Science.gov

Sample records for passive solar commercial

  1. Passive Solar Commercial Demonstration Program: Phase I. Final report

    SciTech Connect

    1981-02-10

    The passive solar retrofit of a small existing commercial/residential building is described. An add on gallery/sunspace is integrated into the existing structure both in terms of energy and architectural functioning. The sunspace solution maximizes the amount of south facing glass for solar heat gain, while still allowing a deep penetration of daylight into the existing buildings. (MHR)

  2. An economic model for passive solar designs in commercial environments

    NASA Astrophysics Data System (ADS)

    Powell, J. W.

    1980-06-01

    The model incorporates a life cycle costing approach that focuses on the costs of purchase, installation, maintenance, repairs, replacement, and energy. It includes a detailed analysis of tax laws affecting the use of solar energy in commercial buildings. Possible methods of treating difficult to measure benefits and costs, such as effects of the passive solar design on resale value of the building and on lighting costs, rental income from the building, and the use of commercial space, are presented. The model is illustrated in two case examples of prototypical solar design for low rise commercial buildings in an urban setting.

  3. Passive solar renovation of an existing commercial greenhouse

    SciTech Connect

    McGinnis, J.W.; Whitehead, N.

    1980-01-01

    The renovation of an existing 1800 square foot commercial greenhouse to incorporate passive solar reliant and energy conserving features is detailed. The Aquatic-Agriculture Institute for Research, a non-profit group, sponsored the project to develop efficient production methods to raise vegetables and fish at the community level. The performance of the remodeled greenhouse will be compared to the performance of the same greenhouse as it was originally designed. The restored greenhouse began operation in September 1979. Accurate fuel and temperature records maintained through-out the past winter, show the cost of back-up heating under operating conditions to be approximately $150.00. Old fuel receipts dating back into the 1940's show an average use of 2000 gallons of heating fuel each winter prior to remodeling. This would indicate a yearly fuel savings of better than 90% through the use of passive solar techniques.

  4. Passive solar technology

    SciTech Connect

    Watson, D

    1981-04-01

    The present status of passive solar technology is summarized, including passive solar heating, cooling and daylighting. The key roles of the passive solar system designer and of innovation in the building industry are described. After definitions of passive design and a summary of passive design principles are given, performance and costs of passive solar technology are discussed. Passive energy design concepts or methods are then considered in the context of the overall process by which building decisions are made to achieve the integration of new techniques into conventional design. (LEW).

  5. Cooperative passive-solar commercial retrofit. Final report, September 1, 1980-December 31, 1982

    SciTech Connect

    Brown, W.T.

    1982-12-01

    The primary objectives of this project were: the conversion of an existing south-facing storefront into a trombe'-wall passive solar collector, the sharing of information on simple low-cost energy alternatives with the local community, and the reduction of the store building's dependence on non-renewable fossil fuel for space heating. Six 6' wide pre-assembled collector glazing panels were mounted on a 12' high by 36' long portion of the south-facing masonry wall. Vent-holes were cut through the wall at each panel to provide air inlets and outlets for the collector and monitoring equipment was installed to record performance. A series of hands-on construction workshops were attended by Co-op and community members. During these sessions, collector components were assembled. The panels were installed on April 22, 1981 in celebration of Earth Day. Additional sessions were held to complete the project, make necessary modifications and install sensors. Project personnel participated in several energy-education activities, including workshops, seminars and alternative energy home tours. A community-based energy resource council was founded with the assistance of several key Co-op project members and a fully-illustrated How-To manual, entitled Passive Solar Collector: A Trombe'-Wall Retrofit Guide was published. Finally, a variety of energy conservation measures were undertaken. These included a new airlock store entry, insulated store ceiling, destratification ceiling fans and wood-burning furnaces have combined with the passive solar collector to substantially reduce the use of fuel oil for heat.

  6. Passive solar energy: the genesis for architectural innovations in commercial buildings

    SciTech Connect

    Kroner, W.M.; Smith, P.N.

    1981-01-01

    The Campus Information Center (CIC) at Rensselaer Polytechnic Institute, Troy, New York, integrates environmental controls, energy conservation measures, and passive solar design. It demonstrates what can be done when the client, architect, and engineer work together to create a building that synthesizes energy-related technologies with architectural excellence in a cost effective manner. This paper discusses the unique process that led to the timely design of the CIC. It also provides specific information about three of the CIC's innovative systems: the multipath energy flow system, the individualized comfort system, and the building instrumentation system.

  7. User evaluation study of passive solar residences

    SciTech Connect

    Towle, S.

    1980-03-01

    Speculation exists regarding the readiness of various passive techniques for commercialization and the market potential for residential applications. This paper discusses the preliminary findings of a market assessment study designed to document user experiences with passive solar energy. Owners and builders of passive solar homes were interviewed and asked to comment on personal experiences with their homes.

