerging technologies in the electric grid and consumer electronics. This article presents a discussion of the state-of-the-art in electricity management in smart homes, the various enabling technologies that will accelerate this concept, and topics around consumer behavior with respect to energy usage.

Electric Energy Management in the Smart Home: Perspectives on Enabling Technologies and Consumer Behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zipperer, A.; Aloise-Young, P. A.; Suryanarayanan, S.

2013-08-01

Smart homes hold the potential for increasing energy efficiency, decreasing costs of energy use, decreasing the carbon footprint by including renewable resources, and trans-forming the role of the occupant. At the crux of the smart home is an efficient electric energy management system that is enabled by emerging technologies in the electricity grid and consumer electronics. This article presents a discussion of the state-of-the-art in electricity management in smart homes, the various enabling technologies that will accelerate this concept, and topics around consumer behavior with respect to energy usage.

(Power sector efficiency analysis in Costa Rica). [Power Sector Efficiency Analysis in Costa Rica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waddle, D.B.

I traveled to San Jose, Costa Rica, to review the state of the electric power utility with a team of specialists, including a transmission and distribution specialist, a hydroelectric engineering specialist, and a thermal power plant specialist. The purpose of the mission was to determine the costs and benefits of efficiency improvements to supply side technologies employed by the Instituto Costarricense de Electricidad, the national power company in Costa Rica, and the potential contribution of these efficiency measures to the future electric power needs of Costa Rica.

Time-varying value of electric energy efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mims, Natalie A.; Eckman, Tom; Goldman, Charles

Electric energy efficiency resources save energy and may reduce peak demand. Historically, quantification of energy efficiency benefits has largely focused on the economic value of energy savings during the first year and lifetime of the installed measures. Due in part to the lack of publicly available research on end-use load shapes (i.e., the hourly or seasonal timing of electricity savings) and energy savings shapes, consideration of the impact of energy efficiency on peak demand reduction (i.e., capacity savings) has been more limited. End-use load research and the hourly valuation of efficiency savings are used for a variety of electricity planningmore » functions, including load forecasting, demand-side management and evaluation, capacity and demand response planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service. This study reviews existing literature on the time-varying value of energy efficiency savings, provides examples in four geographically diverse locations of how consideration of the time-varying value of efficiency savings impacts the calculation of power system benefits, and identifies future research needs to enhance the consideration of the time-varying value of energy efficiency in cost-effectiveness screening analysis. Findings from this study include: -The time-varying value of individual energy efficiency measures varies across the locations studied because of the physical and operational characteristics of the individual utility system (e.g., summer or winter peaking, load factor, reserve margin) as well as the time periods during which savings from measures occur. -Across the four locations studied, some of the largest capacity benefits from energy efficiency are derived from the deferral of transmission and distribution system infrastructure upgrades. However, the deferred cost of such upgrades also exhibited the greatest range in value of all the components of avoided costs across the locations studied. -Of the five energy efficiency measures studied, those targeting residential air conditioning in summer-peaking electric systems have the most significant added value when the total time-varying value is considered. -The increased use of rooftop solar systems, storage, and demand response, and the addition of electric vehicles and other major new electricity-consuming end uses are anticipated to significantly alter the load shape of many utility systems in the future. Data used to estimate the impact of energy efficiency measures on electric system peak demands will need to be updated periodically to accurately reflect the value of savings as system load shapes change. -Publicly available components of electric system costs avoided through energy efficiency are not uniform across states and utilities. Inclusion or exclusion of these components and differences in their value affect estimates of the time-varying value of energy efficiency. -Publicly available data on end-use load and energy savings shapes are limited, are concentrated regionally, and should be expanded.« less

10 CFR 490.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Efficiency and Renewable Energy or any other DOE official to whom the Assistant Secretary's duties under this... an electric motor that draws current from rechargeable storage batteries, fuel cells or other sources... batteries, fuel cells, photovoltaic arrays, or other sources of electric current and may include an electric...

10 CFR 490.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Efficiency and Renewable Energy or any other DOE official to whom the Assistant Secretary's duties under this... an electric motor that draws current from rechargeable storage batteries, fuel cells or other sources... batteries, fuel cells, photovoltaic arrays, or other sources of electric current and may include an electric...

10 CFR 490.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Efficiency and Renewable Energy or any other DOE official to whom the Assistant Secretary's duties under this... an electric motor that draws current from rechargeable storage batteries, fuel cells or other sources... batteries, fuel cells, photovoltaic arrays, or other sources of electric current and may include an electric...

10 CFR 490.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Efficiency and Renewable Energy or any other DOE official to whom the Assistant Secretary's duties under this... an electric motor that draws current from rechargeable storage batteries, fuel cells or other sources... batteries, fuel cells, photovoltaic arrays, or other sources of electric current and may include an electric...

A multi-criteria evaluation of high efficiency clothes dryers: Gas and electric

DOE Office of Scientific and Technical Information (OSTI.GOV)

deMonsabert, S.; LaFrance, P.M.

1999-11-01

The results of an in-depth analysis to address the possible solutions to save energy and mitigate environmental damage caused by clothes dryers are presented in this paper. The analysis includes an environmental evaluation of gas and electric dryers. Various dryer technologies such as microwave, heat pump, heat recovery, and other designs are analyzed. Highly efficient clothes washers with increased moisture extraction that may reduce dryer impacts are also included within the analysis. The analysis includes the development of a multi-objective decision model that is solved for the short- and long-term to provide optimal courses of action. The results of themore » analysis revealed that fuel switching from electricity to natural gas was the optimal short-term solution. This measure could save a projected 2.5 MMT of carbon emissions annually by the year 2010. The optimal long-term alternative was not clear. The results showed that the option to research and develop a new high efficiency dryer was marginally better than fuel switching.« less

Time-Varying Value of Energy Efficiency in Michigan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mims, Natalie; Eckman, Tom; Schwartz, Lisa C.

Quantifying the time-varying value of energy efficiency is necessary to properly account for all of its benefits and costs and to identify and implement efficiency resources that contribute to a low-cost, reliable electric system. Historically, most quantification of the benefits of efficiency has focused largely on the economic value of annual energy reduction. Due to the lack of statistically representative metered end-use load shape data in Michigan (i.e., the hourly or seasonal timing of electricity savings), the ability to confidently characterize the time-varying value of energy efficiency savings in the state, especially for weather-sensitive measures such as central air conditioning,more » is limited. Still, electric utilities in Michigan can take advantage of opportunities to incorporate the time-varying value of efficiency into their planning. For example, end-use load research and hourly valuation of efficiency savings can be used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service (KEMA 2012). In addition, accurately calculating the time-varying value of efficiency may help energy efficiency program administrators prioritize existing offerings, set incentive or rebate levels that reflect the full value of efficiency, and design new programs.« less

Electricity savings potentials in the residential sector of Bahrain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akbari, H.; Morsy, M.G.; Al-Baharna, N.S.

1996-08-01

Electricity is the major fuel (over 99%) used in the residential, commercial, and industrial sectors in Bahrain. In 1992, the total annual electricity consumption in Bahrain was 3.45 terawatt-hours (TWh), of which 1.95 TWh (56%) was used in the residential sector, 0.89 TWh (26%) in the commercial sector, and 0.59 TWh (17%) in the industrial sector. Agricultural energy consumption was 0.02 TWh (less than 1%) of the total energy use. In Bahrain, most residences are air conditioned with window units. The air-conditioning electricity use is at least 50% of total annual residential use. The contribution of residential AC to themore » peak power consumption is even more significant, approaching 80% of residential peak power demand. Air-conditioning electricity use in the commercial sector is also significant, about 45% of the annual use and over 60% of peak power demand. This paper presents a cost/benefit analysis of energy-efficient technologies in the residential sector. Technologies studied include: energy-efficient air conditioners, insulating houses, improved infiltration, increasing thermostat settings, efficient refrigerators and freezers, efficient water heaters, efficient clothes washers, and compact fluorescent lights. We conservatively estimate a 32% savings in residential electricity use at an average cost of about 4 fils per kWh. (The subsidized cost of residential electricity is about 12 fils per kWh. 1000 fils = 1 Bahrain Dinar = US$ 2.67). We also discuss major policy options needed for implementation of energy-efficiency technologies.« less

Overcoming the Adoption Barrier to Electric Flight

NASA Technical Reports Server (NTRS)

Borer, Nicholas K.; Nickol, Craig L.; Jones, Frank P.; Yasky, Richard J.; Woodham, Kurt; Fell, Jared S.; Litherland, Brandon L.; Loyselle, Patricia L.; Provenza, Andrew J.; Kohlman, Lee W.;

System Dynamics Modeling of Households' Electricity Consumption and Cost-Income Ratio: a Case Study of Latvia

NASA Astrophysics Data System (ADS)

Bariss, Uldis; Bazbauers, Gatis; Blumberga, Andra; Blumberga, Dagnija

2017-11-01

Increased energy efficiency of the building sector is high on the list of priorities for energy policy since better energy efficiency would help to reduce impact on climate change and increase security of energy supply. One aim of the present study was to find a relative effect of growth of demand for energy services due to changes in income, energy consumption per unit of demand due to technological development, changes in electricity price and household income on household electricity consumption in Latvia. The method applied included system dynamics modeling and data from a household survey regarding the relationship between electricity saving activities and the electricity cost-income ratio. The results revealed that, in direct contrast to the expected, a potential reduction of the electricity consumption is rather insensitive to electricity price and electricity cost-income ratio, and that the efficiency of technologies could be the main drivers for future electricity savings. The results suggest that support to advancement of technologies and faster replacement of inefficient ones rather than influencing the energy price could be effective energy policy measures. The model, developed in the study could be used in similar assessments in other countries.

78 FR 72077 - Energy Efficiency Program for Industrial Equipment: Final Determination Classifying UL...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... Verification Services Inc. as a Nationally Recognized Certification Program for Small Electric Motors AGENCY... FURTHER INFORMATION CONTACT: Mr. Lucas Adin, U.S. Department of Energy, Building Technologies Office, Mail... conservation requirements for, among other things, electric motors and small electric motors, including test...

Comparative efficiency of technologies for conversion and transportation of energy resources of Russia's eastern regions to NEA countries

NASA Astrophysics Data System (ADS)

Kler, Aleksandr; Tyurina, Elina; Mednikov, Aleksandr

2018-01-01

The paper presents perspective technologies for combined conversion of fossil fuels into synthetic liquid fuels and electricity. The comparative efficiency of various process flows of conversion and transportation of energy resources of Russia's east that are aimed at supplying electricity to remote consumers is presented. These also include process flows based on production of synthetic liquid fuel.

A system-level mathematical model for evaluation of power train performance of load-leveled electric-vehicles

NASA Technical Reports Server (NTRS)

Purohit, G. P.; Leising, C. J.

1984-01-01

The power train performance of load leveled electric vehicles can be compared with that of nonload leveled systems by use of a simple mathematical model. This method of measurement involves a number of parameters including the degree of load leveling and regeneration, the flywheel mechanical to electrical energy fraction, and efficiencies of the motor, generator, flywheel, and transmission. Basic efficiency terms are defined and representative comparisons of a variety of systems are presented. Results of the study indicate that mechanical transfer of energy into and out of the flywheel is more advantageous than electrical transfer. An optimum degree of load leveling may be achieved in terms of the driving cycle, battery characteristics, mode of mechanization, and the efficiency of the components. For state of the art mechanically coupled flyheel systems, load leveling losses can be held to a reasonable 10%; electrically coupled systems can have losses that are up to six times larger. Propulsion system efficiencies for mechanically coupled flywheel systems are predicted to be approximately the 60% achieved on conventional nonload leveled systems.

Economic and environmental comparison of conventional, hybrid, electric and hydrogen fuel cell vehicles

NASA Astrophysics Data System (ADS)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

Published data from various sources are used to perform economic and environmental comparisons of four types of vehicles: conventional, hybrid, electric and hydrogen fuel cell. The production and utilization stages of the vehicles are taken into consideration. The comparison is based on a mathematical procedure, which includes normalization of economic indicators (prices of vehicles and fuels during the vehicle life and driving range) and environmental indicators (greenhouse gas and air pollution emissions), and evaluation of an optimal relationship between the types of vehicles in the fleet. According to the comparison, hybrid and electric cars exhibit advantages over the other types. The economic efficiency and environmental impact of electric car use depends substantially on the source of the electricity. If the electricity comes from renewable energy sources, the electric car is advantageous compared to the hybrid. If electricity comes from fossil fuels, the electric car remains competitive only if the electricity is generated on board. It is shown that, if electricity is generated with an efficiency of about 50-60% by a gas turbine engine connected to a high-capacity battery and an electric motor, the electric car becomes advantageous. Implementation of fuel cells stacks and ion conductive membranes into gas turbine cycles permits electricity generation to increase to the above-mentioned level and air pollution emissions to decrease. It is concluded that the electric car with on-board electricity generation represents a significant and flexible advance in the development of efficient and ecologically benign vehicles.

Ultra clean burner for an AMTEC system suitable for hybrid electric vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mital, R.; Sievers, R.K.; Hunt, T.K.

1997-12-31

High power Alkali Metal Thermal to Electric Converter (AMTEC) systems have the potential to make the hybrid electric vehicle (HEV) program a success by meeting the challenging standards put forth by the EPA for the automobile industry. The premise of the whole concept of using AMTEC cells, as discussed by Hunt et al. (1995), for power generation in HEV`s is based on the utilization of a high efficiency external combustion system. The key requirement being a burner which will produce extremely low quantities of carbon monoxide and oxides of nitrogen, emit minimal amounts of hydrocarbon, will have high radiative andmore » convective efficiencies and at least a 4:1 turndown ratio. This work presents one such burner which has the potential to meet all of these demands and more. After investigation of a number of burners, including, metal fiber, ported metal, ceramic fiber and ported ceramic, it is believed that cellular ceramic burners will be the best candidates for integration with AMTEC cells for a high power system suitable for hybrid electric vehicles. A detailed study which includes the operating range, radiation efficiency, total heat transfer efficiency, spectral intensity, exit gas temperature and pollutant emission indices measurement has been carried out on circular and square shaped burners. Total heat transfer efficiencies as high as 65--70% have been measured using a water calorimeter. With efficient recuperation, a burner/recuperator efficiency of 80% at peak power and 90% at peak efficiency operating points are conceivable with this burner. Establishment of combustion within the porous matrix leads to low peak temperatures and hence lower NO{sub x}. The emission indices of CO and HC are also quite low. The stability range measurements show a 6:1 turndown ratio at an equivalence ratio of 0.9.« less

Technical assessment of discarded tires gasification as alternative technology for electricity generation.

PubMed

Machin, Einara Blanco; Pedroso, Daniel Travieso; de Carvalho, João Andrade

2017-10-01

Concern about contamination associated with the disposal of tires has led to the search for technologies to reuse discarded tires, which include the use of Tire Derived Fuel (TDF) as fuel in advanced thermal-conversion processes, this allows the energy use of these wastes at affordable costs and reduces the environmental impact on scrap tires disposal. A theoretical assessment of the technical viability of TDF gasification for electric and thermal power generation, from the producer gas combustion in an internal combustion engine and in a gas turbine, was performed. The combustion of producer gas derived from the gasification of TDF in an internal combustion engine driving a generator (ICE-G) appears as the more efficient route for electricity generation when compared with the efficiency obtained with the use of gas turbine (GT-G). A higher global efficiency, considering the electric and thermal generation efficiency can be expected with the use of TDF producer gas in GT-G, where is expected an overall efficiency of 77.49%. The assessment shows that is possible produces up to 7.67MJ and 10.62MJ of electric and thermal energy per kilogram of TDF gasified using an ICE-G and up to 6.06MJ and 13.03MJ of electric and thermal energy respectively per kilogram of gasified TDF using a GT-G. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study of aircraft electrical power systems

NASA Technical Reports Server (NTRS)

1972-01-01

The formulation of a philosophy for devising a reliable, efficient, lightweight, and cost effective electrical power system for advanced, large transport aircraft in the 1980 to 1985 time period is discussed. The determination and recommendation for improvements in subsystems and components are also considered. All aspects of the aircraft electrical power system including generation, conversion, distribution, and utilization equipment were considered. Significant research and technology problem areas associated with the development of future power systems are identified. The design categories involved are: (1) safety-reliability, (2) power type, voltage, frequency, quality, and efficiency, (3) power control, and (4) selection of utilization equipment.

Metro Electric Vehicle Evaluation at the Lewis Research Center

NASA Image and Video Library

1976-05-21

The National Aeronautics and Space Administration (NASA) Lewis Research Center tested 16 commercially-manufactured electric vehicles, including this Metro, during the mid-1970s. Lewis and the Energy Research and Development Administration (ERDA) engaged in several energy-related programs in the mid-1970s, including the Electric Vehicle Project. NASA and ERDA undertook the program in 1976 to determine the state of the current electric vehicle technology. As part of the project, Lewis and ERDA tested every commercially available electric car model. Electric Vehicle Associates, located in a Cleveland suburb, modified a Renault 12 vehicle to create this Metro. Its 1040-pound golfcart-type battery provided approximately 106 minutes of operation. The tests analyzed the vehicle’s range, acceleration, coast-down, braking, and energy consumption. Some of the vehicles had analog data recording systems to measure the battery during operation and sensors to determine speed and distance. The researchers found the performance of the different vehicles varied significantly. In general, the range, acceleration, and speed were lower than that found on conventional vehicles. They also found that traditional gasoline-powered vehicles were as efficient as the electric vehicles. The researchers concluded, however, that advances in battery technology and electric drive systems would significantly improve efficiency and performance.

Combined fast multipole-QR compression technique for solving electrically small to large structures for broadband applications

NASA Technical Reports Server (NTRS)

Jandhyala, Vikram (Inventor); Chowdhury, Indranil (Inventor)

2011-01-01

An approach that efficiently solves for a desired parameter of a system or device that can include both electrically large fast multipole method (FMM) elements, and electrically small QR elements. The system or device is setup as an oct-tree structure that can include regions of both the FMM type and the QR type. An iterative solver is then used to determine a first matrix vector product for any electrically large elements, and a second matrix vector product for any electrically small elements that are included in the structure. These matrix vector products for the electrically large elements and the electrically small elements are combined, and a net delta for a combination of the matrix vector products is determined. The iteration continues until a net delta is obtained that is within predefined limits. The matrix vector products that were last obtained are used to solve for the desired parameter.

Powertrain system for a hybrid electric vehicle

DOEpatents

Reed, Jr., Richard G.; Boberg, Evan S.; Lawrie, Robert E.; Castaing, Francois J.

1999-08-31

A hybrid electric powertrain system is provided including an electric motor/generator drivingly engaged with the drive shaft of a transmission. The electric is utilized for synchronizing the rotation of the drive shaft with the driven shaft during gear shift operations. In addition, a mild hybrid concept is provided which utilizes a smaller electric motor than typical hybrid powertrain systems. Because the electric motor is drivingly engaged with the drive shaft of the transmission, the electric motor/generator is driven at high speed even when the vehicle speed is low so that the electric motor/generator provides more efficient regeneration.

Powertrain system for a hybrid electric vehicle

DOEpatents

Reed, R.G. Jr.; Boberg, E.S.; Lawrie, R.E.; Castaing, F.J.

1999-08-31

A hybrid electric powertrain system is provided including an electric motor/generator drivingly engaged with the drive shaft of a transmission. The electric is utilized for synchronizing the rotation of the drive shaft with the driven shaft during gear shift operations. In addition, a mild hybrid concept is provided which utilizes a smaller electric motor than typical hybrid powertrain systems. Because the electric motor is drivingly engaged with the drive shaft of the transmission, the electric motor/generator is driven at high speed even when the vehicle speed is low so that the electric motor/generator provides more efficient regeneration. 34 figs.

Solar photovoltaic charging of lithium-ion batteries

NASA Astrophysics Data System (ADS)

Gibson, Thomas L.; Kelly, Nelson A.

Solar photovoltaic (PV) charging of batteries was tested by using high efficiency crystalline and amorphous silicon PV modules to recharge lithium-ion battery modules. This testing was performed as a proof of concept for solar PV charging of batteries for electrically powered vehicles. The iron phosphate type lithium-ion batteries were safely charged to their maximum capacity and the thermal hazards associated with overcharging were avoided by the self-regulating design of the solar charging system. The solar energy to battery charge conversion efficiency reached 14.5%, including a PV system efficiency of nearly 15%, and a battery charging efficiency of approximately 100%. This high system efficiency was achieved by directly charging the battery from the PV system with no intervening electronics, and matching the PV maximum power point voltage to the battery charging voltage at the desired maximum state of charge for the battery. It is envisioned that individual homeowners could charge electric and extended-range electric vehicles from residential, roof-mounted solar arrays, and thus power their daily commuting with clean, renewable solar energy.

Microstickies agglomeration by electric field.

PubMed

Du, Xiaotang Tony; Hsieh, Jeffery S

2016-01-01

Microstickies deposits on both paper machine and paper products when it agglomerates under step change in ionic strength, pH, temperature and chemical additives. These stickies increase the down time of the paper mill and decrease the quality of paper. The key property of microstickies is its smaller size, which leads to low removal efficiency and difficulties in measurement. Thus the increase of microstickies size help improve both removal efficiency and reduce measurement difficulty. In this paper, a new agglomeration technology based on electric field was investigated. The electric treatment could also increase the size of stickies particles by around 100 times. The synergetic effect between electric field treatment and detacky chemicals/dispersants, including polyvinyl alcohol, poly(diallylmethylammonium chloride) and lignosulfonate, was also studied.

REDOX electrochemical energy storage

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1980-01-01

Reservoirs of chemical solutions can store electrical energy with high efficiency. Reactant solutions are stored outside conversion section where charging and discharging reactions take place. Conversion unit consists of stacks of cells connected together in parallel hydraulically, and in series electrically. Stacks resemble fuel cell batteries. System is 99% ampere-hour efficient, 75% watt hour efficient, and has long projected lifetime. Applications include storage buffering for remote solar or wind power systems, and industrial load leveling. Cost estimates are $325/kW of power requirement plus $51/kWh storage capacity. Mass production would reduce cost by about factor of two.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles. [energy conversion efficiency in electric power plants

NASA Technical Reports Server (NTRS)

Deegan, P. B.

1976-01-01

Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh).

NASA Puffin Electric Tailsitter VTOL Concept

NASA Technical Reports Server (NTRS)

Moore, Mark D.

2010-01-01

Electric propulsion offers dramatic new vehicle mission capabilities, not possible with turbine or reciprocating engines; including high reliability and efficiency, low engine weight and maintenance, low cooling drag and volume required, very low noise and vibration, and zero emissions. The only penalizing characteristic of electric propulsion is the current energy storage technology level, which is set to triple over the next 5-10 years through huge new investments in this field. Most importantly, electric propulsion offers incredible new degrees of freedom in aircraft system integration to achieve unprecedented levels of aerodynamic, propulsive, control, and structural synergistic coupling. A unique characteristic of electric propulsion is that the technology is nearly scale-free, permitting small motors to be parallelized for fail-safe redundancy, or distributed across the airframe for tightly coupled interdisciplinary functionality without significant impacts in motor-controller efficiency or specific weight. Maximizing the potential benefit of electric propulsion is dependent on applying this technology to synergistic mission concepts. The vehicle missions with the most benefit include those which constrain environmental impact (or limit noise, exhaust, or emission signatures) are short range, or where large differences exist in the propulsion system sizing between takeoff and cruise conditions. Electric propulsion offers the following unique capabilities that other propulsion systems can t provide for short range Vertical Takeoff and Landing (VTOL) aircraft; elimination of engine noise and emissions, drastic reduction in engine cooling and radiated heat, drastic reduction in vehicle vibration levels, drastic improvement in reliability and operating costs, variable speed output at full power, for improved cruise efficiency at low tip-speed, elimination of high/hot sizing penalty, and reduction of engine-out penalties.

Stennis Space Center observes 2009 Energy Awareness Day

NASA Technical Reports Server (NTRS)

2009-01-01

Stennis Space Center employees Maria Etheridge (l to r), Linda Sauland Maurice Prevost visit a Coast Electric Power Association display featuring energy-efficient light bulbs during 2009 Energy Awareness Day activities on Oct. 20. The exhibit was one of several energy-efficiency and energy-awareness displays on-site for employees to visit. Vendors included Mississippi Power Company, Coast Electric Power Association, Mississippi Development Authority - Energy Division,Jacobs FOSC Environmental, Southern Energy Technologies, and Siemens Building Technologies.

Stennis Space Center observes 2009 Energy Awareness Day

NASA Image and Video Library

2009-10-20

Stennis Space Center employees Maria Etheridge (l to r), Linda Sauland Maurice Prevost visit a Coast Electric Power Association display featuring energy-efficient light bulbs during 2009 Energy Awareness Day activities on Oct. 20. The exhibit was one of several energy-efficiency and energy-awareness displays on-site for employees to visit. Vendors included Mississippi Power Company, Coast Electric Power Association, Mississippi Development Authority - Energy Division,Jacobs FOSC Environmental, Southern Energy Technologies, and Siemens Building Technologies.

Method and apparatus for improving the performance of a nuclear power electrical generation system

DOEpatents

Tsiklauri, Georgi V.; Durst, Bruce M.

1995-01-01

A method and apparatus for improving the efficiency and performance a of nuclear electrical generation system that comprises the addition of steam handling equipment to an existing plant that results in a surprising increase in plant performance. More particularly, a gas turbine electrical generation system with heat recovery boiler is installed along with a high pressure and a low pressure mixer superheater. Depending upon plant characteristics, the existing moisture separator reheater (MSR) can be either augmented or done away with. The instant invention enables a reduction in T.sub.hot without a derating of the reactor unit, and improves efficiency of the plant's electrical conversion cycle. Coupled with this advantage is a possible extension of the plant's fuel cycle length due to an increased electrical conversion efficiency. The reduction in T.sub.hot further allows for a surprising extension of steam generator life. An additional advantage is the reduction in erosion/corrosion of secondary system components including turbine blades and diaphragms. The gas turbine generator used in the instant invention can also replace or augment existing peak or emergency power needs.

U.S. energy sector impacts of technology innovation, fuel price, and electric sector CO 2 policy: Results from the EMF 32 model intercomparison study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart

We study the impact of achieving technology innovation goals, representing significant technology cost reductions and performance improvements, in both the electric power and end-use sectors by comparing outputs from four energy-economic models through the year 2050. We harmonize model input assumptions and then compare results in scenarios that vary natural gas prices, technology cost and performance metrics, and the implementation of a representative national electricity sector carbon dioxide (CO 2) policy. Achieving the representative technology innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more costmore » competitive. For the models that include domestic natural gas markets, achieving the technology innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices but fewer coal capacity retirements. Some of the models include energy efficiency improvements as part of achieving the high-technology goals. Absent these energy efficiency improvements, low-cost electricity facilitates greater electricity consumption. The effect of implementing a representative electricity sector CO 2 policy differs considerably depending on the cost and performance of generating and end-use technologies. The CO 2 policy influences electric sector evolution in the cases with reference technology assumptions but has little to no influence in the cases that achieve the technology innovation goals. This outcome implies that meeting the representative technology innovation goals achieves a generation mix with similar CO 2 emissions to the representative CO 2 policy but with smaller increases to wholesale electricity prices. Finally, higher natural gas prices, achieving the representative technology innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

Energy Efficiency Under Alternative Carbon Policies. Incentives, Measurement, and Interregional Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinberg, Daniel C.; Boyd, Erin

2015-08-28

In this report, we examine and compare how tradable mass-based polices and tradable rate-based policies create different incentives for energy efficiency investments. Through a generalized demonstration and set of examples, we show that as a result of the output subsidy they create, traditional rate-based policies, those that do not credit energy savings from efficiency measures, reduce the incentive for investment in energy efficiency measures relative to an optimally designed mass-based policy or equivalent carbon tax. We then show that this reduced incentive can be partially addressed by modifying the rate-based policy such that electricity savings from energy efficiency measures aremore » treated as a source of zero-carbon generation within the framework of the standard, or equivalently, by assigning avoided emissions credit to the electricity savings at the rate of the intensity target. These approaches result in an extension of the output subsidy to efficiency measures and eliminate the distortion between supply-side and demand-side options for GHG emissions reduction. However, these approaches do not address electricity price distortions resulting from the output subsidy that also impact the value of efficiency measures. Next, we assess alternative approaches for crediting energy efficiency savings within the framework of a rate-based policy. Finally, we identify a number of challenges that arise in implementing a rate-based policy with efficiency crediting, including the requirement to develop robust estimates of electricity savings in order to assess compliance, and the requirement to track the regionality of the generation impacts of efficiency measures to account for their interstate effects.« less

Telematics and Data Science: Informing Energy-Efficient Mobility: October 25, 2016 - October 31, 2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sears, Edward B; Daley, Ryan; Helm, Matthew

The University of Connecticut (UCONN) is exploring the possibility of adding electric vehicles (EVs) - including battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), or both - to its vehicle fleet. This report presents results of the UCONN fleet EV Suitability pilot program and offers recommendations for transitioning fleet vehicles to EVs as well as implementing adequate charging infrastructure.

A high-efficiency electromechanical battery

NASA Astrophysics Data System (ADS)

Post, Richard F.; Fowler, T. K.; Post, Stephen F.

1993-03-01

In our society there is a growing need for efficient cost-effective means for storing electrical energy. The electric auto is a prime example. Storage systems for the electric utilities, and for wind or solar power, are other examples. While electrochemical cells could in principle supply these needs, the existing E-C batteries have well-known limitations. This article addresses an alternative, the electromechanical battery (EMB). An EMB is a modular unit consisting of an evacuated housing containing a fiber-composite rotor. The rotor is supported by magnetic bearings and contains an integrally mounted permanent magnet array. This article addresses design issues for EMBs with rotors made up of nested cylinders. Issues addressed include rotational stability, stress distributions, generator/motor power and efficiency, power conversion, and cost. It is concluded that the use of EMBs in electric autos could result in a fivefold reduction (relative to the IC engine) in the primary energy input required for urban driving, with a concomitant major positive impact on our economy and on air pollution.

Research on High-efficient Remanufacturing Technologies and Application of Electric Motor

NASA Astrophysics Data System (ADS)

Liu, Ren; Zhao, Yuejin; Yang, Xu; Wang, Gen

2017-09-01

The energy conservation of electric motor system is the key of industrial energy conservation. With the implementation and acceleration of electric motor energy efficiency improvement plan, more and more electric motors are knocked out. High-efficient remanufacturing of electric motor refers to improving the efficiency of electric motor and recycling the resources by replacing the winding, iron core and other components of electric motor on the basis of the low-efficient/outdated electric motors, which conforms to China’s policy of circular economy and resource recovery. The remanufacturing of electric motor not only maximizes the use of resources, but also reduces the energy consumption generated by reprocessing of cast iron, silicon steel sheet and other materials in dismantling of electric motor. However, structures and iron core materials used in design and manufacture of electric motors are different, and the degrees of wear of electric motors are also different under different operating conditions, which further result in diversified design schemes, increased remanufacturing cost and reduced remanufacturing efficiency. This paper analyzes the key process technologies for remanufacturing of electric motors are researched by analyzing the remanufacturing technologies of electric motors, and presents the feasibility to replace the cast-aluminum rotor with cast-copper rotor in high-efficient remanufacturing process of electric motor.

Straight and chopped dc performance data for a General Electric 5BT 2366C10 motor and an EV-1 controller

NASA Technical Reports Server (NTRS)

Edie, P. C.

1981-01-01

Performance data on the General Electric 5BT 2366C10 series wound dc motor and EV-1 Chopper Controller is supplied for the electric vehicle manufacturer. Data is provided for both straight and chopped dc input to the motor, at 2 motor temperature levels. Testing was done at 6 voltage increments to the motor, and 2 voltage increments to the controller. Data results are presented in both tabular and graphical forms. Tabular information includes motor voltage and current input data, motor speed and torque output data, power data and temperature data. Graphical information includes torque-speed, motor power output-speed, torque-current, and efficiency-speed plots under the various operating conditions. The data resulting from this testing shows the speed-torque plots to have the most variance with operating temperature. The maximum motor efficiency is between 86% and 87%, regardless of temperature or mode of operation. When the chopper is utilized, maximum motor efficiency occurs when the chopper duty cycle approaches 100%.

Free-piston engine linear generator for hybrid vehicles modeling study

NASA Astrophysics Data System (ADS)

Callahan, T. J.; Ingram, S. K.

1995-05-01

Development of a free piston engine linear generator was investigated for use as an auxiliary power unit for a hybrid electric vehicle. The main focus of the program was to develop an efficient linear generator concept to convert the piston motion directly into electrical power. Computer modeling techniques were used to evaluate five different designs for linear generators. These designs included permanent magnet generators, reluctance generators, linear DC generators, and two and three-coil induction generators. The efficiency of the linear generator was highly dependent on the design concept. The two-coil induction generator was determined to be the best design, with an efficiency of approximately 90 percent.

40 CFR 86.1867-12 - Optional early CO2 credit programs.

Code of Federal Regulations, 2012 CFR

2012-07-01

... efficiency credits, early advanced technology credits, and early off-cycle technology credits. Manufacturers... an approved value. (F) Carbon-related exhaust emission values for electric, fuel cell, and plug-in hybrid electric model types shall be included in the fleet average determined under paragraph (a)(1) of...

40 CFR 86.1871-12 - Optional early CO2 credit programs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... efficiency credits, early advanced technology credits, and early off-cycle technology credits. Manufacturers... manufacturer may use such an approved value. (F) Carbon-related exhaust emission values for electric, fuel cell, and plug-in hybrid electric model types shall be included in the fleet average determined under...

Straight and chopped dc performance data for a Prestolite MTC-4001 motor and a general electric EV-1 controller

NASA Technical Reports Server (NTRS)

Edie, P. C.

1981-01-01

Performance data on the Prestolite MTC-4001 series wound dc motor and General Electric EV-1 Chopper Controller is supplied for the electric vehicle manufacturer. Data are provided for both straight and chopped dc input to the motor, at 2 motor temperature levels. Testing was done at 6 voltage increments to the motor, and 2 voltage increments to the controller. Data results are presented in both tabular and graphical forms. Tabular information includes motor voltage and current input data, motor speed and torque output data, power data and temperature data. Graphical information includes torque-speed, motor power output-speed, torque-current, and efficiency-speed plots under the various operating conditions. The data resulting from this testing show the speed-torque plots to have the most variance with operating temperature. The maximum motor efficiency is between 76% and 82%, regardless of temperature or mode of operation.

Development of the electric vehicle analyzer

NASA Astrophysics Data System (ADS)

Dickey, Michael R.; Klucz, Raymond S.; Ennix, Kimberly A.; Matuszak, Leo M.

1990-06-01

The increasing technological maturity of high power (greater than 20 kW) electric propulsion devices has led to renewed interest in their use as a means of efficiently transferring payloads between earth orbits. Several systems and architecture studies have identified the potential cost benefits of high performance Electric Orbital Transfer Vehicles (EOTVs). These studies led to the initiation of the Electric Insertion Transfer Experiment (ELITE) in 1988. Managed by the Astronautics Laboratory, ELITE is a flight experiment designed to sufficiently demonstrate key technologies and options to pave the way for the full-scale development of an operational EOTV. An important consideration in the development of the ELITE program is the capability of available analytical tools to simulate the orbital mechanics of a low thrust, electric propulsion transfer vehicle. These tools are necessary not only for ELITE mission planning exercises but also for continued, efficient, accurate evaluation of DoD space transportation architectures which include EOTVs. This paper presents such a tool: the Electric Vehicle Analyzer (EVA).

Energy conversion in isothermal nonlinear irreversible processes - struggling for higher efficiency

NASA Astrophysics Data System (ADS)

Ebeling, W.; Feistel, R.

2017-06-01

First we discuss some early work of Ulrike Feudel on structure formation in nonlinear reactions including ions and the efficiency of the conversion of chemical into electrical energy. Then we give some survey about isothermal energy conversion from chemical to higher forms of energy like mechanical, electrical and ecological energy. Isothermal means here that there are no temperature gradients within the model systems. We consider examples of energy conversion in several natural processes and in some devices like fuel cells. Further, as an example, we study analytically the dynamics and efficiency of a simple "active circuit" converting chemical into electrical energy and driving currents which is roughly modeling fuel cells. Finally we investigate an analogous ecological system of Lotka-Volterra type consisting of an "active species" consuming some passive "chemical food". We show analytically for both these models that the efficiency increases with the load, reaches values higher then 50 percent in a narrow regime of optimal load and goes beyond some maximal load abruptly to zero.

Study of the electrical and thermal performances of photovoltaic thermal collector-compound parabolic concentrated

NASA Astrophysics Data System (ADS)

Jaaz, Ahed Hameed; Sopian, Kamaruzzaman; Gaaz, Tayser Sumer

2018-06-01

The importance of utilizing the solar energy as a very suitable source among multi-source approaches to replace the conventional energy is on the rise in the last four decades. The invention of the photovoltaic module (PV) could be the corner stone in this process. However, the limited amount of energy obtained from PV was and still the main challenge of full utilization of the solar energy. In this paper, the use of the compound parabolic concentrator (CPC) along with the thermal photovoltaic module (PVT) where the cooling process of the CPC is conducted using a novel technique of water jet impingement has applied experimentally and physically tested. The test includes the effect of water jet impingement on the total power, electrical efficiency, thermal efficiency, and total efficiency on CPC-PVT system. The cooling process at the maximum irradiation by water jet impingement resulted in improving the electrical efficiency by 7%, total output power by 31% and the thermal efficiency by 81%. These results outperform the recent highest results recorded by the most recent work.

Energy efficiency analysis: biomass-to-wheel efficiency related with biofuels production, fuel distribution, and powertrain systems.

PubMed

Huang, Wei-Dong; Zhang, Y-H Percival

2011-01-01

Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens.

Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems

PubMed Central

Huang, Wei-Dong; Zhang, Y-H Percival

2011-01-01

Background Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). Methodology/Principal Findings We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements -- biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case – corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. Significance In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens. PMID:21765941

Method and apparatus for steam mixing a nuclear fueled electricity generation system

DOEpatents

Tsiklauri, Georgi V.; Durst, Bruce M.

1996-01-01

A method and apparatus for improving the efficiency and performance of a nuclear electrical generation system that comprises the addition of steam handling equipment to an existing plant that results in a surprising increase in plant performance. More particularly, a gas turbine electrical generation system with heat recovery boiler is installed along with a micro-jet high pressure and a low pressure mixer superheater. Depending upon plant characteristics, the existing moisture separator reheater (MSR) can be either augmented or done away with. The instant invention enables a reduction in T.sub.hot without a derating of the reactor unit, and improves efficiency of the plant's electrical conversion cycle. Coupled with this advantage is a possible extension of the plant's fuel cycle length due to an increased electrical conversion efficiency. The reduction in T.sub.hot further allows for a surprising extension of steam generator life. An additional advantage is the reduction in erosion/corrosion of secondary system components including turbine blades and diaphragms. The gas turbine generator used in the instant invention can also replace or augment existing peak or emergency power needs. Another benefit of the instant invention is the extension of plant life and the reduction of downtime due to refueling.

Electric power industry restructuring in Australia: Lessons from down-under. Occasional paper No. 20

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray, D.

1997-01-01

Australia`s electric power industry (EPI) is undergoing major restructuring. This restructuring includes commercialization of state-owned electric organization through privatization and through corporatization into separate governmental business units; structural unbundling of generation, transmission, retailing, and distribution; and creation of a National Electricity Market (NEM) organized as a centralized, market-based trading pool for buying and selling electricity. The principal rationales for change in the EPI were the related needs of enhancing international competitiveness, improving productivity, and lowering electric rates. Reducing public debt through privatization also played an important role. Reforms in the EPI are part of the overall economic reform package thatmore » is being implemented in Australia. Enhancing efficiency in the economy through competition is a key objective of the reforms. As the need for reform was being discussed in the early 1990s, Australia`s previous prime minister, Paul Keating, observed that {open_quotes}the engine which drives efficiency is free and open competition.{close_quotes} The optimism about the economic benefits of the full package of reforms across the different sectors of the economy, including the electricity industry, is reflected in estimated benefits of a 5.5 percent annual increase in real gross domestic product and the creation of 30,000 more jobs. The largest source of the benefits (estimated at 25 percent of total benefits) was projected to come from reform of the electricity and gas sectors.« less

Operational and environmental performance in China's thermal power industry: Taking an effectiveness measure as complement to an efficiency measure.

PubMed

Wang, Ke; Zhang, Jieming; Wei, Yi-Ming

2017-05-01

The trend toward a more fiercely competitive and strictly environmentally regulated electricity market in several countries, including China has led to efforts by both industry and government to develop advanced performance evaluation models that adapt to new evaluation requirements. Traditional operational and environmental efficiency measures do not fully consider the influence of market competition and environmental regulations and, thus, are not sufficient for the thermal power industry to evaluate its operational performance with respect to specific marketing goals (operational effectiveness) and its environmental performance with respect to specific emissions reduction targets (environmental effectiveness). As a complement to an operational efficiency measure, an operational effectiveness measure not only reflects the capacity of an electricity production system to increase its electricity generation through the improvement of operational efficiency, but it also reflects the system's capability to adjust its electricity generation activities to match electricity demand. In addition, as a complement to an environmental efficiency measure, an environmental effectiveness measure not only reflects the capacity of an electricity production system to decrease its pollutant emissions through the improvement of environmental efficiency, but it also reflects the system's capability to adjust its emissions abatement activities to fulfill environmental regulations. Furthermore, an environmental effectiveness measure helps the government regulator to verify the rationality of its emissions reduction targets assigned to the thermal power industry. Several newly developed effectiveness measurements based on data envelopment analysis (DEA) were utilized in this study to evaluate the operational and environmental performance of the thermal power industry in China during 2006-2013. Both efficiency and effectiveness were evaluated from the three perspectives of operational, environmental, and joint adjustments to each electricity production system. The operational and environmental performance changes over time were also captured through an effectiveness measure based on the global Malmquist productivity index. Our empirical results indicated that the performance of China's thermal power industry experienced significant progress during the study period and that policies regarding the development and regulation of the thermal power industry yielded the expected effects. However, the emissions reduction targets assigned to China's thermal power industry are loose and conservative. Copyright © 2017 Elsevier Ltd. All rights reserved.

Barriers to electric energy efficiency in Ghana

NASA Astrophysics Data System (ADS)

Berko, Joseph Kofi, Jr.

Development advocates argue that sustainable development strategies are the best means to permanently improve living standards in developing countries. Advocates' arguments are based on the technical, financial, and environmental advantages of sustainable development. However, they have not addressed the organizational and administrative decision-making issues which are key to successful implementation of sustainable development in developing countries. Using the Ghanaian electricity industry as a case study, this dissertation identifies and analyzes organizational structures, administrative mechanisms, and decision-maker viewpoints that critically affect the success of adoption and implementation of energy efficiency within a sustainable development framework. Utilizing semi-structured interviews in field research, decision-makers' perceptions of the pattern of the industry's development, causes of the electricity supply shortfall, and barriers to electricity-use efficiency were identified. Based on the initial findings, the study formulated a set of policy initiatives to establish support for energy use efficiency. In a second set of interviews, these policy suggestions were presented to some of the top decision-makers to elicit their reactions. According to the decision-makers, the electricity supply shortfall is due to rapid urbanization and increased industrial consumption as a result of the structural adjustment program, rural electrification, and the sudden release of suppressed loads. The study found a lack of initiative and collaboration among industry decision-makers, and a related divergence in decision-makers' concerns and viewpoints. Also, lacking are institutional support systems and knowledge of proven energy efficiency strategies and technologies. As a result, planning, and even the range of perceived solutions to choose from are supply-side oriented. The final chapter of the study presents implications of its findings and proposes that any implementation strategy will have to address the different decision-makers' concerns and viewpoints. These include the need for national policies to promote electric energy efficiency and institutional development to provide support, guidance and direction to an energy efficiency effort. It also proposes structural changes within the industry to reduce government influence by creating an independent regulatory board. Finally, it proposes the adoption of integrated resource planning strategies and changes in the supply-side dominated culture within the electric utilities.

Developing Si(Li) nuclear radiation detectors by pulsed electric field treatment

NASA Astrophysics Data System (ADS)

Muminov, R. A.; Radzhapov, S. A.; Saimbetov, A. K.

2009-08-01

Fabrication of Si(Li) nuclear radiation detectors using lithium ion drift under the action of a pulsed electric field is considered. Optimum treatment regime parameters are determined, including the pulse amplitude, duration, and repetition rate. Experimental data are presented, which show that the ion drift in a pulsed electric field decreases the semiconductor bulk compensation time by a factor of two to four and significantly increases the efficiency of detectors.

Smart Grid Maturity Model: Model Definition. A Framework for Smart Grid Transformation

DTIC Science & Technology

2010-09-01

adoption of more efficient and reliable generation sources and would allow consumer-generated electricity (e.g., solar power and wind) to be connected to...program that pays customers (or credits their accounts) for customer-provided electricity such as from solar panels to the grid or electric vehicles...deployed. CUST-5.3 Plug-and-play customer-based generation (e.g., wind and solar ) is supported. This includes the necessary infrastructure, such

16 CFR 305.20 - Paper catalogs and websites.

Code of Federal Regulations, 2011 CFR

2011-01-01

... estimated operating cost is based on a [Year] national average [electricity, natural gas, propane, or oil... natural gas. For more information, visit www.ftc.gov/appliances. (4) The energy efficiency or thermal efficiency ratings for pool heaters, central air conditioners, heat pumps, and furnaces (including boilers...

16 CFR 305.20 - Paper catalogs and websites.

Code of Federal Regulations, 2010 CFR

2010-01-01

... estimated operating cost is based on a [Year] national average [electricity, natural gas, propane, or oil... natural gas. For more information, visit www.ftc.gov/appliances. (4) The energy efficiency or thermal efficiency ratings for pool heaters, central air conditioners, heat pumps, and furnaces (including boilers...

Physics of Efficiency Droop in GaN:Eu Light-Emitting Diodes.

PubMed

Fragkos, Ioannis E; Dierolf, Volkmar; Fujiwara, Yasufumi; Tansu, Nelson

2017-12-01

The internal quantum efficiency (IQE) of an electrically-driven GaN:Eu based device for red light emission is analyzed in the framework of a current injection efficiency model (CIE). The excitation path of the Eu +3 ion is decomposed in a multiple level system, which includes the carrier transport phenomena across the GaN/GaN:Eu/GaN active region of the device, and the interactions among traps, Eu +3 ions and the GaN host. The identification and analysis of the limiting factors of the IQE are accomplished through the CIE model. The CIE model provides a guidance for high IQE in the electrically-driven GaN:Eu based red light emitters.

High-efficiency photovoltaic technology including thermoelectric generation

NASA Astrophysics Data System (ADS)

Fisac, Miguel; Villasevil, Francesc X.; López, Antonio M.

2014-04-01

Nowadays, photovoltaic solar energy is a clean and reliable source for producing electric power. Most photovoltaic systems have been designed and built up for use in applications with low power requirements. The efficiency of solar cells is quite low, obtaining best results in monocrystalline silicon structures, with an efficiency of about 18%. When temperature rises, photovoltaic cell efficiency decreases, given that the short-circuit current is slightly increased, and the open-circuit voltage, fill factor and power output are reduced. To ensure that this does not affect performance, this paper describes how to interconnect photovoltaic and thermoelectric technology into a single structure. The temperature gradient in the solar panel is used to supply thermoelectric cells, which generate electricity, achieving a positive contribution to the total balance of the complete system.

Cell-stimulation therapy of lateral epicondylitis with frequency-modulated low-intensity electric current.

PubMed

Aliyev, R M; Geiger, G

2012-03-01

In addition to the routine therapy, the patients with lateral epicondylitis included into experimental group were subjected to a 12-week cell-stimulation therapy with low-intensity frequency-modulated electric current. The control group received the same routine therapy and sham stimulation (the therapeutic apparatus was not energized). The efficiency of this microcurrent therapy was estimated by comparing medical indices before therapy and at the end of a 12-week therapeutic course using a 10-point pain severity numeric rating scale (NRS) and Roles-Maudsley pain score. The study revealed high therapeutic efficiency of cell-stimulation with low-intensity electric current resulting probably from up-regulation of intracellular transmitters, interleukins, and prostaglandins playing the key role in the regulation of inflammation.

Site operator program final report for fiscal years 1992 through 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francfort, J.E.; Bassett, R.R.; Birasco, S.

The Site Operator Program was an electric vehicle testing and evaluation program sponsored by US Department of Energy and managed at the Idaho National Engineering and Environmental Laboratory. The Program`s goals included the field evaluation of electric vehicles in real-world applications and environments; the support of electric vehicle technology advancement; the development of infrastructure elements necessary to support significant electric vehicle use; and increasing the awareness and acceptance of electric vehicles. This report covers Program activities from 1992 to 1996. The Site Operator Program ended in September 1996, when it was superseded by the Field Operations Program. Electric vehicle testingmore » included baseline performance testing, which was performed in conjunction with EV America. The baseline performance parameters included acceleration, braking, range, energy efficiency, and charging time. The Program collected fleet operations data on electric vehicles operated by the Program`s thirteen partners, comprising electric utilities, universities, and federal agencies. The Program`s partners had over 250 electric vehicles, from vehicle converters and original equipment manufacturers, in their operating fleets. Test results are available via the World Wide Web site at http://ev.inel.gov/sop.« less

Development and application of measurement techniques for evaluating localised magnetic properties in electrical steel

NASA Astrophysics Data System (ADS)

Lewis, N. J.; Anderson, P. I.; Gao, Y.; Robinson, F.

2018-04-01

This paper reports the development of a measurement probe which couples local flux density measurements obtained using the needle probe method with the local magnetising field attained via a Hall effect sensor. This determines the variation in magnetic properties including power loss and permeability at increasing distances from the punched edge of 2.4% and 3.2% Si non-oriented electrical steel sample. Improvements in the characterisation of the magnetic properties of electrical steels would aid in optimising the efficiency in the design of electric machines.

Modeling of a Ne/Xe dielectric barrier discharge excilamp for improvement of VUV radiation production

NASA Astrophysics Data System (ADS)

Khodja, K.; Belasri, A.; Loukil, H.

2017-08-01

This work is devoted to excimer lamp efficiency optimization by using a homogenous discharge model of a dielectric barrier discharge in a Ne-Xe mixture. The model includes the plasma chemistry, electrical circuit, and Boltzmann equation. In this paper, we are particularly interested in the electrical and kinetic properties and light output generated by the DBD. Xenon is chosen for its high luminescence in the range of vacuum UV radiation around 173 nm. Our study is motivated by interest in this type of discharge in many industrial applications, including the achievement of high light output lamps. In this work, we used an applied sinusoidal voltage, frequency, gas pressure, and concentration in the ranges of 2-8 kV, 10-200 kHz, 100-800 Torr, and 10-50%, respectively. The analyzed results concern the voltage V p across the gap, the dielectric voltage V d, the discharge current I, and the particles densities. We also investigated the effect of the electric parameters and xenon concentration on the lamp efficiency. This investigation will allow one to find out the appropriate parameters for Ne/Xe DBD excilamps to improve their efficiency.

Optical management for efficiency enhancement in hybrid organic-inorganic lead halide perovskite solar cells

PubMed Central

Zhang, Hui; Toudert, Johann

2018-01-01

Abstract In a few years only, solar cells using hybrid organic–inorganic lead halide perovskites as optical absorber have reached record photovoltaic energy conversion efficiencies above 20%. To reach and overcome such values, it is required to tailor both the electrical and optical properties of the device. For a given efficient device, optical optimization overtakes electrical one. Here, we provide a synthetic review of recent works reporting or proposing so-called optical management approaches for improving the efficiency of perovskite solar cells, including the use of anti-reflection coatings at the front substrate surface, the design of optical cavities integrated within the device, the incorporation of plasmonic or dielectric nanostructures into the different layers of the device and the structuration of its internal interfaces. We finally give as outlooks some insights into the less-explored management of the perovskite fluorescence and its potential for enhancing the cell efficiency. PMID:29868146

Hybrid Vehicle Technologies and their potential for reducing oil use

NASA Astrophysics Data System (ADS)

German, John

2006-04-01

Vehicles with hybrid gasoline-electric powertrains are starting to gain market share. Current hybrid vehicles add an electric motor, battery pack, and power electronics to the conventional powertrain. A variety of engine/motor configurations are possible, each with advantages and disadvantages. In general, efficiency is improved due to engine shut-off at idle, capture of energy during deceleration that is normally lost as heat in the brakes, downsizing of the conventional engine, and, in some cases, propulsion on the electric motor alone. Ongoing increases in hybrid market share are dependent on cost reduction, especially the battery pack, efficiency synergies with other vehicle technologies, use of the high electric power to provide features desired by customers, and future fuel price and availability. Potential barriers include historically low fuel prices, high discounting of the fuel savings by new vehicle purchasers, competing technologies, and tradeoffs with other factors desired by customers, such as performance, utility, safety, and luxury features.