  8. Passive solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  9. Passive solar commercial buildings: design assistance and demonstration program. Phase 1. Final report

    SciTech Connect

    1981-01-26

    The final design of the Mount Airy Public Library is given. Incremental passive design costs are discussed. Performance and economic analyses are made and the results reported. The design process is thoroughly documented. Considerations discussed are: (1) building energy needs; (2) site energy potentials, (3) matching energy needs with site energy potentials, (4) design indicators for best strategies and concepts, (5) schematic design alternatives, (6) performance testing of the alternatives, (7) design selection, and (8) design development. Weather data and Duke Power electric rates are included. (LEW)

  10. Passive-solar greenhouse

    SciTech Connect

    Not Available

    1982-01-01

    Our project objective was to design, construct, and operate a commercialized (16' x 50') passive, solar greenhouse. The structure was originally intended as a vegetable forcing facility to produce vegetable crops in the off-season. Building and size constraints and economic considerations convinced us to use the greenhouse for producing bedding plants and vegetable starts in the spring, high value vegetables (tomatoes, cucumbers) in the fall and forced bulbs in the winter. This crop sequence allows us to use the greenhouse all year without additional heat as the crops are adopted to the temperature regime of the greenhouse during each particular season. In our first season, the greenhouse performed beautifully. The lowest temperature recorded was 38/sup 0/F after 4 cold, cloudy days in February. The production of bedding plants has allowed us to diversify our products and the early transplants we produced were a great asset to our vegetable farming operation. Although construction cost (4.57 sq. ft.) is higher than that of a conventional polyethylene-covered, quonset-type greenhouse (approx. $1.92 sq. ft.), our annual operating cost is cheaper than that of a conventional greenhouse (0.49 cents sq. ft. versus 0.67 cents sq. ft.) due to a longer usable lifetime of the structure and the elimination of heating costs. Our structure has been toured by interested individuals, school and farm groups. We plan to publicize the structure and its advantages by promoting more visits to the site.

  11. Passive-solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-02-01

    Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

  12. Passive Solar Is Common Sense.

    ERIC Educational Resources Information Center

    Robison, Rita

    1979-01-01

    A checklist of concepts concerning passive solar energy techniques. Many can be applied immediately to existing buildings, while others should be brought into the initial planning of buildings. (Author/MLF)

  13. Passive solar hen house--Second year

    SciTech Connect

    MacDougall, E.A.

    1980-12-01

    This paper describes the second year's study of a passive solar hen house. The first year's study demonstrated that a small flock of hens living in a solar heated environment can produce more eggs at a better feed efficiency than that predicted by the U.S. Department of Agriculture (USDA) for hens housed in standard hen housing. For this second year's work a new flock of Rhode Island Reds was raised and then divided in two groups - one housed in the solar hen house; the other in a barn. The solar housed group showed slightly better feed efficiency, but the barn housed group had better egg production. Both groups produced consistently heavier eggs than comparative commercial hens. However, the commercial hens showed higher feed efficiency than either the barn housed or the solar housed group for the 15 week test.

  14. Neglect mars passive solar progress

    SciTech Connect

    Holzman, D.

    1984-02-01

    The development of solar technology in the United States was reviewed at the annual Passive Solar Update Conference held in Washington D.C. in Sept. 1983. Though it lacked the technological breakthroughs of some past conferences, this conference was notable because the mood was definitely upbeat. The promise of many solar approaches is as great as ever and they now seem to be reliazable.

  15. Passive solar design handbook. Volume 3: Passive solar design analysis

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; Bascomb, J. D.; Kosiewicz, C. E.; Lazarus, G. S.; McFarland, R. D.; Wray, W. O.

    1982-07-01

    Simple analytical methods concerning the design of passive solar heating systems are presented with an emphasis on the average annual heating energy consumption. Key terminology and methods are reviewed. The solar load ratio (SLR) is defined, and its relationship to analysis methods is reviewed. The annual calculation, or Load Collector Ratio (LCR) method, is outlined. Sensitivity data are discussed. Information is presented on balancing conservation and passive solar strategies in building design. Detailed analysis data are presented for direct gain and sunspace systems, and details of the systems are described. Key design parameters are discussed in terms of their impact on annual heating performance of the building. These are the sensitivity data. The SLR correlations for the respective system types are described. The monthly calculation, or SLR method, based on the SLR correlations, is reviewed. Performance data are given for 9 direct gain systems and 15 water wall and 42 Trombe wall systems.

  16. Interior design for passive solar homes

    SciTech Connect

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems has brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building form incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitability of various interior elements.

  17. Passive solar energy information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1980-11-01

    The results of a series of telephone interviews with groups of users of information on passive solar heating and cooling are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven passive groups respondents are analyzed in this report: Federally Funded Researchers, Manufacturer Representatives, Architects, Builders, Educators, Cooperative Extension Service County Agents, and Homeowners. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  18. New England style passive solar

    SciTech Connect

    Kriescher, P.

    2000-06-01

    There are homeowners throughout New England who planned for and built homes that allow them to avoid the sting of winter's high heating bills. These climate-responsive homes rely on passive solar heating, cooling and lighting. An example of such a climate-responsive/passive solar house is the home that Arthur and Terry Becker build on 6 beautiful acres (2.4 hectares) of rolling farm and woodland southeast of Andover, Connecticut, in 1981. They worked very closely with their designer, Al Eggan of K.T. Lear and Associates, to ensure that they would never have to pay for home heating oil, and that they would enjoy a level of year-round comfort that they had not experienced in conventionally built homes.