Photodetector with enhanced light absorption

DOEpatents

Kane, James

1985-01-01

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Integration and Testing Challenges of Small, Multiple Satellite Missions: Experiences From The Space Technology 5 Project

NASA Technical Reports Server (NTRS)

Sauerwein, Timothy A.; Gostomski, Thomas

2007-01-01

This brief presentation describes the mechanical and electrical integration activities and environmental testing challenges of the Space Technology 5 (ST5) Project. Lessons learned during this process are highlighted, including performing mechanical activities serially to gain efficiency through repetition and performing electrical activities based on the level of subsystem expertise available.

Effects of recent energy system changes on CO2 projections for the United States.

PubMed

Lenox, Carol S; Loughlin, Daniel H

2017-09-21

Recent projections of future United States carbon dioxide (CO 2 ) emissions are considerably lower than projections made just a decade ago. A myriad of factors have contributed to lower forecasts, including reductions in end-use energy service demands, improvements in energy efficiency, and technological innovations. Policies that have encouraged these changes include renewable portfolio standards, corporate vehicle efficiency standards, smart growth initiatives, revisions to building codes, and air and climate regulations. Understanding the effects of these and other factors can be advantageous as society evaluates opportunities for achieving additional CO 2 reductions. Energy system models provide a means to develop such insights. In this analysis, the MARKet ALlocation (MARKAL) model was applied to estimate the relative effects of various energy system changes that have happened since the year 2005 on CO 2 projections for the year 2025. The results indicate that transformations in the transportation and buildings sectors have played major roles in lowering projections. Particularly influential changes include improved vehicle efficiencies, reductions in projected travel demand, reductions in miscellaneous commercial electricity loads, and higher efficiency lighting. Electric sector changes have also contributed significantly to the lowered forecasts, driven by demand reductions, renewable portfolio standards, and air quality regulations.

Efficiency in the United States electric industry: Transaction costs, deregulation, and governance structures

NASA Astrophysics Data System (ADS)

Peterson, Carl

Transaction costs economics (TCE) posits that firms have an incentive to bypass the market mechanisms in situations where the cost of using the market is prohibitive. Vertical integration, among other governance mechanisms, can be used to minimize the transactions costs associated with the market mechanism. The study analyses different governance mechanisms, which range from complete vertical integration to the use of market mechanisms, for firms in the US electric sector. This sector has undergone tremendous change in the past decade including the introduction of retail competition in some jurisdictions. As a result of the push toward deregulation of the industry, vertically integration, while still significant in the sector, has steadily been replaced by alternative governance structures. Using a sample of 136 investor-owned electric utilities that reported data the US Federal Energy Regulatory Commission between 1996 and 2002, this study estimates firm level efficiency using Data Envelopment Analysis (DEA) and relates these estimates to governance structure and public policies. The analysis finds that vertical integration is positively related to firm efficiency, although in a non-linear fashion suggesting that hybrid governance structures tend to be associated with lower efficiency scores. In addition, while some evidence is found for negative short-term effects on firm efficiency from the choice to deregulate, this result is sensitive to DEA model choice. Further, competition in retail markets is found to be positively related to firm level efficiency, but the retreat from deregulation, which occurred after 2000, is negatively associated with firm-level efficiency. These results are important in the ongoing academic and public policy debates concerning deregulation of the electric section and indicate that vertical economies remain in the industry, but that competition has provided incentives for improving firm level efficiency.

Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Gao, Zhan; Barnett, Scott A.; Braun, Robert J.

2015-06-01

Electrical energy storage is expected to be a critical component of the future world energy system, performing load-leveling operations to enable increased penetration of renewable and distributed generation. Reversible solid oxide cells, operating sequentially between power-producing fuel cell mode and fuel-producing electrolysis mode, have the capability to provide highly efficient, scalable electricity storage. However, challenges ranging from cell performance and durability to system integration must be addressed before widespread adoption. One central challenge of the system design is establishing effective thermal management in the two distinct operating modes. This work leverages an operating strategy to use carbonaceous reactant species and operate at intermediate stack temperature (650 °C) to promote exothermic fuel-synthesis reactions that thermally self-sustain the electrolysis process. We present performance of a doped lanthanum-gallate (LSGM) electrolyte solid oxide cell that shows high efficiency in both operating modes at 650 °C. A physically based electrochemical model is calibrated to represent the cell performance and used to simulate roundtrip operation for conditions unique to these reversible systems. Design decisions related to system operation are evaluated using the cell model including current density, fuel and oxidant reactant compositions, and flow configuration. The analysis reveals tradeoffs between electrical efficiency, thermal management, energy density, and durability.

The efficiency of the use of composite materials in electrotechnical equipment

NASA Astrophysics Data System (ADS)

Kim, K.; Ivanov, S.

2018-02-01

The indicators of the efficiency of electrical installations are directly connected with the creating and using of new composite materials with the desired performance properties. The practical application of composite materials is one of the perspective scientific and technical directions, providing the increase of the efficiency of electrical installations due to the sealing of current parts by protecting them from the external medium. The technical characteristics of the composite material match to its structure and depend on the properties of the individual components. The verification of the compliance of material parameters is implemented by the methods of the computer analysis of a model of composite material in the form of the structure in which the individual elements have thermodynamic properties of the corresponding phase state. In the study the topology of individual elements in the material structure is defined by the conditional boundaries of the section within the studied composite. The efficiency of using the composite materials includes the raising of electrical safety, increasing the durability, reducing the costs of maintenance and repair and the extension of the scope of installations.

10 CFR 431.17 - Determination of efficiency.

Code of Federal Regulations, 2013 CFR

2013-01-01

... state-registered professional engineer, who is qualified to perform an evaluation of electric motor... EQUIPMENT Electric Motors Test Procedures, Materials Incorporated and Methods of Determining Efficiency § 431.17 Determination of efficiency. When a party determines the energy efficiency of an electric motor...

Nuclear power in the 21st century: Challenges and possibilities.

PubMed

Horvath, Akos; Rachlew, Elisabeth

2016-01-01

The current situation and possible future developments for nuclear power--including fission and fusion processes--is presented. The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors, a substantial research and development effort is required in many fields--from material sciences to safety demonstration--to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity has been set out in a focussed European programme including the international project of ITER after which a fusion electricity DEMO reactor is envisaged.

Analysis of environmental impacts of renewable energy on the Moroccan electricity sector: A System Dynamics approach

NASA Astrophysics Data System (ADS)

Chentouf, M.; Allouch, M.

2018-05-01

Producing electricity at an affordable price while taking into account environmental concerns has become a major challenge in Morocco. Moreover, the technical and financial issues related to renewable electricity plants are still hindering their efficient integration in the country. In fact, the energy sector (both electricity and heat) accounted for more than half of all Greenhouse Gases (GHG) emissions in the kingdom due to the major reliance on fossil fuels for answering the growing local demand. The key strategies to alleviate this critical situation include the integration of more renewable energies in the total energy mix and the enhancement of energy efficiency measures in different sectors. This paper strives to (1) evaluate the potential of carbon dioxide mitigation in Moroccan electricity sector following the actual and projected strategies and (2) highlight the policy schemes to be taken in order to achieve the ambitious carbon dioxide mitigation targets in the mid-term. A system dynamics model was built in order to simulate different scenarios of carbon dioxide mitigation policies up to 2030. The results shows that the achievement of renewable energies projects by 2030 could save 228.143 MtCO2 between 2020 and 2030 and an additional 18.127 MtCO2 could be avoided in the same period by enhancing energy efficiency measures.

Method for making a photodetector with enhanced light absorption

DOEpatents

Kane, James

1987-05-05

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Transformer Efficiency Assessment - Okinawa, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers

The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data ismore » not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.« less

Transformer Efficiency Assessment - Okinawa, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers

2012-05-01

The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data ismore » not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.« less

Biobriefcase electrostatic aerosol collector

DOEpatents

Bell, Perry M [Tracy, CA; Christian, Allen T [Madison, WI; Bailey, Christopher G [Pleasanton, CA; Willis, Ladona [Manteca, CA; Masquelier, Donald A [Tracy, CA; Nasarabadi, Shanavaz L [Livermore, CA

2009-03-17

A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

The efficiency of ultrasonic oscillations transfer into the load

NASA Astrophysics Data System (ADS)

Abramov, O. V.; Abramov, V. O.; Mullakaev, M. S.; Artem'ev, V. V.

2009-11-01

The results of ultrasonic action to the substances have been presented. It is examined, the correlation between the electrical parameters of ultrasonic equipment and acoustic performances of the ultrasonic field in treating the medium, the efficiency of ultrasonic technological facility, and the peculiarities of oscillations introduced into the load under cavitation development. The correlation between the acoustic powers of oscillations securing the needed level of cavitation and desired technological effect, and the electrical parameters of the ultrasonic facility, first of all, the power, is established. The peculiarities of cavitation development in liquids with different physical-chemical properties (including the molten low-melting metals) have been studied, and the acoustic power of oscillations introduced into the load under input variation of electric power to the generator has been also estimated.

Self-Centering Reciprocating-Permanent-Magnet Machine

NASA Technical Reports Server (NTRS)

Bhate, Suresh; Vitale, Nick

1988-01-01

New design for monocoil reciprocating-permanent-magnet electric machine provides self-centering force. Linear permanent-magnet electrical motor includes outer stator, inner stator, and permanent-magnet plunger oscillateing axially between extreme left and right positions. Magnets arranged to produce centering force and allows use of only one coil of arbitrary axial length. Axial length of coil chosen to provide required efficiency and power output.

Electrical machines with superconducting windings. Part 3: Homopolar dc machines

NASA Astrophysics Data System (ADS)

Kullman, D.; Henninger, P.

1981-01-01

The losses in rotating liquid metal contacts and the problems in including liquid metals were theoretically and experimentally studied. These machines are shown realiable. For electric ship propulsion, they are a more efficient method of power transmission than mechanical gearboxes. However, weight reduction as compared to mechanical gearboxes can hardly be achieved with machines fully shielded by magnetic iron.

SNAP 10A ESTIMATED ELECTRICAL CHARACTERISTICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooper, J.C.

1961-06-01

The electrical power characteristics of a SNAP 10A converter are estimated for given fractions of power degradation. Graphs are included showing the power characteristics for instantaneous transients from stabilized operation at the maximum efficiency point, and after system temperature stabilization at the operating point. Open-circuit emf's of the converter are estimated for instantaneous and temperature-stabilized cases. (D.L.C.)

Ambipolar light-emitting organic single-crystal transistors with a grating resonator

PubMed Central

Maruyama, Kenichi; Sawabe, Kosuke; Sakanoue, Tomo; Li, Jinpeng; Takahashi, Wataru; Hotta, Shu; Iwasa, Yoshihiro; Takenobu, Taishi

2015-01-01

Electrically driven organic lasers are among the best lasing devices due to their rich variety of emission colors as well as other advantages, including printability, flexibility, and stretchability. However, electrically driven lasing in organic materials has not yet been demonstrated because of serious luminescent efficiency roll-off under high current density. Recently, we found that the organic ambipolar single-crystal transistor is an excellent candidate for lasing devices because it exhibits less efficient roll-off, high current density, and high luminescent efficiency. Although a single-mode resonator combined with light-emitting transistors (LETs) is necessary for electrically driven lasing devices, the fragility of organic crystals has strictly limited the fabrication of resonators, and LETs with optical cavities have never been fabricated until now. To achieve this goal, we improved the soft ultraviolet-nanoimprint lithography method and demonstrated electroluminescence from a single-crystal LET with a grating resonator, which is a crucial milestone for future organic lasers. PMID:25959455

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nester, Patrick

The rooftop Photovoltaic (PV) panels and radiant piping project was constructed by Fort Mason Center as part of its $21 million comprehensive rehabilitation of the Pier 2 shed which include the shed’s electrical, natural gas and water systems. Fort Mason Center improved performance while reducing energy and water usage and costs to demonstrate the efficiencies and opportunities available to large multi-function facilities. The scalable demand of these facilities required a layered approach to conservation, control and production. The project employed a comprehensive retrofit of electrical natural gas, and plumbing systems to maximize efficiency and lower carbon footprint specifically to demonstratemore » the effectiveness of these strategies in a public setting with varied and diverse use. The project was completed in July 2014 and met the expected outcomes regarding increased comfort and operational efficiency throughout the Pier 2 shed as well as on site electrical generation of current consumption. The entire Pier 2 shed project won a 2015 California Preservation Foundation design award for historic rehabilitation.« less

Change-of-Pace Electric Vehicle at the Lewis Research Center

NASA Image and Video Library

1977-04-21

The National Aeronautics and Space Administration (NASA) Lewis Research Center tested 16 commercially-manufactured electric vehicles, including this modified Pacer, during the mid-1970s. The Electric Vehicle Project was just one of several energy-related programs that Lewis and the Energy Research and Development Administration (ERDA) undertook in the mid-1970s. NASA and ERDA embarked on this program in 1976 to determine the state of the current electric vehicle technology. As part of the project, Lewis tested a fleet composed of every commercially available electric car. The Cleveland-area Electric Vehicle Associates modified an American Motors Pacer vehicle to create this Change-of-Pace Coupe. It was powered by twenty 6-volt batteries whose voltage could be varied by a foot control. The tests analyzed the vehicle’s range, acceleration, coast-down, braking, and energy consumption. Some of the vehicles had analog data recording systems to measure the battery during operation and sensors to determine speed and distance. Lewis researchers found that the vehicle performance varied significantly from model to model. In general, the range, acceleration, and speed were lower than conventional vehicles. They also found that traditional gasoline-powered vehicles were as efficient as the electric vehicles. The researchers concluded, however, that advances in battery technology and electric drive systems would significantly improve the performance and efficiency.

Energy efficiency in the U.S. residential sector: An engineering and economic assessment of opportunities for large energy savings and greenhouse gas emissions reductions

NASA Astrophysics Data System (ADS)

Lima de Azevedo, Ines Margarida

Energy efficiency and conservation is a very promising part of a portfolio of the needed strategies to mitigate climate change. Several technologies and energy efficiency measures in the residential sector offer potential for large energy savings. However, while energy efficiency options are currently considered as a means of reducing carbon emissions, there is still large uncertainty about the effect of such measures on overall carbon savings. The first part of this thesis provides a national assessment of the energy efficiency potential in the residential sector under several different scenarios, which include the perspectives of different economic agents (consumers, utilities, ESCOs, and a society). The scenarios also include maximizing energy, electricity or carbon dioxide savings. The second part of this thesis deals with a detailed assessment of the potential for white-light LEDs for energy and carbon dioxide savings in the U.S. commercial and residential sectors. Solid-state lighting shows great promise as a source of efficient, affordable, color-balanced white light. Indeed, assuming market discount rates, the present work demonstrates that white solid-state lighting already has a lower levelized annual cost (LAC) than incandescent bulbs and that it will be lower than that of the most efficient fluorescent bulbs by the end of this decade. However, a large literature indicates that households do not make their decisions in terms of simple expected economic value. The present analysis shows that incorporating the findings from literature on high implicit discount rates from households when performing decisions towards efficient technologies delays the adoption of white LEDs by a couple of years. After a review of the technology, the present work compares the electricity consumption, carbon emissions and cost-effectiveness of current lighting technologies, when accounting for expected performance evolution through 2015. Simulations of lighting electricity consumption and implicit greenhouse gases emissions for the U.S. residential and commercial sectors through 2015 under different policy scenarios (voluntary solid-state lighting adoption, implementation of lighting standards in new construction and rebate programs or equivalent subsidies) are also included.

Experimental study of a fuel cell power train for road transport application

NASA Astrophysics Data System (ADS)

Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

High frequency x-ray generator basics.

PubMed

Sobol, Wlad T

2002-02-01

The purpose of this paper is to present basic functional principles of high frequency x-ray generators. The emphasis is put on physical concepts that determine the engineering solutions to the problem of efficient generation and control of high voltage power required to drive the x-ray tube. The physics of magnetically coupled circuits is discussed first, as a background for the discussion of engineering issues related to high-frequency power transformer design. Attention is paid to physical processes that influence such factors as size, efficiency, and reliability of a high voltage power transformer. The basic electrical circuit of a high frequency generator is analyzed next, with focus on functional principles. This section investigates the role and function of basic components, such as power supply, inverter, and voltage doubler. Essential electronic circuits of generator control are then examined, including regulation of voltage, current and timing of electrical power delivery to the x-ray tube. Finally, issues related to efficient feedback control, including basic design of the AEC circuitry are reviewed.

Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells

PubMed Central

Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

2015-01-01

Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC). PMID:26218470

Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells.

PubMed

Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

2015-07-28

Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC).

Do Membranes Dream of Electric Tubes? Advanced Membranes Using Carbon Nanotube - Polymer Nanocomposites

NASA Astrophysics Data System (ADS)

de Lannoy, Charles-Francois Pedro Claude Karolek Ghislain

Membrane technologies represent an energy efficient, effective solution for treating municipal and commercial waters/wastewaters. Membranes are predominantly polymer-based and despite steady advances in polymeric materials, they continue to suffer from operational problems including biofouling and breakages. This work addresses these two disparate problems by developing novel CNT-polymer nanocomposite materials that contain variously functionalized carbon nanotubes (fCNTs) in low quantities (<0.5wt%). Several strategies have been employed to achieve highly functional CNT-polymer nanocomposite membranes including blend mixing, ionic charge association, and covalent cross-linking with monomer and oligomer constituents. These CNT-polymer nanocomposite membranes were compared to traditional polymer membranes across various properties including increased Young's Modulus, changes in surface hydrophilicity, fine control over molecular weight cut-off and flux, and surface electrical conductivity. Membranes with high surface electrical conductivity were further tested for their anti-biofouling properties. Finally, CNT stability and polymer compatibility were evaluated throughout membrane manufacture, use, and cleaning. The incorporation of CNTs mixed in bulk phase and linked through ionic associations in polymer matrices showed significant (50%) increases in Young's modulus for certain CNT functionalizations and derivatization percent. Membranes formed with high surface electrical conductivity demonstrated almost complete resistance to biofouling (> 95%) in long-term bacterially challenged experiments. CNTs and polymer mixtures that lacked covalent or ionic bonds were susceptible to significant (up to 10%) loss of CNTs during membrane non-solvent gelation and aggressive chemical cleaning treatment. Functionalized carbon nanotubes endow polymer membranes with their unique strength and electrically conductive properties. These added properties were demonstrated to greatly improve membrane operational efficiency and membrane longevity. CNT-polymer nanocomposite membranes offer low-energy, high-efficiency, and long-lifetime alternatives to traditional polymer membranes. With further advances in polymeric nanomaterials, membrane technology has the potential for wide applicability across many fields outside of water filtration and desalination.

Essays on pricing electricity and electricity derivatives in deregulated markets

NASA Astrophysics Data System (ADS)

Popova, Julia

2008-10-01

This dissertation is composed of four essays on the behavior of wholesale electricity prices and their derivatives. The first essay provides an empirical model that takes into account the spatial features of a transmission network on the electricity market. The spatial structure of the transmission grid plays a key role in determining electricity prices, but it has not been incorporated into previous empirical models. The econometric model in this essay incorporates a simple representation of the transmission system into a spatial panel data model of electricity prices, and also accounts for the effect of dynamic transmission system constraints on electricity market integration. Empirical results using PJM data confirm the existence of spatial patterns in electricity prices and show that spatial correlation diminishes as transmission lines become more congested. The second essay develops and empirically tests a model of the influence of natural gas storage inventories on the electricity forward premium. I link a model of the effect of gas storage constraints on the higher moments of the distribution of electricity prices to a model of the effect of those moments on the forward premium. Empirical results using PJM data support the model's predictions that gas storage inventories sharply reduce the electricity forward premium when demand for electricity is high and space-heating demand for gas is low. The third essay examines the efficiency of PJM electricity markets. A market is efficient if prices reflect all relevant information, so that prices follow a random walk. The hypothesis of random walk is examined using empirical tests, including the Portmanteau, Augmented Dickey-Fuller, KPSS, and multiple variance ratio tests. The results are mixed though evidence of some level of market efficiency is found. The last essay investigates the possibility that previous researchers have drawn spurious conclusions based on classical unit root tests incorrectly applied to wholesale electricity prices. It is well known that electricity prices exhibit both cyclicity and high volatility which varies through time. Results indicate that heterogeneity in unconditional variance---which is not detected by classical unit root tests---may contribute to the appearance of non-stationarity.

Round Trip Energy Efficiency of NASA Glenn Regenerative Fuel Cell System

NASA Technical Reports Server (NTRS)

Garcia, Christopher P.; Chang, Bei-jiann; Johnson, Donald W.; Bents, David J.; Scullin, Vincent J.; Jakupca, Ian J.; Scullin, Vincent J.; Jakupca, Ian J.

2006-01-01

NASA Glenn Research Center (GRC) has recently demonstrated a Polymer Electrolyte Membrane (PEM) based hydrogen/oxygen regenerative fuel cell system (RFCS) that operated for a charge/discharge cycle with round trip efficiency (RTE) greater than 50 percent. The regenerative fuel cell system (RFCS) demonstrated closed loop energy storage over a pressure range of 90 to 190 psig. In charge mode, a constant electrical power profile of 7.1 kWe was absorbed by the RFCS and stored as pressurized hydrogen and oxygen gas. In discharge mode, the system delivered 3 to 4 kWe of electrical power along with product water. Fuel cell and electrolyzer power profiles and polarization performance are documented in this paper. Individual cell performance and the variation of cell voltages within the electrochemical stacks are also reported. Fuel cell efficiency, electrolyzer efficiency, and the system RTE were calculated from the test data and are included below.

Effect of external applied electric field on the silicon solar cell's thermodynamic efficiency

NASA Astrophysics Data System (ADS)

Zieba Falama, R.; Mibaile, Justin; Guemene Dountio, E.; Djongyang, Noël; Doka, Serge Y.; Kofane, Timoleon C.

2017-03-01

This paper presents a possible solution to improve the efficiency of photovoltaic solar cells. An external electric field is applied on a silicon photovoltaic solar cell, inducing band-trap ionization of charge carriers. Output current is then monitored and the thermodynamic efficiency is calculated. Results show on the one hand a significant increase in efficiency for a certain margin of applied electric field, and on the another hand the instabilities of efficiency. A simple approach is then suggested for the implementation of these results. An efficiency of 67% has been reached for an applied electric of 1586 V/Cm.

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER (prime contractor) was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the tenth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting January 1, 2003 and ending March 31, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the ninth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2002 and ending December 31, 2002. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research (GEGR) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEGR (prime contractor) was awardedmore » a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GEGR, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling with best-case scenario assumptions, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the eleventh quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2003 and ending June 30, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less

Energy Efficient Demonstration Proves Powerful in Home Retrofits -

Science.gov Websites

project team that included key Navy stakeholders at the regional and Naval Base Guam installation levels was Naval Base Guam in Apra Harbor, which has 1,369 houses for its active-duty Navy and family members millions." Given Naval Base Guam's high electricity rates of $0.50 per kilowatt hour, the efficiency

Closed Brayton Cycle (CBC) Power Generation from an Electric Systems Perspective

NASA Astrophysics Data System (ADS)

Halsey, David G.; Fox, David A.

2006-01-01

Several forms of closed cycle heat engines exist to produce electrical energy suitable for space exploration or planetary surface applications. These engines include Stirling and Closed Brayton Cycle (CBC). Of these two, CBC has often been cited as providing the best balance of mass and efficiency for deep space or planetary power systems. Combined with an alternator on the same shaft, the hermetically sealed system provides the potential for long life and reliable operation. There is also a list of choices for the type of alternator. Choices include wound rotor machines, induction machines, switched reluctance machines, and permanent magnet generators (PMGs). In trades involving size, mass and efficiency the PMG is a favorable solution. This paper will discuss the consequences of using a CBC-PMG source for an electrical power system, and the system parameters that must be defined and controlled to provide a stable, useful power source. Considerations of voltage, frequency (including DC), and power quality will be discussed. Load interactions and constraints for various power types will also be addressed. Control of the CBC-PMG system during steady state operation and startup is also a factor.s

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, Kirk A.; Burchell, Timothy D.; Judkins, Roddie R.

1998-01-01

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply airstream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium.

Terrestrial Applications of Extreme Environment Stirling Space Power Systems

NASA Technical Reports Server (NTRS)

Dyson, Rodger. W.

2012-01-01

NASA has been developing power systems capable of long-term operation in extreme environments such as the surface of Venus. This technology can use any external heat source to efficiently provide electrical power and cooling; and it is designed to be extremely efficient and reliable for extended space missions. Terrestrial applications include: use in electric hybrid vehicles; distributed home co-generation/cooling; and quiet recreational vehicle power generation. This technology can reduce environmental emissions, petroleum consumption, and noise while eliminating maintenance and environmental damage from automotive fluids such as oil lubricants and air conditioning coolant. This report will provide an overview of this new technology and its applications.

Competition and Cooperation of Distributed Generation and Power System

NASA Astrophysics Data System (ADS)

Miyake, Masatoshi; Nanahara, Toshiya

Advances in distributed generation technologies together with the deregulation of an electric power industry can lead to a massive introduction of distributed generation. Since most of distributed generation will be interconnected to a power system, coordination and competition between distributed generators and large-scale power sources would be a vital issue in realizing a more desirable energy system in the future. This paper analyzes competitions between electric utilities and cogenerators from the viewpoints of economic and energy efficiency based on the simulation results on an energy system including a cogeneration system. First, we examine best response correspondence of an electric utility and a cogenerator with a noncooperative game approach: we obtain a Nash equilibrium point. Secondly, we examine the optimum strategy that attains the highest social surplus and the highest energy efficiency through global optimization.

Steam sterilisation's energy and water footprint.

PubMed

McGain, Forbes; Moore, Graham; Black, Jim

2017-03-01

Objective The aim of the present study was to quantify hospital steam steriliser resource consumption to provide baseline environmental data and identify possible efficiency gains. We sought to find the amount of steriliser electricity and water used for active cycles and for idling (standby), and the relationship between the electricity and water consumption and the mass and type of items sterilised. Methods We logged a hospital steam steriliser's electricity and water meters every 5min for up to 1 year. We obtained details of all active cycles (standard 134°C and accessory or 'test' cycles), recording item masses and types. Relationships were investigated for both the weight and type of items sterilised with electricity and water consumption. Results Over 304 days there were 2173 active cycles, including 1343 standard 134°C cycles that had an average load mass of 21.2kg, with 32% of cycles <15kg. Electricity used for active cycles was 32652kWh (60% of total), whereas the water used was 1243495L (79%). Standby used 21457kWh (40%) electricity and 329200L (21%) water. Total electricity and water consumption per mass sterilised was 1.9kWhkg -1 and 58Lkg -1 , respectively. The linear regression model predicting electricity use was: kWh=15.7+ 0.14×mass (in kg; R 2 =0.58, P<0.01). Models for water and item type were poor. Electricity and water use fell from 3kWhkg -1 and 200Lkg -1 , respectively, for 5-kg loads to 0.5kWhkg -1 and 20Lkg -1 , respectively, for 40-kg loads. Conclusions Considerable electricity and water use occurred during standby, load mass was only moderately predictive of electricity consumption and light loads were common yet inefficient. The findings of the present study are a baseline for steam sterilisation's environmental footprint and identify areas to improve efficiencies. What is known about the topic? There is increasing interest in the environmental effects of healthcare. Life cycle assessment ('cradle to grave') provides a scientific method of analysing environmental effects. Although data of the effects of steam sterilisation are integral to the life cycles of reusable items and procedures using such items, there are few data available. Further, there is scant information regarding the efficiency of the long-term in-hospital use of sterilisers. What does this paper add? We quantified, for the first time, long-term electricity and water use of a hospital steam steriliser. We provide useful input data for future life cycle assessments of all reusable, steam-sterilised equipment. Further, we identified opportunities for improved steriliser efficiencies, including rotating off idle sterilisers and reducing the number of light steriliser loads. Finally, others could use our methods to examine steam sterilisers and many other energy-intensive items of hospital equipment. What are the implications for practitioners? We provide useful input data for all researchers examining the environmental footprint of reusable hospital equipment and procedures using such equipment. As a result of the present study, staff in the hospital sterile supply department have reduced steam steriliser electricity and water use considerably without impeding sterilisation throughput (and reduced time inefficiencies). Many other hospitals could benefit from similar methods to improve steam steriliser and other hospital equipment efficiencies.

Production efficiencies of U.S. electric generation plants: Effects of data aggregation and greenhouse gas and renewable energy policy

NASA Astrophysics Data System (ADS)

Lynes, Melissa Kate

Over the last few decades there has been a shift in electricity production in the U.S. Renewable energy sources are becoming more widely used. In addition, electric generation plants that use coal inputs are more heavily regulated than a couple decades ago. This shift in electricity production was brought on by changes in federal policy -- a desire for electricity produced in the U.S. which led to policies being adopted that encourage the use of renewable energy. The change in production practices due to policies may have led to changes in the productivity of electric generation plants. Multiple studies have examined the most efficient electric generation plants using the data envelopment analysis (DEA) approach. This study builds on past research to answer three questions: 1) Does the level of aggregation of fuel input variables affect the plant efficiency scores and how does the efficiency of renewable energy input compare to nonrenewable energy inputs; 2) Are policies geared toward directly or indirectly reducing greenhouse gas emissions affecting the production efficiencies of greenhouse gas emitting electric generation plants; and 3) Do renewable energy policies and the use of intermittent energy sources (i.e. wind and solar) affect the productivity growth of electric generation plants. All three analysis, presented in three essays, use U.S. plant level data obtained from the Energy Information Administration to answer these questions. The first two essays use DEA to determine the pure technical, overall technical, and scale efficiencies of electric generation plants. The third essay uses DEA within the Malmquist index to assess the change in productivity over time. Results indicate that the level of aggregation does matter particularly for scale efficiency. This implies that valuable information is likely lost when fuel inputs are aggregated together. Policies directly focused on reducing greenhouse gas emissions may improve the production efficiencies of greenhouse gas emitting electric generation plants. However, renewable energy policies do not have an effect on productivity growth. Renewable energy inputs are found to be as efficient if not more efficient than traditional energy sources.

Variable cross-section windings for efficiency improvement of electric machines

NASA Astrophysics Data System (ADS)

Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

2018-02-01

Implementation of energy-saving technologies in industry is impossible without efficiency improvement of electric machines. The article considers the ways of efficiency improvement and mass and dimensions reduction of electric machines with electronic control. Features of compact winding design for stators and armatures are described. Influence of compact winding on thermal and electrical process is given. Finite element method was used in computer simulation.

Artificial muscles on heat

NASA Astrophysics Data System (ADS)

McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

2014-03-01

Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

Grid-Level Application of Electrical Energy Storage: Example Use Cases in the United States and China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yingchen; Gevorgian, Vahan; Wang, Caixia

Electrical energy storage (EES) systems are expected to play an increasing role in helping the United States and China-the world's largest economies with the two largest power systems-meet the challenges of integrating more variable renewable resources and enhancing the reliability of power systems by improving the operating capabilities of the electric grid. EES systems are becoming integral components of a resilient and efficient grid through a diverse set of applications that include energy management, load shifting, frequency regulation, grid stabilization, and voltage support.

Isotope Brayton electric power system for the 500 to 2500 watt range

NASA Technical Reports Server (NTRS)

Macosko, R. P.; Barna, G. J.; Block, H. B.; Ingle, B. D.

1972-01-01

An extensive study was conducted at the Lewis Research Center to evaluate an isotope Brayton electric power system for use in the 500 to 2500 W power range. Overall system simplicity was emphasized in order to reduce parasitic power losses and improve system reliability. Detailed parametric cycle analysis, conceptual component designs, and evaluation of system packaging were included. A single-loop system (gas) with six major components including one rotating unit was selected. Calculated net system efficiency varies from 23 to 28 percent over the power range.

The impact of state energy programs and other contextual factors on U.S. buildings energy consumption

NASA Astrophysics Data System (ADS)

Ofori-Boadu, Andrea N. Y. A.

High energy consumption in the United States has been influenced by populations, climates, income and other contextual factors. In the past decades, U.S. energy policies have pursued energy efficiency as a national strategy for reducing U.S. environmental degradation and dependence on foreign oils. The quest for improved energy efficiency has led to the development of energy efficient technologies and programs. The implementation of energy programs in the complex U.S. socio-technical environment is believed to promote the diffusion of energy efficiency technologies. However, opponents doubt the fact that these programs have the capacity to significantly reduce U.S. energy consumption. In order to contribute to the ongoing discussion, this quantitative study investigated the relationships existing among electricity consumption/ intensity, energy programs and contextual factors in the U.S. buildings sector. Specifically, this study sought to identify the significant predictors of electricity consumption and intensity, as well as estimate the overall impact of selected energy programs on electricity consumption and intensity. Using state-level secondary data for 51 U.S. states from 2006 to 2009, seven random effects panel data regression models confirmed the existence of significant relationships among some energy programs, contextual factors, and electricity consumption/intensity. The most significant predictors of improved electricity efficiency included the price of electricity, public benefits funds program, building energy codes program, financial and informational incentives program and the Leadership in Energy and Environmental Design (LEED) program. Consistently, the Southern region of the U.S. was associated with high electricity consumption and intensity; while the U.S. commercial sector was the greater benefactor from energy programs. On the average, energy programs were responsible for approximately 7% of the variation observed in electricity consumption and intensity, over and above the variation associated with the contextual factors. This study also had implications in program implementation theory, and revealed that resource availability, stringency and adherence had significant impacts on program outcomes. Using seven classification tables, this study categorized and matched the predictors of electricity consumption and intensity with the specific energy sectors in which they demonstrated significance. Project developers, energy advocates, policy makers, program administrators, building occupants and other stakeholders could use study findings in conjunction with other empirical findings, to make informed decisions regarding the adoption, continuation or discontinuation of energy programs, while taking contextual factors into consideration. The adoption and efficient implementation of the most significant programs could reduce U.S. electricity consumption, and in the long term, probably reduce U.S. energy waste, environmental degradation, energy imports, energy prices, and demands for expanding energy generation and distribution infrastructure.

The production of consuming less: Energy efficiency, climate change, and light bulbs in North Carolina

NASA Astrophysics Data System (ADS)

Thoyre, Autumn

In this research, I have analyzed the production of consuming less electricity through a case study of promotions of compact fluorescent light bulbs (CFLs). I focused on the CFL because it has been heavily promoted by environmentalists and electricity companies as a key tool for solving climate change, yet such promotions appear counter-intuitive. The magnitude of CFL promotions by environmentalists is surprising because CFLs can only impact less than 1% of U.S. greenhouse gas emissions. CFL promotions by electricity providers are surprising given such companies' normal incentives to sell more of their product. I used political ecological and symbolic interactionist theories, qualitative methods of data collection (including interviews, participant-observation, texts, and images), and a grounded theory analysis to understand this case. My findings suggest that, far from being a self-evident technical entity, energy efficiency is produced as an idea, a part of identities, a resource, and a source of value through social, political, and economic processes. These processes include identity formation and subjectification; gender-coded household labor; and corporate appropriation of household value resulting from environmental governance. I show how environmentalists use CFLs to make and claim neoliberal identities, proposing the concept of green neoliberal identity work as a mechanism through which neoliberal ideologies are translated into practices. I analyze how using this seemingly easy energy efficient technology constitutes labor that is gendered in ways that reflect and reproduce inequalities. I show how electricity companies have used environmental governance to valorize and appropriate home energy efficiency as an accumulation strategy. I conclude by discussing the symbolic power of CFLs, proposing a theory of green obsolescence, and framing the production of energy efficiency as a global production network. I found that promoting energy efficiency involves consuming less energy by consuming more technologies. This research contributes to understandings of how environmentalists become laboring subjects in an era of neoliberalism and how energy companies are responding to the threat of climate change by turning mitigation into an opportunity for profit.

[Electrical response of inner membrane structures of corynebacteria during electrotransformation].

PubMed

Tiurin, M V; Voroshilova, E B; Rostova, Iu G; Oparina, N Iu; Gusiatiner, M M

1998-01-01

The efficiency of the electrotransformation of intact cells of corynebacteria by a solitary impulse with a complex shape amounted to 10(6) transformants/microgram of plasmid pNV1 DNA at an electric field strength of 14.2 kW/cm; the voltage-current curve of the cell samples was nonlinear. Under these conditions, the structure of the electric current impulse passing intact cells or protoplasts included oscillations characterized by increasing amplitude and a duration of 170 microseconds, which were not detected in the structure of the electric current impulses at field strengths insufficient for obtaining transformants. These changes in the impulse shape suggest the involvement of internal closed membrane structures in the electrical response of cells to the exogenous electric impulse. Most probably, under conditions of electrical treatment optimal for transformation, electropores are formed in the intracellular membranes of corynebacteria.

Multi-scale and multi-physics model of the uterine smooth muscle with mechanotransduction.

PubMed

Yochum, Maxime; Laforêt, Jérémy; Marque, Catherine

2018-02-01

Preterm labor is an important public health problem. However, the efficiency of the uterine muscle during labor is complex and still poorly understood. This work is a first step towards a model of the uterine muscle, including its electrical and mechanical components, to reach a better understanding of the uterus synchronization. This model is proposed to investigate, by simulation, the possible role of mechanotransduction for the global synchronization of the uterus. The electrical diffusion indeed explains the local propagation of contractile activity, while the tissue stretching may play a role in the synchronization of distant parts of the uterine muscle. This work proposes a multi-physics (electrical, mechanical) and multi-scales (cell, tissue, whole uterus) model, which is applied to a realistic uterus 3D mesh. This model includes electrical components at different scales: generation of action potentials at the cell level, electrical diffusion at the tissue level. It then links these electrical events to the mechanical behavior, at the cellular level (via the intracellular calcium concentration), by simulating the force generated by each active cell. It thus computes an estimation of the intra uterine pressure (IUP) by integrating the forces generated by each active cell at the whole uterine level, as well as the stretching of the tissue (by using a viscoelastic law for the behavior of the tissue). It finally includes at the cellular level stretch activated channels (SACs) that permit to create a loop between the mechanical and the electrical behavior (mechanotransduction). The simulation of different activated regions of the uterus, which in this first "proof of concept" case are electrically isolated, permits the activation of inactive regions through the stretching (induced by the electrically active regions) computed at the whole organ scale. This permits us to evidence the role of the mechanotransduction in the global synchronization of the uterus. The results also permit us to evidence the effect on IUP of this enhanced synchronization induced by the presence of SACs. This proposed simplified model will be further improved in order to permit a better understanding of the global uterine synchronization occurring during efficient labor contractions. Copyright © 2017 Elsevier Ltd. All rights reserved.

It's a Clean Machine

NASA Technical Reports Server (NTRS)

1998-01-01

Under an SBIR (Small Business Innovative Research) from Lewis Research Center, Precision Combustion, Inc. (PCI) developed the Advanced Technology Catalytic Combustor. The research proved the viability of efficient, cost-effective catalytic reduction of gas turbine nitrogen oxide emissions along with fuel efficiency. PCI has signed agreements with Westinghouse, other gas turbine manufacturers, including Capstone Turbine Corporation to develop a catalytic combustor for their hybrid electric vehicle.

Carbon fiber composite molecular sieve electrically regenerable air filter media

DOEpatents

Wilson, K.A.; Burchell, T.D.; Judkins, R.R.

1998-10-27

An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply air stream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium. 3 figs.

78 FR 18974 - Increasing Market and Planning Efficiency Through Improved Software; Notice of Technical...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-28

... bring together experts from diverse backgrounds and experiences including electric system operators... transmission switching; AC optimal power flow modeling; and use of active and dynamic transmission ratings. In... variability of the system, including forecast error? [cir] How can outage probability be captured in...

Reusable Hybrid Propellant Modules for Outer-Space Transport

NASA Technical Reports Server (NTRS)

Mazanek, Daniel D.; Mankins, John C.

2005-01-01

A report summarizes the concept of reusable hybrid propellant modules (HPMs), which would be used in outer space for long-term cryogenic storage of liquefied spacecraft-propellant gases, including for example, oxygen and hydrogen for combustion-based chemical rocket engines and xenon for electric thrusters. The HPM concept would provide the fundamental building block for an efficient, reusable in-space transportation system for both crewed and uncrewed missions. Each HPM would be equipped to implement an advanced zero-boil-off method of managing cryogenic fluids, and would include a fluid-transfer interface comprising standardized fittings that would be compatible with fittings on all supply facilities and on spacecraft to be supplied. The HPM, combined with a chemical or electric orbital transfer spacecraft, would provide an integrated propulsion system. HPMs would supply chemical propellant for time-critical transfers such as crewed missions, and utilize the more efficient electric-propulsion transfer vehicles to transport filled HPMs to the destinations and to return empty HPMs back to near-Earth orbits or other intermediate locations for replenishment and reuse. The HPM prepositioned using electric propulsion would provide the chemical propellant for the crew s return trip in a much more efficient manner than a chemical-only approach. The propellants to fill the HPMs would be delivered from the Earth or other initial supply locations to the intermediate locations by use of automated, compatible spacecraft designed specifically for that purpose. Additionally, multiple HPMs could be aggregated and positioned in orbits and on planets, moons, and asteroids to supply fluids to orbiting and interplanetary spacecraft.

Grid Data and Tools | Grid Modernization | NREL

Science.gov Websites

technologies and strategies, including renewable resource data sets and models of the electric power system . Renewable Resource Data A library of resource information to inform the design of efficient, integrated

A Programmable High-Voltage Compliance Neural Stimulator for Deep Brain Stimulation in Vivo

PubMed Central

Gong, Cihun-Siyong Alex; Lai, Hsin-Yi; Huang, Sy-Han; Lo, Yu-Chun; Lee, Nicole; Chen, Pin-Yuan; Tu, Po-Hsun; Yang, Chia-Yen; Lin, James Chang-Chieh; Chen, You-Yin

2015-01-01

Deep brain stimulation (DBS) is one of the most effective therapies for movement and other disorders. The DBS neurosurgical procedure involves the implantation of a DBS device and a battery-operated neurotransmitter, which delivers electrical impulses to treatment targets through implanted electrodes. The DBS modulates the neuronal activities in the brain nucleus for improving physiological responses as long as an electric discharge above the stimulation threshold can be achieved. In an effort to improve the performance of an implanted DBS device, the device size, implementation cost, and power efficiency are among the most important DBS device design aspects. This study aims to present preliminary research results of an efficient stimulator, with emphasis on conversion efficiency. The prototype stimulator features high-voltage compliance, implemented with only a standard semiconductor process, without the use of extra masks in the foundry through our proposed circuit structure. The results of animal experiments, including evaluation of evoked responses induced by thalamic electrical stimuli with our fabricated chip, were shown to demonstrate the proof of concept of our design. PMID:26029954

Development of Structural Energy Storage for Aeronautics Applications

NASA Technical Reports Server (NTRS)

Santiago-Dejesus, Diana; Loyselle, Patricia L.; Demattia, Brianne; Bednarcyk, Brett; Olson, Erik; Smith, Russell; Hare, David

2017-01-01

The National Aeronautics and Space Administration (NASA) has identified Multifunctional Structures for High Efficiency Lightweight Load-bearing Storage (M-SHELLS) as critical to development of hybrid gas-electric propulsion for commercial aeronautical transport in the N+3 timeframe. The established goals include reducing emissions by 80 and fuel consumption by 60 from todays state of the art. The advancement will enable technology for NASA Aeronautics Research Mission Directorates (ARMD) Strategic Thrust 3 to pioneer big leaps in efficiency and environmental performance for ultra-efficient commercial transports, as well as Strategic Thrust 4 to pioneer low-carbon propulsion technology in the transition to that scheme. The M-SHELLS concept addresses the hybrid gas-electric highest risk with its primary objective: to save structures energy storage system weight for future commercial hybrid electric propulsion aircraft by melding the load-carrying structure with energy storage in a single material. NASA's multifunctional approach also combines supercapacitor and battery chemistries in a synergistic energy storage arrangement in tandem with supporting good mechanical properties. The arrangement provides an advantageous combination of specific power, energy, and strength.

Electric dipole-quadrupole hybridization induced enhancement of second-harmonic generation in T-shaped plasmonic heterodimers.

PubMed

Guo, Kai; Zhang, Yong-Liang; Qian, Cheng; Fung, Kin-Hung

2018-04-30

In this work, we demonstrate computationally that electric dipole-quadrupole hybridization (EDQH) could be utilized to enhance plasmonic SHG efficiency. To this end, we construct T-shaped plasmonic heterodimers consisting of a short and a long gold nanorod with finite element method simulation. By controlling the strength of capacitive coupling between two gold nanorods, we explore the effect of EDQH evolution on the SHG process, including the SHG efficiency enhancement, corresponding near-field distribution, and far-field radiation pattern. Simulation results demonstrate that EDQH could enhance the SHG efficiency by a factor >100 in comparison with that achieved by an isolated gold nanorod. Additionally, the far-field pattern of the SHG could be adjusted beyond the well-known quadrupolar distribution and confirms that EDQH plays an important role in the SHG process.

Efficient and equitable spatial allocation of renewable power plants at the country scale

NASA Astrophysics Data System (ADS)

Drechsler, Martin; Egerer, Jonas; Lange, Martin; Masurowski, Frank; Meyerhoff, Jürgen; Oehlmann, Malte

2017-09-01

Globally, the production of renewable energy is undergoing rapid growth. One of the most pressing issues is the appropriate allocation of renewable power plants, as the question of where to produce renewable electricity is highly controversial. Here we explore this issue through analysis of the efficient and equitable spatial allocation of wind turbines and photovoltaic power plants in Germany. We combine multiple methods, including legal analysis, economic and energy modelling, monetary valuation and numerical optimization. We find that minimum distances between renewable power plants and human settlements should be as small as is legally possible. Even small reductions in efficiency lead to large increases in equity. By considering electricity grid expansion costs, we find a more even allocation of power plants across the country than is the case when grid expansion costs are neglected.

Significantly Enhanced Energy Density in Nanocomposite Capacitors Combining the TiO2 Nanorod Array with Poly(vinylidene fluoride).

PubMed

Yao, Lingmin; Pan, Zhongbin; Liu, Shaohui; Zhai, Jiwei; Chen, Haydn H D

2016-10-05

A novel inorganic/polymer nanocomposite, using 1-dimensional TiO 2 nanorod array as fillers (TNA) and poly(vinylidene fluoride) (PVDF) as matrix, has been successfully synthesized for the first time. A carefully designed process sequence includes several steps with the initial epitaxial growth of highly oriented TNA on the fluorine-doped tin oxide (FTO) conductive glass. Subsequently, PVDF is embedded into the nanorods by the spin-coating method followed by annealing and quenching processes. This novel structure with dispersive fillers demonstrates a successful compromise between the electric displacement and breakdown strength, resulting in a dramatic increase in the electric polarization which leads to a significant improvement on the energy density and discharge efficiency. The nanocomposites with various height ratios of fillers between the TNA and total film thickness were investigated by us. The results show that nanocomposite with 18% height ratio fillers obtains maximum increase in the energy density (10.62 J cm -3 ) at a lower applied electric field of 340 MV m -1 , and it also illustrates a higher efficiency (>85%) under the electric field less than 100 MV m -1 . Even when the electric field reached 340 MV m -1 , the efficiency of nanocomposites can still maintained at ∼70%. This energy density exceeds most of the previously reported TiO 2 -based nanocomposite values at such a breakdown strength, which provides another promising design for the next generation of dielectric nanocomposite material, by using the highly oriented nanorod array as fillers for the higher energy density capacitors. Additionally, the finite element simulation has been employed to analyze the distribution of electric fields and electric flux density to explore the inherent mechanism of the higher performance of the TNA/PVDF nanocomposites.

The research and application of the power big data

NASA Astrophysics Data System (ADS)

Zhang, Suxiang; Zhang, Dong; Zhang, Yaping; Cao, Jinping; Xu, Huiming

2017-01-01

Facing the increasing environment crisis, how to improve energy efficiency is the important problem. Power big data is main support tool to realize demand side management and response. With the promotion of smart power consumption, distributed clean energy and electric vehicles etc get wide application; meanwhile, the continuous development of the Internet of things technology, more applications access the endings in the grid power link, which leads to that a large number of electric terminal equipment, new energy access smart grid, and it will produce massive heterogeneous and multi-state electricity data. These data produce the power grid enterprise's precious wealth, as the power big data. How to transform it into valuable knowledge and effective operation becomes an important problem, it needs to interoperate in the smart grid. In this paper, we had researched the various applications of power big data and integrate the cloud computing and big data technology, which include electricity consumption online monitoring, the short-term power load forecasting and the analysis of the energy efficiency. Based on Hadoop, HBase and Hive etc., we realize the ETL and OLAP functions; and we also adopt the parallel computing framework to achieve the power load forecasting algorithms and propose a parallel locally weighted linear regression model; we study on energy efficiency rating model to comprehensive evaluate the level of energy consumption of electricity users, which allows users to understand their real-time energy consumption situation, adjust their electricity behavior to reduce energy consumption, it provides decision-making basis for the user. With an intelligent industrial park as example, this paper complete electricity management. Therefore, in the future, power big data will provide decision-making support tools for energy conservation and emissions reduction.

Reducing GHG emissions in the United States' transportation sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Sujit; Andress, David A; Nguyen, Tien

Reducing GHG emissions in the U.S. transportation sector requires both the use of highly efficient propulsion systems and low carbon fuels. This study compares reduction potentials that might be achieved in 2060 for several advanced options including biofuels, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fuel cell electric vehicles (FCEV), assuming that technical and cost reduction targets are met and necessary fueling infrastructures are built. The study quantifies the extent of the reductions that can be achieved through increasing engine efficiency and transitioning to low-carbon fuels separately. Decarbonizing the fuels is essential for achieving large reductions inmore » GHG emissions, and the study quantifies the reductions that can be achieved over a range of fuel carbon intensities. Although renewables will play a vital role, some combination of coal gasification with carbon capture and sequestration, and/or nuclear energy will likely be needed to enable very large reductions in carbon intensities for hydrogen and electricity. Biomass supply constraints do not allow major carbon emission reductions from biofuels alone; the value of biomass is that it can be combined with other solutions to help achieve significant results. Compared with gasoline, natural gas provides 20% reduction in GHG emissions in internal combustion engines and up to 50% reduction when used as a feedstock for producing hydrogen or electricity, making it a good transition fuel for electric propulsion drive trains. The material in this paper can be useful information to many other countries, including developing countries because of a common factor: the difficulty of finding sustainable, low-carbon, cost-competitive substitutes for petroleum fuels.« less

Efficiency arcjet thruster with controlled arc startup and steady state attachment

NASA Technical Reports Server (NTRS)

Smith, William W. (Inventor); Knowles, Steven C. (Inventor)

1989-01-01

An improved efficiency arcjet thruster has a constrictor and electrically-conductive nozzle anode defining an arc chamber, and an electrically-conductive rod having a tip spaced upstream from the constrictor and defining a cathode spaced from the anode by a gap generally coextensive with the arc chamber. An electrical potential is applied to the anode and cathode to generate an electrical arc in the arc chamber from the cathode to anode. Catalytically decomposed hydrazine is supplied to the arc chamber with generation of the arc so as to produce thermal heating and expansion thereof through the nozzle. The constrictor can have a electrically insulative portion disposed between the cathode tip and the nozzle anode, and an electrically-conductive anode extension disposed along the insulative portion so as to define an auxiliary gap with the cathode tip substantially smaller than the gap defined between the cathode and nozzle anode for facilitating startup of arc generation. The constrictor can also include an electrically-conductive electrode with a variable electrical potential to vary the shape of the arc generated in the arc chamber. Also, the cathode is mounted for axial movement such that the gap between its tip and the nozzle anode can be varied to facilitate a generally nonerosive generation of the electrical arc at startup and reliable steady state operation. Further, the arc chamber can have a nonparallel subsonic-to-supersonic transition configuration, or alternatively solely a nonparallel supersonic configuration, for improved arc attachment.

Electricity supply efficiency and organizational growth and profitability in Lagos, Nigeria

NASA Astrophysics Data System (ADS)

Adeleke, Adedeji Tajudeen

A modern and efficient infrastructure is a basic necessity for economic development and integration into the global economy. The specific problem was the inadequate and unreliable supply of electricity to manufacturing corporations in Lagos, Nigeria. The purpose of the current quantitative correlational research study was to examine if there was a correlation between electricity supply efficiency and organizational growth and profitability in manufacturing corporations in Lagos, Nigeria. The population of the current correlational research study involved 28 out of 34 manufacturing corporations from various industrial sectors in Lagos, Nigeria, that are listed and traded on the Nigerian Stock Exchange. Spearman rho correlations were used to assess the relationships between independent variables of electricity supply efficiency levels and the dependent variables of organizational growth and profitability. The result of the correlational analysis of the data revealed that there was a statistically significant, strong positive correlation between the Average Gross Income (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.57; p = 0.002. A statistically significant, strong positive correlation was found between the Average Balance Sheet Size (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.54; p = 0.003. A statistically significant, strong positive correlation between the Average Profit After Tax (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.60; p = 0.001, was found. No statistically significant correlation between the Average Return on Investment (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.19; p = 0.33, was discovered.

Analysis of alternative pathways for reducing nitrogen oxide emissions.

PubMed

Loughlin, Daniel H; Kaufman, Katherine R; Lenox, Carol S; Hubbell, Bryan J

2015-09-01

Strategies for reducing tropospheric ozone (O3) typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the U.S., these traditional controls may not be sufficient to achieve the National Ambient Air Quality Standard for ozone. We apply the MARKet ALlocation (MARKAL) energy system model in a sensitivity analysis to explore whether additional NOx reductions can be achieved through extensive electrification of passenger vehicles, adoption of energy efficiency and conservation measures within buildings, and deployment of wind and solar power in the electric sector. Nationally and for each region of the country, we estimate the NOx implications of these measures. Energy efficiency and renewable electricity are shown to reduce NOx beyond traditional controls. Wide-spread light duty vehicle electrification produces varied results, with NOx increasing in some regions and decreasing in others. However, combining vehicle electrification with renewable electricity reduces NOx in all regions. State governments are charged with developing plans that demonstrate how air quality standards will be met and maintained. The results presented here provide an indication of the national and regional NOx reductions available beyond traditional controls via extensive adoption of energy efficiency, renewable electricity, and vehicle electrification.

Chapter 28: Nanomaterials for Energy Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurst, Katherine E; Luther, Joseph M; Ban, Chunmei

2017-01-02

A wide variety of nanomaterials have been applied to energy related applications, including nanofibers, nanocrystalline materials, nanoparticles, and thin film nanocoatings. Solid-state lighting offers significant advantages in energy efficiency compared to traditional lighting technologies. The potential for nanostructured solid-state lighting devices is excellent as it enjoys significant economic drivers in energy efficiency. Fuel cells convert chemical energy to electrical energy through electrochemical reactions at an anode and cathode. The conversion of biomass to fuels and chemicals offers great potential to reduce energy dependence on petroleum and reduce green house gas emissions. Batteries involve the production and storage of electrical charge,more » the transfer of cations and electrical current, each based on electrochemical reactions and chemical reactants. Battery performance relies on the complex processes and factors that affect the transport of charge in the reactants, and across the interface between the chemical phases.« less

New, efficient and viable system for ethanol fuel utilization on combined electric/internal combustion engine vehicles

NASA Astrophysics Data System (ADS)

Sato, André G.; Silva, Gabriel C. D.; Paganin, Valdecir A.; Biancolli, Ana L. G.; Ticianelli, Edson A.

2015-10-01

Although ethanol can be directly employed as fuel on polymer-electrolyte fuel cells (PEMFC), its low oxidation kinetics in the anode and the crossover to the cathode lead to a substantial reduction of energy conversion efficiency. However, when fuel cell driven vehicles are considered, the system may include an on board steam reformer for converting ethanol into hydrogen, but the hydrogen produced contains carbon monoxide, which limits applications in PEMFCs. Here, we present a system consisting of an ethanol dehydrogenation catalytic reactor for producing hydrogen, which is supplied to a PEMFC to generate electricity for electric motors. A liquid by-product effluent from the reactor can be used as fuel for an integrated internal combustion engine, or catalytically recycled to extract more hydrogen molecules. Power densities comparable to those of a PEMFC operating with pure hydrogen are attained by using the hydrogen rich stream produced by the ethanol dehydrogenation reactor.

Thermo-Magneto-Electric Generator Arrays for Active Heat Recovery System

PubMed Central

Chun, Jinsung; Song, Hyun-Cheol; Kang, Min-Gyu; Kang, Han Byul; Kishore, Ravi Anant; Priya, Shashank

2017-01-01

Continued emphasis on development of thermal cooling systems is being placed that can cycle low grade heat. Examples include solar powered unmanned aerial vehicles (UAVs) and data storage servers. The power efficiency of solar module degrades at elevated temperature, thereby, necessitating the need for heat extraction system. Similarly, data centres in wireless computing system are facing increasing efficiency challenges due to high power consumption associated with managing the waste heat. We provide breakthrough in addressing these problems by developing thermo-magneto-electric generator (TMEG) arrays, composed of soft magnet and piezoelectric polyvinylidene difluoride (PVDF) cantilever. TMEG can serve dual role of extracting the waste heat and converting it into useable electricity. Near room temperature second-order magnetic phase transition in soft magnetic material, gadolinium, was employed to obtain mechanical vibrations on the PVDF cantilever under small thermal gradient. TMEGs were shown to achieve high vibration frequency at small temperature gradients, thereby, demonstrating effective heat transfer. PMID:28145516

Thermo-Magneto-Electric Generator Arrays for Active Heat Recovery System.

PubMed

Chun, Jinsung; Song, Hyun-Cheol; Kang, Min-Gyu; Kang, Han Byul; Kishore, Ravi Anant; Priya, Shashank

2017-02-01

Continued emphasis on development of thermal cooling systems is being placed that can cycle low grade heat. Examples include solar powered unmanned aerial vehicles (UAVs) and data storage servers. The power efficiency of solar module degrades at elevated temperature, thereby, necessitating the need for heat extraction system. Similarly, data centres in wireless computing system are facing increasing efficiency challenges due to high power consumption associated with managing the waste heat. We provide breakthrough in addressing these problems by developing thermo-magneto-electric generator (TMEG) arrays, composed of soft magnet and piezoelectric polyvinylidene difluoride (PVDF) cantilever. TMEG can serve dual role of extracting the waste heat and converting it into useable electricity. Near room temperature second-order magnetic phase transition in soft magnetic material, gadolinium, was employed to obtain mechanical vibrations on the PVDF cantilever under small thermal gradient. TMEGs were shown to achieve high vibration frequency at small temperature gradients, thereby, demonstrating effective heat transfer.

Robust network data envelopment analysis approach to evaluate the efficiency of regional electricity power networks under uncertainty.

PubMed

Fathollah Bayati, Mohsen; Sadjadi, Seyed Jafar

2017-01-01

In this paper, new Network Data Envelopment Analysis (NDEA) models are developed to evaluate the efficiency of regional electricity power networks. The primary objective of this paper is to consider perturbation in data and develop new NDEA models based on the adaptation of robust optimization methodology. Furthermore, in this paper, the efficiency of the entire networks of electricity power, involving generation, transmission and distribution stages is measured. While DEA has been widely used to evaluate the efficiency of the components of electricity power networks during the past two decades, there is no study to evaluate the efficiency of the electricity power networks as a whole. The proposed models are applied to evaluate the efficiency of 16 regional electricity power networks in Iran and the effect of data uncertainty is also investigated. The results are compared with the traditional network DEA and parametric SFA methods. Validity and verification of the proposed models are also investigated. The preliminary results indicate that the proposed models were more reliable than the traditional Network DEA model.

Robust network data envelopment analysis approach to evaluate the efficiency of regional electricity power networks under uncertainty

PubMed Central

Sadjadi, Seyed Jafar

2017-01-01

In this paper, new Network Data Envelopment Analysis (NDEA) models are developed to evaluate the efficiency of regional electricity power networks. The primary objective of this paper is to consider perturbation in data and develop new NDEA models based on the adaptation of robust optimization methodology. Furthermore, in this paper, the efficiency of the entire networks of electricity power, involving generation, transmission and distribution stages is measured. While DEA has been widely used to evaluate the efficiency of the components of electricity power networks during the past two decades, there is no study to evaluate the efficiency of the electricity power networks as a whole. The proposed models are applied to evaluate the efficiency of 16 regional electricity power networks in Iran and the effect of data uncertainty is also investigated. The results are compared with the traditional network DEA and parametric SFA methods. Validity and verification of the proposed models are also investigated. The preliminary results indicate that the proposed models were more reliable than the traditional Network DEA model. PMID:28953900

Generation of electrical power

DOEpatents

Hursen, Thomas F.; Kolenik, Steven A.; Purdy, David L.

1976-01-01

A heat-to-electricity converter is disclosed which includes a radioactive heat source and a thermoelectric element of relatively short overall length capable of delivering a low voltage of the order of a few tenths of a volt. Such a thermoelectric element operates at a higher efficiency than longer higher-voltage elements; for example, elements producing 6 volts. In the generation of required power, thermoelectric element drives a solid-state converter which is controlled by input current rather than input voltage and operates efficiently for a high signal-plus-noise to signal ratio of current. The solid-state converter has the voltage gain necessary to deliver the required voltage at the low input of the thermoelectric element.

A dynamic model to assess tradeoffs in power production and riverine ecosystem protection.

PubMed

Miara, Ariel; Vörösmarty, Charles J

2013-06-01

Major strategic planning decisions loom as society aims to balance energy security, economic development and environmental protection. To achieve such balance, decisions involving the so-called water-energy nexus must necessarily embrace a regional multi-power plant perspective. We present here the Thermoelectric Power & Thermal Pollution Model (TP2M), a simulation model that simultaneously quantifies thermal pollution of rivers and estimates efficiency losses in electricity generation as a result of fluctuating intake temperatures and river flows typically encountered across the temperate zone. We demonstrate the model's theoretical framework by carrying out sensitivity tests based on energy, physical and environmental settings. We simulate a series of five thermoelectric plants aligned along a hypothetical river, where we find that warm ambient temperatures, acting both as a physical constraint and as a trigger for regulatory limits on plant operations directly reduce electricity generation. As expected, environmental regulation aimed at reducing thermal loads at a single plant reduces power production at that plant, but ironically can improve the net electricity output from multiple plants when they are optimally co-managed. On the technology management side, high efficiency can be achieved through the use of natural gas combined cycle plants, which can raise the overall efficiency of the aging population of plants, including that of coal. Tradeoff analysis clearly shows the benefit of attaining such high efficiencies, in terms of both limiting thermal loads that preserve ecosystem services and increasing electricity production that benefits economic development.

Plasma-mediated transfection of RPE

NASA Astrophysics Data System (ADS)

Palanker, D.; Chalberg, T.; Vankov, A.; Huie, P.; Molnar, F. E.; Butterwick, A.; Calos, M.; Marmor, M.; Blumenkranz, M. S.

2006-02-01

A major obstacle in applying gene therapy to clinical practice is the lack of efficient and safe gene delivery techniques. Viral delivery has encountered a number of serious problems including immunological reactions and malignancy. Non-viral delivery methods (liposomes, sonoporation and electroporation) have either low efficiency in-vivo or produce severe collateral damage to ocular tissues. We discovered that tensile stress greatly increases the susceptibility of cellular membranes to electroporation. For synchronous application of electric field and mechanical stress, both are generated by the electric discharge itself. A pressure wave is produced by rapid vaporization of the medium. To prevent termination of electric current by the vapor cavity it is ionized thus restoring its electric conductivity. For in-vivo experiments with rabbits a plasmid DNA was injected into the subretinal space, and RPE was treated trans-sclerally with an array of microelectodes placed outside the eye. Application of 250-300V and 100-200 μs biphasic pulses via a microelectrode array resulted in efficient transfection of RPE without visible damage to the retina. Gene expression was quantified and monitored using bioluminescence (luciferase) and fluorescence (GFP) imaging. Transfection efficiency of RPE with this new technique exceeded that of standard electroporation by a factor 10,000. Safe and effective non-viral DNA delivery to the mammalian retina may help to materialize the enormous potential of the ocular gene therapy. Future experiments will focus on continued characterization of the safety and efficacy of this method and evaluation of long-term transgene expression in the presence of phiC31 integrase.

Simulation study of electric-guided delivery of 0.4µm monodisperse and polydisperse aerosols to the ostiomeatal complex.

PubMed

Xi, Jinxiang; Yuan, Jiayao Eddie; Si, Xiuhua April

2016-05-01

Despite the high prevalence of rhinosinusitis, current inhalation therapy shows limited efficacy due to extremely low drug delivery efficiency to the paranasal sinuses. Novel intranasal delivery systems are needed to enhance targeted delivery to the sinus with therapeutic dosages. An optimization framework for intranasal drug delivery was developed to target polydisperse charged aerosols to the ostiomeatal complex (OMC) with electric guidance. The delivery efficiency of a group of charged aerosols recently reported in the literature was numerically assessed and optimized in an anatomically accurate nose-sinus model. Key design variables included particle charge number, particle size and distribution, electrode strength, and inhalation velocity. Both monodisperse and polydisperse aerosol profiles were considered. Results showed that the OMC delivery efficiency was highly sensitive to the applied electric field and electrostatic charges carried by the particles. Through the synthesis of electric-guidance and point drug release, focused deposition with significantly enhanced dosage in the OMC can be achieved. For 0.4 µm charged aerosols, an OMC delivery efficiency of 51.6% was predicted for monodisperse aerosols and 34.4% for polydisperse aerosols. This difference suggested that the aerosol profile exerted a notable effect on intranasal deliveries. Sensitivity analysis indicated that the OMC deposition fraction was highly sensitive to the charge and size of particles and was less sensitive to the inhalation velocity considered in this study. Experimental studies are needed to validate the numerically optimized designs. Further studies are warranted to investigate the targeted OMC delivery with both electric and acoustics controls, the latter of which has the potential to further deliver the drug particles into the sinus cavity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Towards Smart Grid Dynamic Ratings

NASA Astrophysics Data System (ADS)

Cheema, Jamal; Clark, Adrian; Kilimnik, Justin; Pavlovski, Chris; Redman, David; Vu, Maria

2011-08-01

The energy distribution industry is giving greater attention to smart grid solutions as a means for increasing the capabilities, efficiency and reliability of the electrical power network. The smart grid makes use of intelligent monitoring and control devices throughout the distribution network to report on electrical properties such as voltage, current and power, as well as raising network alarms and events. A further aspect of the smart grid embodies the dynamic rating of electrical assets of the network. This fundamentally involves a rating of the load current capacity of electrical assets including feeders, transformers and switches. The mainstream approach to rate assets is to apply the vendor plate rating, which often under utilizes assets, or in some cases over utilizes when environmental conditions reduce the effective rated capacity, potentially reducing lifetime. Using active intelligence we have developed a rating system that rates assets in real time based upon several events. This allows for a far more efficient and reliable electrical grid that is able to extend further the life and reliability of the electrical network. In this paper we describe our architecture, the observations made during development and live deployment of the solution into operation. We also illustrate how this solution blends with the smart grid by proposing a dynamic rating system for the smart grid.

How to manipulate magnetic states of antiferromagnets

NASA Astrophysics Data System (ADS)

Song, Cheng; You, Yunfeng; Chen, Xianzhe; Zhou, Xiaofeng; Wang, Yuyan; Pan, Feng

2018-03-01

Antiferromagnetic materials, which have drawn considerable attention recently, have fascinating features: they are robust against perturbation, produce no stray fields, and exhibit ultrafast dynamics. Discerning how to efficiently manipulate the magnetic state of an antiferromagnet is key to the development of antiferromagnetic spintronics. In this review, we introduce four main methods (magnetic, strain, electrical, and optical) to mediate the magnetic states and elaborate on intrinsic origins of different antiferromagnetic materials. Magnetic control includes a strong magnetic field, exchange bias, and field cooling, which are traditional and basic. Strain control involves the magnetic anisotropy effect or metamagnetic transition. Electrical control can be divided into two parts, electric field and electric current, both of which are convenient for practical applications. Optical control includes thermal and electronic excitation, an inertia-driven mechanism, and terahertz laser control, with the potential for ultrafast antiferromagnetic manipulation. This review sheds light on effective usage of antiferromagnets and provides a new perspective on antiferromagnetic spintronics.

Applications of superconductor technologies to transportation

NASA Astrophysics Data System (ADS)

Rote, D. M.; Herring, J. S.; Sheahen, T. P.

1989-06-01

This report assesses transportation applications of superconducting devices, such as rotary motors and generators, linear synchronous motors, energy storage devices, and magnets. Among conventional vehicles, ships appear to have the greatest potential for maximizing the technical benefits of superconductivity, such as smaller, lighter, and more-efficient motors and, possibly, more-efficient generators. Smaller-scale applications include motors for pipeline pumps, all-electric and diesel-electric locomotives, self-propelled rail cars, and electric highway vehicles. For diesel-electric locomotives, superconducting units would eliminate space limitations on tractive power. Superconducting magnetic energy storage devices appear most suitable for regenerative braking or power assistance in grade climbing, rather than for long-term energy storage. With toroidal devices (especially for onboard temporary energy storage), external fields would be eliminated. With regard to new vehicle technologies, the use of superconducting devices would only marginally enhance the benefits of inductive-power-coupled vehicles over conventional electric vehicles, but could enable magnetically levitated (maglev) vehicles to obtain speeds of 520 km/h or more. This feature, together with the quiet, smooth ride, might make maglev vehicles an attractive alternative to intercity highway-vehicle or airlane trips in the range of 100 to 600 miles. Electromagnetic airport applications are not yet feasible.

Triboelectric-generator-driven pulse electrodeposition for micropatterning.

PubMed

Zhu, Guang; Pan, Caofeng; Guo, Wenxi; Chen, Chih-Yen; Zhou, Yusheng; Yu, Ruomeng; Wang, Zhong Lin

2012-09-12

By converting ambient energy into electricity, energy harvesting is capable of at least offsetting, or even replacing, the reliance of small portable electronics on traditional power supplies, such as batteries. Here we demonstrate a novel and simple generator with extremely low cost for efficiently harvesting mechanical energy that is typically present in the form of vibrations and random displacements/deformation. Owing to the coupling of contact charging and electrostatic induction, electric generation was achieved with a cycled process of contact and separation between two polymer films. A detailed theory is developed for understanding the proposed mechanism. The instantaneous electric power density reached as high as 31.2 mW/cm(3) at a maximum open circuit voltage of 110 V. Furthermore, the generator was successfully used without electric storage as a direct power source for pulse electrodeposition (PED) of micro/nanocrystalline silver structure. The cathodic current efficiency reached up to 86.6%. Not only does this work present a new type of generator that is featured by simple fabrication, large electric output, excellent robustness, and extremely low cost, but also extends the application of energy-harvesting technology to the field of electrochemistry with further utilizations including, but not limited to, pollutant degradation, corrosion protection, and water splitting.

High Performance Pulse Tube Cryocoolers

NASA Astrophysics Data System (ADS)

Olson, J. R.; Roth, E.; Champagne, P.; Evtimov, B.; Nast, T. C.

2008-03-01

Lockheed Martin's Advanced Technology Center has been developing pulse tube cryocoolers for more than ten years. Recent innovations include successful testing of four-stage coldheads, no-load temperature below 4 K, and the recent development of a high-efficiency compressor. This paper discusses the predicted performance of single and multiple stage pulse tube coldheads driven by our new 6 kg "M5Midi" compressor, which is capable of 90% efficiency with 200 W input power, and a maximum input power of 1000 W. This compressor retains the simplicity of earlier LM-ATC compressors: it has a moving magnet and an external electrical coil, minimizing organics in the working gas and requiring no electrical penetrations through the pressure wall. Motor losses were minimized during design, resulting in a simple, easily-manufactured compressor with state-of-the-art motor efficiency. The predicted cryocooler performance is presented as simple formulae, allowing an engineer to include the impact of a highly-optimized cryocooler into a full system analysis. Performance is given as a function of the heat rejection temperature and the cold tip temperatures and cooling loads.

Analysis of Household Electricity Consumption Patterns and Economy of Water Heating Shifting and Saving Bulbs

NASA Astrophysics Data System (ADS)

Rosin, Argo; Moller, Taavi; Lehtla, Madis; Hoimoja, Hardi

2010-01-01

This article analyses household electricity consumption based on an object in Estonia. Energy consumption of workday and holiday by loads (including high and low tariff energy consumption) is discussed. The final part describes the evaluation of profitability of common investments of consumption shifting and replacing inefficient devices with more efficient ones. Additionally it describes shifting problems and shifting equipment profitability in real-time tariff system.

Rigorous theory of graded thermoelectric converters including finite heat transfer coefficients

NASA Astrophysics Data System (ADS)

Gerstenmaier, York Christian; Wachutka, Gerhard

2017-11-01

Maximization of thermoelectric (TE) converter performance with an inhomogeneous material and electric current distribution has been investigated in previous literature neglecting thermal contact resistances to the heat reservoirs. The heat transfer coefficients (HTCs), defined as inverse thermal contact resistances per unit area, are thus infinite, whereas in reality, always parasitic thermal resistances, i.e., finite HTCs, are present. Maximization of the generated electric power and of cooling power in the refrigerator mode with respect to Seebeck coefficients and heat conductivity for a given profile of the material's TE figure of merit Z are mathematically ill-posed problems in the presence of infinite HTCs. As will be shown in this work, a fully self consistent solution is possible for finite HTCs, and in many respects, the results are fundamentally different. A previous theory for 3D devices will be extended to include finite HTCs and is applied to 1D devices. For the heat conductivity profile, an infinite number of solutions exist leading to the same device performance. Cooling power maximization for finite HTCs in 1D will lead to a strongly enhanced corresponding efficiency (coefficient of performance), whereas results with infinite HTCs lead to a non-monotonous temperature profile and coefficient of performance tending to zero for the prescribed heat conductivities. For maximized generated electric power, the corresponding generator efficiency is nearly a constant independent from the finite HTC values. The maximized efficiencies in the generator and cooling mode are equal to the efficiencies for the infinite HTC, provided that the corresponding powers approach zero. These and more findings are condensed in 4 theorems in the conclusions.

DSM Electricity Savings Potential in the Buildings Sector in APP Countries

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNeil, MIchael; Letschert, Virginie; Shen, Bo

2011-01-12

The global economy has grown rapidly over the past decade with a commensurate growth in the demand for electricity services that has increased a country's vulnerability to energy supply disruptions. Increasing need of reliable and affordable electricity supply is a challenge which is before every Asia Pacific Partnership (APP) country. Collaboration between APP members has been extremely fruitful in identifying potential efficiency upgrades and implementing clean technology in the supply side of the power sector as well established the beginnings of collaboration. However, significantly more effort needs to be focused on demand side potential in each country. Demand side managementmore » or DSM in this case is a policy measure that promotes energy efficiency as an alternative to increasing electricity supply. It uses financial or other incentives to slow demand growth on condition that the incremental cost needed is less than the cost of increasing supply. Such DSM measures provide an alternative to building power supply capacity The type of financial incentives comprise of rebates (subsidies), tax exemptions, reduced interest loans, etc. Other approaches include the utilization of a cap and trade scheme to foster energy efficiency projects by creating a market where savings are valued. Under this scheme, greenhouse gas (GHG) emissions associated with the production of electricity are capped and electricity retailers are required to meet the target partially or entirely through energy efficiency activities. Implementation of DSM projects is very much in the early stages in several of the APP countries or localized to a regional part of the country. The purpose of this project is to review the different types of DSM programs experienced by APP countries and to estimate the overall future potential for cost-effective demand-side efficiency improvements in buildings sectors in the 7 APP countries through the year 2030. Overall, the savings potential is estimated to be 1.7 thousand TWh or 21percent of the 2030 projected base case electricity demand. Electricity savings potential ranges from a high of 38percent in India to a low of 9percent in Korea for the two sectors. Lighting, fans, and TV sets and lighting and refrigeration are the largest contributors to residential and commercial electricity savings respectively. This work presents a first estimates of the savings potential of DSM programs in APP countries. While the resulting estimates are based on detailed end-use data, it is worth keeping in mind that more work is needed to overcome limitation in data at this time of the project.« less

High efficiency motor selection handbook

NASA Astrophysics Data System (ADS)

McCoy, Gilbert A.; Litman, Todd; Douglass, John G.

1990-10-01

Substantial reductions in energy and operational costs can be achieved through the use of energy-efficient electric motors. A handbook was compiled to help industry identify opportunities for cost-effective application of these motors. It covers the economic and operational factors to be considered when motor purchase decisions are being made. Its audience includes plant managers, plant engineers, and others interested in energy management or preventative maintenance programs.

Bridging Climate Change Resilience and Mitigation in the Electricity Sector Through Renewable Energy and Energy Efficiency: Emerging Climate Change and Development Topics for Energy Sector Transformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cox, Sarah L; Hotchkiss, Elizabeth L; Bilello, Daniel E

Reliable, safe, and secure electricity is essential for economic and social development and a necessary input for many sectors of the economy. However, electricity generation and associated processes make up a significant portion of global greenhouse gas (GHG) emissions contributing to climate change. Furthermore, electricity systems are vulnerable to climate change impacts - both short-term events and changes over the longer term. This vulnerability presents both near-term and chronic challenges in providing reliable, affordable, equitable, and sustainable energy services. Within this context, developing countries face a number of challenges in the energy sector, including the need to reliably meet growingmore » electricity demand, lessen dependence on imported fuels, expand energy access, and improve stressed infrastructure for fuel supply and electricity transmission. Energy efficiency (EE) and renewable energy (RE) technical solutions described in this paper can bridge action across climate change mitigation and resilience through reducing GHG emissions and supporting electric power sector adaptation to increasing climate risk. Integrated planning approaches, also highlighted in this paper, play an integral role in bringing together mitigation and resilience action under broader frameworks. Through supporting EE and RE deployment and integrated planning approaches, unique to specific national and local circumstances, countries can design and implement policies, strategies, and sectoral plans that unite development priorities, climate change mitigation, and resilience.« less

76 FR 37678 - Energy Conservation Program for Consumer Products and Certain Commercial and Industrial Equipment...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... the purpose of Part A-1 of EPCA, which is to improve the efficiency of electric motors and pumps and... to improve the efficiency of electric motors, pumps and certain other industrial equipment to.... Energy Information Administration. \\2\\ Based on Energy Efficiency and Electric Motors, Report PB- 259 129...

Highly efficient and stable inverted perovskite solar cell employing PEDOT:GO composite layer as a hole transport layer.

PubMed

Yu, Jae Choul; Hong, Ji A; Jung, Eui Dae; Kim, Da Bin; Baek, Soo-Min; Lee, Sukbin; Cho, Shinuk; Park, Sung Soo; Choi, Kyoung Jin; Song, Myoung Hoon

2018-01-18

The beneficial use of a hole transport layer (HTL) as a substitution for poly(3,4-ethlyenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is regarded as one of the most important approaches for improving the stability and efficiency of inverted perovskite solar cells. Here, we demonstrate highly efficient and stable inverted perovskite solar cells by applying a GO-doped PEDOT:PSS (PEDOT:GO) film as an HTL. The high performance of this solar cell stems from the excellent optical and electrical properties of the PEDOT:GO film, including a higher electrical conductivity, a higher work function related to the reduced contact barrier between the perovskite layer and the PEDOT:GO layer, enhanced crystallinity of the perovskite crystal, and suppressed leakage current. Moreover, the device with the PEDOT:GO layer showed excellent long-term stability in ambient air conditions. Thus, the enhancement in the efficiency and the excellent stability of inverted perovskite solar cells are promising for the eventual commercialization of perovskite optoelectronic devices.

Assessment of Interval Data and Their Potential Application to Residential Electricity End-Use Modeling, An

EIA Publications

2015-01-01

The Energy Information Administration (EIA) is investigating the potential benefits of incorporating interval electricity data into its residential energy end use models. This includes interval smart meter and submeter data from utility assets and systems. It is expected that these data will play a significant role in informing residential energy efficiency policies in the future. Therefore, a long-term strategy for improving the RECS end-use models will not be complete without an investigation of the current state of affairs of submeter data, including their potential for use in the context of residential building energy modeling.

Modeling, hybridization, and optimal charging of electrical energy storage systems

NASA Astrophysics Data System (ADS)

Parvini, Yasha

The rising rate of global energy demand alongside the dwindling fossil fuel resources has motivated research for alternative and sustainable solutions. Within this area of research, electrical energy storage systems are pivotal in applications including electrified vehicles, renewable power generation, and electronic devices. The approach of this dissertation is to elucidate the bottlenecks of integrating supercapacitors and batteries in energy systems and propose solutions by the means of modeling, control, and experimental techniques. In the first step, the supercapacitor cell is modeled in order to gain fundamental understanding of its electrical and thermal dynamics. The dependence of electrical parameters on state of charge (SOC), current direction and magnitude (20-200 A), and temperatures ranging from -40°C to 60°C was embedded in this computationally efficient model. The coupled electro-thermal model was parameterized using specifically designed temporal experiments and then validated by the application of real world duty cycles. Driving range is one of the major challenges of electric vehicles compared to combustion vehicles. In order to shed light on the benefits of hybridizing a lead-acid driven electric vehicle via supercapacitors, a model was parameterized for the lead-acid battery and combined with the model already developed for the supercapacitor, to build the hybrid battery-supercapacitor model. A hardware in the loop (HIL) setup consisting of a custom built DC/DC converter, micro-controller (muC) to implement the power management strategy, 12V lead-acid battery, and a 16.2V supercapacitor module was built to perform the validation experiments. Charging electrical energy storage systems in an efficient and quick manner, motivated to solve an optimal control problem with the objective of maximizing the charging efficiency for supercapacitors, lead-acid, and lithium ion batteries. Pontryagins minimum principle was used to solve the problems analytically. Efficiency analysis for constant power (CP) and optimal charging strategies under different charging times (slow and fast) was performed. In case of the lithium ion battery, the model included the electronic as well as polarization resistance. Furthermore, in order to investigate the influence of temperature on the internal resistance of the lithium ion battery, the optimal charging problem for a three state electro-thermal model was solved using dynamic programming (DP). The ability to charge electric vehicles is a pace equivalent to fueling a gasoline car will be a game changer in the widespread acceptability and feasibility of the electric vehicles. Motivated by the knowledge gained from the optimal charging study, the challenges facing the fast charging of lithium ion batteries are investigated. In this context, the suitable models for the study of fast charging, high rate anode materials, and different charging strategies are studied. The side effects of fast charging such as lithium plating and mechanical failure are also discussed. This dissertation has targeted some of the most challenging questions in the field of electrical energy storage systems and the reported results are applicable to a wide range of applications such as in electronic gadgets, medical devices, electricity grid, and electric vehicles.

Hybrid and Plug-In Electric Vehicles (Spanish Version); Clean Cities, Energy Efficiency & Renewable Energy (EERE) (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This is a Spanish-language brochure about hybrid and plug-in electric vehicles, which use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), all-electric vehicles (EVs). Together, they have great potential to cut U.S. petroleum use and vehicle emissions.

Voltage Controller Saves Energy, Prolongs Life of Motors

NASA Technical Reports Server (NTRS)

2007-01-01

In 1985, Power Efficiency Corporation of Las Vegas licensed NASA voltage controller technology from Marshall Space Flight Center. In the following years, Power Efficiency made patented improvements to the technology and marketed the resulting products throughout the world as the Performance Controller and the Power Efficiency energy-saving soft start. Soft start gradually introduces power to an electric motor, thus eliminating the harsh, violent mechanical stresses of having the device go from a dormant state to one of full activity; prevents it from running too hot; and increases the motor's lifetime. The product can pay for itself through the reduction in electricity consumed (according to Power Efficiency, within 3 years), depending on the duty cycle of the motor and the prevailing power rates. In many instances, the purchaser is eligible for special utility rebates for the environmental protection it provides. Common applications of Power Efficiency's soft start include mixers, grinders, granulators, conveyors, crushers, stamping presses, injection molders, elevators with MG sets, and escalators. The device has been retrofitted onto equipment at major department store chains, hotels, airports, universities, and for various manufacturers

Highly Polarized Fluorescent Illumination Using Liquid Crystal Phase.

PubMed

Gim, Min-Jun; Turlapati, Srikanth; Debnath, Somen; Rao, Nandiraju V S; Yoon, Dong Ki

2016-02-10

Liquid crystal (LC) materials are currently the dominant electronic materials in display technology because of the ease of control of molecular orientation using an electric field. However, this technology requires the fabrication of two polarizers to create operational displays, reducing light transmission efficiency below 10%. It is therefore desirable to develop new technologies to enhance the light efficiency while maintaining or improving other properties such as the modulation speed of the molecular orientation. Here we report a uniaxial-oriented B7 smectic liquid crystalline film, using fluorescent bent-core LC molecules, a chemically modified substrate, and an in-plane electric field. A LC droplet under homeotropic boundary conditions of air/LC as well as LC/substrate exhibits large focal conic like optical textures. The in-plane electric field induced uniaxial orientation of the LC molecules, in which molecular polar directors are aligned in the direction of the electric field. This highly oriented LC film exhibits linearly polarized luminescence and microsecond time-scale modulation characteristics. The resultant device is both cheap and easy to fabricate and thus has great potential for electro-optic applications, including LC displays, bioimaging systems, and optical communications.

Including Energy Efficiency and Renewable Energy Policies in Electricity Demand Projections

EPA Pesticide Factsheets

Find more information on how state and local air agencies can identify on-the-books EE/RE policies, develop a methodology for projecting a jurisdiction's energy demand, and estimate the change in power sector emissions.

Dilute group III-V nitride intermediate band solar cells with contact blocking layers

DOEpatents

Walukiewicz, Wladyslaw; Yu, Kin Man

2015-02-24

An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

Dilute Group III-V nitride intermediate band solar cells with contact blocking layers

DOEpatents

Walukiewicz, Wladyslaw [Kensington, CA; Yu, Kin Man [Lafayette, CA

2012-07-31

An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

DOE Office of Scientific and Technical Information (OSTI.GOV)

New inverter-driven ASHPs are gaining ground in colder climates. These systems operate at sub-zero temperatures without the use of electric resistance backup. There are still uncertainties, however, about cold-climate capacity and efficiency in cold weather and questions such as measuring: power consumption, supply, return, and outdoor air temperatures, and air flow through the indoor fan coil. CARB observed a wide range of operating efficiencies and outputs from site to site. Maximum capacities were found to be generally in line with manufacturer's claims as outdoor temperatures fell to -10 degrees F. The reasons for the wide range in heating performance likelymore » include: low indoor air flow rates, poor placement of outdoor units, relatively high return air temperatures, thermostat set back, integration with existing heating systems, and occupants limiting indoor fan speed. Even with lower efficiencies than published in other studies, most of the heat pumps here still provide heat at lower cost than oil, propane, or certainly electric resistance systems.« less

Energy efficiency indicators for high electric-load buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar

2003-06-01

Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

Comparison of cutting efficiencies between electric and air-turbine dental handpieces.

PubMed

Choi, Charlson; Driscoll, Carl F; Romberg, Elaine

2010-02-01

Dentistry is gravitating toward the increased use of electric handpieces. The dental professional should have sufficient evidence to validate the switch from an air-turbine handpiece to an electric handpiece. However, there is little research quantifying the cutting efficiency of electric and air-turbine handpieces. Studies that do quantify cutting efficiency typically do so with only a single material. The purpose of this study was to compare the cutting efficiency of an electric handpiece and an air-turbine handpiece, using various materials commonly used in dentistry. Seven materials: Macor (machinable glass ceramic), silver amalgam, aluminum oxide, zirconium oxide, high noble metal alloy, noble metal alloy, and base metal alloy, were each cut with a bur 220 times; 110 times with an electric handpiece, and 110 times with an air-turbine handpiece. The weight difference of the material was calculated by subtracting the weight of the material after a cut from the weight of the material before the cut. The cutting efficiency was calculated by dividing the weight difference by the duration of the cut (g/s). Data were analyzed by a 2-way analysis of variance followed by Tukey's Honestly Significant Difference (HSD) test (alpha=.05). The electric handpiece cut more efficiently than the air-turbine handpiece (F=3098.9, P<.001). In particular, the high noble metal alloy, silver amalgam, and Macor were cut more efficiently with the electric handpiece (0.0383 +/-0.0002 g/s, 0.0260 +/-0.0002 g/s, and 0.0122 +/-0.0002 g/s, respectively) than with the air-turbine handpiece (0.0125 +/-0.0002 g/s, 0.0142 +/-0.0002 g/s, and 0.008 +/-0.0002 g/s, respectively). The electric handpiece is more efficient at cutting various materials used in dentistry, especially machinable glass ceramic, silver amalgam, and high noble alloy, than the air-turbine handpiece.

NASA Solar Array Demonstrates Commercial Potential

NASA Technical Reports Server (NTRS)

Creech, Gray

2006-01-01

A state-of-the-art solar-panel array demonstration site at NASA's Dryden Flight Research Center provides a unique opportunity for studying the latest in high-efficiency solar photovoltaic cells. This five-kilowatt solar-array site (see Figure 1) is a technology-transfer and commercialization success for NASA. Among the solar cells at this site are cells of a type that was developed in Dryden Flight Research Center s Environmental Research Aircraft and Sensor Technology (ERAST) program for use in NASA s Helios solar-powered airplane. This cell type, now denoted as A-300, has since been transferred to SunPower Corporation of Sunnyvale, California, enabling mass production of the cells for the commercial market. High efficiency separates these advanced cells from typical previously commercially available solar cells: Whereas typical previously commercially available cells are 12 to 15 percent efficient at converting sunlight to electricity, these advanced cells exhibit efficiencies approaching 23 percent. The increase in efficiency is due largely to the routing of electrical connections behind the cells (see Figure 2). This approach to increasing efficiency originated as a solution to the problem of maximizing the degree of utilization of the limited space available atop the wing of the Helios airplane. In retrospect, the solar cells in use at this site could be used on Helios, but the best cells otherwise commercially available could not be so used, because of their lower efficiencies. Historically, solar cells have been fabricated by use of methods that are common in the semiconductor industry. One of these methods includes the use of photolithography to define the rear electrical-contact features - diffusions, contact openings, and fingers. SunPower uses these methods to produce the advanced cells. To reduce fabrication costs, SunPower continues to explore new methods to define the rear electrical-contact features. The equipment at the demonstration site includes two fixed-angle solar arrays and one single-axis Sun-tracking array. One of the fixed arrays contains typical less-efficient commercial solar cells and is being used as a baseline for comparison of the other fixed array, which contains the advanced cells. The Sun-tracking array tilts to follow the Sun, using an advanced, real-time tracking device rather than customary pre-programmed mechanisms. Part of the purpose served by the demonstration is to enable determination of any potential advantage of a tracking array over a fixed array. The arrays are monitored remotely on a computer that displays pertinent information regarding the functioning of the arrays.

Study of Conical Pulsed Inductive Thruster with Multiple Modes of Operation

NASA Technical Reports Server (NTRS)

Miller, Robert; Eskridge, Richard; Martin, Adam; Rose, Frank

2008-01-01

An electrodeless, pulsed, inductively coupled thruster has several advantages over current electric propulsion designs. The efficiency of a pulsed inductive thruster is dependent upon the pulse characteristics of the device. Therefore, these thrusters are throttleable over a wide range of thrust levels by varying the pulse rate without affecting the thruster efficiency. In addition, by controlling the pulse energy and the mass bit together, the ISP of the thruster can also be varied with minimal efficiency loss over a wide range of ISP levels. Pulsed inductive thrusters will work with a multitude of propellants, including ammonia. Thus, a single pulsed inductive thruster could be used to handle a multitude of mission needs from high thrust to high ISP with one propulsion solution that would be variable in flight. A conical pulsed inductive lab thruster has been built to study this form of electric propulsion in detail. This thruster incorporates many advantages that are meant to enable this technology as a viable space propulsion technology. These advantages include incorporation of solid state switch technology for all switching needs of the thruster and pre-ionization of the propellant gas prior to acceleration. Pre-ionizing will significantly improve coupling efficiency between drive and bias fields and the plasma. This enables lower pulse energy levels without efficiency reduction. Pre-ionization can be accomplished at a small fraction of the drive pulse energy.

Coordinating Demand-Side Efficiency Evaluation, Measurement and Verification Among Western States: Options for Documenting Energy and Non-Energy Impacts for the Power Sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiller, Steven R.; Schwartz, Lisa C.

Demand-side energy efficiency (efficiency) represents a low-cost opportunity to reduce electricity consumption and demand and provide a wide range of non-energy benefits, including avoiding air pollution. Efficiency-related energy and non-energy impacts are determined and documented by implementing evaluation, measurement and verification (EM&V) systems. This technical brief describes efficiency EM&V coordination strategies that Western states can consider taking on together, outlines EM&V-related products that might be appropriate for multistate coordination, and identifies some implications of coordination. Coordinating efficiency EM&V activities can save both time and costs for state agencies and stakeholders engaged in efficiency activities and can be particularly beneficial formore » multiple states served by the same utility. First, the brief summarizes basic information on efficiency, its myriad potential benefits and EM&V for assessing those benefits. Second, the brief introduces the concept of multistate EM&V coordination in the context of assessing such benefits, including achievement of state and federal goals to reduce air pollutants.1 Next, the brief presents three coordination strategy options for efficiency EM&V: information clearinghouse/exchange, EM&V product development, and a regional energy efficiency tracking system platform. The brief then describes five regional EM&V products that could be developed on a multistate basis: EM&V reporting formats, database of consistent deemed electricity savings values, glossary of definitions and concepts, efficiency EM&V methodologies, and EM&V professional standards or accreditation processes. Finally, the brief discusses options for next steps that Western states can take to consider multistate coordination on efficiency EM&V. Appendices provide background information on efficiency and EM&V, as well as definitions and suggested resources on the covered topics. This brief is intended to inform state public utility commissions, boards for public and consumer-owned utilities, state energy offices and air agencies, and other organizations involved in discussions about the use of efficiency EM&V.« less

Conical structures for highly efficient solar cell applications

NASA Astrophysics Data System (ADS)

Korany, Fatma M. H.; Hameed, Mohamed Farhat O.; Hussein, Mohamed; Mubarak, Roaa; Eladawy, Mohamed I.; Obayya, Salah Sabry A.

2018-01-01

Improving solar cell efficiency is a critical research topic. Nowadays, light trapping techniques are a promising way to enhance solar cell performance. A modified nanocone nanowire (NW) is proposed and analyzed for solar cell applications. The suggested NW consists of conical and truncated conical units. The geometrical parameters are studied using a three-dimensional (3-D) finite difference time-domain (FDTD) method to achieve broadband absorption through the reported design and maximize its ultimate efficiency. The analyzed parameters are absorption spectra, ultimate efficiency, and short circuit current density. The numerical results prove that the proposed structure is superior compared with cone, truncated cone, and cylindrical NWs. The reported design achieves an ultimate efficiency of 44.21% with substrate and back reflector. Further, short circuit current density of 36.17 mA / cm2 is achieved by the suggested NW. The electrical performance analysis of the proposed structure including doping concentration, junction thickness, and Shockley-Read-Hall recombination is also investigated. The electrical simulations show that a power conversion efficiency of 17.21% can be achieved using the proposed NW. The modified nanocone has advantages of broadband absorption enhancement, low cost, and fabrication feasibility.

Efficiency limits of laser power converters for optical power transfer applications

NASA Astrophysics Data System (ADS)

Mukherjee, J.; Jarvis, S.; Perren, M.; Sweeney, S. J.

2013-07-01

We have developed III-V-based high-efficiency laser power converters (LPCs), optimized specifically for converting monochromatic laser radiation at the eye-safe wavelength of 1.55 µm into electrical power. The applications of these photovoltaic cells include high-efficiency space-based and terrestrial laser power transfer and subsequent conversion to electrical power. In addition, these cells also find use in fibre-optic power delivery, remote powering of subcutaneous equipment and several other optical power delivery applications. The LPC design is based on lattice-matched InGaAsP/InP and incorporates elements for photon-recycling and contact design for efficient carrier extraction. Here we compare results from electro-optical design simulations with experimental results from prototype devices studied both in the lab and in field tests. We analyse wavelength and temperature dependence of the LPC characteristics. An experimental conversion efficiency of 44.6% [±1%] is obtained from the prototype devices under monochromatic illumination at 1.55 µm (illumination power density of 1 kW m-2) at room temperature. Further design optimization of our LPC is expected to scale the efficiency beyond 50% at 1 kW m-2.

Determination of thermal properties of commercial Ni-MH cells

NASA Astrophysics Data System (ADS)

Darcy, Eric C.

1994-02-01

The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

Third-harmonic generation from Mie-type resonances of isolated all-dielectric nanoparticles

NASA Astrophysics Data System (ADS)

Melik-Gaykazyan, Elizaveta V.; Shcherbakov, Maxim R.; Shorokhov, Alexander S.; Staude, Isabelle; Brener, Igal; Neshev, Dragomir N.; Kivshar, Yuri S.; Fedyanin, Andrey A.

2017-03-01

Subwavelength silicon nanoparticles are known to support strongly localized Mie-type modes, including those with resonant electric and magnetic dipolar polarizabilities. Here we compare experimentally the efficiency of the third-harmonic generation from isolated silicon nanodiscs for resonant excitation at the two types of dipolar resonances. Using nonlinear spectroscopy, we observe that the magnetic dipolar mode yields more efficient third-harmonic radiation in contrast to the electric dipolar (ED) mode. This is further supported by full-wave numerical simulations, where the volume-integrated local fields and the directly simulated nonlinear response are shown to be negligible at the ED resonance compared with the magnetic one. This article is part of the themed issue 'New horizons for nanophotonics'.

Determination of thermal properties of commercial Ni-MH cells

NASA Technical Reports Server (NTRS)

Darcy, Eric C.

1994-01-01

The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

Critical Infrastructure Protection: EMP Impacts on the U.S. Electric Grid

NASA Astrophysics Data System (ADS)

Boston, Edwin J., Jr.

The purpose of this research is to identify the United States electric grid infrastructure systems vulnerabilities to electromagnetic pulse attacks and the cyber-based impacts of those vulnerabilities to the electric grid. Additionally, the research identifies multiple defensive strategies designed to harden the electric grid against electromagnetic pulse attack that include prevention, mitigation and recovery postures. Research results confirm the importance of the electric grid to the United States critical infrastructures system and that an electromagnetic pulse attack against the electric grid could result in electric grid degradation, critical infrastructure(s) damage and the potential for societal collapse. The conclusions of this research indicate that while an electromagnetic pulse attack against the United States electric grid could have catastrophic impacts on American society, there are currently many defensive strategies under consideration designed to prevent, mitigate and or recover from an electromagnetic pulse attack. However, additional research is essential to further identify future target hardening opportunities, efficient implementation strategies and funding resources.

76 FR 40050 - Semiannual Regulatory Agenda

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... analyses: Energy Efficiency Standards for Certain Commercial and Industrial Electric Motors. Issued in... for Certain Commercial and Industrial Electric Motors. DEPARTMENT OF ENERGY (DOE) Energy Efficiency... and Industrial Electric Motors Legal Authority: 42 U.S.C. 6313(b)(4)(B) Abstract: The Energy...

Low cost, lightweight fuel cell elements

NASA Technical Reports Server (NTRS)

Kindler, Andrew (Inventor)

2001-01-01

New fuel cell elements for use in liquid feed fuel cells are provided. The elements including biplates and endplates are low in cost, light in weight, and allow high efficiency operation. Electrically conductive elements are also a part of the fuel cell elements.

Some Aspects of PDC Electrolysis

NASA Astrophysics Data System (ADS)

Poláčik, Ján; Pospíšil, Jiří

2016-10-01

In this paper, aspects of pulsed direct current (PDC) water splitting are described. Electrolysis is a simple and well-known method to produce hydrogen. The efficiency is relatively low in normal conditions using conventional DC. PDC in electrolysis brings about many advantages. It increases efficiency of hydrogen production, and performance of the electrolyser may be smoothly controlled without compromising efficiency of the process. In our approach, ultra-short pulses are applied. This method enhances efficiency of electrical energy in the process of decomposition of water into hydrogen and oxygen. Efficiency depends on frequency, shape and width of the electrical pulses. Experiments proved that efficiency was increased by 2 to 8 per cent. One of the prospects of PDC electrolysis producing hydrogen is in increase of efficiency of energy storage efficiency in the hydrogen. There are strong efforts to make the electrical grid more efficient and balanced in terms of production by installing electricity storage units. Using hydrogen as a fuel decreases air pollution and amount of carbon dioxide emissions in the air. In addition to energy storage, hydrogen is also important in transportation and chemical industry.

The NASA Energy Conservation Program

NASA Technical Reports Server (NTRS)

Gaffney, G. P.

1977-01-01

Large energy-intensive research and test equipment at NASA installations is identified, and methods for reducing energy consumption outlined. However, some of the research facilities are involved in developing more efficient, fuel-conserving aircraft, and tradeoffs between immediate and long-term conservation may be necessary. Major programs for conservation include: computer-based systems to automatically monitor and control utility consumption; a steam-producing solid waste incinerator; and a computer-based cost analysis technique to engineer more efficient heating and cooling of buildings. Alternate energy sources in operation or under evaluation include: solar collectors; electric vehicles; and ultrasonically emulsified fuel to attain higher combustion efficiency. Management support, cooperative participation by employees, and effective reporting systems for conservation programs, are also discussed.

10 CFR 431.12 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... method or AEDM means, with respect to an electric motor, a method of calculating the total power loss and average full load efficiency. Average full load efficiency means the arithmetic mean of the full load efficiencies of a population of electric motors of duplicate design, where the full load efficiency of each...

Introduction to session on materials and structures

NASA Technical Reports Server (NTRS)

Vosteen, L. F.

1978-01-01

A review was given of the development of composites for aircraft. Supporting base technology and the Aircraft Energy Efficiency Composites Program are included. Specific topics discussed include: (1) environmental effects on materials; (2) material quality and chemical characterization; (3) design and analysis methods; (4) structural durability; (5) impact sensitivity; (6) carbon fiber electrical effects; and (7) composite components.

78 FR 15341 - Auto Supply Chain Trade Mission to Mexico City and Monterrey, Mexico; September 23-26, 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-11

.... In 2012, Mexico produced more than 2.8 million cars- and the projection for 2013 is 3 million cars... car manufacturing, including smaller car sizes and increased fuel efficiency. The aftermarket is... opportunities include: Spare and replacement parts for gasoline and diesel engines; electrical parts, collision...

Modeling of a thermally integrated 10 kWe planar solid oxide fuel cell system with anode offgas recycling and internal reforming by discretization in flow direction

NASA Astrophysics Data System (ADS)

Wahl, Stefanie; Segarra, Ana Gallet; Horstmann, Peter; Carré, Maxime; Bessler, Wolfgang G.; Lapicque, François; Friedrich, K. Andreas

2015-04-01

Combined heat and power production (CHP) based on solid oxide fuel cells (SOFC) is a very promising technology to achieve high electrical efficiency to cover power demand by decentralized production. This paper presents a dynamic quasi 2D model of an SOFC system which consists of stack and balance of plant and includes thermal coupling between the single components. The model is implemented in Modelica® and validated with experimental data for the stack UI-characteristic and the thermal behavior. The good agreement between experimental and simulation results demonstrates the validity of the model. Different operating conditions and system configurations are tested, increasing the net electrical efficiency to 57% by implementing an anode offgas recycle rate of 65%. A sensitivity analysis of characteristic values of the system like fuel utilization, oxygen-to-carbon ratio and electrical efficiency for different natural gas compositions is carried out. The result shows that a control strategy adapted to variable natural gas composition and its energy content should be developed in order to optimize the operation of the system.

Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

DOEpatents

Haaland, C.M.; Deeds, W.E.

1999-07-13

A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.

Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

DOEpatents

Haaland, Carsten M.; Deeds, W. Edward

1999-01-01

A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output.

Department of Energy Semiannual Regulatory Agenda

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... Water Heaters; and (2) Energy Efficiency Standards for Certain Commercial and Industrial Electric Motors... Standards for Certain Commercial and Industrial Electric Motors..... 1904-AC28 Energy Efficiency and... FOR CERTAIN COMMERCIAL AND INDUSTRIAL ELECTRIC MOTORS Legal Authority: 42 USC 6313(b)(4)(B) Abstract...

75 FR 79759 - Regulatory Agenda

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... Efficiency Standards for Certain Commercial and Industrial Electric Motors. The Plan appears in both the... Commercial and Industrial Electric Motors..... 1904-AC28 Energy Efficiency and Renewable Energy--Completed... COMMERCIAL AND INDUSTRIAL ELECTRIC MOTORS Legal Authority: 42 USC 6313(b)(4)(B) Abstract: The Energy Policy...

SOSPAC- SOLAR SPACE POWER ANALYSIS CODE

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1994-01-01

The Solar Space Power Analysis Code, SOSPAC, was developed to examine the solar thermal and photovoltaic power generation options available for a satellite or spacecraft in low earth orbit. SOSPAC is a preliminary systems analysis tool and enables the engineer to compare the areas, weights, and costs of several candidate electric and thermal power systems. The configurations studied include photovoltaic arrays and parabolic dish systems to produce electricity only, and in various combinations to provide both thermal and electric power. SOSPAC has been used for comparison and parametric studies of proposed power systems for the NASA Space Station. The initial requirements are projected to be about 40 kW of electrical power, and a similar amount of thermal power with temperatures above 1000 degrees Centigrade. For objects in low earth orbit, the aerodynamic drag caused by suitably large photovoltaic arrays is very substantial. Smaller parabolic dishes can provide thermal energy at a collection efficiency of about 80%, but at increased cost. SOSPAC allows an analysis of cost and performance factors of five hybrid power generating systems. Input includes electrical and thermal power requirements, sun and shade durations for the satellite, and unit weight and cost for subsystems and components. Performance equations of the five configurations are derived, and the output tabulates total weights of the power plant assemblies, area of the arrays, efficiencies, and costs. SOSPAC is written in FORTRAN IV for batch execution and has been implemented on an IBM PC computer operating under DOS with a central memory requirement of approximately 60K of 8 bit bytes. This program was developed in 1985.

Control Demonstration of Multiple Doubly-Fed Induction Motors for Hybrid Electric Propulsion

NASA Technical Reports Server (NTRS)

Sadey, David J.; Bodson, Marc; Csank, Jeffrey T.; Hunker, Keith R.; Theman, Casey J.; Taylor, Linda M.

2017-01-01

The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application.The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application. DFIMs are attractive for several reasons, including but not limited to the ability to self-start, ability to operate sub- and super-synchronously, and requiring only fractionally rated power converters on a per-unit basis depending on the required range of operation. The focus of this paper is based specifically on the presentation and analysis of a novel strategy which allows for independent operation of each of the aforementioned doubly-fed induction motors. This strategy includes synchronization, soft-start, and closed loop speed control of each motor as a means of controlling output thrust; be it concurrently or differentially. The demonstration of this strategy has recently been proven out on a low power test bed using fractional horsepower machines. Simulation and hardware test results are presented in the paper.

Recycled Thermal Energy from High Power Light Emitting Diode Light Source.

PubMed

Ji, Jae-Hoon; Jo, GaeHun; Ha, Jae-Geun; Koo, Sang-Mo; Kamiko, Masao; Hong, JunHee; Koh, Jung-Hyuk

2018-09-01

In this research, the recycled electrical energy from wasted thermal energy in high power Light Emitting Diode (LED) system will be investigated. The luminous efficiency of lights has been improved in recent years by employing the high power LED system, therefore energy efficiency was improved compared with that of typical lighting sources. To increase energy efficiency of high power LED system further, wasted thermal energy should be re-considered. Therefore, wasted thermal energy was collected and re-used them as electrical energy. The increased electrical efficiency of high power LED devices was accomplished by considering the recycled heat energy, which is wasted thermal energy from the LED. In this work, increased electrical efficiency will be considered and investigated by employing the high power LED system, which has high thermal loss during the operating time. For this research, well designed thermoelement with heat radiation system was employed to enhance the collecting thermal energy from the LED system, and then convert it as recycled electrical energy.

78 FR 6232 - Energy Conservation Program: Test Procedures for Conventional Cooking Products With Induction...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-30

... Surface efficiency deviation interval technology unit % % ( ) % Large A Electric Coil... 1 69.79 1.59 1.97... Surface efficiency deviation interval technology unit % % ( ) % Large A Electric Coil... 1 64.52 0.87 1.08... technology unit % % ( ) % Large A Electric Coil... 1 79.81 1.66 2.06 B Electric........ 1 61.81 2.83 3.52...

Three state-of-the-art individual electric and hybrid vehicle test reports, volume 2

NASA Technical Reports Server (NTRS)

1978-01-01

Procedures used in determining the energy efficiency and economy of a gasoline-electric hybrid taxi, an electric passenger car, and an electric van are described. Tabular and graphic data show results of driving cycle and constant speed tests, energy distribution to various components, efficiency of the components, and, for the hybrid vehicle, the emissions.

Analysis of initial performance of Solergy's HCPV/T system at Rome-Fiumicino International Airport

NASA Astrophysics Data System (ADS)

Micheli, Leonardo; Femia, Giuseppe; Liani, Martina; Poli, Ruggero; Banin, Yoav; Lanzara, Giovanni; Kurtz, Sarah

2017-09-01

A commercial HCPV/T system, developed by Solergy, is installed at the airport of Rome, in Italy, as part of a prototype smart grid. The system is rated at 15 kW AC electric and 20 kW thermal and is used to provide both electricity for charging electric vehicles and heat for a conventional thermal power plant. This paper presents an analysis of the performance of the system, operating since March 2017, which achieves a combined peak efficiency of 48%. This study incorporates also an investigation on the improvements that can benefit the system, including a new type of receiver with improved heat dissipation.

Sizing Power Components of an Electrically Driven Tail Cone Thruster and a Range Extender

NASA Technical Reports Server (NTRS)

Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy

2016-01-01

The aeronautics industry has been challenged on many fronts to increase efficiency, reduce emissions, and decrease dependency on carbon-based fuels. This paper provides an overview of the turboelectric and hybrid electric technologies being developed under NASA's Advanced Air Transportation Technology (AATT) Project and discusses how these technologies can impact vehicle design. The discussion includes an overview of key hybrid electric studies and technology investments, the approach to making informed investment decisions based on key performance parameters and mission studies, and the power system architectures for two candidate aircraft. Finally, the power components for a single-aisle turboelectric aircraft with an electrically driven tail cone thruster and for a hybrid-electric nine-passenger aircraft with a range extender are parametrically sized, and the sensitivity of these components to key parameters is presented.

Time-Domain Computation Of Electromagnetic Fields In MMICs

NASA Technical Reports Server (NTRS)

Lansing, Faiza S.; Rascoe, Daniel L.

1995-01-01

Maxwell's equations solved on three-dimensional, conformed orthogonal grids by finite-difference techniques. Method of computing frequency-dependent electrical parameters of monolithic microwave integrated circuit (MMIC) involves time-domain computation of propagation of electromagnetic field in response to excitation by single pulse at input terminal, followed by computation of Fourier transforms to obtain frequency-domain response from time-domain response. Parameters computed include electric and magnetic fields, voltages, currents, impedances, scattering parameters, and effective dielectric constants. Powerful and efficient means for analyzing performance of even complicated MMIC.

Optimal management of batteries in electric systems

DOEpatents

Atcitty, Stanley; Butler, Paul C.; Corey, Garth P.; Symons, Philip C.

2002-01-01

An electric system including at least a pair of battery strings and an AC source minimizes the use and maximizes the efficiency of the AC source by using the AC source only to charge all battery strings at the same time. Then one or more battery strings is used to power the load while management, such as application of a finish charge, is provided to one battery string. After another charge cycle, the roles of the battery strings are reversed so that each battery string receives regular management.

Design of an Electric Propulsion System for SCEPTOR

NASA Technical Reports Server (NTRS)

Dubois, Arthur; van der Geest, Martin; Bevirt, JoeBen; Clarke, Sean; Christie, Robert J.; Borer, Nicholas K.

2016-01-01

The rise of electric propulsion systems has pushed aircraft designers towards new and potentially transformative concepts. As part of this effort, NASA is leading the SCEPTOR program which aims at designing a fully electric distributed propulsion general aviation aircraft. This article highlights critical aspects of the design of SCEPTOR's propulsion system conceived at Joby Aviation in partnership with NASA, including motor electromagnetic design and optimization as well as cooling system integration. The motor is designed with a finite element based multi-objective optimization approach. This provides insight into important design tradeoffs such as mass versus efficiency, and enables a detailed quantitative comparison between different motor topologies. Secondly, a complete design and Computational Fluid Dynamics analysis of the air breathing cooling system is presented. The cooling system is fully integrated into the nacelle, contains little to no moving parts and only incurs a small drag penalty. Several concepts are considered and compared over a range of operating conditions. The study presents trade-offs between various parameters such as cooling efficiency, drag, mechanical simplicity and robustness.

Thermal Management and Reliability of Power Electronics and Electric Machines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, Sreekant

2016-09-19

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

Crystal growth and materials research in photovoltaics: progress and challenges

NASA Astrophysics Data System (ADS)

Surek, Thomas

2005-02-01

Photovoltaics (PV) is solar electric power—a semiconductor-based technology that converts sunlight to electricity. Three decades of research has led to the discovery of new materials and devices and new processing techniques for low-cost manufacturing. This has resulted in improved sunlight-to-electricity conversion efficiencies, improved outdoor reliability, and lower module and system costs. The manufacture and sale of PV has grown into a $5 billion industry worldwide, with more than 740 megawatts of PV modules shipped in 2003. This paper reviews the significant progress that has occurred in PV materials and devices research over the past 30 years, focusing on the advances in crystal growth and materials research, and examines the challenges to reaching the ultimate potential of current-generation (crystalline silicon), next-generation (thin films and concentrators), and future-generation PV technologies. The latter includes innovative materials and device concepts that hold the promise of significantly higher conversion efficiencies and/or much lower costs.

Power Without Wires (POWOW)

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W., Jr.; Howell, Joe (Technical Monitor)

2002-01-01

Electric propulsion has emerged as a cost-effective solution to a wide range of satellite applications. Deep Space 1 successfully demonstrated electric propulsion as the primary propulsion source for a satellite. The POWOW concept is a solar-electric propelled spacecraft capable of significant cargo and short trip times for traveling to Mars. There it would enter areosynchronous orbit (Mars GEO equivalent) and beam power to surface installations via lasers. The concept has been developed with industrial partner expertise in high efficiency solar cells, advanced concentrator modules, innovative arrays, and high power electric propulsion systems. The present baseline spacecraft design providing 898 kW using technologies expected to be available in 2003 will be described. Areal power densities approaching 350 W/sq m at 80 C operating temperatures and wing level specific powers of over 350 W/kg are projected. Details of trip times and payloads to Mars are presented. Electric propulsion options include Hall, MPD, and ion thrusters of various power levels and trade studies have been conducted to define the most advantageous options. Because the design is modular, learning curve methodology has been applied to determine expected cost reductions and is included.

10 CFR 431.445 - Determination of small electric motor efficiency.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) General requirements. The average full-load efficiency of each basic model of small electric motor must be... this section, provided, however, that an AEDM may be used to determine the average full-load efficiency of one or more of a manufacturer's basic models only if the average full-load efficiency of at least...

10 CFR 431.445 - Determination of small electric motor efficiency.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) General requirements. The average full-load efficiency of each basic model of small electric motor must be... this section, provided, however, that an AEDM may be used to determine the average full-load efficiency of one or more of a manufacturer's basic models only if the average full-load efficiency of at least...

The New NASA-STD-4005 and NASA-HDBK-4006, Essentials for Direct-Drive Solar Electric Propulsion

NASA Technical Reports Server (NTRS)

Ferguson, Dale C.

2007-01-01

High voltage solar arrays are necessary for direct-drive solar electric propulsion, which has many advantages, including simplicity and high efficiency. Even when direct-drive is not used, the use of high voltage solar arrays leads to power transmission and conversion efficiencies in electric propulsion Power Management and Distribution. Nevertheless, high voltage solar arrays may lead to temporary power disruptions, through the so-called primary electrostatic discharges, and may permanently damage arrays, through the so-called permanent sustained discharges between array strings. Design guidance is needed to prevent these solar array discharges, and to prevent high power drains through coupling between the electric propulsion devices and the high voltage solar arrays. While most electric propulsion systems may operate outside of Low Earth Orbit, the plasmas produced by their thrusters may interact with the high voltage solar arrays in many ways similarly to Low Earth Orbit plasmas. A brief description of previous experiences with high voltage electric propulsion systems will be given in this paper. There are two new official NASA documents available free through the NASA Standards website to help in designing and testing high voltage solar arrays for electric propulsion. They are NASA-STD-4005, the Low Earth Orbit Spacecraft Charging Design Standard, and NASA-HDBK-4006, the Low Earth Orbit Spacecraft Charging Design Handbook. Taken together, they can both educate the high voltage array designer in the engineering and science of spacecraft charging in the presence of dense plasmas and provide techniques for designing and testing high voltage solar arrays to prevent electrical discharges and power drains.

The Light-Induced Field-Effect Solar Cell Concept - Perovskite Nanoparticle Coating Introduces Polarization Enhancing Silicon Cell Efficiency.

PubMed

Wang, Yusheng; Xia, Zhouhui; Liu, Lijia; Xu, Weidong; Yuan, Zhongcheng; Zhang, Yupeng; Sirringhaus, Henning; Lifshitz, Yeshayahu; Lee, Shui-Tong; Bao, Qiaoliang; Sun, Baoquan

2017-05-01

Solar cell generates electrical energy from light one via pulling excited carrier away under built-in asymmetry. Doped semiconductor with antireflection layer is general strategy to achieve this including crystalline silicon (c-Si) solar cell. However, loss of extra energy beyond band gap and light reflection in particular wavelength range is known to hinder the efficiency of c-Si cell. Here, it is found that part of short wavelength sunlight can be converted into polarization electrical field, which strengthens asymmetry in organic-c-Si heterojunction solar cell through molecule alignment process. The light harvested by organometal trihalide perovskite nanoparticles (NPs) induces molecular alignment on a conducting polymer, which generates positive electrical surface field. Furthermore, a "field-effect solar cell" is successfully developed and implemented by combining perovskite NPs with organic/c-Si heterojunction associating with light-induced molecule alignment, which achieves an efficiency of 14.3%. In comparison, the device with the analogous structure without perovskite NPs only exhibits an efficiency of 12.7%. This finding provides a novel concept to design solar cell by sacrificing part of sunlight to provide "extra" asymmetrical field continuously as to drive photogenerated carrier toward respective contacts under direct sunlight. Moreover, it also points out a method to combine promising perovskite material with c-Si solar cell. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energy Efficiency for Electrical Technology.

ERIC Educational Resources Information Center

Scharmann, Larry, Ed.

Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in electrical technology. The following topics are examined: where to look for energy waste; conservation methods for electrical consumers, for…

Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, M.

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors, and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making HEVs practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, R.A.; Downing, B.R.; Pearce, T.C.

The consumption of primary energy by diesel, petrol and electric versions of a light van was compared under high-density urban traffic conditions. The vehicles were driven repeatedly round a 10km route in Central London and measurements of fuel consumption, distance travelled and time were made for each route section. Multiple regression analysis established vehicle sensitivities to variations in average speed, payload, road type, regenerated energy (electric vehicle), kinetic energy, weather and driver. The diesel vehicle used primary energy more efficiently than either the petrol or the electric vehicle over the entire speed range observed, the ratio of energy consumption (diesel:petrol:electric)more » being 100:185:198 at the average speed during the experiment (17.58km/h). The petrol vehicle was more efficient than the electric over most of the speed range, but was less efficient at speeds below about 14km/h. It is concluded that the diesel vehicle is the most efficient for urban delivery duties.« less

Energy efficiency of high-rise buildings

NASA Astrophysics Data System (ADS)

Zhigulina, Anna Yu.; Ponomarenko, Alla M.

2018-03-01

The article is devoted to analysis of tendencies and advanced technologies in the field of energy supply and energy efficiency of tall buildings, to the history of the emergence of the concept of "efficiency" and its current interpretation. Also the article show the difference of evaluation criteria of the leading rating systems LEED and BREEAM. Authors reviewed the latest technologies applied in the construction of energy efficient buildings. Methodological approach to the design of tall buildings taking into account energy efficiency needs to include the primary energy saving; to seek the possibility of production and accumulation of alternative electric energy by converting energy from the sun and wind with the help of special technical devices; the application of regenerative technologies.

The Northeastern United States Energy-Water Nexus: Climate Change Impacts and Alternative Water Management Strategies for the Power Sector

NASA Astrophysics Data System (ADS)

Miara, A.; Macknick, J.; Vorosmarty, C. J.; Cohen, S. M.; Rosenzweig, B.

2014-12-01

The Northeastern United States (NE) relies heavily on thermoelectric power plants (90% of total capacity) to provide electricity to more than 70 million people. This region's power plants require consistent, large volumes of water at sufficiently cold temperatures to generate electricity efficiently, and withdraw approximately 10.5 trillion gallons of water annually. Previous findings indicate that assessments of future electricity pathways must account for water availability, water temperature and the changing climate, as changes in these conditions may limit operational efficiency in the future. To account for such electric system vulnerabilities, we have created a link between an electricity system capacity expansion model (ReEDS) and a hydrologic model that is coupled to a power plant simulation model (FrAMES-TP2M) that allows for a new approach to analyze electricity system development, performance, and environmental impacts. Together, these coupled tools allow us to estimate electricity development and operations in the context of a changing climate and impacts on the seasonal spatial and temporal variability of water resources, downstream thermal effluents that cause plant-to-plant interferences and harm aquatic habitat, economic costs of water conservation methods and associated carbon emissions. In this study, we test and compare a business-as-usual strategy with three alternative water management scenarios that include changes in cooling technologies and water sources utilized for the years 2014-2050. Results of these experiments can provide useful insight into the feasibility of the electricity expansion scenarios in terms of associated water use and thermal impacts, carbon emissions, the cost of generating electricity, and also highlight the importance of accounting for water resources in future power sector planning and performance assessments.

Two essays on efficiency in the electric power industry: Measurement of technical and allocative efficiency

NASA Astrophysics Data System (ADS)

Gardiner, John Corby

The electric power industry market structure has changed over the last twenty years since the passage of the Public Utility Regulatory Policies Act (PURPA). These changes include the entry by unregulated generator plants and, more recently, the deregulation of entry and price in the retail generation market. Such changes have introduced and expanded competitive forces on the incumbent electric power plants. Proponents of this deregulation argued that the enhanced competition would lead to a more efficient allocation of resources. Previous studies of power plant technical and allocative efficiency have failed to measure technical and allocative efficiency at the plant level. In contrast, this study uses panel data on 35 power plants over 59 years to estimate technical and allocative efficiency of each plant. By using a flexible functional form, which is not constrained by the assumption that regulation is constant over the 59 years sampled, the estimation procedure accounts for changes in both state and national regulatory/energy policies that may have occurred over the sample period. The empirical evidence presented shows that most of the power plants examined have operated more efficiently since the passage of PURPA and the resultant increase of competitive forces. Chapter 2 extends the model used in Chapter 1 and clarifies some issues in the efficiency literature by addressing the case where homogeneity does not hold. A more general model is developed for estimating both input and output inefficiency simultaneously. This approach reveals more information about firm inefficiency than the single estimation approach that has previously been used in the literature. Using the more general model, estimates are provided on the type of inefficiency that occurs as well as the cost of inefficiency by type of inefficiency. In previous studies, the ranking of firms by inefficiency has been difficult because of the cardinal and ordinal differences between different types of inefficiency estimates. However, using the general approach, this study illustrates that plants can be ranked by overall efficiency.

Enhancement of extracellular electron transfer and bioelectricity output by synthetic porin.

PubMed

Yong, Yang-Chun; Yu, Yang-Yang; Yang, Yun; Liu, Jing; Wang, Jing-Yuan; Song, Hao

2013-02-01

The microbial fuel cell (MFC), is a promising environmental biotechnology for harvesting electricity energy from organic wastes. However, low bacterial membrane permeability of electron shuttles is a limiting factor that restricts the electron shuttle-mediated extracellular electron transfer (EET) from bacteria to electrodes, thus the electricity power output of MFCs. To this end, we heterologously expressed a porin protein OprF from Pseudomonas aeruginosa PAO1 into Escherichia coli, which dramatically increased its membrane permeability, delivering a much higher current output in MFCs than its parental strain (BL21). We found that the oprF-expression strain showed more efficient EET than its parental strain. More strikingly, the enhanced membrane permeability also rendered the oprF-expression strain an efficient usage of riboflavin as the electron shuttle, whereas its parental strain was incapable of. Our results substantiated that membrane permeability is crucial for the efficient EET, and indicated that the expression of synthetic porins could be an efficient strategy to enhance bioelectricity generation by microorganisms (including electrogenic bacteria) in MFCs. Copyright © 2012 Wiley Periodicals, Inc.

Synthetic Biology and Microbial Fuel Cells: Towards Self-Sustaining Life Support Systems

NASA Technical Reports Server (NTRS)

Hogan, John Andrew

2014-01-01

NASA ARC and the J. Craig Venter Institute (JCVI) collaborated to investigate the development of advanced microbial fuels cells (MFCs) for biological wastewater treatment and electricity production (electrogenesis). Synthetic biology techniques and integrated hardware advances were investigated to increase system efficiency and robustness, with the intent of increasing power self-sufficiency and potential product formation from carbon dioxide. MFCs possess numerous advantages for space missions, including rapid processing, reduced biomass and effective removal of organics, nitrogen and phosphorus. Project efforts include developing space-based MFC concepts, integration analyses, increasing energy efficiency, and investigating novel bioelectrochemical system applications

Performance of an off-grid solar home in northwestern Vermont

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rawlings, L.K.

1997-12-31

In 1995 an off-grid integrated solar home was built in Middlesex, VT for Peter Clark and Gloria DeSousa. This home was included as a pilot home in the US DOE PV:BONUS program to develop factory-built integrated solar homes. The home incorporates a 1.44 KW PV system, 0.6 KW of wind turbine capacity, and very high-efficiency electrical loads. The home also features passive solar design, high-efficiency heating systems, and a greenhouse-based septic treatment system. The performance of the PV system and the wind system, and the total power usage of the household, are measured and recorded by a data acquisition system.more » The home`s electrical loads have operated very efficiently, using on average about one tenth the power used by the average American residence. The PV system has operated reliably and efficiently, providing about 97% of the power needs of the home. The wind turbines have operated efficiently, but the wind regime at the site has not been sufficient to generate more than 1% of the total power needs. The other 2% has been provided by a gasoline backup generator.« less

An accurate and efficient method for piezoelectric coated functional devices based on the two-dimensional Green’s function for a normal line force and line charge

NASA Astrophysics Data System (ADS)

Hou, Peng-Fei; Zhang, Yang

2017-09-01

Because most piezoelectric functional devices, including sensors, actuators and energy harvesters, are in the form of a piezoelectric coated structure, it is valuable to present an accurate and efficient method for obtaining the electro-mechanical coupling fields of this coated structure under mechanical and electrical loads. With this aim, the two-dimensional Green’s function for a normal line force and line charge on the surface of coated structure, which is a combination of an orthotropic piezoelectric coating and orthotropic elastic substrate, is presented in the form of elementary functions based on the general solution method. The corresponding electro-mechanical coupling fields of this coated structure under arbitrary mechanical and electrical loads can then be obtained by the superposition principle and Gauss integration. Numerical results show that the presented method has high computational precision, efficiency and stability. It can be used to design the best coating thickness in functional devices, improve the sensitivity of sensors, and improve the efficiency of actuators and energy harvesters. This method could be an efficient tool for engineers in engineering applications.

Dan Says - Continuum Magazine | NREL

Science.gov Websites

transportation system-from developing more efficient electric and hydrogen fuel-cell vehicles to inventing infrastructure are more daunting than those we are overcoming in developing and integrating renewable electricity more efficient, and developing the technology needed to put more electric and biofuel vehicles on the

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2014 CFR

2014-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2014-01-01 2014-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2012 CFR

2012-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2012-01-01 2012-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2013 CFR

2013-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2013-01-01 2013-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

Thermoelectric refrigerator

NASA Technical Reports Server (NTRS)

Park, Brian V. (Inventor); Smith, Jr., Malcolm C. (Inventor); McGrath, Ralph D. (Inventor); Gilley, Michael D. (Inventor); Criscuolo, Lance (Inventor); Nelson, John L. (Inventor)

1996-01-01

A refrigerator is provided which combines the benefits of superinsulation materials with thermoelectric devices and phase change materials to provide an environmentally benign system that is energy efficient and can maintain relatively uniform temperatures for extended periods of time with relatively low electrical power requirements. The refrigerator includes a thermoelectric assembly having a thermoelectric device with a hot sink and a cold sink. The superinsulation materials include a plurality of vacuum panels. The refrigerator is formed from an enclosed structure having a door. The vacuum panels may be contained within the walls of the enclosed structure and the door. By mounting the thermoelectric assembly on the door, the manufacturer of the enclosed structure is simplified and the overall R rating of the refrigerator increased. Also an electrical motor and propellers may be mounted on the door to assist in the circulation of air to improve the efficiency of the cold sink and the hot sink. A propeller and/or impeller is preferably mounted within the refrigerator to assist in establishing the desired air circulation flow path.

Feasibility of Large High-Powered Solar Electric Propulsion Vehicles: Issues and Solutions

NASA Technical Reports Server (NTRS)

Capadona, Lynn A.; Woytach, Jeffrey M.; Kerslake, Thomas W.; Manzella, David H.; Christie, Robert J.; Hickman, Tyler A.; Schneidegger, Robert J.; Hoffman, David J.; Klem, Mark D.

2012-01-01

Human exploration beyond low Earth orbit will require the use of enabling technologies that are efficient, affordable, and reliable. Solar electric propulsion (SEP) has been proposed by NASA s Human Exploration Framework Team as an option to achieve human exploration missions to near Earth objects (NEOs) because of its favorable mass efficiency as compared to traditional chemical systems. This paper describes the unique challenges and technology hurdles associated with developing a large high-power SEP vehicle. A subsystem level breakdown of factors contributing to the feasibility of SEP as a platform for future exploration missions to NEOs is presented including overall mission feasibility, trip time variables, propellant management issues, solar array power generation, array structure issues, and other areas that warrant investment in additional technology or engineering development.

Energy Efficiency and Renewable Energy Program. Bibliography, 1993 edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughan, K.H.

1993-06-01

The Bibliography contains listings of publicly available reports, journal articles, and published conference papers sponsored by the DOE Office of Energy Efficiency and Renewable Energy and published between 1987 and mid-1993. The topics of Bibliography include: analysis and evaluation; building equipment research; building thermal envelope systems and materials; district heating; residential and commercial conservation program; weatherization assistance program; existing buildings research program; ceramic technology project; alternative fuels and propulsion technology; microemulsion fuels; industrial chemical heat pumps; materials for advanced industrial heat exchangers; advanced industrial materials; tribology; energy-related inventions program; electric energy systems; superconducting technology program for electric energy systems; thermalmore » energy storage; biofuels feedstock development; biotechnology; continuous chromatography in multicomponent separations; sensors for electrolytic cells; hydropower environmental mitigation; environmental control technology; continuous fiber ceramic composite technology.« less

Effects of electrode settings on chlorine generation efficiency of electrolyzing seawater.

PubMed

Hsu, Guoo-Shyng Wang; Hsia, Chih-Wei; Hsu, Shun-Yao

2015-12-01

Electrolyzed water has significant disinfection effects, can comply with food safety regulations, and is environmental friendly. We investigated the effects of immersion depth of electrodes, stirring, electrode size, and electrode gap on the properties and chlorine generation efficiency of electrolyzing seawater and its storage stability. Results indicated that temperature and oxidation-reduction potential (ORP) of the seawater increased gradually, whereas electrical conductivity decreased steadily in electrolysis. During the electrolysis process, pH values and electric currents also decreased slightly within small ranges. Additional stirring or immersing the electrodes deep under the seawater significantly increased current density without affecting its electric efficiency and current efficiency. Decreasing electrode size or increasing electrode gap decreased chlorine production and electric current of the process without affecting its electric efficiency and current efficiency. Less than 35% of chlorine in the electrolyzed seawater was lost in a 3-week storage period. The decrement trend leveled off after the 1 st week of storage. The electrolyzing system is a convenient and economical method for producing high-chlorine seawater, which will have high potential applications in agriculture, aquaculture, or food processing. Copyright © 2015. Published by Elsevier B.V.

Electric urban delivery trucks: energy use, greenhouse gas emissions, and cost-effectiveness.

PubMed

Lee, Dong-Yeon; Thomas, Valerie M; Brown, Marilyn A

2013-07-16

We compare electric and diesel urban delivery trucks in terms of life-cycle energy consumption, greenhouse gas (GHG) emissions, and total cost of ownership (TCO). The relative benefits of electric trucks depend heavily on vehicle efficiency associated with drive cycle, diesel fuel price, travel demand, electric drive battery replacement and price, electricity generation and transmission efficiency, electric truck recharging infrastructure, and purchase price. For a drive cycle with frequent stops and low average speed such as the New York City Cycle (NYCC), electric trucks emit 42-61% less GHGs and consume 32-54% less energy than diesel trucks, depending upon vehicle efficiency cases. Over an array of possible conditions, the median TCO of electric trucks is 22% less than that of diesel trucks on the NYCC. For a drive cycle with less frequent stops and high average speed such as the City-Suburban Heavy Vehicle Cycle (CSHVC), electric trucks emit 19-43% less GHGs and consume 5-34% less energy, but cost 1% more than diesel counterparts. Considering current and projected U.S. regional electricity generation mixes, for the baseline case, the energy use and GHG emissions ratios of electric to diesel trucks range from 48 to 82% and 25 to 89%, respectively.

Automating a spacecraft electrical power system using expert systems

NASA Technical Reports Server (NTRS)

Lollar, L. F.

1991-01-01

Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

Effects of electrode gap and electric current on chlorine generation of electrolyzed deep ocean water.

PubMed

Hsu, Guoo-Shyng Wang; Hsu, Shun-Yao

2018-04-01

Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmental friendly. A two-factor central composite design was adopted for studying the effects of electrode gap and electric current on chlorine generation efficiency of electrolyzed deep ocean water. Deep ocean water was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode in a constant-current operation mode. Results showed that current density, chlorine concentration, and electrolyte temperature increased with electric current, while electric efficiency decreased with electric current and electrode gap. An electrode gap of less than 11.7 mm, and a low electric current appeared to be a more energy efficient design and operation condition for the electrolysis system. Copyright © 2017. Published by Elsevier B.V.

NREL Center for Photovoltaics

ScienceCinema

None

2017-12-09

Solar cells, also called photovoltaics (PV) by solar cell scientists, convert sunlight directly into electricity. Solar cells are often used to power calculators and watches. The performance of a solar cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that make up the cell. Because of this, a typical commercial solar cell has an efficiency of 15%—about one-sixth of the sunlight striking the cell generates electricity. Low efficiencies mean that larger arrays are needed, and that means higher cost. Improving solar cell efficiencies while holding down the cost per cell is an important goal of the PV industry, researchers at the National Renewable Energy Laboratory (NREL) and other U.S. Department of Energy (DOE) laboratories, and they have made significant progress. The first solar cells, built in the 1950s, had efficiencies of less than 4%.

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the fifth quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending December 31, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab- and bench-scale experimental testing, pilot-scale design, and economic studies.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the seventh quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2002 and ending June 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab-/bench-scale experimental testing and pilot-scale design.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the third quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2001 and ending June 30, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, objectives of this program, and provides a summary of program activities covering program management and progress in first year tasks including lab- and bench-scale design, facilities preparation, and engineering studies.« less

[Promoting efficiency of microbial extracellular electron transfer by synthetic biology].

PubMed

Li, Feng; Song, Hao

2017-03-25

Electroactive bacteria, including electrigenic bacteria (exoelectrogens) and electroautotrophic bacteria, implement microbial bioelectrocatalysis processes via bi-directional exchange of electrons and energy with environments, enabling a wide array of applications in environmental and energy fields, including microbial fuel cells (MFC), microbial electrolysis cells (MEC), microbial electrosynthesis (MES) to produce electricity and bulk fine chemicals. However, the low efficiency in the extracellular electron transfer (EET) of exoelectrogens and electrotrophic microbes limited their industrial applications. Here, we reviewed synthetic biology approaches to engineer electroactive microorganisms to break the bottleneck of their EET pathways, to achieve higher efficiency of EET of a number of electroactive microorganisms. Such efforts will lead to a breakthrough in the applications of these electroactive microorganisms and microbial electrocatalysis systems.

Analysis of hybrid electric/thermofluidic inputs for wet shape memory alloy actuators

NASA Astrophysics Data System (ADS)

Flemming, Leslie; Mascaro, Stephen

2013-01-01

A wet shape memory alloy (SMA) actuator is characterized by an SMA wire embedded within a compliant fluid-filled tube. Heating and cooling of the SMA wire produces a linear contraction and extension of the wire. Thermal energy can be transferred to and from the wire using combinations of resistive heating and free/forced convection. This paper analyzes the speed and efficiency of a simulated wet SMA actuator using a variety of control strategies involving different combinations of electrical and thermofluidic inputs. A computational fluid dynamics (CFD) model is used in conjunction with a temperature-strain model of the SMA wire to simulate the thermal response of the wire and compute strains, contraction/extension times and efficiency. The simulations produce cycle rates of up to 5 Hz for electrical heating and fluidic cooling, and up to 2 Hz for fluidic heating and cooling. The simulated results demonstrate efficiencies up to 0.5% for electric heating and up to 0.2% for fluidic heating. Using both electric and fluidic inputs concurrently improves the speed and efficiency of the actuator and allows for the actuator to remain contracted without continually delivering energy to the actuator, because of the thermal capacitance of the hot fluid. The characterized speeds and efficiencies are key requirements for implementing broader research efforts involving the intelligent control of electric and thermofluidic networks to optimize the speed and efficiency of wet actuator arrays.

Adimensional theory of shielding in ultracold collisions of dipolar rotors

NASA Astrophysics Data System (ADS)

González-Martínez, Maykel L.; Bohn, John L.; Quéméner, Goulven

2017-09-01

We investigate the electric field shielding of ultracold collisions of dipolar rotors, initially in their first rotational excited state, using an adimensional approach. We establish a map of good and bad candidates for efficient evaporative cooling based on this shielding mechanism, by presenting the ratio of elastic over quenching processes as a function of a rescaled rotational constant B ˜=B /sE3 and a rescaled electric field F ˜=d F /B . B ,d ,F ,andsE 3 are respectively the rotational constant, the full electric dipole moment of the molecules, the applied electric field, and a characteristic dipole-dipole energy. We identify two groups of bi-alkali-metal dipolar molecules. The first group, including RbCs, NaK, KCs, LiK, NaRb, LiRb, NaCs, and LiCs, is favorable with a ratio over 1000 at collision energies equal to (or even higher than) their characteristic dipolar energy. The second group, including LiNa and KRb, is not favorable. More generally, for molecules well described by Hund's case b, our adimensional study provides the conditions of efficient evaporative cooling. The range of appropriate rescaled rotational constant and rescaled field is approximately B ˜≥108 and 3.25 ≤F ˜≤3.8 , with a maximum ratio reached for F ˜≃3.4 for a given B ˜. We also discuss the importance of the electronic van der Waals interaction on the adimensional character of our study.

The Emerging Interdependence of the Electric Power Grid & Information and Communication Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taft, Jeffrey D.; Becker-Dippmann, Angela S.

2015-08-01

This paper examines the implications of emerging interdependencies between the electric power grid and Information and Communication Technology (ICT). Over the past two decades, electricity and ICT infrastructure have become increasingly interdependent, driven by a combination of factors including advances in sensor, network and software technologies and progress in their deployment, the need to provide increasing levels of wide-area situational awareness regarding grid conditions, and the promise of enhanced operational efficiencies. Grid operators’ ability to utilize new and closer-to-real-time data generated by sensors throughout the system is providing early returns, particularly with respect to management of the transmission system formore » purposes of reliability, coordination, congestion management, and integration of variable electricity resources such as wind generation.« less

Wind energy conversion system

DOEpatents

Longrigg, Paul

1987-01-01

The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

Results from the Operational Testing of the General Electric Smart Grid Capable Electric Vehicle Supply Equipment (EVSE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, Richard Barney; Scoffield, Don; Bennett, Brion

2013-12-01

The Idaho National Laboratory conducted testing and analysis of the General Electric (GE) smart grid capable electric vehicle supply equipment (EVSE), which was a deliverable from GE for the U.S. Department of Energy FOA-554. The Idaho National Laboratory has extensive knowledge and experience in testing advanced conductive and wireless charging systems though INL’s support of the U.S. Department of Energy’s Advanced Vehicle Testing Activity. This document details the findings from the EVSE operational testing conducted at the Idaho National Laboratory on the GE smart grid capable EVSE. The testing conducted on the EVSE included energy efficiency testing, SAE J1772 functionalitymore » testing, abnormal conditions testing, and charging of a plug-in vehicle.« less

Potential reduction of energy consumption in public university library

NASA Astrophysics Data System (ADS)

Noranai, Z.; Azman, ADF

2017-09-01

Efficient electrical energy usage has been recognized as one of the important factor to reduce cost of electrical energy consumption. Various parties have been emphasized about the importance of using electrical energy efficiently. Inefficient usage of electrical energy usage lead to biggest factor increasing of administration cost in Universiti Tun Hussein Onn Malaysia. With this in view, a project the investigate potential reduction electrical energy consumption in Universiti Tun Hussein Onn Malaysia was carried out. In this project, a case study involving electrical energy consumption of Perpustakaan Tunku Tun Aminah was conducted. The scopes of this project are to identify energy consumption in selected building and to find the factors that contributing to wastage of electrical energy. The MS1525:2001, Malaysian Standard - Code of practice on energy efficiency and use of renewable energy for non-residential buildings was used as reference. From the result, 4 saving measure had been proposed which is change type of the lamp, install sensor, decrease the number of lamp and improve shading coefficient on glass. This saving measure is suggested to improve the efficiency of electrical energy consumption. Improve of human behaviour toward saving energy measure can reduce 10% from the total of saving cost while on building technical measure can reduce 90% from total saving cost.

Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes

NASA Astrophysics Data System (ADS)

Pérez-Aparicio, Elena; Lillo-Bravo, Isidoro; Moreno-Tejera, Sara; Silva-Pérez, Manuel

2017-06-01

Thermal energy for industrial processes can be generated using thermal (ST) or photovoltaic (PV) solar energy. ST energy has traditionally been the most favorable option due to its cost and efficiency. Current costs and efficiencies values make the PV solar energy become an alternative to ST energy as supplier of industrial process heat. The aim of this study is to provide a useful tool to decide in each case which option is economically and environmentally the most suitable alternative. The methodology used to compare ST and PV systems is based on the calculation of the levelized cost of energy (LCOE) and greenhouse gas emissions (GHG) avoided by using renewable technologies instead of conventional sources of energy. In both cases, these calculations depend on costs and efficiencies associated with ST or PV systems and the conversion factor from thermal or electrical energy to GHG. To make these calculations, a series of hypotheses are assumed related to consumer and energy prices, operation, maintenance and replacement costs, lifetime of the system or working temperature of the industrial process. This study applies the methodology at five different sites which have been selected taking into account their radiometric and meteorological characteristics. In the case of ST energy three technologies are taken into account, compound parabolic concentrator (CPC), linear Fresnel collector (LFC) and parabolic trough collector (PTC). The PV option includes two ways of use of generated electricity, an electrical resistance or a combination of an electrical resistance and a heat pump (HP). Current values of costs and efficiencies make ST system remains as the most favorable option. These parameters may vary significantly over time. The evolution of these parameters may convert PV systems into the most favorable option for particular applications.

Electricity from methane by reversing methanogenesis

PubMed Central

McAnulty, Michael J.; G. Poosarla, Venkata; Kim, Kyoung-Yeol; Jasso-Chávez, Ricardo; Logan, Bruce E.; Wood, Thomas K.

2017-01-01

Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of: (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate; (ii) micro-organisms from methane-acclimated sludge (including Paracoccus denitrificans) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create a microbial fuel cell that converts methane directly into significant electrical current. Notably, this methane microbial fuel cell operates at high Coulombic efficiency. PMID:28513579

Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bird, Lori; Davidson, Carolyn; McLaren, Joyce

With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset,more » on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.« less

Electricity from methane by reversing methanogenesis

NASA Astrophysics Data System (ADS)

McAnulty, Michael J.; G. Poosarla, Venkata; Kim, Kyoung-Yeol; Jasso-Chávez, Ricardo; Logan, Bruce E.; Wood, Thomas K.

2017-05-01

Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of: (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate; (ii) micro-organisms from methane-acclimated sludge (including Paracoccus denitrificans) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create a microbial fuel cell that converts methane directly into significant electrical current. Notably, this methane microbial fuel cell operates at high Coulombic efficiency.

Optimization of a hybrid electric power system design for large commercial buildings: An application design guide

NASA Astrophysics Data System (ADS)

Lee, Keun

Renewable energy in different forms has been used in various applications for survival since the beginning of human existence. However, there is a new dire need to reevaluate and recalibrate the overall energy issue both nationally and globally. This includes, but is not limited to, the finite availability of fossil fuel, energy sustainability with an increasing demand, escalating energy costs, environmental impact such as global warming and green-house gases, to name a few. This dissertation is primarily focused and related to the production and usage of electricity from non-hydro renewable sources. Among non-hydro renewable energy sources, electricity generation from wind and solar energy are the fastest-growing technologies in the United States and in the world. However, due to the intermittent nature of such renewable sources, energy storage devices are required to maintain proper operation of the grid system and in order to increase reliability. A hybrid system, as the name suggests, is a combination of different forms of non-renewable and renewable energy generation, with or without storage devices. Hybrid systems, when applied properly, are able to improve reliability and enhance stability, reduce emissions and noise pollution, provide continuous power, increase operation life, reduce cost, and efficiently use all available energy. In the United States (U.S.), buildings consume approximately 40% of the total primary energy and 74% of the total electricity. Therefore, reduction of energy consumption and improved energy efficiency in U.S. buildings will play a vital role in the overall energy picture. Electrical energy usage for any such building varies widely depending on age (construction technique), electricity and natural gas usage, appearance, location and climate. In this research, a hybrid system including non-renewable and renewable energy generation with storage devices specifically for building applications, is studied in detail. This research deals with the optimization of the hybrid system design (which consists of PV panels and/or wind turbines and/or storage devices for building applications) by developing an algorithm designed to make the system cost effective and energy efficient. Input data includes electrical load demand profile of the buildings, buildings' structural and geographical characteristics, real time pricing of electricity, and the costs of hybrid systems and storage devices. When the electrical load demand profile of a building that is being studied is available, a measured demand profile is directly used as input data. However, if that information is not available, a building's electric load demand is estimated using a developed algorithm based on three large data sources from a public domain, and used as input data. Using the acquired input data, the algorithm of this research is designed and programmed in order to determine the size of renewable components and to minimize the total yearly net cost. This dissertation also addresses the parametric sensitivity analysis to determine which factors are more significant and are expected to produce useful guidelines in the decision making process. An engineered and more practical, simplified solution has been provided for the optimized design process.

Detailed thermodynamic investigation of an ICE-driven, natural gas-fueled, 1 kWe micro-CHP generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taie, Zachary; West, Brian H.; Szybist, James P.

Here, the purpose of this work is to record the baseline performance of a state-of-the-art micro-combined heat and power (mCHP) system. A second goal of this work is to provide detailed thermodynamic first and second law performance measurements of the internal combustion engine and generator subsystems. A global technology survey was conducted to identify the leading mCHP systems in the 1 kW electric range. The Honda ECOWILL was identified as the state-of-the-art system in the United States, and an unused unit was procured. The ECOWILL underwent round-robin performance testing at three independent laboratories. First law (energy) and second law (exergy)more » analyses were conducted on the steady state data. Analysis revealed the ECOWILL operated at a first law electrical efficiency of 23.5 ± 0.4% and a utilization factor of 74.5 ± 3.2%. The primary energy loss was heat transfer from the device, followed by chemical and thermal energy in the exhaust stack. The second law analysis showed the ECOWILL operated at a second law electrical efficiency of 23.1 ± 0.4% and total (including exergy in both the electrical and recovered waste heat streams) second law efficiency of 30.2 ± 2.3%. Key areas of exergy destruction were, in decreasing magnitude, heat transfer, combustion irreversibility, and generator and friction losses.« less

Detailed thermodynamic investigation of an ICE-driven, natural gas-fueled, 1 kWe micro-CHP generator

DOE PAGES

Taie, Zachary; West, Brian H.; Szybist, James P.; ...

2018-05-03

Here, the purpose of this work is to record the baseline performance of a state-of-the-art micro-combined heat and power (mCHP) system. A second goal of this work is to provide detailed thermodynamic first and second law performance measurements of the internal combustion engine and generator subsystems. A global technology survey was conducted to identify the leading mCHP systems in the 1 kW electric range. The Honda ECOWILL was identified as the state-of-the-art system in the United States, and an unused unit was procured. The ECOWILL underwent round-robin performance testing at three independent laboratories. First law (energy) and second law (exergy)more » analyses were conducted on the steady state data. Analysis revealed the ECOWILL operated at a first law electrical efficiency of 23.5 ± 0.4% and a utilization factor of 74.5 ± 3.2%. The primary energy loss was heat transfer from the device, followed by chemical and thermal energy in the exhaust stack. The second law analysis showed the ECOWILL operated at a second law electrical efficiency of 23.1 ± 0.4% and total (including exergy in both the electrical and recovered waste heat streams) second law efficiency of 30.2 ± 2.3%. Key areas of exergy destruction were, in decreasing magnitude, heat transfer, combustion irreversibility, and generator and friction losses.« less

76 FR 65710 - Decision and Order Amending Waivers Granted to Mitsubishi Electric & Electronics USA, Inc. From...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. CAC-037] Decision and Order Amending Waivers Granted to Mitsubishi Electric & Electronics USA, Inc. From the Department... Efficiency and Renewable Energy. Decision and Order In the Matter of: Mitsubishi Electric & Electronics USA...

Advanced lighting guidelines: 1993. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eley, C.; Tolen, T.M.; Benya, J.R.

1993-12-31

The 1993 Advanced Lighting Guidelines document consists of twelve guidelines that provide an overview of specific lighting technologies and design application techniques utilizing energy-efficient lighting practice. Lighting Design Practice assesses energy-efficient lighting strategies, discusses lighting issues, and explains how to obtain quality lighting design and consulting services. Luminaires and Lighting Systems surveys luminaire equipment designed to take advantage of advanced technology lamp products and includes performance tables that allow for accurate estimation of luminaire light output and power input. The additional ten guidelines -- Computer-Aided Lighting Design, Energy-Efficient Fluorescent Ballasts, Full-Size Fluorescent Lamps, Compact Fluorescent Lamps, Tungsten-Halogen Lamps, Metal Halidemore » and HPS Lamps, Daylighting and Lumen Maintenance, Occupant Sensors, Time Scheduling Systems, and Retrofit Control Technologies -- each provide a product technology overview, discuss current products on the lighting equipment market, and provide application techniques. This document is intended for use by electric utility personnel involved in lighting programs, lighting designers, electrical engineers, architects, lighting manufacturers` representatives, and other lighting professionals.« less

Fusion energy for space missions in the 21st Century

NASA Technical Reports Server (NTRS)

Schulze, Norman R.

1991-01-01

Future space missions were hypothesized and analyzed and the energy source for their accomplishment investigated. The mission included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous mission with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing the High Energy Space Mission were investigated. Potential energy options which could provide the propulsion and electric power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified.

Design of efficient and simple interface testing equipment for opto-electric tracking system

NASA Astrophysics Data System (ADS)

Liu, Qiong; Deng, Chao; Tian, Jing; Mao, Yao

2016-10-01

Interface testing for opto-electric tracking system is one important work to assure system running performance, aiming to verify the design result of every electronic interface matching the communication protocols or not, by different levels. Opto-electric tracking system nowadays is more complicated, composed of many functional units. Usually, interface testing is executed between units manufactured completely, highly depending on unit design and manufacture progress as well as relative people. As a result, it always takes days or weeks, inefficiently. To solve the problem, this paper promotes an efficient and simple interface testing equipment for opto-electric tracking system, consisting of optional interface circuit card, processor and test program. The hardware cards provide matched hardware interface(s), easily offered from hardware engineer. Automatic code generation technique is imported, providing adaption to new communication protocols. Automatic acquiring items, automatic constructing code architecture and automatic encoding are used to form a new program quickly with adaption. After simple steps, a standard customized new interface testing equipment with matching test program and interface(s) is ready for a waiting-test system in minutes. The efficient and simple interface testing equipment for opto-electric tracking system has worked for many opto-electric tracking system to test entire or part interfaces, reducing test time from days to hours, greatly improving test efficiency, with high software quality and stability, without manual coding. Used as a common tool, the efficient and simple interface testing equipment for opto-electric tracking system promoted by this paper has changed traditional interface testing method and created much higher efficiency.

Analysis of Initial Performance of Solergy's HCPV/T System at Rome-Fiumicino International Airport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurtz, Sarah; Micheli, Leonardo; v, Giuseppe

A commercial HCPV/T system, developed by Solergy, is installed at the airport of Rome, in Italy, as part of a prototype smart grid. The system is rated at 15 kW AC electric and 20 kW thermal and is used to provide both electricity for charging electric vehicles and heat for a conventional thermal power plant. This paper presents an analysis of the performance of the system, operating since March 2017, which achieves a combined peak efficiency of 48%. This study incorporates also an investigation on the improvements that can benefit the system, including a new type of receiver with improvedmore » heat dissipation.« less

Modified Gold Electrode and Hollow Mn3O4 Nanoparticles as Electrode Materials for Microbial Fuel Cell Applications

NASA Astrophysics Data System (ADS)

Dhungana, Pramod

Microbial fuel cell (MFC) technology has attracted great attention in the scientific community as it offers the possibility of extraction of electricity from wide range of soluble and dissolved organic waste or renewable biomass, including sludge, waste water and cellulosic biomass. Microbial fuel cells are devices that utilize microbial metabolic processes to convert chemical energy via the oxidation of organic substances to produce electric current. MFCs consist of two chambers, an anode and cathode, separated by ion-permeable materials. The efficiency of producing electricity using the MFC depends on several factors such as immobilization of microorganisms on anode, mode of electron transfer, types of substrate/fuel and effectiveness of cathode materials for oxygen reduction reaction (ORR). In this work, in order to immobilize the microorganisms on anode materials, we have investigated the surface modification of gold electrode (anode) using alkyl dithiol and aryl thiol with glucose. The modification processes were characterized by using contact angle measurements and proton nuclear magnetic resonance (NMR). In order to study the effectiveness of cathode materials for ORR, we have synthesized hollow Mn3O 4 nanoparticles which are electrically very poor. Therefore, the hollow nanoparticles were mixed with electrically conductive multi-walled carbon nanotube as support and optimized the mixing process. This composite material shows enhanced ORR activity in all types of pH conditions. In future, we will focus to integrate anode and cathode in MFC to check its efficiency to produce electricity.

Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes

NASA Astrophysics Data System (ADS)

Fina, Michael Dane

Organic light-emitting diodes (OLEDs) have made tremendous technological progress in the past two decades and have emerged as a top competitor for next generation light-emitting displays and lighting. State-of-the-art OLEDs have been reported in literature to approach, and even surpass, white fluorescent tube efficiency. However, despite rapid technological progress, efficiency metrics must be improved to compete with traditional inorganic light-emitting diode (LED) technology. Organic materials possess specialized traits that permit manipulations to the light-emitting cavity. Overall, as demonstrated within, these modifications can be used to improve electrical and optical device efficiencies. This work is focused at analyzing the effects that nanopatterned geometric modifications to the organic active layers play on device efficiency. In general, OLED efficiency is complicated by the complex, coupled processes which contribute to spontaneous dipole emission. A composite of three sub-systems (electrical, exciton and optical) ultimately dictate the OLED device efficiency. OLED electrical operation is believed to take place via a low-mobility-modified Schottky injection process. In the injection-limited regime, geometric effects are expected to modify the local electric field leading to device current enhancement. It is shown that the patterning effect can be used to enhance charge carrier parity, thereby enhancing overall recombination. Current density and luminance characteristics are shown to be improved by OLED nanopatterning from both the model developed within and experimental techniques. Next, the optical enhancement effects produced by the nanopatterned array are considered. Finite-difference time-domain (FDTD) simulations are used to determine positional, spectral optical enhancement for the nanopatterned device. The results show beneficial effects to the device performance. The optical enhancements are related to the reduction in internal radiative quenching (improved internal quantum efficiency) and improvement in light extraction (improved outcoupling efficiency). Furthermore, the electrical model is used to construct a positional radiative efficiency map that when combined with the optical enhancement reveals the overall external quantum efficiency enhancement.

Wireless Sensor for Measuring Pump Efficiency: Small Business Voucher Project with KCF Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fugate, David L.; Liu, Xiaobing; Gehl, Anthony C.

This document is to fulfill the final report requirements for the Small Business Voucher (SBV) CRADA project with ORNL and KCF Technologies (CRADA/NFE-16-06133). Pumping systems account for nearly 20% of the world’s electrical energy demand and range from 25-50% of the energy usage in many industrial and building power plants. The energy cost is the largest element in the total cost of owning a pump (~40%). In response to a recent DOE mandate for improved pump efficiency pump manufacturers are preparing for the changes that the impending regulations will bring, including design improvements. This mandate also establishes a need formore » new low cost pump efficiency measurement systems. The standard industry definition of pump efficiency is the mechanical water horsepower delivered divided by the electrical horsepower input to the motor. KCF Technologies has developed a new sensor measurement technique to estimate fluid pump efficiency using a thermodynamic approach. KCF Technologies applied for a SBV grant with ORNL as the research partner. KCF needed a research partner with the proper facilities to demonstrate the efficacy of its wireless sensor unit for measuring pump efficiency. The ORNL Building Technologies Research and Integration Center (BTRIC) test resources were used to test and demonstrate the successful measurement of pump efficiency with the KCF sensor technology. KCF is now working on next steps to commercialize this sensing technology.« less

Dynamic modeling and evaluation of solid oxide fuel cell - combined heat and power system operating strategies

NASA Astrophysics Data System (ADS)

Nanaeda, Kimihiro; Mueller, Fabian; Brouwer, Jacob; Samuelsen, Scott

Operating strategies of solid oxide fuel cell (SOFC) combined heat and power (CHP) systems are developed and evaluated from a utility, and end-user perspective using a fully integrated SOFC-CHP system dynamic model that resolves the physical states, thermal integration and overall efficiency of the system. The model can be modified for any SOFC-CHP system, but the present analysis is applied to a hotel in southern California based on measured electric and heating loads. Analysis indicates that combined heat and power systems can be operated to benefit both the end-users and the utility, providing more efficient electric generation as well as grid ancillary services, namely dispatchable urban power. Design and operating strategies considered in the paper include optimal sizing of the fuel cell, thermal energy storage to dispatch heat, and operating the fuel cell to provide flexible grid power. Analysis results indicate that with a 13.1% average increase in price-of-electricity (POE), the system can provide the grid with a 50% operating range of dispatchable urban power at an overall thermal efficiency of 80%. This grid-support operating mode increases the operational flexibility of the SOFC-CHP system, which may make the technology an important utility asset for accommodating the increased penetration of intermittent renewable power.

Method and apparatus for improving the performance of a steam driven power system by steam mixing

DOEpatents

Tsiklauri, Georgi V.; Durst, Bruce M.; Prichard, Andrew W.; Reid, Bruce D.; Burritt, James

1998-01-01

A method and apparatus for improving the efficiency and performance of a steam driven power plant wherein addition of steam handling equipment to an existing plant results in a surprising increase in plant performance. For Example, a gas turbine electrical generation system with heat recovery boiler may be installed along with a micro-jet high pressure and a low pressure mixer superheater. Depending upon plant characteristics, the existing moisture separator reheater (MSR) can be either augmented or done away with. The instant invention enables a reduction in T.sub.hot without a derating of the reactor unit, and improves efficiency of the plant's electrical conversion cycle. Coupled with this advantage is a possible extension of the plant's fuel cycle length due to an increased electrical conversion efficiency. The reduction in T.sub.hot further allows for a surprising extension of steam generator life. An additional advantage is the reduction in erosion/corrosion of secondary system components including turbine blades and diaphragms. The gas turbine generator used in the instant invention can also replace or augment existing peak or emergency power needs. Another benefit of the instant invention is the extension of plant life and the reduction of downtime due to refueling.

A thermodynamic approach for selecting operating conditions in the design of reversible solid oxide cell energy systems

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Kazempoor, Pejman; Braun, Robert J.

2016-01-01

Reversible solid oxide cell (ReSOC) systems are being increasingly considered for electrical energy storage, although much work remains before they can be realized, including cell materials development and system design optimization. These systems store electricity by generating a synthetic fuel in electrolysis mode and subsequently recover electricity by electrochemically oxidizing the stored fuel in fuel cell mode. System thermal management is improved by promoting methane synthesis internal to the ReSOC stack. Within this strategy, the cell-stack operating conditions are highly impactful on system performance and optimizing these parameters to suit both operating modes is critical to achieving high roundtrip efficiency. Preliminary analysis shows the thermoneutral voltage to be a useful parameter for analyzing ReSOC systems and the focus of this study is to quantitatively examine how it is affected by ReSOC operating conditions. The results reveal that the thermoneutral voltage is generally reduced by increased pressure, and reductions in temperature, fuel utilization, and hydrogen-to-carbon ratio. Based on the thermodynamic analysis, many different combinations of these operating conditions are expected to promote efficient energy storage. Pressurized systems can achieve high efficiency at higher temperature and fuel utilization, while non-pressurized systems may require lower stack temperature and suffer from reduced energy density.

Reduced vibration motor winding arrangement

DOEpatents

Slavik, C.J.; Rhudy, R.G.; Bushman, R.E.

1997-11-11

An individual phase winding arrangement having a sixty electrical degree phase belt width for use with a three phase motor armature includes a delta connected phase winding portion and a wye connected phase winding portion. Both the delta and wye connected phase winding portions have a thirty electrical degree phase belt width. The delta and wye connected phase winding portions are each formed from a preselected number of individual coils each formed, in turn, from an unequal number of electrical conductor turns in the approximate ratio of {radical}3. The individual coils of the delta and wye connected phase winding portions may either be connected in series or parallel. This arrangement provides an armature winding for a three phase motor which retains the benefits of the widely known and utilized thirty degree phase belt concept, including improved mmf waveform and fundamental distribution factor, with consequent reduced vibrations and improved efficiency. 4 figs.

2009 Fuel Cell Market Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vincent, Bill; Gangi, Jennifer; Curtin, Sandra

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States aremore » investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.« less

2009 Fuel Cell Market Report, November 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States aremore » investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.« less

Reduced vibration motor winding arrangement

DOEpatents

Slavik, Charles J.; Rhudy, Ralph G.; Bushman, Ralph E.

1997-01-01

An individual phase winding arrangement having a sixty electrical degree phase belt width for use with a three phase motor armature includes a delta connected phase winding portion and a wye connected phase winding portion. Both the delta and wye connected phase winding portions have a thirty electrical degree phase belt width. The delta and wye connected phase winding portions are each formed from a preselected number of individual coils each formed, in turn, from an unequal number of electrical conductor turns in the approximate ratio of .sqroot.3. The individual coils of the delta and wye connected phase winding portions may either be connected in series or parallel. This arrangement provides an armature winding for a three phase motor which retains the benefits of the widely known and utilized thirty degree phase belt concept, including improved mmf waveform and fundamental distribution factor, with consequent reduced vibrations and improved efficiency.

Impedance-matched Marx generators

NASA Astrophysics Data System (ADS)

Stygar, W. A.; LeChien, K. R.; Mazarakis, M. G.; Savage, M. E.; Stoltzfus, B. S.; Austin, K. N.; Breden, E. W.; Cuneo, M. E.; Hutsel, B. T.; Lewis, S. A.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Reisman, D. B.; Sceiford, M. E.; Wisher, M. L.

2017-04-01

We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs). The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with L C time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22 -Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19 -Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.

Isotope Brayton electric power system for the 500 to 2500 watt range.

NASA Technical Reports Server (NTRS)

Macosko, R. P.; Barna, G. J.; Block, H. B.; Ingle, B. D.

1972-01-01

An extensive study was conducted at the Lewis Research Center to evaluate an isotope Brayton electric power system for use in the 500 to 2500 W power range. The study emphasized overall system simplicity in order to reduce parasitic power losses and improve system reliability. The study included detailed parametric cycle analysis, conceptual component designs, and evaluation of system packaging. The study has resulted in the selection of a single-loop system (gas) with six major components including one rotating unit. Calculated net system efficiency varies from 23 to 28% over the power range. The use of the Pu-238 heat source being developed for the Multi-Hundred-Watt Radioisotope Thermoelectric Generator program was assumed.

High voltage photovoltaic power converter

DOEpatents

Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

2001-01-01

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

What we can learn from measurements of air electric conductivity in 222Rn-rich atmosphere

NASA Astrophysics Data System (ADS)

Seran, E.; Godefroy, M.; Pili, E.; Michielsen, N.; Bondiguel, S.

2017-02-01

Electric conductivity of air is an important characteristic of the electric properties of an atmosphere. Testing instruments to measure electric conductivity ranging from 10-13 to 10-9 S m-1 in natural conditions found in the Earth atmosphere is not an easy task. One possibility is to use stratospheric balloon flights; another (and a simpler one) is to look for terrestrial environments with significant radioactive decay. In this paper we present measurements carried out with different types of conductivity sensors in two 222Rn-rich environments, i.e., in the Roselend underground tunnel (French Alps) and in the Institute of Radioprotection and Nuclear Safety BACCARA (BAnC de CAllibrage du RAdon) chamber. The concept of the conductivity sensor is based on the classical time relaxation method. New elements in our design include isolation of the sensor sensitive part (electrode) from the external electric field and sensor miniaturization. This greatly extends the application domain of the sensor and permits to measure air electric conductivity when the external electric field is high and varies from few tens of V m-1 to up to few tens of kV m-1. This is suitable to propose the instrument for a planetary mission. Two-fold objectives were attained as the outcome of these tests and their analysis. First was directly related to the performances of the conductivity sensors and the efficiency of the conductivity sensor design to shield the external electric field. Second objective aimed at understanding the decay mechanisms of 222Rn and its progeny in atmosphere and the impact of the enclosed space on the efficiency of gas ionization.

Solar collector array

DOEpatents

Hall, John Champlin; Martins, Guy Lawrence

2015-09-06

A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

Reduced energy consumption by massive thermoelectric waste heat recovery in light duty trucks

NASA Astrophysics Data System (ADS)

Magnetto, D.; Vidiella, G.

2012-06-01

The main objective of the EC funded HEATRECAR project is to reduce the energy consumption and curb CO2 emissions of vehicles by massively harvesting electrical energy from the exhaust system and re-use this energy to supply electrical components within the vehicle or to feed the power train of hybrid electrical vehicles. HEATRECAR is targeting light duty trucks and focuses on the development and the optimization of a Thermo Electric Generator (TEG) including heat exchanger, thermoelectric modules and DC/DC converter. The main objective of the project is to design, optimize and produce a prototype system to be tested on a 2.3l diesel truck. The base case is a Thermo Electric Generator (TEG) producing 1 KWel at 130 km/h. We present the system design and estimated output power from benchmark Bi2Te3 modules. We discuss key drivers for the optimization of the thermal-to-electric efficiency, such as materials, thermo-mechanical aspects and integration.

FY2011 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) announced in May 2011 a new cooperative research effort comprising DOE, the U.S. Council for Automotive Research (composed of automakers Ford Motor Company, General Motors Company, and Chrysler Group), Tesla Motors, and representatives of the electric utility and petroleum industries. Known as U.S. DRIVE (Driving Research and Innovation for Vehicle efficiency and Energy sustainability), it represents DOE's commitment to developing public-private partnerships to fund high risk-high reward research into advanced automotive technologies. The new partnership replaces and builds upon the partnership known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research') that ran frommore » 2002 through 2010 and the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machines (PEEM) subprogram within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor (EM), and traction drive system technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the PEEM subprogram has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The PEEM subprogram supports the efforts of the U.S. DRIVE partnership through a three phase approach intended to: (1) identify overall propulsion and vehicle related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component R&D activities; (2) develop and validate individual subsystems and components, including EMs and PE; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), battery electric vehicles, and fuel-cell-powered automobiles that meet the goals of the VTP. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, efficiency, and cost targets for the PE and EM subsystems of the traction drive system. Areas of development include: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency with the ability to accommodate higher temperature environments while achieving high reliability; (3) converter concepts that use methods of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control through innovative packaging technologies; and (6) integrated motor-inverter traction drive system concepts. ORNL's PEEM research program conducts fundamental research, evaluates hardware, and assists in the technical direction of the VTP Advanced Power Electronics and Electric Motors (APEEM) program. In this role, ORNL serves on the U.S. DRIVE Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. DOE's continuing R&D into advanced vehicle technologies for transportation offers the possibility of reducing the nation's dependence on foreign oil and the negative economic impacts of crude oil price fluctuations. It also supports the Administration's goal of deploying 1 million PHEVs by 2015.« less

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

PubMed Central

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

2016-01-01

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery. PMID:27193507

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

NASA Astrophysics Data System (ADS)

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

2016-05-01

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes.

PubMed

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R

2016-05-19

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.

Strategic avionics technology definition studies. Subtask 3-1A: Electrical Actuation (ELA) systems

NASA Technical Reports Server (NTRS)

Lum, Ben T. F.; Pond, Charles; Dermott, William

1993-01-01

This interim report presents the preliminary results of an electrical actuation (ELA) system study (subtask TA3-1A) to support the NASA strategic avionics technology definition studies. The final report of this ELA study is scheduled for September 30, 1993. The topics are presented in viewgraph form and include the following ELA technology demonstration testing; ELA system baseline; power and energy requirements for shuttle effector systems; power efficiency and losses of ELA effector systems; and power and energy requirements for ELA power sources.

MATERIALS SCIENCE: New Tigers in the Fuel Cell Tank.

PubMed

Service, R F

2000-06-16

After decades of incremental advances, a spurt of findings suggests that fuel cells that run on good old fossil fuels are almost ready for prime time. Although conventional ceramic cells, known as solid oxide fuel cells, require expensive heat-resistant materials, a new generation of SOFCs, including one featured on page 2031, converts hydrocarbons directly into electricity at lower temperatures. And a recent demonstration of a system of standard SOFCs large enough to light up more than 200 homes showed that it is the most efficient large-scale electrical generator ever designed.

Photovoltaic Power Station with Ultracapacitors for Storage

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Kolacz, John S.; Soltis, Richard F.; Tavernelli, Paul F.

2003-01-01

A solar photovoltaic power station in which ultracapacitors, rather than batteries, are used to store energy is discussed. Developments in the semiconductor industry have reduced the cost and increased the attainable efficiency of commercially available photovoltaic panels; as a result, photovoltaic generation of power for diverse applications has become practical. Photovoltaic generation can provide electric power in remote locations where electric power would otherwise not be available. Photovoltaic generation can also afford independence from utility systems. Applications include supplying power to scientific instruments and medical equipment in isolated geographical regions.

75 FR 6180 - Mission Statement; Secretarial China Clean Energy Business Development Mission; May 16-21, 2010

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-08

... addition, Hong Kong has an efficient, transparent legal system based on common law principles that offer... 2020. The current grid infrastructure system is unable to support greater electricity movement from... sector, including traditional transmission/distribution systems and smart grid technologies, offers huge...

Graphite-based photovoltaic cells

DOEpatents

Lagally, Max; Liu, Feng

2010-12-28

The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.

Coal-Powered Electric Generating Unit Efficiency and Reliability Dialogue: Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Emmanuel

Coal continues to play a critical role in powering the Nation’s electricity generation, especially for baseload power plants. With aging coal generation assets facing decreased performance due to the state of the equipment, and with challenges exacerbated by the current market pressures on the coal sector, there are opportunities to advance early-stage technologies that can retrofit or replace equipment components. These changes will eventually result in significant improvements in plant performance once further developed and deployed by industry. Research and development in areas such as materials, fluid dynamics, fuel properties and preparation characteristics, and a new generation of plant controlsmore » can lead to new components and systems that can help improve the efficiency and reliability of coal-fired power plants significantly, allowing these assets to continue to provide baseload power. Coal stockpiles at electricity generation plants are typically large enough to provide 30 to 60 days of power prior to resupply—significantly enhancing the stability and reliability of the U.S. electricity sector. Falling prices for non-dispatchable renewable energy and mounting environmental regulations, among other factors, have stimulated efforts to improve the efficiency of these coal-fired electric generating units (EGUs). In addition, increased reliance on natural gas and non-dispatchable energy sources has spurred efforts to further increase the reliability of coal EGUs. The Coal Powered EGU Efficiency and Reliability Dialogue brought together stakeholders from across the coal EGU industry to discuss methods for improvement. Participants at the event reviewed performance-enhancing innovations in coal EGUs, discussed the potential for data-driven management practices to increase efficiency and reliability, investigated the impacts of regulatory compliance on coal EGU performance, and discussed upcoming challenges for the coal industry. This report documents the key findings and research suggestions discussed at the event. Discussions at the workshop will aid DOE in developing a set of distinct initiatives that can be pursued by government and industry to realize promising technological pursuits. DOE plans to use the results of the Dialogue coupled with ongoing technical analysis of efficiency opportunities within the coal-fired fleet, and additional studies to develop a comprehensive strategy for capitalizing on thermal efficiency improvements. Expected Power Plant Efficiency Improvements include developing cost-effective, efficient, and reliable technologies for boilers, turbines, and sensors and controls to improve the reliability and efficiency of existing coal-based power plants. The Office of Fossil Energy at DOE plans to work with industry to develop knowledge pertaining to advanced technologies and systems that industry can subsequently develop. These technologies and systems will increase reliability, add operational flexibility and improve efficiency, thereby providing more robust power generation infrastructure. The following table lists the research suggestions and questions for further investigation that were identified by participants in each session of the dialogue.« less

Coupled optical and electrical study of thin-film InGaAs photodetector integrated with surface InP Mie resonators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Dong; Song, Jiakun; Yu, Hailong

2016-03-14

High-index dielectric and semiconductor nanostructures with characteristics of low absorption loss and artificially controlled scattering properties have grasped an increasing attention for improving the performance of thin-film photovoltaic devices. In this work, combined optical and electrical simulations were performed for thin-film InP/In{sub 0.53}Ga{sub 0.47}As/InP hetero-junction photodetector with periodically arranged InP nano-cylinders in the in-coupling configuration. It is found that the carefully designed InP nano-cylinders possess strongly substrate-coupled Mie resonances and can effectively couple incident light into the guided mode, both of which significantly increase optical absorption. Further study from the electrical aspects shows that enhancement of external quantum efficiency ismore » as high as 82% and 83% in the configurations with the optimized nano-cylinders and the optimized period, respectively. Moreover, we demonstrate that the integration of InP nano-cylinders does not degrade the electrical performance, since the surface recombination is effectively suppressed by separating the absorber layer where carriers generate and the air/semiconductor interface. The comprehensive modeling including optical and electrical perspectives provides a more practical description for device performance than the optical-only simulation and is expected to advance the design of thin-film absorber layer based optoelectronic devices for fast response and high efficiency.« less

Systems Analysis of GPS Electrical Power System Redesign

DTIC Science & Technology

1995-12-01

Table 8 - System Efficiencies & Multipliers for Solar Direct Model (12:102; 15:864) Component Efficiency AMTEC 0.180 Receiver and Thermal Energy Storage...and low temperatures of the working fluid. Extreme high and low temperatures provide a greater efficiency , but require extensive thermal control and...direct conversion category. The Alkali Metal Thermal -to-Electric Converter ( AMTEC ) shows mass and cost savings due to efficiencies significantly higher

Quantum efficiency as a device-physics interpretation tool for thin-film solar cells

NASA Astrophysics Data System (ADS)

Nagle, Timothy J.

2007-12-01

Thin-film solar cells made from CdTe and CIGS p-type absorbers are promising candidates for generating pollution-free electricity. The challenge faced by the thin-film photovoltaics (PV) community is to improve the electrical properties of devices, without straying from low-cost, industry-friendly techniques. This dissertation will focus on the use of quantum-efficiency (QE) measurements to deduce the device physics of thin-film devices, in the hope of improving electrical properties and efficiencies of PV materials. Photons which are absorbed, but not converted into electrical energy can modify the energy bands in the solar cell. Under illumination, photoconductivity in the CdS window layer can result in bands different from those in the dark. QE data presented here was taken under a variety of light-bias conditions. These results suggest that 0.10 sun of white-light bias incident on the CdS layer is usually sufficient to achieve accurate QE results. QE results are described by models based on carrier collection by drift and diffusion, and photon absorption. These models are sensitive to parameters such as carrier mobility and lifetime. Comparing calculated QE curves with experiments, it was determined that electron lifetimes in CdTe are less than 0.1 ns. Lifetime determinations also suggest that copper serves as a recombination center in CdTe. The spatial uniformity of QE results has been investigated with the LBIC apparatus, and several experiments are described which investigate cell uniformity. Electrical variations that occur in solar cells often occur in a nonuniform fashion, and can be detected with the LBIC apparatus. Studies discussed here include investigation of patterned deposition of Cu in back-contacts, the use of high-resistivity TCO layers to mitigate nonuniformity, optical effects, and local shunts. CdTe devices with transparent back contacts were also studied with LBIC, including those that received a strong bromine/dichrol/hydrazine (BDH) etch and those that received a weak bromine etch at the back contact. Back-side results showed improved uniformity in BDH-etched devices, attributed to better back contacts in these devices. In thin-absorber devices, the uniformity trend would likely extend to front-side measurements.

Essays on empirical analysis of multi-unit auctions: Impacts of financial transmission rights on the restructured electricity industry

NASA Astrophysics Data System (ADS)

Zang, Hailing

This dissertation uses recently developed empirical methodologies for the study of multi-unit auctions to test the impacts of Financial Transmission Rights (FTRs) on the competitiveness of restructured electricity markets. FTRs are a special type of financial option that hedge against volatility in the cost of transporting electricity over the grid. Policy makers seek to use the prices of FTRs as market signals to incentivize efficient investment and utilization of transmission capacity. However, prices will not send the correct signals if market participants strategically use FTRs. This dissertation uses data from the Texas electricity market to test whether the prices of FTRs are efficient to achieve such goals. The auctions studied are multi-unit, uniform-price, sealed-bid auctions. The first part of the dissertation studies the auctions on the spot market of the wholesale electricity industry. I derive structural empirical models to test theoretical predictions as to whether bidders fully internalize the effect of FTRs on profits into their bidding decisions. I find that bidders are learning as to how to optimally bid above marginal cost for their inframarginal capacities. The bidders also learn to bid to include FTRs into their profit maximization problem during the course of the first year. But starting from the second year, they deviated from optimal bidding that includes FTRs in the profit maximization problems. Counterfactual analysis show that the primary effect of FTRs on market outcomes is changing the level of prices rather than production efficiency. Finally, I find that in most months, the current allocations of FTRs are statistically equivalent to the optimal allocations. The second part of the dissertation studies the bidding behavior in the FTR auctions. I find that FTRs' strategic impact on the FTR purchasing behavior is significant for large bidders---firms exercising market power in the FTR auctions. Second, trader forecasts future FTR credit very accurately while large generators' forecasts of future FTR credit tends to be biased upward. Finally, the bid shading patterns are consistent with theoretical predictions and support the existence of common values.

Energy Division annual progress report for period ending September 30, 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report covers work done during FY 1983 by the staff of the Energy Division and its subcontractors and by colleagues in other Oak Ridge National Laboratory divisions working on Energy Division projects. The work can be divided into four areas: (1) analysis and assessment, (2) models and data systems, (3) research to improve the efficiency of energy use and to improve electric power transmission and distribution, and (4) research utilization. Support came principally from the US Department of Energy (DOE), the US Nuclear Regulatory Commission, and the US Department of Defense, but also from a number of other agenciesmore » and organizations. Analysis and assessment included work on (a) environmental issues, including those deriving from the preparation of environmental impact statements; (b) energy and resource analysis; and (c) emergency preparedness. The models and data systems area involved research on evaluating and developing energy, environment, and engineering simulation models and on devising large data management systems, evaluating user data requirements, and compiling data bases. Research on improving the efficiency of energy use was focused primarily on the buildings and electricity sectors. A major effort on heat pump technology, which includes both heat-activated and electrically driven systems, continues. An important aspect of all the work was research utilization. Since the Energy Division is doing applied research, results are, by definition, intended to solve problems or answer questions of DOE and other sponsors. However, there are other users, and research utilization activities include technology transfer, commercialization efforts, outreach to state and regional organizations, and, of course, information dissemination.« less

Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

NASA Astrophysics Data System (ADS)

Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

2017-07-01

The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

Calorimetric Measurement for Internal Conversion Efficiency of Photovoltaic Cells/Modules Based on Electrical Substitution Method

NASA Astrophysics Data System (ADS)

Saito, Terubumi; Tatsuta, Muneaki; Abe, Yamato; Takesawa, Minato

2018-02-01

We have succeeded in the direct measurement for solar cell/module internal conversion efficiency based on a calorimetric method or electrical substitution method by which the absorbed radiant power is determined by replacing the heat absorbed in the cell/module with the electrical power. The technique is advantageous in that the reflectance and transmittance measurements, which are required in the conventional methods, are not necessary. Also, the internal quantum efficiency can be derived from conversion efficiencies by using the average photon energy. Agreements of the measured data with the values estimated from the nominal values support the validity of this technique.

Focused technology: Nuclear propulsion

NASA Technical Reports Server (NTRS)

Miller, Thomas J.

1991-01-01

The topics presented are covered in viewgraph form and include: nuclear thermal propulsion (NTP), which challenges (1) high temperature fuel and materials, (2) hot hydrogen environment, (3) test facilities, (4) safety, (5) environmental impact compliance, and (6) concept development, and nuclear electric propulsion (NEP), which challenges (1) long operational lifetime, (2) high temperature reactors, turbines, and radiators, (3) high fuel burn-up reactor fuels, and designs, (4) efficient, high temperature power conditioning, (5) high efficiency, and long life thrusters, (6) safety, (7) environmental impact compliance, and (8) concept development.

[Modeling and analysis of volume conduction based on field-circuit coupling].

PubMed

Tang, Zhide; Liu, Hailong; Xie, Xiaohui; Chen, Xiufa; Hou, Deming

2012-08-01

Numerical simulations of volume conduction can be used to analyze the process of energy transfer and explore the effects of some physical factors on energy transfer efficiency. We analyzed the 3D quasi-static electric field by the finite element method, and developed A 3D coupled field-circuit model of volume conduction basing on the coupling between the circuit and the electric field. The model includes a circuit simulation of the volume conduction to provide direct theoretical guidance for energy transfer optimization design. A field-circuit coupling model with circular cylinder electrodes was established on the platform of the software FEM3.5. Based on this, the effects of electrode cross section area, electrode distance and circuit parameters on the performance of volume conduction system were obtained, which provided a basis for optimized design of energy transfer efficiency.

Turbokon scientific and production implementation company—25 years of activity

NASA Astrophysics Data System (ADS)

Favorskii, O. N.; Leont'ev, A. I.; Milman, O. O.

2016-05-01

The main results of studies performed at ZAO Turbokon NPVP in cooperation with leading Russian scientific organizations during 25 years of its activity in the field of development of unique ecologically clean electric power and heat production technologies are described. They include the development and experimental verification using prototypes and full-scale models of highly efficient air-cooled condensers for steam turbines, a high temperature gas steam turbine for stationary and transport power engineering, a nonfuel technology of electric power production using steam turbine installations with a unit power of 4-20 MW at gas-main pipelines and industrial boiler houses and heat stations. The results of efforts in the field of reducing vibroactivity of power equipment for transport installations are given. Basic directions of further research for increasing the efficiency and ecological safety of home power engineering are discussed.

Electrical heating of soils using high efficiency electrode patterns and power phases

DOEpatents

Buettner, Harley M.

1999-01-01

Powerline-frequency electrical (joule) heating of soils using a high efficiency electrode configuration and power phase arrangement. The electrode configuration consists of several heating or current injection electrodes around the periphery of a volume of soil to be heated, all electrodes being connected to one phase of a multi-phase or a single-phase power system, and a return or extraction electrode or electrodes located inside the volume to be heated being connected to the remaining phases of the multi-phase power system or to the neutral side of the single-phase power source. This electrode configuration and power phase arrangement can be utilized anywhere where powerline frequency soil heating is applicable and thus has many potential uses including removal of volatile organic compounds such as gasoline and tricholorethylene (TCE) from contaminated areas.

Integration of regenerative shock absorber into vehicle electric system

NASA Astrophysics Data System (ADS)

Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

2014-03-01

Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

FY2007 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as 'FreedomCAR' (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieving the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid and fuel-cell-powered automobiles that meet the goals of the FreedomCAR and Vehicle Technologies Program. A key element in making hybrid electric vehicles (HEVs) practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Office of FreedomCAR and Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2007 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less

Al-Coated Conductive Fiber Filters for High-Efficiency Electrostatic Filtration: Effects of Electrical and Fiber Structural Properties.

PubMed

Choi, Dong Yun; An, Eun Jeong; Jung, Soo-Ho; Song, Dong Keun; Oh, Yong Suk; Lee, Hyung Woo; Lee, Hye Moon

2018-04-10

Through the direct decomposition of an Al precursor ink AlH 3 {O(C 4 H 9 ) 2 }, we fabricated an Al-coated conductive fiber filter for the efficient electrostatic removal of airborne particles (>99%) with a low pressure drop (~several Pascals). The effects of the electrical and structural properties of the filters were investigated in terms of collection efficiency, pressure drop, and particle deposition behavior. The collection efficiency did not show a significant correlation with the extent of electrical conductivity, as the filter is electrostatically charged by the metallic Al layers forming electrical networks throughout the fibers. Most of the charged particles were collected via surface filtration by Coulombic interactions; consequently, the filter thickness had little effect on the collection efficiency. Based on simulations of various fiber structures, we found that surface filtration can transition to depth filtration depending on the extent of interfiber distance. Therefore, the effects of structural characteristics on collection efficiency varied depending on the degree of the fiber packing density. This study will offer valuable information pertaining to the development of a conductive metal/polymer composite air filter for an energy-efficient and high-performance electrostatic filtration system.

Technique for Solving Electrically Small to Large Structures for Broadband Applications

NASA Technical Reports Server (NTRS)

Jandhyala, Vikram; Chowdhury, Indranil

2011-01-01

Fast iterative algorithms are often used for solving Method of Moments (MoM) systems, having a large number of unknowns, to determine current distribution and other parameters. The most commonly used fast methods include the fast multipole method (FMM), the precorrected fast Fourier transform (PFFT), and low-rank QR compression methods. These methods reduce the O(N) memory and time requirements to O(N log N) by compressing the dense MoM system so as to exploit the physics of Green s Function interactions. FFT-based techniques for solving such problems are efficient for spacefilling and uniform structures, but their performance substantially degrades for non-uniformly distributed structures due to the inherent need to employ a uniform global grid. FMM or QR techniques are better suited than FFT techniques; however, neither the FMM nor the QR technique can be used at all frequencies. This method has been developed to efficiently solve for a desired parameter of a system or device that can include both electrically large FMM elements, and electrically small QR elements. The system or device is set up as an oct-tree structure that can include regions of both the FMM type and the QR type. The system is enclosed with a cube at a 0- th level, splitting the cube at the 0-th level into eight child cubes. This forms cubes at a 1st level, recursively repeating the splitting process for cubes at successive levels until a desired number of levels is created. For each cube that is thus formed, neighbor lists and interaction lists are maintained. An iterative solver is then used to determine a first matrix vector product for any electrically large elements as well as a second matrix vector product for any electrically small elements that are included in the structure. These matrix vector products for the electrically large and small elements are combined, and a net delta for a combination of the matrix vector products is determined. The iteration continues until a net delta is obtained that is within the predefined limits. The matrix vector products that were last obtained are used to solve for the desired parameter. The solution for the desired parameter is then presented to a user in a tangible form; for example, on a display.

Centrifugal compressor design for electrically assisted boost

NASA Astrophysics Data System (ADS)

Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

2013-12-01

Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

Experimental Investigations from the Operation of a 2 Kw Brayton Power Conversion Unit and a Xenon Ion Thruster

NASA Technical Reports Server (NTRS)

Mason, Lee; Birchenough, Arthur; Pinero, Luis

2004-01-01

A 2 kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton converters and ion thrusters are potential candidates for use on future high power NEP missions such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of existing lower power test hardware provided a cost-effective means to investigate the critical electrical interface between the power conversion system and ion propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Experimental Investigation from the Operation of a 2 kW Brayton Power Conversion Unit and a Xenon Ion Thruster

NASA Technical Reports Server (NTRS)

Hervol, David; Mason, Lee; Birchenough, Art; Pinero, Luis

2004-01-01

A 2kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton Converters and ion thrusters are potential candidates for use on future high power NEP mission such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of a existing lower power test hardware provided a cost effective means to investigate the critical electrical interface between the power conversion system and the propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Electric-field-driven switching of individual magnetic skyrmions

NASA Astrophysics Data System (ADS)

Hsu, Pin-Jui; Kubetzka, André; Finco, Aurore; Romming, Niklas; von Bergmann, Kirsten; Wiesendanger, Roland

2017-02-01

Controlling magnetism with electric fields is a key challenge to develop future energy-efficient devices. The present magnetic information technology is mainly based on writing processes requiring either local magnetic fields or spin torques, but it has also been demonstrated that magnetic properties can be altered on the application of electric fields. This has been ascribed to changes in magnetocrystalline anisotropy caused by spin-dependent screening and modifications of the band structure, changes in atom positions or differences in hybridization with an adjacent oxide layer. However, the switching between states related by time reversal, for example magnetization up and down as used in the present technology, is not straightforward because the electric field does not break time-reversal symmetry. Several workarounds have been applied to toggle between bistable magnetic states with electric fields, including changes of material composition as a result of electric fields. Here we demonstrate that local electric fields can be used to switch reversibly between a magnetic skyrmion and the ferromagnetic state. These two states are topologically inequivalent, and we find that the direction of the electric field directly determines the final state. This observation establishes the possibility to combine electric-field writing with the recently envisaged skyrmion racetrack-type memories.

Lightweighting Impacts on Fuel Economy, Cost, and Component Losses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooker, A. D.; Ward, J.; Wang, L.

2013-01-01

The Future Automotive Systems Technology Simulator (FASTSim) is the U.S. Department of Energy's high-level vehicle powertrain model developed at the National Renewable Energy Laboratory. It uses a time versus speed drive cycle to estimate the powertrain forces required to meet the cycle. It simulates the major vehicle powertrain components and their losses. It includes a cost model based on component sizing and fuel prices. FASTSim simulated different levels of lightweighting for four different powertrains: a conventional gasoline engine vehicle, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a battery electric vehicle (EV). Weight reductions impacted themore » conventional vehicle's efficiency more than the HEV, PHEV and EV. Although lightweighting impacted the advanced vehicles' efficiency less, it reduced component cost and overall costs more. The PHEV and EV are less cost effective than the conventional vehicle and HEV using current battery costs. Assuming the DOE's battery cost target of $100/kWh, however, the PHEV attained similar cost and lightweighting benefits. Generally, lightweighting was cost effective when it costs less than $6/kg of mass eliminated.« less

Peak oil demand: the role of fuel efficiency and alternative fuels in a global oil production decline.

PubMed

Brandt, Adam R; Millard-Ball, Adam; Ganser, Matthew; Gorelick, Steven M

2013-07-16

Some argue that peak conventional oil production is imminent due to physical resource scarcity. We examine the alternative possibility of reduced oil use due to improved efficiency and oil substitution. Our model uses historical relationships to project future demand for (a) transport services, (b) all liquid fuels, and (c) substitution with alternative energy carriers, including electricity. Results show great increases in passenger and freight transport activity, but less reliance on oil. Demand for liquids inputs to refineries declines significantly after 2070. By 2100 transport energy demand rises >1000% in Asia, while flattening in North America (+23%) and Europe (-20%). Conventional oil demand declines after 2035, and cumulative oil production is 1900 Gbbl from 2010 to 2100 (close to the U.S. Geological Survey median estimate of remaining oil, which only includes projected discoveries through 2025). These results suggest that effort is better spent to determine and influence the trajectory of oil substitution and efficiency improvement rather than to focus on oil resource scarcity. The results also imply that policy makers should not rely on liquid fossil fuel scarcity to constrain damage from climate change. However, there is an unpredictable range of emissions impacts depending on which mix of substitutes for conventional oil gains dominance-oil sands, electricity, coal-to-liquids, or others.

The Treatment of PPCP-Containing Sewage in an Anoxic/Aerobic Reactor Coupled with a Novel Design of Solid Plain Graphite-Plates Microbial Fuel Cell

PubMed Central

Chang, Yi-Tang; Yang, Chu-Wen; Chang, Yu-Jie; Chang, Ting-Chieh; Wei, Da-Jiun

2014-01-01

Synthetic sewage containing high concentrations of pharmaceuticals and personal care products (PPCPs, mg/L level) was treated using an anoxic/aerobic (A/O) reactor coupled with a microbial fuel cell (MFC) at hydraulic retention time (HRT) of 8 h. A novel design of solid plain graphite plates (SPGRPs) was used for the high surface area biodegradation of the PPCP-containing sewage and for the generation of electricity. The average CODCr and total nitrogen removal efficiencies achieved were 97.20% and 83.75%, respectively. High removal efficiencies of pharmaceuticals, including acetaminophen, ibuprofen, and sulfamethoxazole, were also obtained and ranged from 98.21% to 99.89%. A maximum power density of 532.61 mW/cm2 and a maximum coulombic efficiency of 25.20% were measured for the SPGRP MFC at the anode. Distinct differences in the bacterial community were presented at various locations including the mixed liquor suspended solids and biofilms. The bacterial groups involved in PPCP biodegradation were identified as Dechloromonas spp., Sphingomonas sp., and Pseudomonas aeruginosa. This design, which couples an A/O reactor with a novel design of SPGRP MFC, allows the simultaneous removal of PPCPs and successful electricity production. PMID:25197659

Power-to-heat in adiabatic compressed air energy storage power plants for cost reduction and increased flexibility

NASA Astrophysics Data System (ADS)

Dreißigacker, Volker

2018-04-01

The development of new technologies for large-scale electricity storage is a key element in future flexible electricity transmission systems. Electricity storage in adiabatic compressed air energy storage (A-CAES) power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. For further improvements in cost efficiencies and flexibility, system modifications are necessary. Therefore, a novel concept regarding the integration of an electrical heating component is investigated. This modification allows increased power plant flexibilities and decreasing component sizes due to the generated high temperature heat with simultaneously decreasing total round trip efficiencies. For an exemplarily A-CAES case simulation studies regarding the electrical heating power and thermal energy storage sizes were conducted to identify the potentials in cost reduction of the central power plant components and the loss in round trip efficiency.

Metal-Air Batteries: (Latest citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1997-01-01

The bibliography contains citations concerning applications of metal-air batteries. Topics include systems that possess different practical energy densities at specific powers. Coverage includes the operation of air electrodes at different densities and performance results. The systems are used in electric vehicles as a cost-effective method to achieve reliability and efficiency. Zinc-air batteries are covered more thoroughly in a separate bibliography. (Contains 50-250 citations and includes a subject term index and title list.)

Comparative Assessment of Gasification Based Coal Power Plants with Various CO2 Capture Technologies Producing Electricity and Hydrogen

PubMed Central

2014-01-01

Seven different types of gasification-based coal conversion processes for producing mainly electricity and in some cases hydrogen (H2), with and without carbon dioxide (CO2) capture, were compared on a consistent basis through simulation studies. The flowsheet for each process was developed in a chemical process simulation tool “Aspen Plus”. The pressure swing adsorption (PSA), physical absorption (Selexol), and chemical looping combustion (CLC) technologies were separately analyzed for processes with CO2 capture. The performances of the above three capture technologies were compared with respect to energetic and exergetic efficiencies, and the level of CO2 emission. The effect of air separation unit (ASU) and gas turbine (GT) integration on the power output of all the CO2 capture cases is assessed. Sensitivity analysis was carried out for the CLC process (electricity-only case) to examine the effect of temperature and water-cooling of the air reactor on the overall efficiency of the process. The results show that, when only electricity production in considered, the case using CLC technology has an electrical efficiency 1.3% and 2.3% higher than the PSA and Selexol based cases, respectively. The CLC based process achieves an overall CO2 capture efficiency of 99.9% in contrast to 89.9% for PSA and 93.5% for Selexol based processes. The overall efficiency of the CLC case for combined electricity and H2 production is marginally higher (by 0.3%) than Selexol and lower (by 0.6%) than PSA cases. The integration between the ASU and GT units benefits all three technologies in terms of electrical efficiency. Furthermore, our results suggest that it is favorable to operate the air reactor of the CLC process at higher temperatures with excess air supply in order to achieve higher power efficiency. PMID:24578590

Comparative Assessment of Gasification Based Coal Power Plants with Various CO2 Capture Technologies Producing Electricity and Hydrogen.

PubMed

Mukherjee, Sanjay; Kumar, Prashant; Hosseini, Ali; Yang, Aidong; Fennell, Paul

2014-02-20

Seven different types of gasification-based coal conversion processes for producing mainly electricity and in some cases hydrogen (H 2 ), with and without carbon dioxide (CO 2 ) capture, were compared on a consistent basis through simulation studies. The flowsheet for each process was developed in a chemical process simulation tool "Aspen Plus". The pressure swing adsorption (PSA), physical absorption (Selexol), and chemical looping combustion (CLC) technologies were separately analyzed for processes with CO 2 capture. The performances of the above three capture technologies were compared with respect to energetic and exergetic efficiencies, and the level of CO 2 emission. The effect of air separation unit (ASU) and gas turbine (GT) integration on the power output of all the CO 2 capture cases is assessed. Sensitivity analysis was carried out for the CLC process (electricity-only case) to examine the effect of temperature and water-cooling of the air reactor on the overall efficiency of the process. The results show that, when only electricity production in considered, the case using CLC technology has an electrical efficiency 1.3% and 2.3% higher than the PSA and Selexol based cases, respectively. The CLC based process achieves an overall CO 2 capture efficiency of 99.9% in contrast to 89.9% for PSA and 93.5% for Selexol based processes. The overall efficiency of the CLC case for combined electricity and H 2 production is marginally higher (by 0.3%) than Selexol and lower (by 0.6%) than PSA cases. The integration between the ASU and GT units benefits all three technologies in terms of electrical efficiency. Furthermore, our results suggest that it is favorable to operate the air reactor of the CLC process at higher temperatures with excess air supply in order to achieve higher power efficiency.

High to ultra-high power electrical energy storage.

PubMed

Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

2011-12-14

High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

Electric-Drive Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Septon, Kendall K

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

FY2010 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from ''Freedom'' and ''Cooperative Automotive Research''), it represents DOE's commitment to developing public-private partnerships to fund high risk, high payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ranmore » from 1993 through 2001. The Oak Ridge National Laboratory's (ORNL's) Advanced Power Electronics and Electric Machines (APEEM) subprogram within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE) and electric motor technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the APEEM subprogram has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three phase approach intended to: (1) identify overall propulsion and vehicle related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and PE; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), battery electric vehicles, and fuel-cell-powered automobiles that meet the goals of the VTP. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the PE and electrical machines subsystems of the traction drive system. Areas of development include: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency, with the ability to accommodate higher temperature environments while achieving high reliability; (3) converter concepts that use methods of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control through innovative packaging technologies; and (6) integrated motor/inverter concepts. ORNL's Power Electronics and Electric Machines Research Program conducts fundamental research, evaluates hardware, and assists in the technical direction of the VTP APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2010 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, and they are indicated at the end of each section for readers interested in pursuing details of the work.« less

Light funnel concentrator panel for solar power

NASA Technical Reports Server (NTRS)

1987-01-01

The solar concentrator design concept provides a theoretical concentration efficiency of 96 percent with power-to-weight ratios as high as 50 W/kg. Further, it eliminates the need for fragile reflective coatings and is very tolerant to pointing inaccuracies. The concept differs from conventional reflective mirrors and lens design in that is uses the principle of total internal reflection in order to funnel incident sunlight into a concentrator photovoltaic cell. The feasibility of the light funnel concentrator concept was determined through a balanced approach of analysis, development, and fabrication of prototypes, and testing of components. A three-dimensional optical model of the light funnel concentrator and photovoltaic cell was developed in order to assess the ultimate performance of such systems. In addition, a thermal and structural analysis of a typical unit was made. Techniques of fabricating the light funnel cones, optically coupling them to GaAs concentrator cells, bonding the funnels to GaAs cells, making electrical interconnects, and bonding substrates was explored and a prototype light funnel concentrator unit was fabricated and tested. Testing of the system included measurements of optical concentrating efficiency, optical concentrator to cell coupling efficiency, and electrical efficiency.

River Gardens Intermediate-Care Facility water-to-air heating and air-conditioning demonstration project. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, R.C.

An integrated system of heat pumps is used to reject heat into or extract heat from circulating water from a shallow well adjacent to the river to demonstrate the efficiency and fuel cost savings of water-to-air heat pumps, without the expense of drilling a deep well. Water is returned unpolluted to the Guadalupe River and is circulated through a five-building complex at River Gardens Intermediate Care Facility for the Mentally Retarded in New Braunfels, Texas. The water is used as a heat source or sink for 122 heat pumps providing space heating and cooling, and for refrigeration and freezer units.more » The system was not installed as designed, which resulted in water pumping loads being higher than the original design. Electrical consumption for pumping water represented 36 to 37% of system electrical consumption. Without the water pumping load, the water-to-air system was an average of 25% more efficient in heating than a comparable air-to-air unit with resistance heating. With water pumping load included, the installed system averaged 17% less efficient in cooling and 19% more efficient in heating than the comparable unit.« less

Spatially-explicit life cycle assessment of sun-to-wheels transportation pathways in the U.S.

PubMed

Geyer, Roland; Stoms, David; Kallaos, James

2013-01-15

Growth in biofuel production, which is meant to reduce greenhouse gas (GHG) emissions and fossil energy demand, is increasingly seen as a threat to food supply and natural habitats. Using photovoltaics (PV) to directly convert solar radiation into electricity for battery electric vehicles (BEVs) is an alternative to photosynthesis, which suffers from a very low energy conversion efficiency. Assessments need to be spatially explicit, since solar insolation and crop yields vary widely between locations. This paper therefore compares direct land use, life cycle GHG emissions and fossil fuel requirements of five different sun-to-wheels conversion pathways for every county in the contiguous U.S.: Ethanol from corn or switchgrass for internal combustion vehicles (ICVs), electricity from corn or switchgrass for BEVs, and PV electricity for BEVs. Even the most land-use efficient biomass-based pathway (i.e., switchgrass bioelectricity in U.S. counties with hypothetical crop yields of over 24 tonnes/ha) requires 29 times more land than the PV-based alternative in the same locations. PV BEV systems also have the lowest life cycle GHG emissions throughout the U.S. and the lowest fossil fuel inputs, except for locations with hypothetical switchgrass yields of 16 or more tonnes/ha. Including indirect land use effects further strengthens the case for PV.

An Assessment Model for Energy Efficiency Program Planning in Electric Utilities: Case of the Pacific of Northwest U.S.A

NASA Astrophysics Data System (ADS)

Iskin, Ibrahim

Energy efficiency stands out with its potential to address a number of challenges that today's electric utilities face, including increasing and changing electricity demand, shrinking operating capacity, and decreasing system reliability and flexibility. Being the least cost and least risky alternative, the share of energy efficiency programs in utilities' energy portfolios has been on the rise since the 1980s, and their increasing importance is expected to continue in the future. Despite holding great promise, the ability to determine and invest in only the most promising program alternatives plays a key role in the successful use of energy efficiency as a utility-wide resource. This issue becomes even more significant considering the availability of a vast number of potential energy efficiency programs, the rapidly changing business environment, and the existence of multiple stakeholders. This dissertation introduces hierarchical decision modeling as the framework for energy efficiency program planning in electric utilities. The model focuses on the assessment of emerging energy efficiency programs and proposes to bridge the gap between technology screening and cost/benefit evaluation practices. This approach is expected to identify emerging technology alternatives which have the highest potential to pass cost/benefit ratio testing procedures and contribute to the effectiveness of decision practices in energy efficiency program planning. The model also incorporates rank order analysis and sensitivity analysis for testing the robustness of results from different stakeholder perspectives and future uncertainties in an attempt to enable more informed decision-making practices. The model was applied to the case of 13 high priority emerging energy efficiency program alternatives identified in the Pacific Northwest, U.S.A. The results of this study reveal that energy savings potential is the most important program management consideration in selecting emerging energy efficiency programs. Market dissemination potential and program development and implementation potential are the second and third most important, whereas ancillary benefits potential is the least important program management consideration. The results imply that program value considerations, comprised of energy savings potential and ancillary benefits potential; and program feasibility considerations, comprised of program development and implementation potential and market dissemination potential, have almost equal impacts on assessment of emerging energy efficiency programs. Considering the overwhelming number of value-focused studies and the few feasibility-focused studies in the literature, this finding clearly shows that feasibility-focused studies are greatly understudied. The hierarchical decision model developed in this dissertation is generalizable. Thus, other utilities or power systems can adopt the research steps employed in this study as guidelines and conduct similar assessment studies on emerging energy efficiency programs of their interest.

Diffraction of Harmonic Flexural Waves in a Cracked Elastic Plate Carrying Electrical Current

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Hasanyan, Davresh; Librescu, iviu; Qin, Zhanming

2005-01-01

The scattering effect of harmonic flexural waves at a through crack in an elastic plate carrying electrical current is investigated. In this context, the Kirchhoffean bending plate theory is extended as to include magnetoelastic interactions. An incident wave giving rise to bending moments symmetric about the longitudinal z-axis of the crack is applied. Fourier transform technique reduces the problem to dual integral equations, which are then cast to a system of two singular integral equations. Efficient numerical computation is implemented to get the bending moment intensity factor for arbitrary frequency of the incident wave and of arbitrary electrical current intensity. The asymptotic behaviour of the bending moment intensity factor is analysed and parametric studies are conducted.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Small Wind Electric Systems: A Colorado Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it'smore » possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

Bexar County Parking Garage Photovoltaic Panels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weir, Golda

2012-01-23

The main objective of the Bexar County Parking Garage Photovoltaic (PV) Panel project is to install a PV System that will promote the use of renewable energy. This project will also help sustain Bexar County ongoing greenhouse gas emissions reduction and energy efficiency goals. The scope of this project includes the installation of a 100-kW system on the top level of a new 236,285 square feet parking garage. The PV system consists of 420 solar panels that covers 7,200 square feet and is tied into the electric-grid. It provides electricity to the office area located within the garage. The estimatedmore » annual electricity production of the PV system is 147,000 kWh per year.« less

Study of advanced electric propulsion system concept using a flywheel for electric vehicles

NASA Technical Reports Server (NTRS)

Younger, F. C.; Lackner, H.

1979-01-01

Advanced electric propulsion system concepts with flywheels for electric vehicles are evaluated and it is predicted that advanced systems can provide considerable performance improvement over existing electric propulsion systems with little or no cost penalty. Using components specifically designed for an integrated electric propulsion system avoids the compromises that frequently lead to a loss of efficiency and to inefficient utilization of space and weight. A propulsion system using a flywheel power energy storage device can provide excellent acceleration under adverse conditions of battery degradation due either to very low temperatures or high degrees of discharge. Both electrical and mechanical means of transfer of energy to and from the flywheel appear attractive; however, development work is required to establish the safe limits of speed and energy storage for advanced flywheel designs and to achieve the optimum efficiency of energy transfer. Brushless traction motor designs using either electronic commutation schemes or dc-to-ac inverters appear to provide a practical approach to a mass producible motor, with excellent efficiency and light weight. No comparisons were made with advanced system concepts which do not incorporate a flywheel.

Effect of the depth base along the vertical on the electrical parameters of a vertical parallel silicon solar cell in open and short circuit

NASA Astrophysics Data System (ADS)

Sahin, Gokhan; Kerimli, Genber

2018-03-01

This article presented a modeling study of effect of the depth base initiating on vertical parallel silicon solar cell's photovoltaic conversion efficiency. After the resolution of the continuity equation of excess minority carriers, we calculated the electrical parameters such as the photocurrent density, the photovoltage, series resistance and shunt resistances, diffusion capacitance, electric power, fill factor and the photovoltaic conversion efficiency. We determined the maximum electric power, the operating point of the solar cell and photovoltaic conversion efficiency according to the depth z in the base. We showed that the photocurrent density decreases with the depth z. The photovoltage decreased when the depth base increases. Series and shunt resistances were deduced from electrical model and were influenced and the applied the depth base. The capacity decreased with the depth z of the base. We had studied the influence of the variation of the depth z on the electrical parameters in the base.

Electricity generation and nutrients removal from high-strength liquid manure by air-cathode microbial fuel cells.

PubMed

Lin, Hongjian; Wu, Xiao; Nelson, Chad; Miller, Curtis; Zhu, Jun

2016-01-01

Air-cathode microbial fuel cells (MFCs) are widely tested to recover electrical energy from waste streams containing organic matter. When high-strength wastewater, such as liquid animal manure, is used as a medium, inhibition on anode and cathode catalysts potentially impairs the effectiveness of MFC performance in power generation and pollutant removal. This study evaluated possible inhibitive effects of liquid swine manure components on MFC power generation, improved liquid manure-fed MFCs performance by pretreatment (dilution and selective adsorption), and modeled the kinetics of organic matter and nutrients removal kinetics. Parameters monitored included pH, conductivity, chemical oxygen demand (COD), volatile fatty acids (VFAs), total ammoniacal nitrogen (TAN), nitrite, nitrate, and phosphate concentrations. The removals of VFA and TAN were efficient, indicated by the short half-life times of 4.99 and 7.84 d, respectively. The mechanism for phosphate decrease was principally the salt precipitation on cathode, but the removal was incomplete after 42-d operation. MFC with an external resistor of 2.2 kΩ and fed with swine wastewater generated relatively small power (28.2 μW), energy efficiency (0.37%) and Coulombic efficiency (1.5%). Dilution of swine wastewater dramatically improved the power generation as the inhibitory effect was decreased. Zeolite and granular activated carbon were effective in the selective adsorption of ammonia or organic matter in swine wastewater, and so substantially improved the power generation, energy efficiency, and Coulombic efficiency. A smaller external resistor in the circuit was also observed to promote the organic matter degradation and thus to shorten the treatment time. Overall, air-cathode MFCs are promising for generating electrical power from livestock wastewater and meanwhile reducing the level of organic matter and nutrients.

An assessment of efficient water heating options for an all-electric single family residence in a mixed-humid climate.

PubMed

Balke, Elizabeth C; Healy, William M; Ullah, Tania

2016-12-01

An evaluation of a variety of efficient water heating strategies for an all-electric single family home located in a mixed-humid climate is conducted using numerical modeling. The strategies considered include various combinations of solar thermal, heat pump, and electric resistance water heaters. The numerical model used in the study is first validated against a year of field data obtained on a dual-tank system with a solar thermal preheat tank feeding a heat pump water heater that serves as a backup. Modeling results show that this configuration is the most efficient of the systems studied over the course of a year, with a system coefficient of performance (COP sys ) of 2.87. The heat pump water heater alone results in a COP sys of 1.9, while the baseline resistance water heater has a COP sys of 0.95. Impacts on space conditioning are also investigated by considering the extra energy consumption required of the air source heat pump to remove or add heat from the conditioned space by the water heating system. A modified COP sys that incorporates the heat pump energy consumption shows a significant drop in efficiency for the dual tank configuration since the heat pump water heater draws the most heat from the space in the heating season while the high temperatures in the solar storage tank during the cooling season result in an added heat load to the space. Despite this degradation in the COP sys , the combination of the solar thermal preheat tank and the heat pump water heater is the most efficient option even when considering the impacts on space conditioning.

An assessment of efficient water heating options for an all-electric single family residence in a mixed-humid climate

PubMed Central

Balke, Elizabeth C.; Healy, William M.; Ullah, Tania

2016-01-01

An evaluation of a variety of efficient water heating strategies for an all-electric single family home located in a mixed-humid climate is conducted using numerical modeling. The strategies considered include various combinations of solar thermal, heat pump, and electric resistance water heaters. The numerical model used in the study is first validated against a year of field data obtained on a dual-tank system with a solar thermal preheat tank feeding a heat pump water heater that serves as a backup. Modeling results show that this configuration is the most efficient of the systems studied over the course of a year, with a system coefficient of performance (COPsys) of 2.87. The heat pump water heater alone results in a COPsys of 1.9, while the baseline resistance water heater has a COPsys of 0.95. Impacts on space conditioning are also investigated by considering the extra energy consumption required of the air source heat pump to remove or add heat from the conditioned space by the water heating system. A modified COPsys that incorporates the heat pump energy consumption shows a significant drop in efficiency for the dual tank configuration since the heat pump water heater draws the most heat from the space in the heating season while the high temperatures in the solar storage tank during the cooling season result in an added heat load to the space. Despite this degradation in the COPsys, the combination of the solar thermal preheat tank and the heat pump water heater is the most efficient option even when considering the impacts on space conditioning. PMID:27990058

Toyota Prius HEV neurocontrol and diagnostics.

PubMed

Prokhorov, Danil V

2008-01-01

A neural network controller for improved fuel efficiency of the Toyota Prius hybrid electric vehicle is proposed. A new method to detect and mitigate a battery fault is also presented. The approach is based on recurrent neural networks and includes the extended Kalman filter. The proposed approach is quite general and applicable to other control systems.

Physical Analysis of an Electric Resistor Heating

ERIC Educational Resources Information Center

Perea Martins, J. E. M.

2018-01-01

This work describes a simple experiment to measure the resistor temperature as a function of the applied power and proves that it is an efficient way to introduce some important physical concepts in classroom, including the Joule's first law, hot-spot temperature, thermal resistance, thermal dissipation constant, time constant and the Newton's law…

76 FR 17577 - Increased Scope of Coverage for Electric Motors

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-30

... motors do not include a full frame, front plate, bearings, shaft, or shaft support. Because the ability.... chosen, the efficiency of these motors is therefore dependent on the application. Because of this, they... face plate, and therefore can be tested with a ``dummy test bracket'' using the current test procedure...

Low-Cost High-Pressure Hydrogen Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cropley, Cecelia C.; Norman, Timothy J.

Electrolysis of water, particularly in conjunction with renewable energy sources, is potentially a cost-effective and environmentally friendly method of producing hydrogen at dispersed forecourt sites, such as automotive fueling stations. The primary feedstock for an electrolyzer is electricity, which could be produced by renewable sources such as wind or solar that do not produce carbon dioxide or other greenhouse gas emissions. However, state-of-the-art electrolyzer systems are not economically competitive for forecourt hydrogen production due to their high capital and operating costs, particularly the cost of the electricity used by the electrolyzer stack. In this project, Giner Electrochemical Systems, LLC (GES)more » developed a low cost, high efficiency proton-exchange membrane (PEM) electrolysis system for hydrogen production at moderate pressure (300 to 400 psig). The electrolyzer stack operates at differential pressure, with hydrogen produced at moderate pressure while oxygen is evolved at near-atmospheric pressure, reducing the cost of the water feed and oxygen handling subsystems. The project included basic research on catalysts and membranes to improve the efficiency of the electrolysis reaction as well as development of advanced materials and component fabrication methods to reduce the capital cost of the electrolyzer stack and system. The project culminated in delivery of a prototype electrolyzer module to the National Renewable Energy Laboratory for testing at the National Wind Technology Center. Electrolysis cell efficiency of 72% (based on the lower heating value of hydrogen) was demonstrated using an advanced high-strength membrane developed in this project. This membrane would enable the electrolyzer system to exceed the DOE 2012 efficiency target of 69%. GES significantly reduced the capital cost of a PEM electrolyzer stack through development of low cost components and fabrication methods, including a 60% reduction in stack parts count. Economic analysis indicates that hydrogen could be produced for $3.79 per gge at an electricity cost of $0.05/kWh by the lower-cost PEM electrolyzer developed in this project, assuming high-volume production of large-scale electrolyzer systems.« less

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

NASA Astrophysics Data System (ADS)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-11-01

This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Electric Power: Contemporary Issues and the Federal Role in Oversight and Regulation.

DTIC Science & Technology

1981-12-21

Regulatory Commission NRECA National Rural Electric Cooperative Asso- ciation PURPA Public Utility Regulatory Policies Act of 1978 REA Rural...energy efficiency standards for certain products and processes, and sets standards for solar energy and conservation in Federal buildings. PURPA --the...conservation, efficient use of facilities and resources, and equitable rates to electric consumers. PURPA also (1) encourages the use of cogeneration and

10 CFR Appendix B to Subpart B of... - Uniform Test Method for Measuring Nominal Full Load Efficiency of Electric Motors

Code of Federal Regulations, 2014 CFR

2014-01-01

... vertical solid shaft normal thrust general purpose electric motor (subtype II), in which case it shall be... solid shaft shall be inserted, bolted to the non-drive end of the motor and welded on the drive end... Efficiency of Electric Motors B Appendix B to Subpart B of Part 431 Energy DEPARTMENT OF ENERGY ENERGY...

DMS Advanced Applications for Accommodating High Penetrations of DERs and Microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pratt, Annabelle; Veda, Santosh; Maitra, Arindam

Efficient and effective management of the electric distribution system requires an integrated approach to allow various systems to work in harmony, including distribution management systems (DMS), distributed energy resources (DERs), distributed energy resources management systems, and microgrids. This study highlights some outcomes from a recent project sponsored by the US Department of Energy, Office of Electricity Delivery and Energy Reliability, including information about (i) the architecture of these integrated systems and (ii) expanded functions of two example DMS applications to accommodate DERs: volt-var optimisation and fault location, isolation, and service restoration. In addition, the relevant DER group functions necessary tomore » support communications between the DMS and a microgrid controller in grid-tied mode are identified.« less

Energy-saving management modelling and optimization for lead-acid battery formation process

NASA Astrophysics Data System (ADS)

Wang, T.; Chen, Z.; Xu, J. Y.; Wang, F. Y.; Liu, H. M.

2017-11-01

In this context, a typical lead-acid battery producing process is introduced. Based on the formation process, an efficiency management method is proposed. An optimization model with the objective to minimize the formation electricity cost in a single period is established. This optimization model considers several related constraints, together with two influencing factors including the transformation efficiency of IGBT charge-and-discharge machine and the time-of-use price. An example simulation is shown using PSO algorithm to solve this mathematic model, and the proposed optimization strategy is proved to be effective and learnable for energy-saving and efficiency optimization in battery producing industries.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

Characterizing Synergistic Water and Energy Efficiency at the Residential Scale Using a Cost Abatement Curve Approach

NASA Astrophysics Data System (ADS)

Stillwell, A. S.; Chini, C. M.; Schreiber, K. L.; Barker, Z. A.

2015-12-01

Energy and water are two increasingly correlated resources. Electricity generation at thermoelectric power plants requires cooling such that large water withdrawal and consumption rates are associated with electricity consumption. Drinking water and wastewater treatment require significant electricity inputs to clean, disinfect, and pump water. Due to this energy-water nexus, energy efficiency measures might be a cost-effective approach to reducing water use and water efficiency measures might support energy savings as well. This research characterizes the cost-effectiveness of different efficiency approaches in households by quantifying the direct and indirect water and energy savings that could be realized through efficiency measures, such as low-flow fixtures, energy and water efficient appliances, distributed generation, and solar water heating. Potential energy and water savings from these efficiency measures was analyzed in a product-lifetime adjusted economic model comparing efficiency measures to conventional counterparts. Results were displayed as cost abatement curves indicating the most economical measures to implement for a target reduction in water and/or energy consumption. These cost abatement curves are useful in supporting market innovation and investment in residential-scale efficiency.

Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

PubMed

Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

2017-10-01

Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

Research on data collection key technology of smart electric energy meters

NASA Astrophysics Data System (ADS)

Chen, Xiangqun; Huang, Rui; Shen, Liman; Chen, Hao; Xiong, Dezhi; Xiao, Xiangqi; Mouhailiu; Renheng, Xu

2018-02-01

In recent years, smart electric energy meters are demand at 70 million to 90 million with the strong smart grid construction every year in China. However, there are some issues in smart electric energy meters data collection such as the interference of environment, low collection efficiency and inability to work when the power is off. In order to solve these issues above, it uses the RFID communication technology to collect the numbers and electric energy information of smart electric energy meters on the basis of the existing smart electric energy meters, and the related data collection communication experiments were made. The experimental result shows that the electric information and other data batch collection of RFID smart electric energy meters are realized in power and power off. It improves the efficiency and the overall success rate is 99.2% within 2 meters. It provides a new method for smart electric energy meters data collection.

Transportation economics and energy

NASA Astrophysics Data System (ADS)

Soltani Sobh, Ali

The overall objective of this research is to study the impacts of technology improvement including fuel efficiency increment, extending the use of natural gas vehicle and electric vehicles on key parameters of transportation. In the first chapter, a simple economic analysis is used in order to demonstrate the adoption rate of natural gas vehicles as an alternative fuel vehicle. The effect of different factors on adoption rate of commuters is calculated in sensitivity analysis. In second chapter the VMT is modeled and forecasted under influence of CNG vehicles in different scenarios. The VMT modeling is based on the time series data for Washington State. In order to investigate the effect of population growth on VMT, the per capita model is also developed. In third chapter the effect of fuel efficiency improvement on fuel tax revenue and greenhouse emission is examined. The model is developed based on time series data of Washington State. The rebound effect resulted from fuel efficiency improvement is estimated and is considered in fuel consumption forecasting. The reduction in fuel tax revenue and greenhouse gas (GHG) emissions as two outcomes of lower fuel consumption are computed. In addition, the proper fuel tax rate to restitute the revenue is suggested. In the fourth chapter effective factors on electric vehicles (EV) adoption is discussed. The constructed model is aggregated binomial logit share model that estimates the modal split between EV and conventional vehicles for different states over time. Various factors are incorporated in the utility function as explanatory variables in order to quantify their effect on EV adoption choices. The explanatory variables include income, VMT, electricity price, gasoline price, urban area and number of EV stations.

Enhancing Solar Cell Efficiencies through 1-D Nanostructures

PubMed Central

2009-01-01

The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

Ecodriving in hybrid electric vehicles--Exploring challenges for user-energy interaction.

PubMed

Franke, Thomas; Arend, Matthias Georg; McIlroy, Rich C; Stanton, Neville A

2016-07-01

Hybrid electric vehicles (HEVs) can help to reduce transport emissions; however, user behaviour has a significant effect on the energy savings actually achieved in everyday usage. The present research aimed to advance understanding of HEV drivers' ecodriving strategies, and the challenges for optimal user-energy interaction. We conducted interviews with 39 HEV drivers who achieved above-average fuel efficiencies. Regression analyses showed that technical system knowledge and ecodriving motivation were both important predictors for ecodriving efficiency. Qualitative data analyses showed that drivers used a plethora of ecodriving strategies and had diverse conceptualisations of HEV energy efficiency regarding aspects such as the efficiency of actively utilizing electric energy or the efficiency of different acceleration strategies. Drivers also reported several false beliefs regarding HEV energy efficiency that could impair ecodriving efforts. Results indicate that ecodriving support systems should facilitate anticipatory driving and help users locate and maintain drivetrain states of maximum efficiency. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Cooperative role of electrical stimulation on microbial metabolism and selection of thermophilic communities for p-fluoronitrobenzene treatment.

PubMed

Zhang, Xueqin; Shen, Dongsheng; Feng, Huajun; Wang, Yanfeng; Li, Na; Han, Jingyi; Long, Yuyang

2015-01-01

A novel thermophilic bioelectrochemical system (TBES) based on electrical stimulation was established for the enhanced treatment of p-fluoronitrobenzene (p-FNB) wastewater. p-FNB removal rate constant in the TBES was 78.6% higher than that of the mesophilic BES (MBES), the elevation of which owing to high-temperature overtook the rate improvement of 50.8% in the electrocatalytic system (ECS). Additionally, an overwhelming mineralization efficiency of 91.96% ± 5.70% was obtained in the TBES. The superiority of TBES was attributed to the integrated role of electrical stimulation and high-temperature. Electrical stimulation provided an alternative for the microbial growth independent energy requirements, compensating insufficient energy support from p-FNB metabolism under the high-temperature stress. Besides, electrical stimulation facilitated microbial community evolution to form specific thermophilic biocatalysis. The uniquely selected thermophilic microorganisms including Coprothermobacter sp. and other ones cooperated to enhance p-FNB mineralization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

NASA Astrophysics Data System (ADS)

Luengo-Kovac, M.; Huang, S.; Del Gaudio, D.; Occena, J.; Goldman, R. S.; Raimondi, R.; Sih, V.

2017-11-01

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in InxGa1 -xAs epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin-polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to reproduce the experimental finding that the crystal direction with the smaller net spin-orbit field has larger electrical spin generation efficiency and are used to predict how sample parameters affect the magnitude of the current-induced spin polarization.

Design studies of continuously variable transmissions for electric vehicles

NASA Technical Reports Server (NTRS)

Parker, R. J.; Loewenthal, S. H.; Fischer, G. K.

1981-01-01

Preliminary design studies were performed on four continuously variable transmission (CVT) concepts for use with a flywheel equipped electric vehicle of 1700 kg gross weight. Requirements of the CVT's were a maximum torque of 450 N-m (330 lb-ft), a maximum output power of 75 kW (100 hp), and a flywheel speed range of 28,000 to 14,000 rpm. Efficiency, size, weight, cost, reliability, maintainability, and controls were evaluated for each of the four concepts which included a steel V-belt type, a flat rubber belt type, a toroidal traction type, and a cone roller traction type. All CVT's exhibited relatively high calculated efficiencies (68 percent to 97 percent) over a broad range of vehicle operating conditions. Estimated weight and size of these transmissions were comparable to or less than equivalent automatic transmission. The design of each concept was carried through the design layout stage.

Sistemas Eolicos Pequenos para Generacion de Electridad (Spanish version of Small Wind Electric Systems: A U.S. Consumer's Guide) (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2005-07-01

This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system tomore » the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority (Revised) (Brochure)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-06-01

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connectmore » a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.« less

Electrical pelvic floor stimulation in the management of urinary incontinence due to neuropathic overactive bladder.

PubMed

Ishigooka, M; Hashimoto, T; Izumiya, K; Katoh, T; Yaguchi, H; Nakada, T; Handa, Y; Hoshimiya, N

1993-01-01

Electrical pelvic floor stimulation employing a portable functional electrical stimulation system with percutaneously indwelling electrodes was carried out to improve detrusor urinary incontinence. Cyclic stimulation using negative going pulse trains of 20 Hz was applied 3 to 6 times daily to the bilateral pudendal nerves distributing to the pelvic floor muscles for the purpose of strengthening these muscles, including the urethral sphincter, and simultaneously, suppressing detrusor overactivity and increasing cystometric capacity. Electrical training for 4-8 weeks resulted in an improvement of urinary incontinence in five of six patients. In two of six cases incontinence had subjectively disappeared. Urodynamic investigations demonstrated an increase in detrusor reflex threshold and less tendency for abortive detrusor contraction. No apparent complications were encountered during these periods. This procedure appears to be efficient for the management of patients with detrusor incontinence who respond poorly to conservative therapies.

Electricity generation from carbon monoxide in a single chamber microbial fuel cell.

PubMed

Mehta, P; Hussain, A; Tartakovsky, B; Neburchilov, V; Raghavan, V; Wang, H; Guiot, S R

2010-05-05

Electricity production from carbon monoxide (CO) is demonstrated in a single chamber microbial fuel cell (MFC) with a CoTMPP-based air cathode. The MFC was inoculated with anaerobic sludge and continuously sparged with CO as a sole carbon source. Volumetric power output was maximized at a CO flow rate of 4.8LLR(-1)d(-1) reaching 6.4mWLR(-1). Several soluble and gaseous degradation products including hydrogen, methane, and acetate were detected, resulting in a relatively low apparent Coulombic efficiency of 8.7%. Tests also demonstrated electricity production from hydrogen and acetate with the highest and fastest increase in voltage exhibited after acetate injection. It is hypothesized that electricity generation in a CO-fed MFC is accomplished by a consortium of carboxydotrophic and carbon monoxide - tolerant anodophilic microorganisms. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

Conceptual study of superconducting urban area power systems

NASA Astrophysics Data System (ADS)

Noe, Mathias; Bach, Robert; Prusseit, Werner; Willén, Dag; Gold-acker, Wilfried; Poelchau, Juri; Linke, Christian

2010-06-01

Efficient transmission, distribution and usage of electricity are fundamental requirements for providing citizens, societies and economies with essential energy resources. It will be a major future challenge to integrate more sustainable generation resources, to meet growing electricity demand and to renew electricity networks. Research and development on superconducting equipment and components have an important role to play in addressing these challenges. Up to now, most studies on superconducting applications in power systems have been concentrated on the application of specific devices like for example cables and current limiters. In contrast to this, the main focus of our study is to show the consequence of a large scale integration of superconducting power equipment in distribution level urban power systems. Specific objectives are to summarize the state-of-the-art of superconducting power equipment including cooling systems and to compare the superconducting power system with respect to energy and economic efficiency with conventional solutions. Several scenarios were considered starting from the replacement of an existing distribution level sub-grid up to a full superconducting urban area distribution level power system. One major result is that a full superconducting urban area distribution level power system could be cost competitive with existing solutions in the future. In addition to that, superconducting power systems offer higher energy efficiency as well as a number of technical advantages like lower voltage drops and improved stability.

Simulating pad-electrodes with high-definition arrays in transcranial electric stimulation

NASA Astrophysics Data System (ADS)

Kempe, René; Huang, Yu; Parra, Lucas C.

2014-04-01

Objective. Research studies on transcranial electric stimulation, including direct current, often use a computational model to provide guidance on the placing of sponge-electrode pads. However, the expertise and computational resources needed for finite element modeling (FEM) make modeling impractical in a clinical setting. Our objective is to make the exploration of different electrode configurations accessible to practitioners. We provide an efficient tool to estimate current distributions for arbitrary pad configurations while obviating the need for complex simulation software. Approach. To efficiently estimate current distributions for arbitrary pad configurations we propose to simulate pads with an array of high-definition (HD) electrodes and use an efficient linear superposition to then quickly evaluate different electrode configurations. Main results. Numerical results on ten different pad configurations on a normal individual show that electric field intensity simulated with the sampled array deviates from the solutions with pads by only 5% and the locations of peak magnitude fields have a 94% overlap when using a dense array of 336 electrodes. Significance. Computationally intensive FEM modeling of the HD array needs to be performed only once, perhaps on a set of standard heads that can be made available to multiple users. The present results confirm that by using these models one can now quickly and accurately explore and select pad-electrode montages to match a particular clinical need.

A new strategy on utilizing nitrogen doped TiO{sub 2} in nanostructured solar cells: Embedded multifunctional N-TiO{sub 2} scattering particles in mesoporous photoanode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shogh, Shiva; Mohammadpour, Raheleh; Iraji zad, Azam, E-mail: Iraji@sharif.edu

2015-12-15

Highlights: • N-doped TiO{sub 2} scattering particles were synthesized for embedding into commercial photoanode of dye sensitized solar cells. • Embedded scatterers improved optical and electrical features of the cells. • These multifunctional scatterers increased cell performance up to 17%. - Abstract: Aggregated sub-micron size nitrogen doped TiO{sub 2} (N-TiO{sub 2}) particles with superior optical and electrical features were successfully synthesized for embedding into commercial mesoporous TiO{sub 2} photoelectrode of dye sensitized solar cells (DSSCs) as the light scattering particles compared to undoped one. X-ray photoelectron spectroscopy and absorption spectra confirmed that the titanium dioxide is sufficiently doped by nitrogenmore » in N-TiO{sub 2} sample. Employing these high-surface N-TiO{sub 2} in mesoporous photoelectrode of solar cells, the power conversion efficiency of 8% has been achieved which shows 17% improvement for the optimum embedded level of doping (30 wt%) compared to commercial photoelectrode without additive; while enhanced efficiency is only 3% embedding undoped sub-micron size TiO{sub 2} particles. These results can introduce the novel multifunctional photoelectrode for nanostructured solar cells with enhanced values of scattering efficiency and improved electrical features including trap states density reduction in comparison to commercial mesoporous photoelectrodes.« less

Determinants of residential electricity consumption: Using smart meter data to examine the effect of climate, building characteristics, appliance stock, and occupants' behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kavousian, A; Rajagopal, R; Fischer, M

2013-06-15

We propose a method to examine structural and behavioral determinants of residential electricity consumption, by developing separate models for daily maximum (peak) and minimum (idle) consumption. We apply our method on a data set of 1628 households' electricity consumption. The results show that weather, location and floor area are among the most important determinants of residential electricity consumption. In addition to these variables, number of refrigerators and entertainment devices (e.g., VCRs) are among the most important determinants of daily minimum consumption, while number of occupants and high-consumption appliances such as electric water heaters are the most significant determinants of dailymore » maximum consumption. Installing double-pane windows and energy-efficient lights helped to reduce consumption, as did the energy-conscious use of electric heater. Acknowledging climate change as a motivation to save energy showed correlation with lower electricity consumption. Households with individuals over 55 or between 19 and 35 years old recorded lower electricity consumption, while pet owners showed higher consumption. Contrary to some previous studies, we observed no significant correlation between electricity consumption and income level, home ownership, or building age. Some otherwise energy-efficient features such as energy-efficient appliances, programmable thermostats, and insulation were correlated with slight increase in electricity consumption. (C) 2013 Elsevier Ltd. All rights reserved.« less

A 15kWe (nominal) solar thermal electric power conversion concept definition study: Steam Rankine reheat reciprocator system

NASA Technical Reports Server (NTRS)

Fuller, H.; Demler, R.; Poulin, E.; Dantowitz, P.

1979-01-01

An evaluation was made of the potential of a steam Rankine reheat reciprocator engine to operate at high efficiency in a point-focusing distributed receiver solar thermal-electric power system. The scope of the study included the engine system and electric generator; not included was the solar collector/mirror or the steam generator/receiver. A parametric analysis of steam conditions was completed leading to the selection of 973 K 12.1 MPa as the steam temperature/pressure for a conceptual design. A conceptual design was completed for a two cylinder/ opposed engine operating at 1800 rpm directly coupled to a commercially available induction generator. A unique part of the expander design is the use of carbon/graphite piston rings to eliminate the need for using oil as an upper cylinder lubricant. The evaluation included a system weight estimate of 230 kg at the mirror focal point with the condenser mounted separately on the ground. The estimated cost of the overall system is $1932 or $90/kW for the maximum 26 kW output.

High efficiency and stable white OLED using a single emitter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jian

2016-01-18

The ultimate objective of this project was to demonstrate an efficient and stable white OLED using a single emitter on a planar glass substrate. The focus of the project is on the development of efficient and stable square planar phosphorescent emitters and evaluation of such class of materials in the device settings. Key challenges included improving the emission efficiency of molecular dopants and excimers, controlling emission color of emitters and their excimers, and improving optical and electrical stability of emissive dopants. At the end of this research program, the PI has made enough progress to demonstrate the potential of excimer-basedmore » white OLED as a cost-effective solution for WOLED panel in the solid state lighting applications.« less

Electric vehicle motors and controllers

NASA Technical Reports Server (NTRS)

Secunde, R. R.

1981-01-01

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

Electric vehicle motors and controllers

NASA Astrophysics Data System (ADS)

Secunde, R. R.

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

Features of electromagnetic processes in electric gas turbine installations

NASA Astrophysics Data System (ADS)

Kislyakov, M. A.; Chernov, V. A.; Maksimkin, V. L.; Bozhin, Yu. M.

2017-12-01

Electric gas turbine aggregates are considered in terms of ensuring reliable operation of gas-dynamic bearings. A complex of unfavorable factors affecting this unit of the installation is described, including rotor unbalance, eccentricity, irregularity of armature field rotation, its amplitude variation during rotor rotation, etc. The studies have shown that it is possible to increase the efficiency of EGTA by increasing the number of armature winding phases (i.e. reducing electromagnetic torque ripples), amplifying the damping circuits on the rotor, as well as by introducing pulse-width modulation of currents in the phases and flexible feedbacks.

Magnetohydrodynamic drag reduction and its efficiency

NASA Astrophysics Data System (ADS)

Shatrov, V.; Gerbeth, G.

2007-03-01

We present results of direct numerical simulations of a turbulent channel flow influenced by electromagnetic forces. The magnetohydrodynamic Lorentz force is created by the interaction of a steady magnetic field and electric currents fed to the fluid via electrodes placed at the wall surface. Two different cases are considered. At first, a time-oscillating electric current and a steady magnetic field create a spanwise time-oscillating Lorentz force. In the second case, a stationary electric current and a steady magnetic field create a steady, mainly streamwise Lorentz force. Besides the viscous drag, the importance of the electromagnetic force acting on the wall is figured out. Regarding the energetic efficiency, it is demonstrated that in all cases a balance between applied and flow-induced electric currents improves the efficiency significantly. But even then, the case of a spanwise oscillating Lorentz force remains with a very low efficiency, whereas for the self-propelled regime in the case of a steady streamwise force, much higher efficiencies are found. Still, no set of parameters has yet been found for which an energetic breakthrough, i.e., a saved power exceeding the used power, is reached.

Electrical properties of III-Nitride LEDs: Recombination-based injection model and theoretical limits to electrical efficiency and electroluminescent cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, Aurelien, E-mail: adavid@soraa.com; Hurni, Christophe A.; Young, Nathan G.

The current-voltage characteristic and ideality factor of III-Nitride quantum well light-emitting diodes (LEDs) grown on bulk GaN substrates are investigated. At operating temperature, these electrical properties exhibit a simple behavior. A model in which only active-region recombinations have a contribution to the LED current is found to account for experimental results. The limit of LED electrical efficiency is discussed based on the model and on thermodynamic arguments, and implications for electroluminescent cooling are examined.

Configuring a fuel cell based residential combined heat and power system

NASA Astrophysics Data System (ADS)

Ahmed, Shabbir; Papadias, Dionissios D.; Ahluwalia, Rajesh K.

2013-11-01

The design and performance of a fuel cell based residential combined heat and power (CHP) system operating on natural gas has been analyzed. The natural gas is first converted to a hydrogen-rich reformate in a steam reformer based fuel processor, and the hydrogen is then electrochemically oxidized in a low temperature polymer electrolyte fuel cell to generate electric power. The heat generated in the fuel cell and the available heat in the exhaust gas is recovered to meet residential needs for hot water and space heating. Two fuel processor configurations have been studied. One of the configurations was explored to quantify the effects of design and operating parameters, which include pressure, temperature, and steam-to-carbon ratio in the fuel processor, and fuel utilization in the fuel cell. The second configuration applied the lessons from the study of the first configuration to increase the CHP efficiency. Results from the two configurations allow a quantitative comparison of the design alternatives. The analyses showed that these systems can operate at electrical efficiencies of ∼46% and combined heat and power efficiencies of ∼90%.

Highly Efficient Vector-Inversion Pulse Generators

NASA Technical Reports Server (NTRS)

Rose, Franklin

2004-01-01

Improved transmission-line pulse generators of the vector-inversion type are being developed as lightweight sources of pulsed high voltage for diverse applications, including spacecraft thrusters, portable x-ray imaging systems, impulse radar systems, and corona-discharge systems for sterilizing gases. In this development, more than the customary attention is paid to principles of operation and details of construction so as to the maximize the efficiency of the pulse-generation process while minimizing the sizes of components. An important element of this approach is segmenting a pulse generator in such a manner that the electric field in each segment is always below the threshold for electrical breakdown. One design of particular interest, a complete description of which was not available at the time of writing this article, involves two parallel-plate transmission lines that are wound on a mandrel, share a common conductor, and are switched in such a manner that the pulse generator is divided into a "fast" and a "slow" section. A major innovation in this design is the addition of ferrite to the "slow" section to reduce the size of the mandrel needed for a given efficiency.

Closed Cycle Magnetohydrodynamic Nuclear Space Power Generation Using Helium/Xenon Working Plasma

NASA Technical Reports Server (NTRS)

Litchford, R. J.; Harada, N.

2005-01-01

A multimegawatt-class nuclear fission powered closed cycle magnetohydrodynamic space power plant using a helium/xenon working gas has been studied, to include a comprehensive system analysis. Total plant efficiency was expected to be 55.2 percent including pre-ionization power. The effects of compressor stage number, regenerator efficiency, and radiation cooler temperature on plant efficiency were investigated. The specific mass of the power generation plant was also examined. System specific mass was estimated to be 3 kg/kWe for a net electrical output power of 1 MWe, 2-3 kg/kWe at 2 MWe, and approx.2 kg/KWe at >3 MWe. Three phases of research and development plan were proposed: (1) Phase I-proof of principle, (2) Phase II-demonstration of power generation, and (3) Phase III-prototypical closed loop test.

Data on electrical energy conservation using high efficiency motors for the confidence bounds using statistical techniques.

PubMed

Shaikh, Muhammad Mujtaba; Memon, Abdul Jabbar; Hussain, Manzoor

2016-09-01

In this article, we describe details of the data used in the research paper "Confidence bounds for energy conservation in electric motors: An economical solution using statistical techniques" [1]. The data presented in this paper is intended to show benefits of high efficiency electric motors over the standard efficiency motors of similar rating in the industrial sector of Pakistan. We explain how the data was collected and then processed by means of formulas to show cost effectiveness of energy efficient motors in terms of three important parameters: annual energy saving, cost saving and payback periods. This data can be further used to construct confidence bounds for the parameters using statistical techniques as described in [1].

Commonwealth of the Northern Mariana Islands Strategic Energy Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conrad, M. D.; Ness, J. E.

2013-07-01

Describes various energy strategies available to CNMI to meet the territory's goal of diversifying fuel sources and reducing fossil energy consumption. The information presented in this strategic energy plan will be used by the CNMI Governor's Energy Task Force to develop an energy action plan. Available energy strategies include policy changes, education and outreach, and expanding the use of a range of energy technologies, including renewable electricity production and buildings energy efficiency and conservation.

Hybrid Turbine Electric Vehicle

NASA Technical Reports Server (NTRS)

Viterna, Larry A.

1997-01-01

Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

Final Report to the National Energy Technology Laboratory on FY09-FY13 Cooperative Research with the Consortium for Electric Reliability Technology Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vittal, Vijay

2015-11-04

The Consortium for Electric Reliability Technology Solutions (CERTS) was formed in 1999 in response to a call from U.S. Congress to restart a federal transmission reliability R&D program to address concerns about the reliability of the U.S. electric power grid. CERTS is a partnership between industry, universities, national laboratories, and government agencies. It researches, develops, and disseminates new methods, tools, and technologies to protect and enhance the reliability of the U.S. electric power system and the efficiency of competitive electricity markets. It is funded by the U.S. Department of Energy’s Office of Electricity Delivery and Energy Reliability (OE). This reportmore » provides an overview of PSERC and CERTS, of the overall objectives and scope of the research, a summary of the major research accomplishments, highlights of the work done under the various elements of the NETL cooperative agreement, and brief reports written by the PSERC researchers on their accomplishments, including research results, publications, and software tools.« less

Research on the impacts of large-scale electric vehicles integration into power grid

NASA Astrophysics Data System (ADS)

Su, Chuankun; Zhang, Jian

2018-06-01

Because of its special energy driving mode, electric vehicles can improve the efficiency of energy utilization and reduce the pollution to the environment, which is being paid more and more attention. But the charging behavior of electric vehicles is random and intermittent. If the electric vehicle is disordered charging in a large scale, it causes great pressure on the structure and operation of the power grid and affects the safety and economic operation of the power grid. With the development of V2G technology in electric vehicle, the study of the charging and discharging characteristics of electric vehicles is of great significance for improving the safe operation of the power grid and the efficiency of energy utilization.

[Electricity generation and contaminants degradation performances of a microbial fuel cell fed with Dioscorea zingiberensis wastewater].

PubMed

Li, Hui; Zhu, Xiu-Ping; Xu, Nan; Ni, Jin-Ren

2011-01-01

The electricity generation performance of a microbial fuel cell (MFC) utilizing Dioscorea zingiberensis wastewater was studied with an H-shape reactor. Indexes including pH, conductivity, oxidation peak potential and chemical oxygen demand (COD) of the anolyte were monitored to investigate the contaminants degradation performance of the MFC during the electricity generation process, besides, contaminant ingredients in anodic influent and effluent were analyzed by GC-MS and IR spectra as well. The maximum power density of the MFC could achieve 118.1 mW/m2 and the internal resistance was about 480 omega. Connected with a 1 000 omega external resistance, the output potential was about 0.4 V. Fed with 5 mL Dioscorea zingiberensis wastewater, the electricity generation lasted about 133 h and the coulombic efficiency was about 3.93%. At the end of electricity generation cycle, COD decreased by 90.1% while NH4(+) -N decreased by 66.8%. Furfural compounds, phenols and some other complicated organics could be decomposed and utilized in the electricity generation process, and the residual contaminants in effluent included some long-chain fatty acids, esters, ethers, and esters with benzene ring, cycloalkanes, cycloolefins, etc. The results indicate that MFC, which can degrade and utilize the organic contaminants in Dioscorea zingiberensis wastewater simultaneously, provides a new approach for resource recovery treatment of Dioscorea zingiberensis wastewater.

Electrical conductivity, dielectric response and space charge dynamics of an electroactive polymer with and without nanofiller reinforcement

NASA Astrophysics Data System (ADS)

Kochetov, R.; Tsekmes, I. A.; Morshuis, P. H. F.

2015-07-01

Electroactive polymers have gained considerable attention over the last 20 years for exhibiting a large displacement in response to electrical stimulation. The promising fields of application include wave energy converters, muscle-like actuators, sensors, robotics, and biomimetics. For an electrical engineer, electroactive polymers can be seen as a dielectric elastomer film or a compliant capacitor with a highly deformable elastomeric medium. If the elastomer is pre-stretched and pre-charged, a reduction of the tensile force lets the elastomer revert to its original form and increases the electrical potential. The light weight of electroactive polymers, low cost, high intrinsic breakdown strength, cyclical way of operation, reliable performance, and high efficiency can be exploited to utilize the elastomeric material as a transducer. The energy storage for a linear dielectric polymer is determined by its relative permittivity and the applied electric field. The latter is limited by the dielectric breakdown strength of the material. Therefore, to generate a high energy density of a flexible capacitor, the film must be used at the voltage level close to the material’s breakdown or inorganic particles with high dielectric permittivity which can be introduced into the polymer matrix. In the present study, silicone-titania elastomer nanocomposites were produced and the influence of nanoparticles on the macroscopic dielectric properties of the neat elastomer including space charge dynamics, complex permittivity, and electrical conductivity, were investigated.

Study of EHD flow generator's efficiencies utilizing pin to single ring and multi-concentric rings electrodes

NASA Astrophysics Data System (ADS)

Sumariyah; Kusminart; Hermanto, A.; Nuswantoro, P.

2016-11-01

EHD flow or ionic wind yield corona discharge is a stream coming from the ionized gas. EHD is generated by a strong electric field and its direction follows the electric field lines. In this study, the efficiency of the EHD flow generators utilizing pin-multi concentric rings electrodes (P-MRE) and the EHD pin-single ring electrode (P-SRE) have been measured. The comparison of efficiencies two types of the generator has been done. EHD flow was generated by using a high-voltage DC 0-10 KV on the electrode pin with a positive polarity and electrode ring/ multi-concentric rings of negative polarity. The efficiency was calculated by comparison between the mechanical power of flow to the electrical power that consumed. We obtained that the maximum efficiency of EHD flow generator utilizing pin-multi concentric rings electrodes was 0.54% and the maximum efficiency of EHD flow generator utilizing a pin-single ring electrode was 0.23%. Efficiency of EHD with P-MRE 2.34 times Efficiency of EHD with P-SRE

Conversion of visible light to electrical energy - Stable cadmium selenide photoelectrodes in aqueous electrolytes

NASA Technical Reports Server (NTRS)

Wrighton, M. S.; Ellis, A. B.; Kaiser, S. W.

1977-01-01

Stabilization of n-type CdSe to photoanodic dissolution is reported. The stabilization is accomplished by the competitive oxidation of S(--) or S(n)(--) at the CdSe photoanode in an electrochemical cell. Such stabilized cells are shown to sustain the conversion of low energy (not less than 1.7 eV) visible light to electricity with good efficiency and no deterioration of the CdSe photoelectrode or of the electrolyte. The electrolyte undergoes no net chemical change because the oxidation occurring at the photoelectrode is reversed at the cathode. Conversion of monochromatic light at 633 nm to electricity is shown to be up to approximately 9% efficient with output potentials of approximately 0.4 V. Conversion of solar energy to electricity is estimated to be approximately 2% efficient.

How to increase the efficiency of the electrical discharge method for destruction of nonconductive solid materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voitenko, N. V., E-mail: tevn@hvd.tpu.ru; Yudin, A. S.; Kuznetsova, N. S.

The paper deals with the relevance of using electrical discharge technology for construction works in the city. The technical capabilities of the installation for the multi-borehole electro-discharge splitting off and destruction of rocks and concrete are described. The ways to increase the efficiency of the electrical discharge method for the destruction of solids are proposed. In order to augment the discharge circuit energy, the energy storage is separated into two individual capacitor batteries. The throttle with the inductance of 28.6 μH is installed in one of the batteries, which increases the duration of the channel energy release to 400 μsmore » and the efficiency of electrical discharge splitting off of concrete.« less

Transparent conductor-embedding nanocones for selective emitters: optical and electrical improvements of Si solar cells

PubMed Central

Kim, Joondong; Yun, Ju-Hyung; Kim, Hyunyub; Cho, Yunae; Park, Hyeong-Ho; Kumar, M. Melvin David; Yi, Junsin; Anderson, Wayne A.; Kim, Dong-Wook

2015-01-01

Periodical nanocone-arrays were employed in an emitter region for high efficient Si solar cells. Conventional wet-etching process was performed to form the nanocone-arrays for a large area, which spontaneously provides the graded doping features for a selective emitter. This enables to lower the electrical contact resistance and enhances the carrier collection due to the high electric field distribution through a nanocone. Optically, the convex-shaped nanocones efficiently reduce light-reflection and the incident light is effectively focused into Si via nanocone structure, resulting in an extremely improved the carrier collection performances. This nanocone-arrayed selective emitter simultaneously satisfies optical and electrical improvement. We report the record high efficiency of 16.3% for the periodically nanoscale patterned emitter Si solar cell. PMID:25787933

Transparent conductor-embedding nanocones for selective emitters: optical and electrical improvements of Si solar cells.

PubMed

Kim, Joondong; Yun, Ju-Hyung; Kim, Hyunyub; Cho, Yunae; Park, Hyeong-Ho; Kumar, M Melvin David; Yi, Junsin; Anderson, Wayne A; Kim, Dong-Wook

2015-03-19

Periodical nanocone-arrays were employed in an emitter region for high efficient Si solar cells. Conventional wet-etching process was performed to form the nanocone-arrays for a large area, which spontaneously provides the graded doping features for a selective emitter. This enables to lower the electrical contact resistance and enhances the carrier collection due to the high electric field distribution through a nanocone. Optically, the convex-shaped nanocones efficiently reduce light-reflection and the incident light is effectively focused into Si via nanocone structure, resulting in an extremely improved the carrier collection performances. This nanocone-arrayed selective emitter simultaneously satisfies optical and electrical improvement. We report the record high efficiency of 16.3% for the periodically nanoscale patterned emitter Si solar cell.

Independent Analysis of Real-Time, Measured Performance Data From Microcogenerative Fuel Cell Systems Installed in Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dillon, Heather E.; Colella, Whitney G.

2015-06-01

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to 15 distinct 5 kW-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a 1 s sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initialmore » data indicate that the FCSs have relatively stable performance and a long-term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer's stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer's stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4 degrees C, lower than the manufacturer's stated maximum hot water delivery temperature of 65 degrees C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at rated value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at rated value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at rated value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS Unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%. The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a maximum decline in electric power output of approximately 18% was observed over a 500 h period in Jan. 2012.« less

Development of a nonazeotropic heat pump for crew hygiene water heating

NASA Technical Reports Server (NTRS)

Walker, David H.; Deming, Glenn I.

1991-01-01

A heat pump system is currently under development to produce hot water for crew hygiene on future manned space missions. The heat pump uses waste heat sources and a nonazeotropic working fluid in a highly efficient cycle. The potential benefits include a reduction in peak power draw from 2 to 5 kW for electric cartridge heaters to just more than 100 W for the heat pump. As part of the heat pump development project, a unique high efficiency compressor was developed to maintain lubrication in a zero-gravity environment.

The energy efficient engine project

NASA Technical Reports Server (NTRS)

Macioce, L. E.; Schaefer, J. W.; Saunders, N. T.

1980-01-01

The Energy Efficient Engine Project is directed at providing, by 1984, the advanced technologies which could be used for a generation of fuel conservative turbofan engines. The project is conducted through contracts with the General Electric Company and Pratt and Whitney Aircraft. The scope of the entire project and the current status of these efforts are summarized. A description of the preliminary designs of the fully developed engines is included and the potential benefits of these advanced engines, as well as highlights of some of the component technology efforts conducted to date, are discussed.

Small modular reactor modeling using modelica for nuclear-renewable hybrid energy systems applications

DOE PAGES

Mikkelson, Daniel; Chang, Chih -Wei; Cetiner, Sacit M.; ...

2015-10-01

Here, the U.S. Department of Energy (DOE) supports research and development (R&D) that could lead to more efficient utilization of clean energy generation sources, including renewable and nuclear options, to meet grid demand and industrial thermal energy needs [1]. One hybridization approach being investigated by the DOE Offices of Nuclear Energy (NE) and the DOE Energy Efficiency and Renewable Energy (EERE) is tighter coupling of nuclear and renewable energy sources to better manage overall energy use for the combined electricity, industrial manufacturing, and transportation sectors.

[Complex stimulation of the locomotor and psycholingual develop- ment of children with perinatal lesions of the central nervous system].

PubMed

Skvortsov, I A; Khavkhun, L A; Ustinova, E V; I'lin, L B

1989-01-01

In 121 children with perinatal CNS damage a combined therapy was performed including, besides routine drug treatment, imitation stimulation of age-matched posture-++-tonic attitudes and motor skills, metameric reflexotherapy aimed at the CNS region lesioned, magnetotherapy, electric laser puncture targeted at correction of dysfunctioning brain structures. Treatment efficiency was controlled by the brain "development profile" derived from formalized neurological and neuropsychological investigations, and electroneuromyography. The efficiency of the therapy was considerably decreased by the 3rd semester of life.

Optimal integration of daylighting and electric lighting systems using non-imaging optics

NASA Astrophysics Data System (ADS)

Scartezzini, J.-L.; Linhart, F.; Kaegi-Kolisnychenko, E.

2007-09-01

Electric lighting is responsible for a significant fraction of electricity consumption within non-residential buildings. Making daylight more available in office and commercial buildings can lead as a consequence to important electricity savings, as well as to the improvement of occupants' visual performance and wellbeing. Over the last decades, daylighting technologies have been developed for that purpose, some of them having proven to be highly efficient such as anidolic daylighting systems. Based on non-imaging optics these optical devices were designed to achieve an efficient collection and redistribution of daylight within deep office rooms. However in order to benefit from the substantial daylight provision obtained through these systems and convert it into effective electricity savings, novel electric lighting strategies are required. An optimal integration of high efficacy light sources and efficient luminaries based on non-imaging optics with anidolic daylighting systems can lead to such novel strategies. Starting from the experience gained through the development of an Anidolic Integrated Ceiling (AIC), this paper presents an optimal integrated daylighting and electric lighting system. Computer simulations based on ray-tracing techniques were used to achieve the integration of 36W fluorescent tubes and non-imaging reflectors with an advanced daylighting system. Lighting power densities lower than 4 W/m2 can be achieved in this way within the corresponding office room. On-site monitoring of an integrated daylighting and electric lighting system carried out on a solar experimental building confirmed the energy and visual performance of such a system: it showed that low lighting power densities can be achieved by combining an anidolic daylighting system with very efficient electric light sources and luminaries.

Control and Optimization of Electric Ship Propulsion Systems with Hybrid Energy Storage

NASA Astrophysics Data System (ADS)

Hou, Jun

Electric ships experience large propulsion-load fluctuations on their drive shaft due to encountered waves and the rotational motion of the propeller, affecting the reliability of the shipboard power network and causing wear and tear. This dissertation explores new solutions to address these fluctuations by integrating a hybrid energy storage system (HESS) and developing energy management strategies (EMS). Advanced electric propulsion drive concepts are developed to improve energy efficiency, performance and system reliability by integrating HESS, developing advanced control solutions and system integration strategies, and creating tools (including models and testbed) for design and optimization of hybrid electric drive systems. A ship dynamics model which captures the underlying physical behavior of the electric ship propulsion system is developed to support control development and system optimization. To evaluate the effectiveness of the proposed control approaches, a state-of-the-art testbed has been constructed which includes a system controller, Li-Ion battery and ultra-capacitor (UC) modules, a high-speed flywheel, electric motors with their power electronic drives, DC/DC converters, and rectifiers. The feasibility and effectiveness of HESS are investigated and analyzed. Two different HESS configurations, namely battery/UC (B/UC) and battery/flywheel (B/FW), are studied and analyzed to provide insights into the advantages and limitations of each configuration. Battery usage, loss analysis, and sensitivity to battery aging are also analyzed for each configuration. In order to enable real-time application and achieve desired performance, a model predictive control (MPC) approach is developed, where a state of charge (SOC) reference of flywheel for B/FW or UC for B/UC is used to address the limitations imposed by short predictive horizons, because the benefits of flywheel and UC working around high-efficiency range are ignored by short predictive horizons. Given the multi-frequency characteristics of load fluctuations, a filter-based control strategy is developed to illustrate the importance of the coordination within the HESS. Without proper control strategies, the HESS solution could be worse than a single energy storage system solution. The proposed HESS, when introduced into an existing shipboard electrical propulsion system, will interact with the power generation systems. A model-based analysis is performed to evaluate the interactions of the multiple power sources when a hybrid energy storage system is introduced. The study has revealed undesirable interactions when the controls are not coordinated properly, and leads to the conclusion that a proper EMS is needed. Knowledge of the propulsion-load torque is essential for the proposed system-level EMS, but this load torque is immeasurable in most marine applications. To address this issue, a model-based approach is developed so that load torque estimation and prediction can be incorporated into the MPC. In order to evaluate the effectiveness of the proposed approach, an input observer with linear prediction is developed as an alternative approach to obtain the load estimation and prediction. Comparative studies are performed to illustrate the importance of load torque estimation and prediction, and demonstrate the effectiveness of the proposed approach in terms of improved efficiency, enhanced reliability, and reduced wear and tear. Finally, the real-time MPC algorithm has been implemented on a physical testbed. Three different efforts have been made to enable real-time implementation: a specially tailored problem formulation, an efficient optimization algorithm and a multi-core hardware implementation. Compared to the filter-based strategy, the proposed real-time MPC achieves superior performance, in terms of the enhanced system reliability, improved HESS efficiency, and extended battery life.

Status of a Power Processor for the Prometheus-1 Electric Propulsion System

NASA Technical Reports Server (NTRS)

Pinero, Luis R.; Hill, Gerald M.; Aulisio, Michael; Gerber, Scott; Griebeler, Elmer; Hewitt, Frank; Scina, Joseph

2006-01-01

NASA is developing technologies for nuclear electric propulsion for proposed deep space missions in support of the Exploration initiative under Project Prometheus. Electrical power produced by the combination of a fission-based power source and a Brayton power conversion and distribution system is used by a high specific impulse ion propulsion system to propel the spaceship. The ion propulsion system include the thruster, power processor and propellant feed system. A power processor technology development effort was initiated under Project Prometheus to develop high performance and lightweight power-processing technologies suitable for the application. This effort faces multiple challenges including developing radiation hardened power modules and converters with very high power capability and efficiency to minimize the impact on the power conversion and distribution system as well as the heat rejection system. This paper documents the design and test results of the first version of the beam supply, the design of a second version of the beam supply and the design and test results of the ancillary supplies.

2008 Fuel Cell Technologies Market Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

DOE

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States aremore » investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general business strategy and market focus, as well as, financial information for select publicly-traded companies.« less

FY2009 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Oak Ridge National Laboratory's (ORNL's) Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), all electric vehicles, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency, with the ability to accommodate higher-temperature environments while achieving high reliability; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control and packaging technologies; and (6) integrated motor/inverter concepts. ORNL's Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2009 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less

A reduced-form approach for representing the impacts of wind and solar PV deployment on the structure and operation of the electricity system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Nils; Strubegger, Manfred; McPherson, Madeleine

In many climate change mitigation scenarios, integrated assessment models of the energy and climate systems rely heavily on renewable energy technologies with variable and uncertain generation, such as wind and solar PV, to achieve substantial decarbonization of the electricity sector. However, these models often include very little temporal resolution and thus have difficulty in representing the integration costs that arise from mismatches between electricity supply and demand. The global integrated assessment model, MESSAGE, has been updated to explicitly model the trade-offs between variable renewable energy (VRE) deployment and its impacts on the electricity system, including the implications for electricity curtailment,more » backup capacity, and system flexibility. These impacts have been parameterized using a reduced-form approach, which allows VRE integration impacts to be quantified on a regional basis. In addition, thermoelectric technologies were updated to include two modes of operation, baseload and flexible, to better account for the cost, efficiency, and availability penalties associated with flexible operation. In this paper, the modeling approach used in MESSAGE is explained and the implications for VRE deployment in mitigation scenarios are assessed. Three important stylized facts associated with integrating high VRE shares are successfully reproduced by our modeling approach: (1) the significant reduction in the utilization of non-VRE power plants; (2) the diminishing role for traditional baseload generators, such as nuclear and coal, and the transition to more flexible technologies; and (3) the importance of electricity storage and hydrogen electrolysis in facilitating the deployment of VRE.« less

Calculated Coupling Efficiency Between an Elliptical-Core Optical Fiber and a Silicon Oxynitride Rib Waveguide [Corrected Copy

NASA Technical Reports Server (NTRS)

Tuma, Margaret L.; Beheim, Glenn

1995-01-01

The effective-index method and Marcatili's technique were utilized independently to calculate the electric field profile of a rib channel waveguide. Using the electric field profile calculated from each method, the theoretical coupling efficiency between a single-mode optical fiber and a rib waveguide was calculated using the overlap integral. Perfect alignment was assumed and the coupling efficiency calculated. The coupling efficiency calculation was then repeated for a range of transverse offsets.

Sourcing of Steam and Electricity for Carbon Capture Retrofits.

PubMed

Supekar, Sarang D; Skerlos, Steven J

2017-11-07

This paper compares different steam and electricity sources for carbon capture and sequestration (CCS) retrofits of pulverized coal (PC) and natural gas combined cycle (NGCC) power plants. Analytical expressions for the thermal efficiency of these power plants are derived under 16 different CCS retrofit scenarios for the purpose of illustrating their environmental and economic characteristics. The scenarios emerge from combinations of steam and electricity sources, fuel used in each source, steam generation equipment and process details, and the extent of CO 2 capture. Comparing these scenarios reveals distinct trade-offs between thermal efficiency, net power output, levelized cost, profit, and net CO 2 reduction. Despite causing the highest loss in useful power output, bleeding steam and extracting electric power from the main power plant to meet the CCS plant's electricity and steam demand maximizes plant efficiency and profit while minimizing emissions and levelized cost when wholesale electricity prices are below 4.5 and 5.2 US¢/kWh for PC-CCS and NGCC-CCS plants, respectively. At prices higher than these higher profits for operating CCS retrofits can be obtained by meeting 100% of the CCS plant's electric power demand using an auxiliary natural gas turbine-based combined heat and power plant.

The Increase of Power Efficiency of Underground Coal Mining by the Forecasting of Electric Power Consumption

NASA Astrophysics Data System (ADS)

Efremenko, Vladimir; Belyaevsky, Roman; Skrebneva, Evgeniya

2017-11-01

In article the analysis of electric power consumption and problems of power saving on coal mines are considered. Nowadays the share of conditionally constant costs of electric power for providing safe working conditions underground on coal mines is big. Therefore, the power efficiency of underground coal mining depends on electric power expense of the main technological processes and size of conditionally constant costs. The important direction of increase of power efficiency of coal mining is forecasting of a power consumption and monitoring of electric power expense. One of the main approaches to reducing of electric power costs is increase in accuracy of the enterprise demand in the wholesale electric power market. It is offered to use artificial neural networks to forecasting of day-ahead power consumption with hourly breakdown. At the same time use of neural and indistinct (hybrid) systems on the principles of fuzzy logic, neural networks and genetic algorithms is more preferable. This model allows to do exact short-term forecasts at a small array of input data. A set of the input parameters characterizing mining-and-geological and technological features of the enterprise is offered.

10 CFR 431.14 - Sources for information and guidance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND INDUSTRIAL EQUIPMENT Electric Motors Test Procedures, Materials Incorporated and Methods of..., National Institute of Standards and Technology, 100 Bureau Drive, M/S 2140, Gaithersburg, MD 20899-2140... 150-10, Efficiency of Electric Motors, February 2007. (3) NIST Handbook 150-10 Checklist, Efficiency...

10 CFR 431.14 - Sources for information and guidance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND INDUSTRIAL EQUIPMENT Electric Motors Test Procedures, Materials Incorporated and Methods of..., National Institute of Standards and Technology, 100 Bureau Drive, M/S 2140, Gaithersburg, MD 20899-2140... 150-10, Efficiency of Electric Motors, February 2007. (3) NIST Handbook 150-10 Checklist, Efficiency...

Enhancement in ion adsorption rate and desalination efficiency in a capacitive deionization cell through improved electric field distribution using electrodes composed of activated carbon cloth coated with zinc oxide nanorods.

PubMed

Laxman, Karthik; Myint, Myo Tay Zar; Bourdoucen, Hadj; Dutta, Joydeep

2014-07-09

Electrodes composed of activated carbon cloth (ACC) coated with zinc oxide (ZnO) nanorods are compared with plain ACC electrodes, with respect to their desalination efficiency of a 17 mM NaCl solution at different applied potentials. Polarization of the ZnO nanorods increased the penetration depth and strength of the electric field between the electrodes, leading to an increase in the capacitance and charge efficiency at reduced input charge ratios. Uniform distribution of the electric field lines between two electrodes coated with ZnO nanorods led to faster ion adsorption rates, reduced the electrode saturation time, and increased the average desalination efficiency by ∼45% for all applied potentials. The electrodes were characterized for active surface area, capacitance from cyclic voltammetry, theoretical assessment of surface area utilization, and the magnitude of electric field force acting on an ion of unit charge for each potential.

Fuel-Cell-Powered Electric Motor Drive Analyzed for a Large Airplane

NASA Technical Reports Server (NTRS)

Brown, Gerald V.; Choi, Benjamin B.

2005-01-01

Because of its high efficiency, fuel cell technology may be used to launch a new generation of more-electric aeropropulsion and power systems for future aircraft. Electric-motor-driven airplanes using fuel-cell powerplants would be beneficial to the environment because of fuel savings, low noise, and zero carbon-dioxide emissions. In spite of the fuel cell s efficiency benefit, to produce the same shaft drive power, a fuel cell- powered electric-drive system must be definitely heavier than a turbine-drive system. However, the fuel-cell system s overall efficiency from fuel-to-shaft power is higher than for a turbine-drive system. This means that the fuel consumption rate could be lower than for a conventional system. For heavier, fuel-laden planes for longer flights, we might achieve substantial fuel savings. In the airplane industry, in fact, an efficiency gain of even a few percentage points can make a major economic difference in operating costs.

Mobile lighting apparatus

DOEpatents

Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

2013-05-14

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Broadening the Efficiency Bandwidth Product of Electrically small Antenna through Direct Antenna Modulation (DAM) Transmitting

DTIC Science & Technology

2017-12-04

public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...Project Contribution: International Collaboration: International Travel : National Academy Member: N Person Months Worked: 6.00 Funding...Support: Project Contribution: International Collaboration: International Travel : National Academy Member: N Participant Type

Physical analysis of an electric resistor heating

NASA Astrophysics Data System (ADS)

Perea Martins, J. E. M.

2018-05-01

This work describes a simple experiment to measure the resistor temperature as a function of the applied power and proves that it is an efficient way to introduce some important physical concepts in classroom, including the Joule’s first law, hot-spot temperature, thermal resistance, thermal dissipation constant, time constant and the Newton’s law of cooling.

Electromechanical conversion efficiency for dielectric elastomer generator in different energy harvesting cycles

NASA Astrophysics Data System (ADS)

Cao, Jian-Bo; E, Shi-Ju; Guo, Zhuang; Gao, Zhao; Luo, Han-Pin

2017-11-01

In order to improve electromechanical conversion efficiency for dielectric elastomer generators (DEG), on the base of studying DEG energy harvesting cycles of constant voltage, constant charge and constant electric field intensity, a new combined cycle mode and optimization theory in terms of the generating mechanism and electromechanical coupling process have been built. By controlling the switching point to achieve the best energy conversion cycle, the energy loss in the energy conversion process is reduced. DEG generating test bench which was used to carry out comparative experiments has been established. Experimental results show that the collected energy in constant voltage cycle, constant charge cycle and constant electric field intensity energy harvesting cycle decreases in turn. Due to the factors such as internal resistance losses, electrical losses and so on, actual energy values are less than the theoretical values. The electric energy conversion efficiency by combining constant electric field intensity cycle with constant charge cycle is larger than that of constant electric field intensity cycle. The relevant conclusions provide a basis for the further applications of DEG.

Rapid Conversion from Carbohydrates to Large-Scale Carbon Quantum Dots for All-Weather Solar Cells.

PubMed

Tang, Qunwei; Zhu, Wanlu; He, Benlin; Yang, Peizhi

2017-02-28

A great challenge for state-of-the-art solar cells is to generate electricity in all weather. We present here the rapid conversion of carbon quantum dots (CQDs) from carbohydrates (including glucose, maltol, sucrose) for an all-weather solar cell, which comprises a CQD-sensitized mesoscopic titanium dioxide/long-persistence phosphor (m-TiO 2 /LPP) photoanode, a I - /I 3 - redox electrolyte, and a platinum counter electrode. In virtue of the light storing and luminescent behaviors of LPP phosphors, the generated all-weather solar cells can not only convert sunlight into electricity on sunny days but persistently realize electricity output in all dark-light conditions. The maximized photoelectric conversion efficiency is as high as 15.1% for so-called all-weather CQD solar cells in dark conditions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system tomore » the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This Spanish version of the popular Small Wind Electric Systems: A New Mexico Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a systemmore » to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

Accounting for the Variation of Driver Aggression in the Simulation of Conventional and Advanced Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neubauer, J.; Wood, E.

2013-01-01

Hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles offer the potential to reduce both oil imports and greenhouse gases, as well as to offer a financial benefit to the driver. However, assessing these potential benefits is complicated by several factors, including the driving habits of the operator. We focus on driver aggression, i.e., the level of acceleration and velocity characteristic of travel, to (1) assess its variation within large, real-world drive datasets, (2) quantify its effect on both vehicle efficiency and economics for multiple vehicle types, (3) compare these results to those of standard drive cycles commonlymore » used in the industry, and (4) create a representative drive cycle for future analyses where standard drive cycles are lacking.« less

A solar module fabrication process for HALE solar electric UAV's

NASA Astrophysics Data System (ADS)

Carey, P. G.; Aceves, R. C.; Colella, N. J.; Williams, K. A.; Sinton, R. A.; Glenn, G. S.

1994-12-01

We describe a fabrication process used to manufacture high power-to-weight-ratio flexible solar array modules for use on high-altitude-long-endurance (HALE) solar-electric unmanned air vehicles (UAV's). These modules have achieved power-to-weight ratios of 315 and 396 W/kg for 150 micron-thick monofacial and 110 micron-thick bifacial silicon solar cells, respectively. These calculations reflect average module efficiencies of 15.3% (150 micron) and 14.7% (110 micron) obtained from electrical tests performed by Spectrolab, Inc. under AMO global conditions at 25 C, and include weight contributions from all module components (solar cells, lamination material, bypass diodes, interconnect wires, and adhesive tape used to attach the modules to the wing). The fabrication, testing, and performance of 32 sq m of these modules is described.

A review of test results on parabolic dish solar thermal power modules with dish-mounted Rankine engines and for production of process steam

NASA Technical Reports Server (NTRS)

Jaffe, Leonard D.

1988-01-01

This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

Field distribution and DNA transport in solid tumors during electric field-mediated gene delivery.

PubMed

Henshaw, Joshua W; Yuan, Fan

2008-02-01

Gene therapy has a great potential in cancer treatment. However, the efficacy of cancer gene therapy is currently limited by the lack of a safe and efficient means to deliver therapeutic genes into the nucleus of tumor cells. One method under investigation for improving local gene delivery is based on the use of pulsed electric field. Despite repeated demonstration of its effectiveness in vivo, the underlying mechanisms behind electric field-mediated gene delivery remain largely unknown. Without a thorough understanding of these mechanisms, it will be difficult to further advance the gene delivery. In this review, the electric field-mediated gene delivery in solid tumors will be examined by following individual transport processes that must occur in vivo for a successful gene transfer. The topics of examination include: (i) major barriers for gene delivery in the body, (ii) distribution of electric fields at both cell and tissue levels during the application of external fields, and (iii) electric field-induced transport of genes across each of the barriers. Through this approach, the review summarizes what is known about the mechanisms behind electric field-mediated gene delivery and what require further investigations in future studies.

Energy efficiency design strategies for buildings with grid-connected photovoltaic systems

NASA Astrophysics Data System (ADS)

Yimprayoon, Chanikarn

The building sector in the United States represents more than 40% of the nation's energy consumption. Energy efficiency design strategies and renewable energy are keys to reduce building energy demand. Grid-connected photovoltaic (PV) systems installed on buildings have been the fastest growing market in the PV industry. This growth poses challenges for buildings qualified to serve in this market sector. Electricity produced from solar energy is intermittent. Matching building electricity demand with PV output can increase PV system efficiency. Through experimental methods and case studies, computer simulations were used to investigate the priorities of energy efficiency design strategies that decreased electricity demand while producing load profiles matching with unique output profiles from PV. Three building types (residential, commercial, and industrial) of varying sizes and use patterns located in 16 climate zones were modeled according to ASHRAE 90.1 requirements. Buildings were analyzed individually and as a group. Complying with ASHRAE energy standards can reduce annual electricity consumption at least 13%. With energy efficiency design strategies, the reduction could reach up to 65%, making it possible for PV systems to meet reduced demands in residential and industrial buildings. The peak electricity demand reduction could be up to 71% with integration of strategies and PV. Reducing lighting power density was the best single strategy with high overall performances. Combined strategies such as zero energy building are also recommended. Electricity consumption reductions are the sum of the reductions from strategies and PV output. However, peak electricity reductions were less than their sum because they reduced peak at different times. The potential of grid stress reduction is significant. Investment incentives from government and utilities are necessary. The PV system sizes on net metering interconnection should not be limited by legislation existing in some states. Data from this study provides insight of impacts from applying energy efficiency design strategies in buildings with grid-connected PV systems. With the current transition from traditional electric grids to future smart grids, this information plus large database of various building conditions allow possible investigations needed by governments or utilities in large scale communities for implementing various measures and policies.

Synergistic effect of electrical and chemical factors on endocytosis in micro-discharge plasma gene transfection

NASA Astrophysics Data System (ADS)

Jinno, M.; Ikeda, Y.; Motomura, H.; Isozaki, Y.; Kido, Y.; Satoh, S.

2017-06-01

We have developed a new micro-discharge plasma (MDP)-based gene transfection method, which transfers genes into cells with high efficiency and low cytotoxicity; however, the mechanism underlying the method is still unknown. Studies revealed that the N-acetylcysteine-mediated inhibition of reactive oxygen species (ROS) activity completely abolished gene transfer. In this study, we used laser-produced plasma to demonstrate that gene transfer does not occur in the absence of electrical factors. Our results show that both electrical and chemical factors are necessary for gene transfer inside cells by microplasma irradiation. This indicates that plasma-mediated gene transfection utilizes the synergy between electrical and chemical factors. The electric field threshold required for transfection was approximately 1 kV m-1 in our MDP system. This indicates that MDP irradiation supplies sufficient concentrations of ROS, and the stimulation intensity of the electric field determines the transfection efficiency in our system. Gene transfer by plasma irradiation depends mainly on endocytosis, which accounts for at least 80% of the transfer, and clathrin-mediated endocytosis is a dominant endocytosis. In plasma-mediated gene transfection, alterations in electrical and chemical factors can independently regulate plasmid DNA adhesion and triggering of endocytosis, respectively. This implies that plasma characteristics can be adjusted according to target cell requirements, and the transfection process can be optimized with minimum damage to cells and maximum efficiency. This may explain how MDP simultaneously achieves high transfection efficiency with minimal cell damage.

Development of an International Electric Cooperative Initiative on Energy Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul Clark; David South

NRECA conceived of the International Electric Cooperative Initiative on Energy Efficiency (IECIEE) in order to provide an ongoing means of contributing voluntary actions on greenhouse gas emissions mitigation as an integral component of its international programs and projects. This required designing the IECIEE to be integrated directly with the core interests and attributes of participating cooperatives in the U.S. and Latin America, which was the initial focus area selected for the IECIEE. In the case of NRECA International, the core interests related to promoting and strengthening the electric cooperative model, which has proved highly successful in maximizing operational efficiencies inmore » electric power generation, distribution and retailing, as compared to government-owned entities. The approach involved three basic components: (i) establishing the IECIEE mechanism, which involved setting up a functioning organizational vehicle providing for investment, management, and emissions credit accounting; (ii) developing a portfolio of projects in countries where NRECA International could effectively implement the broader mandate of cooperative development as energy efficient suppliers and distributors of electrical energy; and (iii) conducting outreach to obtain the commitment of participants and resources from U.S. and Latin American cooperatives and partnering agencies in the development financing community.« less

Hybrid and Plug-in Electric Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2014-05-20

Hybrid and plug-in electric vehicles use electricity either as their primary fuel or to improve the efficiency of conventional vehicle designs. This new generation of vehicles, often called electric drive vehicles, can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles(PHEVs), and all-electric vehicles (EVs). Together, they have great potential to reduce U.S. petroleum use.

Description and modelling of the solar-hydrogen-biogas-fuel cell system in GlashusEtt

NASA Astrophysics Data System (ADS)

Hedström, L.; Wallmark, C.; Alvfors, P.; Rissanen, M.; Stridh, B.; Ekman, J.

The need to reduce pollutant emissions and utilise the world's available energy resources more efficiently has led to increased attention towards e.g. fuel cells, but also to other alternative energy solutions. In order to further understand and evaluate the prerequisites for sustainable and energy-saving systems, ABB and Fortum have equipped an environmental information centre, located in Hammarby Sjöstad, Stockholm, Sweden, with an alternative energy system. The system is being used to demonstrate and evaluate how a system based on fuel cells and solar cells can function as a complement to existing electricity and heat production. The stationary energy system is situated on the top level of a three-floor glass building and is open to the public. The alternative energy system consists of a fuel cell system, a photovoltaic (PV) cell array, an electrolyser, hydrogen storage tanks, a biogas burner, dc/ac inverters, heat exchangers and an accumulator tank. The fuel cell system includes a reformer and a polymer electrolyte fuel cell (PEFC) with a maximum rated electrical output of 4 kW el and a maximum thermal output of 6.5 kW th. The fuel cell stack can be operated with reformed biogas, or directly using hydrogen produced by the electrolyser. The cell stack in the electrolyser consists of proton exchange membrane (PEM) cells. To evaluate different automatic control strategies for the system, a simplified dynamic model has been developed in MATLAB Simulink. The model based on measurement data taken from the actual system. The evaluation is based on demand curves, investment costs, electricity prices and irradiation. Evaluation criteria included in the model are electrical and total efficiencies as well as economic parameters.

An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry

2014-03-01

Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feedmore » a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.« less

MW-Class Electric Propulsion System Designs

NASA Technical Reports Server (NTRS)

LaPointe, Michael R.; Oleson, Steven; Pencil, Eric; Mercer, Carolyn; Distefano, Salvador

2011-01-01

Electric propulsion systems are well developed and have been in commercial use for several years. Ion and Hall thrusters have propelled robotic spacecraft to encounters with asteroids, the Moon, and minor planetary bodies within the solar system, while higher power systems are being considered to support even more demanding future space science and exploration missions. Such missions may include orbit raising and station-keeping for large platforms, robotic and human missions to near earth asteroids, cargo transport for sustained lunar or Mars exploration, and at very high-power, fast piloted missions to Mars and the outer planets. The Advanced In-Space Propulsion Project, High Efficiency Space Power Systems Project, and High Power Electric Propulsion Demonstration Project were established within the NASA Exploration Technology Development and Demonstration Program to develop and advance the fundamental technologies required for these long-range, future exploration missions. Under the auspices of the High Efficiency Space Power Systems Project, and supported by the Advanced In-Space Propulsion and High Power Electric Propulsion Projects, the COMPASS design team at the NASA Glenn Research Center performed multiple parametric design analyses to determine solar and nuclear electric power technology requirements for representative 300-kW class and pulsed and steady-state MW-class electric propulsion systems. This paper describes the results of the MW-class electric power and propulsion design analysis. Starting with the representative MW-class vehicle configurations, and using design reference missions bounded by launch dates, several power system technology improvements were introduced into the parametric COMPASS simulations to determine the potential system level benefits such technologies might provide. Those technologies providing quantitative system level benefits were then assessed for technical feasibility, cost, and time to develop. Key assumptions and primary results of the COMPASS MW-class electric propulsion power system study are reported, and discussion is provided on how the analysis might be used to guide future technology investments as NASA moves to more capable high power in-space propulsion systems.

Mechanical, Thermal, and Electrical Energy Storage in a Single Working Body: Electrification and Thermal Effects upon Pressure-Induced Water Intrusion-Extrusion in Nanoporous Solids.

PubMed

Grosu, Yaroslav; Mierzwa, Michał; Eroshenko, Valentine A; Pawlus, Sebastian; Chorażewski, Mirosław; Nedelec, Jean-Marie; Grolier, Jean-Pierre E

2017-03-01

This paper presents the first experimental evidence of pronounced electrification effects upon reversible cycle of forced water intrusion-extrusion in nanoporous hydrophobic materials. Recorded generation of electricity combined with high-pressure calorimetric measurements improves the energy balance of {nanoporous solid + nonwetting liquid} systems by compensating mechanical and thermal energy hysteresis in the cycle. Revealed phenomena provide a novel way of "mechanical to electrical" and/or "thermal to electrical" energy transformation with unprecedented efficiency and additionally open a perspective to increase the efficiency of numerous energy applications based on such systems taking advantage of electricity generation during operational cycle.

Status of photoelectrochemical production of hydrogen and electrical energy

NASA Technical Reports Server (NTRS)

Byvik, C. E.; Walker, G. H.

1976-01-01

The efficiency for conversion of electromagnetic energy to chemical and electrical energy utilizing semiconductor single crystals as photoanodes in electrochemical cells was investigated. Efficiencies as high as 20 percent were achieved for the conversion of 330 nm radiation to chemical energy in the form of hydrogen by the photoelectrolysis of water in a SrTiO3 based cell. The SrTiO3 photoanodes were shown to be stable in 9.5 M NaOH solutions for periods up to 48 hours. Efficiencies of 9 percent were measured for the conversion of broadband visible radiation to hydrogen using n-type GaAs crystals as photoanodes. Crystals of GaAs coated with 500 nm of gold, silver, or tin for surface passivation show no significant change in efficiency. By suppressing the production of hydrogen in a CdSe-based photogalvanic cell, an efficiency of 9 percent was obtained in conversion of 633 nm light to electrical energy. A CdS-based photogalvanic cell produced a conversion efficiency of 5 percent for 500 nm radiation.

Energy manager design for microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Firestone, Ryan; Marnay, Chris

2005-01-01

On-site energy production, known as distributed energy resources (DER), offers consumers many benefits, such as bill savings and predictability, improved system efficiency, improved reliability, control over power quality, and in many cases, greener electricity. Additionally, DER systems can benefit electric utilities by reducing congestion on the grid, reducing the need for new generation and transmission capacity, and offering ancillary services such as voltage support and emergency demand response. Local aggregations of distributed energy resources (DER) that may include active control of on-site end-use energy devices can be called microgrids. Microgrids require control to ensure safe operation and to make dispatchmore » decisions that achieve system objectives such as cost minimization, reliability, efficiency and emissions requirements, while abiding by system constraints and regulatory rules. This control is performed by an energy manager (EM). Preferably, an EM will achieve operation reasonably close to the attainable optimum, it will do this by means robust to deviations from expected conditions, and it will not itself incur insupportable capital or operation and maintenance costs. Also, microgrids can include supervision over end-uses, such as curtailing or rescheduling certain loads. By viewing a unified microgrid as a system of supply and demand, rather than simply a system of on-site generation devices, the benefits of integrated supply and demand control can be exploited, such as economic savings and improved system energy efficiency.« less

Electricity storage using a thermal storage scheme

NASA Astrophysics Data System (ADS)

White, Alexander

2015-01-01

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on "sensible heat" storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

Photovoltaic electric power applied to Unmanned Aerial Vehicles (UAV)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geis, J.; Arnold, J.H.

1994-09-01

Photovoltaic electric-powered flight is receiving a great deal of attention in the context of the United States` Unmanned Aerial Vehicle (UAV) program. This paper addresses some of the enabling technical areas and their potential solutions. Of particular interest are the long-duration, high-altitude class of UAV`s whose mission it is to achieve altitudes between 60,000 and 100,000 feet, and to remain at those altitudes for prolonged periods performing various mapping and surveillance activities. Addressed herein are studies which reveal the need for extremely light-weight and efficient solar cells, high-efficiency electric motor-driven propeller modules, and power management and distribution control elements. Sincemore » the potential payloads vary dramatically in their power consumption and duty cycles, a typical load profile has been selected to provide commonality for the propulsion power comparisons. Since missions vary widely with respect to ground coverage requirements, from repeated orbiting over a localized target to long-distance routes over irregular terrain, the authors have also averaged the power requirements for on-board guidance and control power, as well as ground control and communication link utilization. In the context of the national technology reinvestment program, wherever possible they modeled components and materials which have been qualified for space and defense applications, yet are compatible with civilian UAV activities. These include, but are not limited to, solar cell developments, electric storage technology for diurnal operation, local and ground communications, power management and distribution, and control servo design. And finally, the results of tests conducted by Wright Laboratory on ultralight, highly efficient MOCVD GaAs solar cells purchased from EPI Materials Ltd. (EML) of the UK are presented. These cells were also used for modeling the flight characteristics of UAV aircraft.« less

Photovoltaic electric power applied to Unmanned Aerial Vehicles (UAV)

NASA Technical Reports Server (NTRS)

Geis, Jack; Arnold, Jack H.

1994-01-01

Photovoltaic electric-powered flight is receiving a great deal of attention in the context of the United States' Unmanned Aerial Vehicle (UAV) program. This paper addresses some of the enabling technical areas and their potential solutions. Of particular interest are the long-duration, high-altitude class of UAV's whose mission it is to achieve altitudes between 60,000 and 100,000 feet, and to remain at those altitudes for prolonged periods performing various mapping and surveillance activities. Addressed herein are studies which reveal the need for extremely light-weight and efficient solar cells, high-efficiency electric motor-driven propeller modules, and power management and distribution control elements. Since the potential payloads vary dramatically in their power consumption and duty cycles, a typical load profile has been selected to provide commonality for the propulsion power comparisons. Since missions vary widely with respect to ground coverage requirements, from repeated orbiting over a localized target to long-distance routes over irregular terrain, we have also averaged the power requirements for on-board guidance and control power, as well as ground control and communication link utilization. In the context of the national technology reinvestment program, wherever possible we modeled components and materials which have been qualified for space and defense applications, yet are compatible with civilian UAV activities. These include, but are not limited to, solar cell developments, electric storage technology for diurnal operation, local and ground communications, power management and distribution, and control servo design. And finally, the results of tests conducted by Wright Laboratory on ultralight, highly efficient MOCVD GaAs solar cells purchased from EPI Materials Ltd. (EML) of the UK are presented. These cells were also used for modeling the flight characteristics of UAV aircraft.

Photovoltaic electric power applied to Unmanned Aerial Vehicles (UAV)

NASA Astrophysics Data System (ADS)

Geis, Jack; Arnold, Jack H.

1994-09-01

Photovoltaic electric-powered flight is receiving a great deal of attention in the context of the United States' Unmanned Aerial Vehicle (UAV) program. This paper addresses some of the enabling technical areas and their potential solutions. Of particular interest are the long-duration, high-altitude class of UAV's whose mission it is to achieve altitudes between 60,000 and 100,000 feet, and to remain at those altitudes for prolonged periods performing various mapping and surveillance activities. Addressed herein are studies which reveal the need for extremely light-weight and efficient solar cells, high-efficiency electric motor-driven propeller modules, and power management and distribution control elements. Since the potential payloads vary dramatically in their power consumption and duty cycles, a typical load profile has been selected to provide commonality for the propulsion power comparisons. Since missions vary widely with respect to ground coverage requirements, from repeated orbiting over a localized target to long-distance routes over irregular terrain, we have also averaged the power requirements for on-board guidance and control power, as well as ground control and communication link utilization. In the context of the national technology reinvestment program, wherever possible we modeled components and materials which have been qualified for space and defense applications, yet are compatible with civilian UAV activities. These include, but are not limited to, solar cell developments, electric storage technology for diurnal operation, local and ground communications, power management and distribution, and control servo design. And finally, the results of tests conducted by Wright Laboratory on ultralight, highly efficient MOCVD GaAs solar cells purchased from EPI Materials Ltd. (EML) of the UK are presented. These cells were also used for modeling the flight characteristics of UAV aircraft.

[Research on carbon reduction potential of electric vehicles for low-carbon transportation and its influencing factors].

PubMed

Shi, Xiao-Qing; Li, Xiao-Nuo; Yang, Jian-Xin

2013-01-01

Transportation is the key industry of urban energy consumption and carbon emissions. The transformation of conventional gasoline vehicles to new energy vehicles is an important initiative to realize the goal of developing low-carbon city through energy saving and emissions reduction, while electric vehicles (EV) will play an important role in this transition due to their advantage in energy saving and lower carbon emissions. After reviewing the existing researches on energy saving and emissions reduction of electric vehicles, this paper analyzed the factors affecting carbon emissions reduction. Combining with electric vehicles promotion program in Beijing, the paper analyzed carbon emissions and reduction potential of electric vehicles in six scenarios using the optimized energy consumption related carbon emissions model from the perspective of fuel life cycle. The scenarios included power energy structure, fuel type (energy consumption per 100 km), car type (CO2 emission factor of fuel), urban traffic conditions (speed), coal-power technologies and battery type (weight, energy efficiency). The results showed that the optimized model was able to estimate carbon emissions caused by fuel consumption more reasonably; electric vehicles had an obvious restrictive carbon reduction potential with the fluctuation of 57%-81.2% in the analysis of six influencing factors, while power energy structure and coal-power technologies play decisive roles in life-cycle carbon emissions of electric vehicles with the reduction potential of 78.1% and 81.2%, respectively. Finally, some optimized measures were proposed to reduce transport energy consumption and carbon emissions during electric vehicles promotion including improving energy structure and coal technology, popularizing energy saving technologies and electric vehicles, accelerating the battery R&D and so on. The research provides scientific basis and methods for the policy development for the transition of new energy vehicles in low-carbon transport.

Displacement efficiency of alternative energy and trans-provincial imported electricity in China.

PubMed

Hu, Yuanan; Cheng, Hefa

2017-02-17

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ∼0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ∼10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

Displacement efficiency of alternative energy and trans-provincial imported electricity in China

NASA Astrophysics Data System (ADS)

Hu, Yuanan; Cheng, Hefa

2017-02-01

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ~0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ~10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

Certification and brand identity for energy efficiency in competitive energy services markets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prindle, W.R.; Wiser, R.

Resource commitments for energy efficiency from electricity companies are disappearing rapidly as the regulated Integrated Resource Planning and Demand-Side Management paradigms that fostered them give way to competitive power markets in a restructuring electricity industry. While free-market advocates claim that energy efficiency needs will be taken care of by competitive energy service providers, there is no assurance that efficiency will compete effectively with the panoply of other energy-related (and non-energy-related) services that are beginning to appear in early market offerings. This paper reports the results of a feasibility study for a certification and brand identity program for energy efficiency gearedmore » to competitive power markets. Funded by the Energy Foundation, this study involved a survey and personal interviews with stakeholders, plus a workshop to further the discussion. Stakeholders include independent power marketers and energy service companies, utility affiliate power marketers and energy service companies, government agencies, trade associations, non-profit organizations, equipment manufacturers, and consultants. The paper summarizes the study's findings on such key issues as: Whether a brand identity concept has a critical mass of interest and support; how qualification and certification could work in such a program; how a brand identity could be positioned in the market; how an efficiency brand identity could co-brand with renewable power branding programs and other green marketing efforts; and the resources and components needed to make such a program work on a national scale.« less

Inverted Ultrathin Organic Solar Cells with a Quasi-Grating Structure for Efficient Carrier Collection and Dip-less Visible Optical Absorption.

PubMed

In, Sungjun; Park, Namkyoo

2016-02-23

We propose a metallic-particle-based two-dimensional quasi-grating structure for application to an organic solar cell. With the use of oblate spheroidal nanoparticles in contact with an anode of inverted, ultrathin organic solar cells (OSCs), the quasi-grating structure offers strong hybridization between localized surface plasmons and plasmonic gap modes leading to broadband (300~800 nm) and uniform (average ~90%) optical absorption spectra. Both strong optical enhancement in extreme confinement within the active layer (90 nm) and improved hole collection are thus realized. A coupled optical-electrical multi-physics optimization shows a large (~33%) enhancement in the optical absorption (corresponding to an absorption efficiency of ~47%, AM1.5G weighted, visible) when compared to a control OSC without the quasi-grating structure. That translates into a significant electrical performance gain of ~22% in short circuit current and ~15% in the power conversion efficiency (PCE), leading to an energy conversion efficiency (~6%) which is comparable to that of optically-thick inverted OSCs (3-7%). Detailed analysis on the influences of mode hybridization to optical field distributions, exciton generation rate, charge carrier collection efficiency and electrical conversion efficiency is provided, to offer an integrated understanding on the coupled optical-electrical optimization of ultrathin OSCs.

A study of electric transmission lines for use on the lunar surface

NASA Technical Reports Server (NTRS)

Gaustad, Krista L.; Gordon, Lloyd B.; Weber, Jennifer R.

1994-01-01

The sources for electrical power on a lunar base are said to include solar/chemical, nuclear (static conversion), and nuclear (dynamic conversion). The transmission of power via transmission lines is more practical than power beaming or superconducting because of its low cost and reliable, proven technology. Transmission lines must have minimum mass, maximum efficiency, and the ability to operate reliably in the lunar environment. The transmission line design includes conductor material, insulator material, conductor geometry, conductor configuration, line location, waveform, phase selection, and frequency. This presentation oulines the design. Liquid and gaseous dielectrics are undesirable for long term use in the lunar vacuum due to a high probability of loss. Thus, insulation for high voltage transmission line will most likely be solid dielectric or vacuum insulation.

Assessment of Technologies for Noncryogenic Hybrid Electric Propulsion

NASA Technical Reports Server (NTRS)

Dever, Timothy P.; Duffy, Kirsten P.; Provenza, Andrew J.; Loyselle, Patricia L.; Choi, Benjamin B.; Morrison, Carlos R.; Lowe, Angela M.

2015-01-01

The Subsonic Fixed Wing Project of NASA's Fundamental Aeronautics Program is researching aircraft propulsion technologies that will lower noise, emissions, and fuel burn. One promising technology is noncryogenic electric propulsion, which could be either hybrid electric propulsion or turboelectric propulsion. Reducing dependence on the turbine engine would certainly reduce emissions. However, the weight of the electricmotor- related components that would have to be added would adversely impact the benefits of the smaller turbine engine. Therefore, research needs to be done to improve component efficiencies and reduce component weights. This study projects technology improvements expected in the next 15 and 30 years, including motor-related technologies, power electronics, and energy-storage-related technologies. Motor efficiency and power density could be increased through the use of better conductors, insulators, magnets, bearings, structural materials, and thermal management. Energy storage could be accomplished through batteries, flywheels, or supercapacitors, all of which expect significant energy density growth over the next few decades. A first-order approximation of the cumulative effect of each technology improvement shows that motor power density could be improved from 3 hp/lb, the state of the art, to 8 hp/lb in 15 years and 16 hp/lb in 30 years.

Solar Electric Propulsion Vehicle Demonstration to Support Future Space Exploration Missions

NASA Technical Reports Server (NTRS)

Smith, Bryan K.; Nazario, Margaret L.; Cunningham, Cameron C.

2012-01-01

Human and robotic exploration beyond Low Earth Orbit (LEO) will require enabling capabilities that are efficient, affordable, and reliable. Solar Electric Propulsion (SEP) is highly advantageous because of its favorable in-space mass transfer efficiency compared to traditional chemical propulsion systems. The NASA studies have demonstrated that this advantage becomes highly significant as missions progress beyond Earth orbit. Recent studies of human exploration missions and architectures evaluated the capabilities needed to perform a variety of human exploration missions including missions to Near Earth Objects (NEOs). The studies demonstrated that SEP stages have potential to be the most cost effective solution to perform beyond LEO transfers of high mass cargoes for human missions. Recognizing that these missions require power levels more than 10X greater than current electric propulsion systems, NASA embarked upon a progressive pathway to identify critical technologies needed and a plan for an incremental demonstration mission. The NASA studies identified a 30kW class demonstration mission that can serve as a meaningful demonstration of the technologies, operational challenges, and provide the appropriate scaling and modularity required. This paper describes the planning options for a representative demonstration 30kW class SEP mission.

Integrated propulsion for near-Earth space missions. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Dailey, C. L.; Meissinger, H. F.; Lovberg, R. H.; Zafran, S.

1981-01-01

Tradeoffs between electric propulsion system mass ratio and transfer time from LEO to GEO were conducted parametrically for various thruster efficiency, specific impulse, and other propulsion parameters. A computer model was developed for performing orbit transfer calculations which included the effects of aerodynamic drag, radiation degradation, and occultation. The tradeoff results showed that thruster technology areas for integrated propulsion should be directed towards improving primary thruster efficiency in the range from 1500 to 2500 seconds, and be continued towards reducing specific mass. Comparison of auxiliary propulsion systems showed large total propellant mass savings with integrated electric auxiliary propulsion. Stationkeeping is the most demanding on orbit propulsion requirement. At area densities above 0.5 sq m/kg, East-West stationkeeping requirements from solar pressure exceed North-South stationkeeping requirements from gravitational forces. A solar array pointing strategy was developed to minimize the effects of atmospheric drag at low altitude, enabling electric propulsion to initiate orbit transfer at Shuttle's maximum cargo carrying altitude. Gravity gradient torques are used during ascent to sustain the spacecraft roll motion required for optimum solar array illumination. A near optimum cover glass thickness of 6 mils was established for LEO to GEO transfer.

Magnetic characterization of the stator core of a high-speed motor made of an ultrathin electrical steel sheet using the magnetic property evaluation system

NASA Astrophysics Data System (ADS)

Oka, Mohachiro; Enokizono, Masato; Mori, Yuji; Yamazaki, Kazumasa

2018-04-01

Recently, the application areas for electric motors have been expanding. For instance, electric motors are used in new technologies such as rovers, drones, cars, and robots. The motor used in such machinery should be small, high-powered, highly-efficient, and high-speed. In such motors, loss at high-speed rotation must be especially minimal. Eddy-current loss in the stator core is known to increase greatly during loss at high-speed rotation of the motor. To produce an efficient high-speed motor, we are developing a stator core for a motor using an ultrathin electrical steel sheet with only a small amount of eddy-current loss. Furthermore, the magnetic property evaluation for efficient, high-speed motor stator cores that use conventional commercial frequency is insufficient. Thus, we made a new high-speed magnetic property evaluation system to evaluate the magnetic properties of the efficient high-speed motor stator core. This system was composed of high-speed A/D converters, D/A converters, and a high-speed power amplifier. In experiments, the ultrathin electrical steel sheet dramatically suppressed iron loss and, in particular, eddy-current loss. In addition, a new high-speed magnetic property evaluation system accurately evaluated the magnetic properties of the efficient high-speed motor stator core.

Hybrid photovoltaic-thermoelectric system for concentrated solar energy conversion: Experimental realization and modeling

NASA Astrophysics Data System (ADS)

Beeri, Ofer; Rotem, Oded; Hazan, Eden; Katz, Eugene A.; Braun, Avi; Gelbstein, Yaniv

2015-09-01

An experimental demonstration of the combined photovoltaic (PV) and thermoelectric conversion of concentrated sunlight (with concentration factor, X, up to ˜300) into electricity is presented. The hybrid system is based on a multi-junction PV cell and a thermoelectric generator (TEG). The latter increases the electric power of the system and dissipates some of the excessive heat. For X ≤ 200, the system's maximal efficiency, ˜32%, was mostly due to the contribution from the PV cell. With increasing X and system temperature, the PV cell's efficiency decreased while that of the TEG increased. Accordingly, the direct electrical contribution of the TEG started to dominate in the total system power, reaching ˜20% at X ≈ 290. Using a simple steady state finite element modeling, the cooling effect of the TEG on the hybrid system's efficiency was proved to be even more significant than its direct electrical contribution for high solar concentrations. As a result, the total efficiency contribution of the TEG reached ˜40% at X ≈ 200. This suggests a new system optimization concept that takes into account the PV cell's temperature dependence and the trade-off between the direct electrical generation and cooling capabilities of the TEG. It is shown that the hybrid system has a real potential to exceed 50% total efficiency by using more advanced PV cells and TE materials.

At A Glance: Electric-Drive Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

2016-07-01

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

Measuring modules for the research of compensators of reactive power with voltage stabilization in MATLAB

NASA Astrophysics Data System (ADS)

Vlasayevsky, Stanislav; Klimash, Stepan; Klimash, Vladimir

2017-10-01

A set of mathematical modules was developed for evaluation the energy performance in the research of electrical systems and complexes in the MatLab. In the electrotechnical library SimPowerSystems of the MatLab software, there are no measuring modules of energy coefficients characterizing the quality of electricity and the energy efficiency of electrical apparatus. Modules are designed to calculate energy coefficients characterizing the quality of electricity (current distortion and voltage distortion) and energy efficiency indicators (power factor and efficiency) are presented. There are described the methods and principles of building the modules. The detailed schemes of modules built on the elements of the Simulink Library are presented, in this connection, these modules are compatible with mathematical models of electrical systems and complexes in the MatLab. Also there are presented the results of the testing of the developed modules and the results of their verification on the schemes that have analytical expressions of energy indicators.

10 CFR 431.442 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Electrical and Electronics Engineers, Inc. NEMA means National Electrical Manufacturers Association. Small... Small Electric Motors § 431.442 Definitions. The following definitions are applicable to this subpart: Alternative efficiency determination method, or AEDM, means, with respect to a small electric motor, a method...

10 CFR 431.442 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Electrical and Electronics Engineers, Inc. NEMA means National Electrical Manufacturers Association. Small... Small Electric Motors § 431.442 Definitions. The following definitions are applicable to this subpart: Alternative efficiency determination method, or AEDM, means, with respect to a small electric motor, a method...

10 CFR 431.442 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Electrical and Electronics Engineers, Inc. NEMA means National Electrical Manufacturers Association. Small... Small Electric Motors § 431.442 Definitions. The following definitions are applicable to this subpart: Alternative efficiency determination method, or AEDM, means, with respect to a small electric motor, a method...

10 CFR 431.442 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Electrical and Electronics Engineers, Inc. NEMA means National Electrical Manufacturers Association. Small... Small Electric Motors § 431.442 Definitions. The following definitions are applicable to this subpart: Alternative efficiency determination method, or AEDM, means, with respect to a small electric motor, a method...

10 CFR 431.442 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Electrical and Electronics Engineers, Inc. NEMA means National Electrical Manufacturers Association. Small... Small Electric Motors § 431.442 Definitions. The following definitions are applicable to this subpart: Alternative efficiency determination method, or AEDM, means, with respect to a small electric motor, a method...

Development and Implementation of a Battery-Electric Light-Duty Class 2a Truck including Hybrid Energy Storage

NASA Astrophysics Data System (ADS)

Kollmeyer, Phillip J.

This dissertation addresses two major related research topics: 1) the design, fabrication, modeling, and experimental testing of a battery-electric light-duty Class 2a truck; and 2) the design and evaluation of a hybrid energy storage system (HESS) for this and other vehicles. The work begins with the determination of the truck's peak power and wheel torque requirements (135kW/4900Nm). An electric traction system is then designed that consists of an interior permanent magnet synchronous machine, two-speed gearbox, three-phase motor drive, and LiFePO4 battery pack. The battery pack capacity is selected to achieve a driving range similar to the 2011 Nissan Leaf electric vehicle (73 miles). Next, the demonstrator electric traction system is built and installed in the vehicle, a Ford F150 pickup truck, and an extensive set of sensors and data acquisition equipment is installed. Detailed loss models of the battery pack, electric traction machine, and motor drive are developed and experimentally verified using the driving data. Many aspects of the truck's performance are investigated, including efficiency differences between the two-gear configuration and the optimal gear selection. The remainder focuses on the application of battery/ultracapacitor hybrid energy storage systems (HESS) to electric vehicles. First, the electric truck is modeled with the addition of an ultracapacitor pack and a dc/dc converter. Rule-based and optimal battery/ultracapacitor power-split control algorithms are then developed, and the performance improvements achieved for both algorithms are evaluated for operation at 25°C. The HESS modeling is then extended to low temperatures, where battery resistance increases substantially. To verify the accuracy of the model-predicted results, a scaled hybrid energy storage system is built and the system is tested for several drive cycles and for two temperatures. The HESS performance is then modeled for three variants of the vehicle design, including the prototype electric truck with a different battery pack, the prototype electric truck with a higher power drivetrain and higher towing capability, and an electric city transit bus. Performance advantages provided by the HESS are demonstrated and verified for these vehicles in several areas including: longer vehicle range, improved low-temperature operation with lithium-ion batteries, and reduced battery losses and cycling stresses.

Photovoltaic technology for sustainability: An investigation of the distributed utility concept as a policy framework

NASA Astrophysics Data System (ADS)

Letendre, Steven Emery

The U.S. electric utility sector in its current configuration is unsustainable. The majority of electricity in the United States is produced using finite fossil fuels. In addition, significant potential exists to improve the nation's efficient use of energy. A sustainable electric utility sector will be characterized by increased use of renewable energy sources and high levels of end-use efficiency. This dissertation analyzes two alternative policy approaches designed to move the U.S. electric utility sector toward sustainability. One approach is labeled incremental which involves maintaining the centralized structure of the electric utility sector but facilitating the introduction of renewable energy and efficiency into the electrical system through the pricing mechanism. A second policy approach was described in which structural changes are encouraged based on the emerging distributed utility (DU) concept. A structural policy orientation attempts to capture the unique localized benefits that distributed renewable resources and energy efficiency offer to electric utility companies and their customers. A market penetration analysis of PV in centralized energy supply and distributed peak-shaving applications is conducted for a case-study electric utility company. Sensitivity analysis was performed based on incremental and structural policy orientations. The analysis provides compelling evidence which suggests that policies designed to bring about structural change in the electric utility sector are needed to move the industry toward sustainability. Specifically, the analysis demonstrates that PV technology, a key renewable energy option likely to play an important role in a renewable energy future, will begin to penetrate the electrical system in distributed peak-shaving applications long before the technology is introduced as a centralized energy supply option. Most policies to date, which I term incremental, attempt to encourage energy efficiency and renewables through the pricing system. Based on past policy experience, it is unlikely that such an approach would allow PV to compete in Delaware as an energy supply option in the next ten to twenty years. Alternatively, a market-based, or green pricing, approach will not create significant market opportunities for PV as a centralized energy supply option. However, structural policies designed to encourage the explicit recognition of the localized benefits of distributed resources could result in PV being introduced into the electrical system early in the next century.

Energy use pattern in rice milling industries-a critical appraisal.

PubMed

Goyal, S K; Jogdand, S V; Agrawal, A K

2014-11-01

Rice milling industry is one of the most energy consuming industries. Like capital, labour and material, energy is one of the production factors which used to produce final product. In economical term, energy is demand-derived goods and can be regarded as intermediate good whose demand depends on the demand of final product. This paper deals with various types of energy pattern used in rice milling industries viz., thermal energy, mechanical energy, electrical energy and human energy. The important utilities in a rice mill are water, air, steam, electricity and labour. In a rice mill some of the operations are done manually namely, cleaning, sun drying, feeding paddy to the bucket elevators, weighing and packaging, etc. So the man-hours are also included in energy accounting. Water is used for soaking and steam generation. Electricity is the main energy source for these rice mills and is imported form the state electricity board grids. Electricity is used to run motors, pumps, blowers, conveyors, fans, lights, etc. The variations in the consumption rate of energy through the use of utilities during processing must also accounted for final cost of the finished product. The paddy milling consumes significant quantity of fuels and electricity. The major energy consuming equipments in the rice milling units are; boilers and steam distribution, blowers, pumps, conveyers, elevators, motors, transmission systems, weighing, etc. Though, wide variety of technologies has been evolved for efficient use of energy for various equipments of rice mills, so far, only a few have improved their energy efficiency levels. Most of the rice mills use old and locally available technologies and are also completely dependent on locally available technical personnel.

Projection of distributed-collector solar-thermal electric power plant economics to years 1990-2000

NASA Technical Reports Server (NTRS)

Fujita, T.; Elgabalawi, N.; Herrera, G.; Turner, R. H.

1977-01-01

A preliminary comparative evaluation of distributed-collector solar thermal power plants was undertaken by projecting power plant economics of selected systems to the 1990 to 2000 time frame. The selected systems include: (1) fixed orientation collectors with concentrating reflectors and vacuum tube absorbers, (2) one axis tracking linear concentrator including parabolic trough and variable slat designs, and (3) two axis tracking parabolic dish systems including concepts with small heat engine-electric generator assemblies at each focal point as well as approaches having steam generators at the focal point with pipeline collection to a central power conversion unit. Comparisons are presented primarily in terms of energy cost and capital cost over a wide range of operating load factors. Sensitvity of energy costs for a range of efficiency and cost of major subsystems/components is presented to delineate critical technological development needs.

Extended Policies case

EIA Publications

2016-01-01

The Annual Energy Outlook 2016 (AEO2016) Extended Policies case includes selected policies that go beyond current laws and regulations. Existing tax credits that have scheduled reductions and sunset dates are assumed to remain unchanged through 2040. Other efficiency policies, including corporate average fuel economy standards, appliance standards, and building codes, are expanded beyond current provisions; and the U.S. Environmental Protection Agency (EPA) Clean Power Plan (CPP) regulations that reduce carbon dioxide emissions from electric power generation are tightened after 2030.

High throughput parallel backside contacting and periodic texturing for high-efficiency solar cells

DOEpatents

Daniel, Claus; Blue, Craig A.; Ott, Ronald D.

2014-08-19

Disclosed are configurations of long-range ordered features of solar cell materials, and methods for forming same. Some features include electrical access openings through a backing layer to a photovoltaic material in the solar cell. Some features include textured features disposed adjacent a surface of a solar cell material. Typically the long-range ordered features are formed by ablating the solar cell material with a laser interference pattern from at least two laser beams.

A Multiscale Software Tool for Field/Circuit Co-Simulation

DTIC Science & Technology

2011-12-15

technology fields: Number of graduating undergraduates who achieved a 3.5 GPA to 4.0 (4.0 max scale): Number of graduating undergraduates funded by a...times more efficient than FDTD for such a problem in 3D . The techniques in class (c) above include the discontinuous Galerkin method and multidomain...implements a finite-differential-time-domain method on single field propagation in a 3D space. We consider a cavity model which includes two electric

FORTRAN program for induction motor analysis

NASA Technical Reports Server (NTRS)

Bollenbacher, G.

1976-01-01

A FORTRAN program for induction motor analysis is described. The analysis includes calculations of torque-speed characteristics, efficiency, losses, magnetic flux densities, weights, and various electrical parameters. The program is limited to three-phase Y-connected, squirrel-cage motors. Detailed instructions for using the program are given. The analysis equations are documented, and the sources of the equations are referenced. The appendixes include a FORTRAN symbol list, a complete explanation of input requirements, and a list of error messages.

Motor Drive Technologies for the Power-by-Wire (PBW) Program: Options, Trends and Tradeoffs

NASA Technical Reports Server (NTRS)

Elbuluk, Malik E.; Kankam, M. David

1995-01-01

Power-By-Wire (PBW) is a program involving the replacement of hydraulic and pneumatic systems currently used in aircraft with an all-electric secondary power system. One of the largest loads of the all-electric secondary power system will be the motor loads which include pumps, compressors and Electrical Actuators (EA's). Issues of improved reliability, reduced maintenance and efficiency, among other advantages, are the motivation for replacing the existing aircraft actuators with electrical actuators. An EA system contains four major components. These are the motor, the power electronic converters, the actuator and the control system, including the sensors. This paper is a comparative literature review in motor drive technologies, with a focus on the trends and tradeoffs involved in the selection of a particular motor drive technology. The reported research comprises three motor drive technologies. These are the induction motor (IM), the brushless dc motor (BLDCM) and the switched reluctance motor (SRM). Each of the three drives has the potential for application in the PBW program. Many issues remain to be investigated and compared between the three motor drives, using actual mechanical loads expected in the PBW program.

Three essays on U.S. electricity restructuring

NASA Astrophysics Data System (ADS)

Sergici, Sanem I.

2008-04-01

The traditional structure of the electricity sector in the U.S. has been that of large vertically integrated companies with sole responsibility for distributing power to end users within a franchise area. The restructuring of this sector that has occurred in the past 10-20 years has profoundly altered this picture. This dissertation examines three aspects of that restructuring process. First chapter of my dissertation investigates the impacts of divestitures of generation, an important part of the process of restructuring, on the efficiency of distribution systems. We find that while all divestitures as a group do not significantly affect distribution efficiency, those mandated by state public utility commissions have resulted in large and statistically significant adverse effects on distribution efficiency. Second chapter of my dissertation explores whether independent system operator (ISO) formation in New York has led to operating efficiencies at the unit and the system level. ISOs oversee the centralized management of the grid and the energy market and are expected to promote more efficient power generation. We test these efficiencies focusing on the generation units in New York ISO region from 1998 to 2004 and find that the NYISO formation has introduced limited efficiencies at the unit and the system level. Restructuring in the electricity industry has spawned a new wave of mergers, both raising questions and providing opportunities to examine these mergers. Third chapter of my dissertation investigates the drivers of electric utility mergers consummated between 1992 and 2004. My results provide support for disturbance theory of mergers, size hypothesis, and inefficient management hypothesis as drivers of electric utility mergers. I also find that the adjacency of the service territories is the most noteworthy determinant of the pairings between IOUs.

Efficient 'Foton' electric-discharge KrCl laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panchenko, Aleksei N; Tarasenko, Viktor F

The design of the 'Foton' electric-discharge laser, optimised for operation on the basis of KrCl* molecules, and its energy parameters were investigated. At {lambda} = 222 nm the radiation energy was up to 250 mJ per pulse. The specific output radiation energy was 2.5 J litre{sup -1} and the laser efficiency was in excess of 0.8%. The possibility of further improvement of the characteristics of electric-discharge KrCl lasers are discussed. (lasers)

ENERGY EFFICIENCY AND ENVIRONMENTALLY FRIENDLY DISTRIBUTED ENERGY STORAGE BATTERY

DOE Office of Scientific and Technical Information (OSTI.GOV)

LANDI, J.T.; PLIVELICH, R.F.

2006-04-30

Electro Energy, Inc. conducted a research project to develop an energy efficient and environmentally friendly bipolar Ni-MH battery for distributed energy storage applications. Rechargeable batteries with long life and low cost potentially play a significant role by reducing electricity cost and pollution. A rechargeable battery functions as a reservoir for storage for electrical energy, carries energy for portable applications, or can provide peaking energy when a demand for electrical power exceeds primary generating capabilities.

Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel-oxygen burners

NASA Astrophysics Data System (ADS)

Stepanov, V. A.; Krakht, L. N.; Merker, E. E.; Sazonov, A. V.; Chermenev, E. A.

2015-12-01

The problems of increasing the efficiency of electric steelmaking using fuel-oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.

Energy efficient motion control of the electric bus on route

NASA Astrophysics Data System (ADS)

Kotiev, G. O.; Butarovich, D. O.; Kositsyn, B. B.

2018-02-01

At present, the urgent problem is the reduction of energy costs of urban motor transport. The article proposes a method of solving this problem by developing an energy-efficient law governing the movement of an electric bus along a city route. To solve this problem, an algorithm is developed based on the dynamic programming method. The proposed method allows you to take into account the constraints imposed on the phase coordinates, control action, as well as on the time of the route. In the course of solving the problem, the model of rectilinear motion of an electric bus on a horizontal reference surface is considered, taking into account the assumptions that allow it to be adapted for the implementation of the method. For the formation of a control action in the equations of motion dynamics, an algorithm for changing the traction / braking torque on the wheels of an electric bus is considered, depending on the magnitude of the control parameter and the speed of motion. An optimal phase trajectory was obtained on a selected section of the road for the prototype of an electric bus. The article presents the comparison of simulation results obtained with the optimal energy efficient control law with the results obtained by a test driver. The comparison proved feasibility of the energy efficient control law for the automobile city electric transport.

Electrical and optical modeling of poly(3-hexylthiophene):[6,6]-phenyl-C61 butyric acid methyl ester P3HT-PCBM bulk heterojunction solar cells

NASA Astrophysics Data System (ADS)

Brioua, Fathi; Remram, Mohamed; Nechache, Riad; Bourouina, Hicham

2017-11-01

In this work, we investigate a two-dimensional theoretical model for the photon conversion through an integration of the optical and electrical part of multilayer system in a bulk heterojunction solar cell based on poly(3-hexylthiophene) (P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. The optical properties of the studied structure ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al, such as the exciton generation rate and the electrical field distribution, are predicted at vicinity of the active layer and have been used to solve Poisson and continuity, drift-diffusion equations of the electrical model which characterize the electrical behavior of semiconductor device using finite element method (FEM). The electrical parameters such as power conversion efficiency (PCE), open voltage circuit ( V oc), short-circuit current density ( J sc) and fill factor (FF) are extracted from the current-voltage (J-V) characteristics under illumination and in dark conditions. Highest external quantum efficiency (IPCE), up to 60%, is obtained around 520 nm, while a power conversion efficiency (PCE) value of 3.62% is found to be in good agreement with the literature results. Integration of such theoretical approach into technological applications dealing with optoelectrical material performance will rapidly provide to the user accurate data outputs required for efficient validation of proof-of-concepts.

Enhanced charge efficiency and reduced energy use in capacitive deionization by increasing the discharge voltage.

PubMed

Kim, T; Dykstra, J E; Porada, S; van der Wal, A; Yoon, J; Biesheuvel, P M

2015-05-15

Capacitive deionization (CDI) is an electrochemical method for water desalination using porous carbon electrodes. A key parameter in CDI is the charge efficiency, Λ, which is the ratio of salt adsorption over charge in a CDI-cycle. Values for Λ in CDI are typically around 0.5-0.8, significantly less than the theoretical maximum of unity, due to the fact that not only counterions are adsorbed into the pores of the carbon electrodes, but at the same time coions are released. To enhance Λ, ion-exchange membranes (IEMs) can be implemented. With membranes, Λ can be close to unity because the membranes only allow passage for the counterions. Enhancing the value of Λ is advantageous as this implies a lower electrical current and (at a fixed charging voltage) a reduced energy use. We demonstrate how, without the need to include IEMs, the charge efficiency can be increased to values close to the theoretical maximum of unity, by increasing the cell voltage during discharge, with only a small loss of salt adsorption capacity per cycle. In separate constant-current CDI experiments, where after some time the effluent salt concentration reaches a stable value, this value is reached earlier with increased discharge voltage. We compare the experimental results with predictions of porous electrode theory which includes an equilibrium Donnan electrical double layer model for salt adsorption in carbon micropores. Our results highlight the potential of modified operational schemes in CDI to increase charge efficiency and reduce energy use of water desalination. Copyright © 2014 Elsevier Inc. All rights reserved.

Interoperability Context-Setting Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Widergren, Steven E.; Hardin, Dave; Ambrosio, Ron

2007-01-31

As the deployment of automation technology advances, it touches upon many areas of our corporate and personal lives. A trend is emerging where systems are growing to the extent that integration is taking place with other systems to provide even greater capabilities more efficiently and effectively. GridWise™ provides a vision for this type of integration as it applies to the electric system. Imagine a time in the not too distant future when homeowners can offer the management of their electricity demand to participate in a more efficient and environmentally friendly operation of the electric power grid. They will do thismore » using technology that acts on their behalf in response to information from other components of the electric system. This technology will recognize their preferences to parameters such as comfort and the price of energy to form responses that optimize the local need to a signal that satisfies a higher-level need in the grid. For example, consider a particularly hot day with air stagnation in an area with a significant dependence on wind generation. To manage the forecasted peak electricity demand, the bulk system operator issues a critical peak price warning. Their automation systems alert electric service providers who distribute electricity from the wholesale electricity system to consumers. In response, the electric service providers use their automation systems to inform consumers of impending price increases for electricity. This information is passed to an energy management system at the premises, which acts on the homeowner’s behalf, to adjust the electricity usage of the onsite equipment (which might include generation from such sources as a fuel cell). The objective of such a system is to honor the agreement with the electricity service provider and reduce the homeowner’s bill while keeping the occupants as comfortable as possible. This will include actions such as moving the thermostat on the heating, ventilation, and air-conditioning (HVAC) unit up several degrees. The resulting load reduction becomes part of an aggregated response from the electricity service provider to the bulk system operator who is now in a better position to manage total system load with available generation. Looking across the electric system, from generating plants, to transmission substations, to the distribution system, to factories, office parks, and buildings, automation is growing, and the opportunities for unleashing new value propositions are exciting. How can we facilitate this change and do so in a way that ensures the reliability of electric resources for the wellbeing of our economy and security? The GridWise Architecture Council (GWAC) mission is to enable interoperability among the many entities that interact with the electric power system. A good definition of interoperability is, “The capability of two or more networks, systems, devices, applications, or components to exchange information between them and to use the information so exchanged.” As a step in the direction of enabling interoperability, the GWAC proposes a context-setting framework to organize concepts and terminology so that interoperability issues can be identified and debated, improvements to address issues articulated, and actions prioritized and coordinated across the electric power community.« less

77 FR 47828 - Amended Notice of Intent To Prepare the Hawai'i Clean Energy Programmatic Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-10

... efficiency and renewable energy activities and technologies to be analyzed in the PEIS and, accordingly, has... Renewables, (4) Alternative Transportation Fuels and Modes, and (5) Electrical Transmission and Distribution... Kaua'i; electric vehicle public charging networks; efficient appliance rebates; solar water heating...

Hall devices improve electric motor efficiency

NASA Technical Reports Server (NTRS)

Haeussermann, W.

1979-01-01

Efficiency of electric motors and generators is reduced by radial magnetic forces created by symmetric fields within device. Forces are sensed and counteracted by Hall devices on excitation or control windings. Hall generators directly measure and provide compensating control of anu asymmetry, eliminating additional measurements needed for calibration feedback control loop.

Carbon-free hydrogen production from low rank coal

NASA Astrophysics Data System (ADS)

Aziz, Muhammad; Oda, Takuya; Kashiwagi, Takao

2018-02-01

Novel carbon-free integrated system of hydrogen production and storage from low rank coal is proposed and evaluated. To measure the optimum energy efficiency, two different systems employing different chemical looping technologies are modeled. The first integrated system consists of coal drying, gasification, syngas chemical looping, and hydrogenation. On the other hand, the second system combines coal drying, coal direct chemical looping, and hydrogenation. In addition, in order to cover the consumed electricity and recover the energy, combined cycle is adopted as addition module for power generation. The objective of the study is to find the best system having the highest performance in terms of total energy efficiency, including hydrogen production efficiency and power generation efficiency. To achieve a thorough energy/heat circulation throughout each module and the whole integrated system, enhanced process integration technology is employed. It basically incorporates two core basic technologies: exergy recovery and process integration. Several operating parameters including target moisture content in drying module, operating pressure in chemical looping module, are observed in terms of their influence to energy efficiency. From process modeling and calculation, two integrated systems can realize high total energy efficiency, higher than 60%. However, the system employing coal direct chemical looping represents higher energy efficiency, including hydrogen production and power generation, which is about 83%. In addition, optimum target moisture content in drying and operating pressure in chemical looping also have been defined.

Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

PubMed Central

Shang, Yunfei; Hao, Shuwei; Yang, Chunhui; Chen, Guanying

2015-01-01

Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous), gallium arsenide (GaAs) solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed. PMID:28347095

ACEEE's green book: The environmental guide to cars and trucks, Model year 2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeCicco, J.; Kliesch, J.; Thomas, M.

2000-07-01

This pathbreaking guide ranks cars and trucks according to environmental friendliness. Buyers can compare cars, vans, pickups, and sport utility vehicles by their environmental impacts, including air pollution, global warming, and fuel efficiency. Inside the guide: how to buy the cleanest and most efficient vehicle that meets your needs; Green Scores for all 2000 makes and models, listed by class--compact, mid-size, and large cars, vans, pickups, and sport utilities; Best of 2000 section featuring the greenest models in each class; Green by Design chapter highlighting advanced technologies and what makes some vehicles greener than others; listings for electric and othermore » alternative fuel vehicles in addition to gasoline and diesel vehicles; tips on keeping your vehicle running cleanly and efficiently; and the environmental impacts of vehicles, including global warming and the health effects of vehicle pollution.« less

The Design, Construction, and Experimental Evaluation of a Compact Thermoacoustic-Stirling Engine Generator for Use in a micro-CHP Appliance

NASA Astrophysics Data System (ADS)

Wilcox, Douglas A., Jr.

Micro combined heat and power or micro-CHP is the simultaneous generation of useful heat and electricity on a residential scale. The heat and electricity are produced at the point of use, avoiding the distribution losses associated with a centralized power plant. These appliances combine a conventional gas-fired condensing boiler with an electric power module capable of generating electricity from the heat of combustion. Currently, the leading power modules for micro-CHP appliances are free-piston Stirling engines (FPSEs) which can generate 1050 watts of electricity at a thermal-to-electric efficiency of 26%.[1] These external combustion engines have been under development for the last 25 years, with FPSE micro-CHP appliances only recently being introduced to the commercial market. Publications by developers assert unlimited service life and high efficiency, with low noise and emissions; but despite these claims, the actual reliability and cost of manufacturing has prevented their successful mass-market adoption. A Thermoacoustic-Stirling Engine Generator or TaSEG is one possible alternative to FPSE's. A TaSEG uses a thermoacoustic engine, or acoustic heat engine, which can efficiently convert high temperature heat into acoustic power while maintaining a simple design with fewer moving parts than traditional FPSE's. This simpler engine is coupled to an electrodynamic alternator capable of converting acoustic power into electricity. This thesis outlines the design, construction, and experimental evaluation of a TaSEG which is appropriate for integration with a gas burner inside of a residential micro- CHP appliance. The design methodology is discussed, focusing on how changes in the geometry affected the predicted performance. Details of its construction are given and the performance of the TaSEG is then outlined. The TaSEG can deliver 132 watts of electrical output power to an electric load with an overall measured thermal-to-electric (first law) efficiency of eta T-E=8.32%, corresponding to 14% of Carnot etac. The volumetric power density of this TaSEG is 8.9 kW/m3. While the demonstrated overall efficiency is modest (for reasons that are largely understood), this TaSEG has moved the technology away from laboratory prototypes toward a commercially viable power module having a design configuration suitable for implementation in a micro-CHP appliance. Based on the TaSEG's measured experimental performance results, recommendations for future work that might improve the overall efficiency of the TaSEG are also presented.

Numerical modeling of uncertainty and variability in the technology, manufacturing, and economics of crystalline silicon photovoltaics

NASA Astrophysics Data System (ADS)

Ristow, Alan H.

2008-10-01

Electricity generated from photovoltaics (PV) promises to satisfy the world's ever-growing thirst for energy without significant pollution and greenhouse gas emissions. At present, however, PV is several times too expensive to compete economically with conventional sources of electricity delivered via the power grid. To ensure long-term success, must achieve cost parity with electricity generated by conventional sources of electricity. This requires detailed understanding of the relationship between technology and economics as it pertains to PV devices and systems. The research tasks of this thesis focus on developing and using four types of models in concert to develop a complete picture of how solar cell technology and design choices affect the quantity and cost of energy produced by PV systems. It is shown in this thesis that high-efficiency solar cells can leverage balance-of-systems (BOS) costs to gain an economic advantage over solar cells with low efficiencies. This advantage is quantified and dubbed the "efficiency premium." Solar cell device models are linked to models of manufacturing cost and PV system performance to estimate both PV system cost and performance. These, in turn, are linked to a model of levelized electricity cost to estimate the per-kilowatt-hour cost of electricity produced by the PV system. A numerical PV module manufacturing cost model is developed to facilitate this analysis. The models and methods developed in this thesis are used to propose a roadmap to high-efficiency multicrystalline-silicon PV modules that achieve cost parity with electricity from the grid. The impact of PV system failures on the cost of electricity is also investigated; from this, a methodology is proposed for improving the reliability of PV inverters.

Tunable, Electrically Small, Inductively Coupled Antenna for Transportable Ionospheric Heating

NASA Astrophysics Data System (ADS)

Esser, Benedikt; Mauch, Daniel; Dickens, James; Mankowski, John; Neuber, Andreas

2018-04-01

An electrically small antenna is evaluated for use as the principle radiating element in a mobile ionospheric heating array. Consisting of a small loop antenna inductively coupled to a capacitively loaded loop, the electrically small antenna provides high efficiency with the capability of being tuned within the range of ionospheric heating. At a factor 60 smaller in area than a High-Frequency Active Auroral Research Program element, this antenna provides a compact, efficient radiating element for mobile ionospheric heating. A prototype antenna at 10 MHz was built to study large-scale feasibility and possible use with photoconductive semiconductor switch-based drivers. Based on the experimental study, the design has been extrapolated to a small 6 × 4 array of antennas. At a total power input of 16.1 MW this array is predicted to provide 3.6-GW effective radiated power typically required for ionospheric heating. Array cross talk is addressed, including effects upon individual antenna port parameters. Tuning within the range of ionospheric heating, 3-10 MHz, is made possible without the use of lossy dielectrics through a large capacitive area suited to tune the antenna. Considerations for high power operation across the band are provided including a method of driving the antenna with a simple switcher requiring no radio frequency cabling. Source matching may be improved via adjustment of the coupling between small loop antenna and capacitively loaded loop improving |S11| from -1 to -21 dB at 3 MHz.

Alternative Fuels Data Center: Availability of Hybrid and Plug-In Electric

Science.gov Websites

AddThis.com... More in this section... Electricity Basics Benefits & Considerations Stations Vehicles electricity to improve fuel efficiency. Pre-Owned Vehicles Learn about buying and selling pre-owned and plug-in electric vehicles. Learn more about the benefits and considerations of electricity as a

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

NREL Validates Plug-In Hybrid Truck for Pacific Gas and Electric Company |

Science.gov Websites

Energy Systems Integration Facility | NREL Pacific Gas and Electric Company NREL Validates Plug -In Hybrid Truck for Pacific Gas and Electric Company NREL is evaluating and analyzing a Pacific Gas and Electric Company (PG&E) plug-in hybrid electric utility truck developed by Efficient

Reproducible Growth of High-Quality Cubic-SiC Layers

NASA Technical Reports Server (NTRS)

Neudeck, Philip G.; Powell, J. Anthony

2004-01-01

Semiconductor electronic devices and circuits based on silicon carbide (SiC) are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which devices made from conventional semiconductors cannot adequately perform. The ability of SiC-based devices to function under such extreme conditions is expected to enable significant improvements in a variety of applications and systems. These include greatly improved high-voltage switching for saving energy in public electric power distribution and electric motor drives; more powerful microwave electronic circuits for radar and communications; and sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines.

Design of driving control strategy of torque distribution for two - wheel independent drive electric vehicle

NASA Astrophysics Data System (ADS)

Zhang, Chuanwei; Zhang, Dongsheng; Wen, Jianping

2018-02-01

In order to coordinately control the torque distribution of existing two-wheel independent drive electric vehicle, and improve the energy efficiency and control stability of the whole vehicle, the control strategies based on fuzzy control were designed which adopt the direct yaw moment control as the main line. For realizing the torque coordination simulation of the two-wheel independent drive vehicle, the vehicle model, motor model and tire model were built, including the vehicle 7 - DOF dynamics model, motion equation, torque equation. Finally, in the Carsim - Simulink joint simulation platform, the feasibility of the drive control strategy was verified.

Hydrogen storage with trilithium aluminum hexahydride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nathaniel, T.A.

1998-05-14

Fuel cells have good potential to replace batteries for many applications requiring moderate, portable electric power. Applications being researched can range from cellular telephones and radios to power generators for large camps. The primary advantages of fuel cells include high power density, low temperature operation, silent operation, no poisonous exhausts, high electric efficiency, and fast start-up capability. While many commercial industries are just beginning to look at the opportunities fuel cells present, the space program has driven the development of fuel cell technology. The paper discusses the status of the fuel cell and in particular, the technology for hydrogen storagemore » for fuel cell use.« less

Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

NASA Technical Reports Server (NTRS)

Brown, Dale H.

1976-01-01

A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

Partially Turboelectric Aircraft Drive Key Performance Parameters

NASA Technical Reports Server (NTRS)

Jansen, Ralph H.; Duffy, Kirsten P.; Brown, Gerald V.

2017-01-01

The purpose of this paper is to propose electric drive specific power, electric drive efficiency, and electrical propulsion fraction as the key performance parameters for a partially turboelectric aircraft power system and to investigate their impact on the overall aircraft performance. Breguet range equations for a base conventional turbofan aircraft and a partially turboelectric aircraft are found. The benefits and costs that may result from the partially turboelectric system are enumerated. A break even analysis is conducted to find the minimum allowable electric drive specific power and efficiency, for a given electrical propulsion fraction, that can preserve the range, fuel weight, operating empty weight, and payload weight of the conventional aircraft. Current and future power system performance is compared to the required performance to determine the potential benefit.

Simulation and energy analysis of distributed electric heating system

NASA Astrophysics Data System (ADS)

Yu, Bo; Han, Shenchao; Yang, Yanchun; Liu, Mingyuan

2018-02-01

Distributed electric heating system assistssolar heating systemby using air-source heat pump. Air-source heat pump as auxiliary heat sourcecan make up the defects of the conventional solar thermal system can provide a 24 - hour high - efficiency work. It has certain practical value and practical significance to reduce emissions and promote building energy efficiency. Using Polysun software the system is simulated and compared with ordinary electric boiler heating system. The simulation results show that upon energy request, 5844.5kW energy is saved and 3135kg carbon - dioxide emissions are reduced and5844.5 kWhfuel and energy consumption is decreased with distributed electric heating system. Theeffect of conserving energy and reducing emissions using distributed electric heating systemis very obvious.

Micro-economic analysis of the physical constrained markets: game theory application to competitive electricity markets

NASA Astrophysics Data System (ADS)

Bompard, E.; Ma, Y. C.; Ragazzi, E.

2006-03-01

Competition has been introduced in the electricity markets with the goal of reducing prices and improving efficiency. The basic idea which stays behind this choice is that, in competitive markets, a greater quantity of the good is exchanged at a lower price, leading to higher market efficiency. Electricity markets are pretty different from other commodities mainly due to the physical constraints related to the network structure that may impact the market performance. The network structure of the system on which the economic transactions need to be undertaken poses strict physical and operational constraints. Strategic interactions among producers that game the market with the objective of maximizing their producer surplus must be taken into account when modeling competitive electricity markets. The physical constraints, specific of the electricity markets, provide additional opportunity of gaming to the market players. Game theory provides a tool to model such a context. This paper discussed the application of game theory to physical constrained electricity markets with the goal of providing tools for assessing the market performance and pinpointing the critical network constraints that may impact the market efficiency. The basic models of game theory specifically designed to represent the electricity markets will be presented. IEEE30 bus test system of the constrained electricity market will be discussed to show the network impacts on the market performances in presence of strategic bidding behavior of the producers.

Toward High-Energy-Density, High-Efficiency, and Moderate-Temperature Chip-Scale Thermophotovoltaics

DTIC Science & Technology

2013-04-02

this architecture include concentrated solar photovoltaics , thermoelectrics , and fuel cells. System Testing. Themicroreactorwas ignitedbyhydrogen...2, 3), thermoelectrics (4, 5), and thermophotovoltaics (TPVs) (6, 7). TPVs present an extremely appealing approach for small-scale power sources due...into spectrally confined thermal radiation, optically coupled to low-bandgap photovoltaic (PV) diodes that are electrically interfaced with a unique

Learning energy literacy concepts from energy-efficient homes

NASA Astrophysics Data System (ADS)

Paige, Frederick Eugene

The purpose of this study is to understand ways that occupants' and visitors' interaction with energy efficient home design affects Energy Literacy. Using a case study approach including interviews, surveys, and observations, I examined the potential for affordable energy efficient homes in the Greenville South Carolina area to "teach" concepts from an Energy Literacy framework developed by dozens of educational partners and federal agencies that comprise the U.S. Global Change Research Program Partners. I paid particular attention to concepts from the framework that are transferable to energy decisions beyond a home's walls. My research reveals ways that interaction with high efficiency homes can effect understanding of the following Energy Literacy concepts: human use of energy is subject to limits and constraints, conservation is one way to manage energy resources, electricity is generated in multiple ways, social and technological innovations effect the amount of energy used by society, and energy use can be calculated and monitored. Examples from my case studies show how the at-home examples can make lessons on energy more personally relevant, easy to understand, and applicable. Specifically, I found that: • Home occupants learn the limits of energy in relation to the concrete and constricting costs associated with their consumption. • Heating and cooling techniques showcase the limits and constraints on different sources of energy. • Relatable systems make it easier to understand energy's limits and constraints. • Indistinct and distant power utilities allow consumers to overlook the root of electricity sources. • Visible examples of electricity generation systems make it clear that electricity is generated in multiple ways. • Small and interactive may mean inefficient electricity generation, but efficient energy education. • Perceptions of expense and complexity create a disconnect between residential energy consumers and renewable electricity generation. • Utility bill limits and constraints exemplify the ability to conserve energy resources. • Replicable examples teach lessons on conservation. • Via an understanding of the water-energy nexus, water conservation lessons transfer to energy saving lessons. • Passive design exemplifies how a shift in thinking can conserve energy resources through informed efficient decision-making. • Societal shifts in energy consumption are evident at home. • Efficient homes provide applicable examples of social and technological innovations. • The home is the environment in which memorable lessons on energy are passed through cultures. • Home energy consumption comparisons are a popular and effective social innovation, but people have mixed emotions about their usefulness. • A utility bill communicates that utility companies are monitoring energy use to calculate cost. • Interactivity enhances feedback from energy monitors. • Calculating and monitoring energy use is perceived as a complex mathematical process. • Energy consumption feedback at the appliance level is desired to inform decisions. • There is a separation between personal energy monitoring and public monitoring. Implications of this research are that an energy literate society will have the knowledge that is a prerequisite for the motivation to address energy and climate issues. Educators, policy makers, engineers, and designers all play a role in creating a built environment that encourages energy saving behavior.

Invited review article: physics and Monte Carlo techniques as relevant to cryogenic, phonon, and ionization readout of Cryogenic Dark Matter Search radiation detectors.

PubMed

Leman, Steven W

2012-09-01

This review discusses detector physics and Monte Carlo techniques for cryogenic, radiation detectors that utilize combined phonon and ionization readout. A general review of cryogenic phonon and charge transport is provided along with specific details of the Cryogenic Dark Matter Search detector instrumentation. In particular, this review covers quasidiffusive phonon transport, which includes phonon focusing, anharmonic decay, and isotope scattering. The interaction of phonons in the detector surface is discussed along with the downconversion of phonons in superconducting films. The charge transport physics include a mass tensor which results from the crystal band structure and is modeled with a Herring-Vogt transformation. Charge scattering processes involve the creation of Neganov-Luke phonons. Transition-edge-sensor (TES) simulations include a full electric circuit description and all thermal processes including Joule heating, cooling to the substrate, and thermal diffusion within the TES, the latter of which is necessary to model normal-superconducting phase separation. Relevant numerical constants are provided for these physical processes in germanium, silicon, aluminum, and tungsten. Random number sampling methods including inverse cumulative distribution function (CDF) and rejection techniques are reviewed. To improve the efficiency of charge transport modeling, an additional second order inverse CDF method is developed here along with an efficient barycentric coordinate sampling method of electric fields. Results are provided in a manner that is convenient for use in Monte Carlo and references are provided for validation of these models.

Coordinated EV adoption: double-digit reductions in emissions and fuel use for $40/vehicle-year.

PubMed

Choi, Dong Gu; Kreikebaum, Frank; Thomas, Valerie M; Divan, Deepak

2013-09-17

Adoption of electric vehicles (EVs) would affect the costs and sources of electricity and the United States efficiency requirements for conventional vehicles (CVs). We model EV adoption scenarios in each of six regions of the Eastern Interconnection, containing 70% of the United States population. We develop electricity system optimization models at the multidecade, day-ahead, and hour-ahead time scales, incorporating spatial wind energy modeling, endogenous modeling of CV efficiencies, projections for EV efficiencies, and projected CV and EV costs. We find two means to reduce total consumer expenditure (TCE): (i) controlling charge timing and (ii) unlinking the fuel economy regulations for CVs from EVs. Although EVs provide minimal direct GHG reductions, controlled charging provides load flexibility, lowering the cost of renewable electricity. Without EVs, a 33% renewable electricity standard (RES) would cost $193/vehicle-year more than the reference case (10% RES). Combining a 33% RES, EVs with controlled charging and unlinking would reduce combined electric- and vehicle-sector CO2 emissions by 27% and reduce gasoline consumption by 59% for $40/vehicle-year more than the reference case. Coordinating EV adoption with adoption of controlled charging, unlinked fuel economy regulations, and renewable electricity standards would provide low-cost reductions in emissions and fuel usage.

Endovascular Electrodes for Electrical Stimulation of Blood Vessels for Vasoconstriction - a Finite Element Simulation Study

NASA Astrophysics Data System (ADS)

Kezurer, Noa; Farah, Nairouz; Mandel, Yossi

2016-08-01

Hemorrhagic shock accounts for 30-40 percent of trauma mortality, as bleeding may sometimes be hard to control. Application of short electrical pulses on blood vessels was recently shown to elicit robust vasoconstriction and reduction of blood loss following vascular injury. In this study we present a novel approach for vasoconstriction based on endovascular application of electrical pulses for situations where access to the vessel is limited. In addition to ease of access, we hypothesize that this novel approach will result in a localized and efficient vasoconstriction. Using computer modeling (COMSOL Multiphysics, Electric Currents Module), we studied the effect of endovascular pulsed electrical treatment on abdominal aorta of pigs, and compared the efficiency of different electrodes configurations on the electric field amplitude, homogeneity and locality when applied on a blood vessel wall. Results reveal that the optimal configuration is the endovascular approach where four electrodes are used, spaced 13 mm apart. Furthermore, computer based temperature investigations (bio-heat model, COMSOL Multiphysics) show that the maximum expected temperature rise is of 1.2 degrees; highlighting the safety of the four endovascular electrodes configuration. These results can aid in planning the application of endovascular pulsed electrical treatment as an efficient and safe vasoconstriction approach.

Endovascular Electrodes for Electrical Stimulation of Blood Vessels for Vasoconstriction – a Finite Element Simulation Study

PubMed Central

Kezurer, Noa; Farah, Nairouz; Mandel, Yossi

2016-01-01

Hemorrhagic shock accounts for 30–40 percent of trauma mortality, as bleeding may sometimes be hard to control. Application of short electrical pulses on blood vessels was recently shown to elicit robust vasoconstriction and reduction of blood loss following vascular injury. In this study we present a novel approach for vasoconstriction based on endovascular application of electrical pulses for situations where access to the vessel is limited. In addition to ease of access, we hypothesize that this novel approach will result in a localized and efficient vasoconstriction. Using computer modeling (COMSOL Multiphysics, Electric Currents Module), we studied the effect of endovascular pulsed electrical treatment on abdominal aorta of pigs, and compared the efficiency of different electrodes configurations on the electric field amplitude, homogeneity and locality when applied on a blood vessel wall. Results reveal that the optimal configuration is the endovascular approach where four electrodes are used, spaced 13 mm apart. Furthermore, computer based temperature investigations (bio-heat model, COMSOL Multiphysics) show that the maximum expected temperature rise is of 1.2 degrees; highlighting the safety of the four endovascular electrodes configuration. These results can aid in planning the application of endovascular pulsed electrical treatment as an efficient and safe vasoconstriction approach. PMID:27534438

Compressed Natural Gas Technology for Alternative Fuel Power Plants

NASA Astrophysics Data System (ADS)

Pujotomo, Isworo

2018-02-01

Gas has great potential to be converted into electrical energy. Indonesia has natural gas reserves up to 50 years in the future, but the optimization of the gas to be converted into electricity is low and unable to compete with coal. Gas is converted into electricity has low electrical efficiency (25%), and the raw materials are more expensive than coal. Steam from a lot of wasted gas turbine, thus the need for utilizing exhaust gas results from gas turbine units. Combined cycle technology (Gas and Steam Power Plant) be a solution to improve the efficiency of electricity. Among other Thermal Units, Steam Power Plant (Combined Cycle Power Plant) has a high electrical efficiency (45%). Weakness of the current Gas and Steam Power Plant peak burden still using fuel oil. Compressed Natural Gas (CNG) Technology may be used to accommodate the gas with little land use. CNG gas stored in the circumstances of great pressure up to 250 bar, in contrast to gas directly converted into electricity in a power plant only 27 bar pressure. Stored in CNG gas used as a fuel to replace load bearing peak. Lawyer System on CNG conversion as well as the power plant is generally only used compressed gas with greater pressure and a bit of land.

High efficiency β radioisotope energy conversion using reciprocating electromechanical converters with integrated betavoltaics

NASA Astrophysics Data System (ADS)

Duggirala, Rajesh; Li, Hui; Lal, Amit

2008-04-01

We demonstrate a 5.1% energy conversion efficiency Ni63 radioisotope power generator by integrating silicon betavoltaic converters with radioisotope actuated reciprocating piezoelectric unimorph cantilever converters. The electromechanical energy converter efficiently utilizes both the kinetic energy and the electrical charge of the 0.94μW β radiation from a 9mCi Ni63 thin film source to generate maximum (1) continuous betavoltaic electrical power output of 22nW and (2) pulsed piezoelectric electrical power output of 750μW at 0.07% duty cycle. The electromechanical converters can be potentially used to realize 100year lifetime power sources for powering periodic sampling remote wireless sensor microsystems.

Electric Generator in the System for Damping Oscillations of Vehicles

NASA Astrophysics Data System (ADS)

Serebryakov, A.; Kamolins, E.; Levin, N.

2017-04-01

The control systems for the objects of industry, power generation, transport, etc. are extremely complicated; functional efficiency of these systems determines to a great extent the safe and non-polluting operation as well as convenience of service and repair of such objects. The authors consider the possibility to improve the efficiency of systems for damping oscillations in transport using a combination of electrical (generators of rotational and linear types) and hydraulic means. Better efficiency of functioning is achieved through automatic control over the operational conditions of such a system in order to make it adaptive to variations in the road profile and ambient temperature; besides, it is possible to produce additional electric energy.

High efficiency thermal to electric energy conversion using selective emitters and spectrally tuned solar cells

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

1992-01-01

Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1500 K. Depending on the nature of parasitic losses, overall thermal-to-electric conversion efficiencies greater than 20 percent are feasible.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Jing; Jeong, Young Gyu, E-mail: ygjeong@cnu.ac.kr

High performance elastomeric electric heating elements were prepared by incorporating various contents of pristine multiwalled carbon nanotube (MWCNT) in polydimethylsiloxane (PDMS) matrix by using an efficient solution-casting and curing technique. The pristine MWCNTs were identified to be uniformly dispersed in the PDMS matrix and the electrical percolation of MWCNTs was evaluated to be at ∼0.27 wt. %, where the electrical resistivity of the MWCNT/PDMS composite films dropped remarkably. Accordingly, the composite films with higher MWCNT contents above 0.3 wt. % exhibit excellent electric heating performance in terms of temperature response rapidity and electric energy efficiency at constant applied voltages. In addition, the composite films,more » which were thermally stable up to 250 °C, showed excellent heating-cooling cyclic performance, which was associated with operational stability in actual electric heating applications.« less

Neural network control of a parallel hybrid-electric propulsion system for a small unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Harmon, Frederick G.

2005-11-01

Parallel hybrid-electric propulsion systems would be beneficial for small unmanned aerial vehicles (UAVs) used for military, homeland security, and disaster-monitoring missions. The benefits, due to the hybrid and electric-only modes, include increased time-on-station and greater range as compared to electric-powered UAVs and stealth modes not available with gasoline-powered UAVs. This dissertation contributes to the research fields of small unmanned aerial vehicles, hybrid-electric propulsion system control, and intelligent control. A conceptual design of a small UAV with a parallel hybrid-electric propulsion system is provided. The UAV is intended for intelligence, surveillance, and reconnaissance (ISR) missions. A conceptual design reveals the trade-offs that must be considered to take advantage of the hybrid-electric propulsion system. The resulting hybrid-electric propulsion system is a two-point design that includes an engine primarily sized for cruise speed and an electric motor and battery pack that are primarily sized for a slower endurance speed. The electric motor provides additional power for take-off, climbing, and acceleration and also serves as a generator during charge-sustaining operation or regeneration. The intelligent control of the hybrid-electric propulsion system is based on an instantaneous optimization algorithm that generates a hyper-plane from the nonlinear efficiency maps for the internal combustion engine, electric motor, and lithium-ion battery pack. The hyper-plane incorporates charge-depletion and charge-sustaining strategies. The optimization algorithm is flexible and allows the operator/user to assign relative importance between the use of gasoline, electricity, and recharging depending on the intended mission. A MATLAB/Simulink model was developed to test the control algorithms. The Cerebellar Model Arithmetic Computer (CMAC) associative memory neural network is applied to the control of the UAVs parallel hybrid-electric propulsion system. The CMAC neural network approximates the hyper-plane generated from the instantaneous optimization algorithm and produces torque commands for the internal combustion engine and electric motor. The CMAC neural network controller saves on the required memory as compared to a large look-up table by two orders of magnitude. The CMAC controller also prevents the need to compute a hyper-plane or complex logic every time step.

Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 1: Executive summary. [using coal or coal derived fuels

NASA Technical Reports Server (NTRS)

Corman, J. C.

1976-01-01

A data base for the comparison of advanced energy conversion systems for utility applications using coal or coal-derived fuels was developed. Estimates of power plant performance (efficiency), capital cost, cost of electricity, natural resource requirements, and environmental intrusion characteristics were made for ten advanced conversion systems. Emphasis was on the energy conversion system in the context of a base loaded utility power plant. All power plant concepts were premised on meeting emission standard requirements. A steam power plant (3500 psig, 1000 F) with a conventional coal-burning furnace-boiler was analyzed as a basis for comparison. Combined cycle gas/steam turbine system results indicated competitive efficiency and a lower cost of electricity compared to the reference steam plant. The Open-Cycle MHD system results indicated the potential for significantly higher efficiency than the reference steam plant but with a higher cost of electricity.

Energy efficiency to reduce residential electricity and natural gas use under climate change.

PubMed

Reyna, Janet L; Chester, Mikhail V

2017-05-15

Climate change could significantly affect consumer demand for energy in buildings, as changing temperatures may alter heating and cooling loads. Warming climates could also lead to the increased adoption and use of cooling technologies in buildings. We assess residential electricity and natural gas demand in Los Angeles, California under multiple climate change projections and investigate the potential for energy efficiency to offset increased demand. We calibrate residential energy use against metered data, accounting for differences in building materials and appliances. Under temperature increases, we find that without policy intervention, residential electricity demand could increase by as much as 41-87% between 2020 and 2060. However, aggressive policies aimed at upgrading heating/cooling systems and appliances could result in electricity use increases as low as 28%, potentially avoiding the installation of new generation capacity. We therefore recommend aggressive energy efficiency, in combination with low-carbon generation sources, to offset projected increases in residential energy demand.

Energy efficiency system development

NASA Astrophysics Data System (ADS)

Leman, A. M.; Rahman, K. A.; Chong, Haw Jie; Salleh, Mohd Najib Mohd; Yusof, M. Z. M.

2017-09-01

By subjecting to the massive usage of electrical energy in Malaysia, energy efficiency is now one of the key areas of focus in climate change mitigation. This paper focuses on the development of an energy efficiency system of household electrical appliances for residential areas. Distribution of Questionnaires and pay a visit to few selected residential areas are conducted during the fulfilment of the project as well as some advice on how to save energy are shared with the participants. Based on the collected data, the system developed by the UTHM Energy Team is then evaluated from the aspect of the consumers' behaviour in using electrical appliances and the potential reduction targeted by the team. By the end of the project, 60% of the participants had successfully reduced the electrical power consumption set by the UTHM Energy Team. The reasons for whether the success and the failure is further analysed in this project.

Energy efficiency to reduce residential electricity and natural gas use under climate change

NASA Astrophysics Data System (ADS)

Reyna, Janet L.; Chester, Mikhail V.

2017-05-01

Climate change could significantly affect consumer demand for energy in buildings, as changing temperatures may alter heating and cooling loads. Warming climates could also lead to the increased adoption and use of cooling technologies in buildings. We assess residential electricity and natural gas demand in Los Angeles, California under multiple climate change projections and investigate the potential for energy efficiency to offset increased demand. We calibrate residential energy use against metered data, accounting for differences in building materials and appliances. Under temperature increases, we find that without policy intervention, residential electricity demand could increase by as much as 41-87% between 2020 and 2060. However, aggressive policies aimed at upgrading heating/cooling systems and appliances could result in electricity use increases as low as 28%, potentially avoiding the installation of new generation capacity. We therefore recommend aggressive energy efficiency, in combination with low-carbon generation sources, to offset projected increases in residential energy demand.

A chemistry and material perspective on lithium redox flow batteries towards high-density electrical energy storage.

PubMed

Zhao, Yu; Ding, Yu; Li, Yutao; Peng, Lele; Byon, Hye Ryung; Goodenough, John B; Yu, Guihua

2015-11-21

Electrical energy storage system such as secondary batteries is the principle power source for portable electronics, electric vehicles and stationary energy storage. As an emerging battery technology, Li-redox flow batteries inherit the advantageous features of modular design of conventional redox flow batteries and high voltage and energy efficiency of Li-ion batteries, showing great promise as efficient electrical energy storage system in transportation, commercial, and residential applications. The chemistry of lithium redox flow batteries with aqueous or non-aqueous electrolyte enables widened electrochemical potential window thus may provide much greater energy density and efficiency than conventional redox flow batteries based on proton chemistry. This Review summarizes the design rationale, fundamentals and characterization of Li-redox flow batteries from a chemistry and material perspective, with particular emphasis on the new chemistries and materials. The latest advances and associated challenges/opportunities are comprehensively discussed.

Optimization of gear ratio and power distribution for a multimotor powertrain of an electric vehicle

NASA Astrophysics Data System (ADS)

Urbina Coronado, Pedro Daniel; Orta Castañón, Pedro; Ahuett-Garza, Horacio

2018-02-01

The architecture and design of the propulsion system of electric vehicles are highly important for the reduction of energy losses. This work presents a powertrain composed of four electric motors in which each motor is connected with a different gear ratio to the differential of the rear axle. A strategy to reduce energy losses is proposed, in which two phases are applied. Phase 1 uses a divide-and-conquer approach to increase the overall output efficiency by obtaining the optimal torque distribution for the electric motors. Phase 2 applies a genetic algorithm to find the optimal value of the gear ratios, in which each individual of each generation applies Phase 1. The results show an optimized efficiency map for the output torque and speed of the powertrain. The increase in efficiency and the reduction of energy losses are validated by the use of numerical experiments in various driving cycles.

Conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage.

PubMed

Kano, Shinya; Fujii, Minoru

2017-03-03

We study the conversion efficiency of an energy harvester based on resonant tunneling through quantum dots with heat leakage. Heat leakage current from a hot electrode to a cold electrode is taken into account in the analysis of the harvester operation. Modeling of electrical output indicates that a maximum heat leakage current is not negligible because it is larger than that of the heat current harvested into electrical power. A reduction of heat leakage is required in this energy harvester in order to obtain efficient heat-to-electrical conversion. Multiple energy levels of a quantum dot can increase the output power of the harvester. Heavily doped colloidal semiconductor quantum dots are a possible candidate for a quantum-dot monolayer in the energy harvester to reduce heat leakage, scaling down device size, and increasing electrical output via multiple discrete energy levels.

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision 21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the second annual technical progress report for the Vision 21 AGC program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending September 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less

Autonomous, Decentralized Grid Architecture: Prosumer-Based Distributed Autonomous Cyber-Physical Architecture for Ultra-Reliable Green Electricity Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2012-01-11

GENI Project: Georgia Tech is developing a decentralized, autonomous, internet-like control architecture and control software system for the electric power grid. Georgia Tech’s new architecture is based on the emerging concept of electricity prosumers—economically motivated actors that can produce, consume, or store electricity. Under Georgia Tech’s architecture, all of the actors in an energy system are empowered to offer associated energy services based on their capabilities. The actors achieve their sustainability, efficiency, reliability, and economic objectives, while contributing to system-wide reliability and efficiency goals. This is in marked contrast to the current one-way, centralized control paradigm.

The Future of Utility Customer-Funded Energy Efficiency Programs in the United States: Projected Spending and Savings to 2025

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbose, Galen; Goldman, Charles; Hoffman, Ian

2012-09-11

We develop projections of future spending on, and savings from, energy efficiency programs funded by electric and gas utility customers in the United States, under three scenarios through 2025. Our analysis, which updates a previous LBNL study, relies on detailed bottom-up modeling of current state energy efficiency policies, regulatory decisions, and demand-side management and utility resource plans. The three scenarios are intended to represent a range of potential outcomes under the current policy environment (i.e., without considering possible major new policy developments). By 2025, spending on electric and gas efficiency programs (excluding load management programs) is projected to double frommore » 2010 levels to $9.5 billion in the medium case, compared to $15.6 billion in the high case and $6.5 billion in the low case. Compliance with statewide legislative or regulatory savings or spending targets is the primary driver for the increase in electric program spending through 2025, though a significant share of the increase is also driven by utility DSM planning activity and integrated resource planning. Our analysis suggests that electric efficiency program spending may approach a more even geographic distribution over time in terms of absolute dollars spent, with the Northeastern and Western states declining from over 70% of total U.S. spending in 2010 to slightly more than 50% in 2025, with the South and Midwest splitting the remainder roughly evenly. Under our medium case scenario, annual incremental savings from customer-funded electric energy efficiency programs increase from 18.4 TWh in 2010 in the U.S. (which is about 0.5% of electric utility retail sales) to 28.8 TWh in 2025 (0.8% of retail sales). These savings would offset the majority of load growth in the Energy Information Administration’s most recent reference case forecast, given specific assumptions about the extent to which future energy efficiency program savings are captured in that forecast. However, the pathway that customer-funded efficiency programs ultimately take will depend on a series of key challenges and uncertainties associated both with the broader market and policy context and with the implementation and regulatory oversight of the energy efficiency programs themselves.« less

Technical and legal considerations and solutions in the area of battery charging for electric vehicles

NASA Astrophysics Data System (ADS)

Juda, Z.

2016-09-01

The issue of protecting health of residents of urbanized areas from the effect of excessive particulate matter and toxic components of car exhaust gases imposes the need of introduction of clean electric vehicles to the market. The increasing market availability of electric vehicles, especially in the segment of short-range (neighborhood) vehicles is followed by development of new and advanced infrastructure solutions. This also applies to the increasingly popular hybrid vehicles PHEV (Plug-in Hybrid Electric Vehicles). However, problems with the existing designs are primarily associated with limited driving range on a single battery charge, the density of charging stations in urban and suburban area, energy system efficiency due to increased electricity demand and the unification of solutions for charging stations, on-board chargers and the necessary accessories. Technical solutions are dependent on many factors, including the type and size of battery in the vehicle and access to power grid with increased load capacity. The article discusses the legal and technical actions outlined in the above directions. It shows the available and planned solutions in this area.

Novel polymer composite having diamond particles and boron nitride platelets for thermal management of electric vehicle motors

NASA Astrophysics Data System (ADS)

Nakajima, Anri; Shoji, Atsushi; Yonemori, Kei; Seo, Nobuhide

2016-02-01

Thermal conductivities of silicone matrix polymers including fillers of diamond particles and/or hexagonal boron nitride (h-BN) platelets were systematically investigated in an attempt to find a thermal interface material (TIM) having high isotropic thermal conductivity and high electrical insulating ability to enable efficient heat dissipation from the motor coil ends of electric vehicles. The TIM with mixed fillers of diamond particles and h-BN platelets had a maximum thermal conductivity of 6.1 W m-1 K-1 that was almost isotropic. This is the highest value among the thermal conductivities of TIMs with silicone matrix polymer reported to date. The mechanism behind the thermal conductivity of the TIMs was also examined from the viewpoint of the change in the number of thermally conductive networks and/or a decrease in the thermal resistivity of junctions of neighboring diamond particles through the incorporation of h-BN platelets. The TIMs developed in this study will make it possible to manage the heat of electric motors and will help to popularize electric vehicles.

POwer WithOut Wire (POWOW): A SEP Concept for Space Exploration

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W., Jr.; ONeill, Mark

2000-01-01

Electric propulsion has emerged as a cost-effective solution to a wide range of satellite applications. Deep Space 1 demonstrated electric propulsion as a primary propulsion source for a spacecraft. The POwer WithOut Wires (POWOW) concept has been developed as a solar electric propelled spacecraft that would travel to Mars, for example, enter selenosynchronous orbit and then use lasers to beam power to surface installations. This concept has been developed with industrial expertise in high efficiency solar cells, advanced concentrator modules, innovative arrays, and high power electric propulsion systems. The paper will present the latest version of the spacecraft, the technologies involved, possible missions and trip times to Mars and laser beaming options. The POWOW spacecraft is a general purpose solar electric propulsion system that includes technologies that are directly applicable to commercial and government spacecraft with power levels ranging from 4 kW in Low Earth Orbits (LEO) to about 1 MW. The system is modular and expandable. Learning curve costing methodologies are used to demonstrate cost effectiveness of a modular system.

Prediction and control of neural responses to pulsatile electrical stimulation

NASA Astrophysics Data System (ADS)

Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

2012-04-01

This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

UMR’S DESIGN FOR AN ENVIRONMENTAL STEP AHEAD: SOLAR THERMAL ELECTRIC PANELS

EPA Science Inventory

Not only is the STEP hybrid system effective in its aesthetics but also it is more efficient than its two stand-alone counterparts. The estimated overall efficiency of the STEP system is estimated to be 15-45 percent as compared to a separate thermal and separate electric sy...