  19. Passive solar in China: traditional and new

    SciTech Connect

    Balcomb, J D; Balcomb, S A

    1986-04-01

    The authors' observations of a tradition of passive solar architecture in northern China are described. Tendencies for modern buildings to depart from this tradition are noted. Major passive solar research programs are discussed and experimental buildings are illustrated. It is concluded that the Chinese could realize a major advantage by combining their strong tradition of passive solar architecture with modern insulation methods and improved glazing systems.

  20. Passive solar in the United States: 1976-1986

    SciTech Connect

    Balcomb, J D

    1987-01-01

    A decade of experience in passive solar development in the United States is reviewed. More than 200,000 residential and 15,000 institutional and commercial passive solar buildings have been constructed since 1976. The evolution of the program through its peak in 1980 to the present is described. Methods of performance prediction and evaluation are discussed including analysis methods, design tools, test modules and monitored buildings. Results of the monitoring show excellent performance, generally in agreement with the analysis, for both residences and larger buildings. Passive practice is analyzed and problems are discussed. The current research program is described. Potential savings are estimated.

  1. Gap between active and passive solar heating

    SciTech Connect

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  2. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, Jerry M.; Kurtz, Sarah R.

    1994-01-01

    A high-efficiency heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer.

  3. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, J.M.; Kurtz, S.R.

    1994-05-31

    A high-efficiency heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer. 1 fig.

  4. Tierra Nueva -- A passive solar cohousing project

    SciTech Connect

    Haggard, K.; Cooper, P.

    1999-10-01

    California architects take on the formidable challenges of designing a cohousing project, and discover that the end result is well worth the effort. The Tierra Nueva Cohousing Project consists of living units, a common house, community orchard, community gardens, community play space, space for a future shop and at the periphery of the site, parking, carports and garages. The units use thermal mass, solar heating, passive solar cooling, perimeter insulation on slabs. Design was agreed to by the community as a whole.

  5. Mennonite Nursing Home passive solar demonstration

    SciTech Connect

    Not Available

    1984-03-01

    A long-term nursing care facility and retirement center was designed for passive solar heating. The system comprises thermal mass, thermal insulation, Trombe walls, and direct gain clerestories. Included here is a topical report, analysis of building performance, owner's perspective, designer's perspective, and summary of information dissemination activities. (MHR)

  6. Camp Sacajawea Passive Solar Demonstration Project

    SciTech Connect

    Not Available

    1983-08-31

    The intent of the Passive Solar Demonstration Project was to have: an actual demonstration of the effectiveness of a passive solar design and working automatic shading devices; accurate data of energy saved by the passive design and shading devices; a brochure distributed to architects, builders, and consumers, with the monitoring data and information about the project; and the continued monitoring of the building to help explain to those who are using the building the value of the system; this would not only include the 7000 members, bu visitors and other users of the facility. To accomplish these goals, a monitoring system was installed in the recently build Passive Solar Lodge at Camp Sacajawea on Casper Mountain south of Casper, Wyoming. The building was monitored continously for the remainder of the project. The installation of the automatic shading device, a curtain wall was accomplished but had some difficulty. The results indicate there is some effectiveness of the Curtain Wall, but a quantitative value would be impossible at this time.

  7. Commercialization of solar space power

    NASA Astrophysics Data System (ADS)

    Pant, Alok; Sera, Gary

    1995-01-01

    The objective of this research is to help U.S. companies commercialize renewable energy in India, with a special focus on solar energy. The National Aeronautics and Space Administration (NASA) Mid-Continent Technology Transfer Center (MCTTC) is working with ENTECH, Inc., a solar photovoltaic (SPV) systems manufacturer to form partnerships with Indian companies. MCTTC has conducted both secondary and primary market research and obtained travel funding to meet potential Indian partners face to face. MCTTC and ENTECH traveled to India during June 2-20, 1994, and visited New Delhi, Bombay, Pune and Calcutta. Meetings were held with several key government officials and premier Indian business houses and entrepreneurs in the area of solar energy. A firsthand knowledge of India's renewable energy industry was gained, and companies were qualified in terms of capabilities and commitment to the SPV business. The World Bank has awarded India with 280 million to commercialize renewable energies, including 55 million for SPV. There is a market in India for both small-scale (kW) and large SPV (MW) applications. Each U.S. company needs to form a joint venture with an Indian firm and let the latter identify the states and projects with the greatest business potential. Several big Indian companies and entrepreneurs are planning to enter the SPV business, and they currently are seeking foreign technology partners. Since the lager companies have adopted a more conservative approach, however, partnerships with entrepreneurs might offer the quickest route to market entry in India.

  8. Passive solar in tornado alley

    SciTech Connect

    Kriescher, P.

    2000-02-01

    The renewable energy and energy efficiency industries have long relied on entrepreneurial individuals with a passion for integrating clean energy alternatives into residential and commercial construction. Most of these individuals were drawn into sustainable energy design during time of inflationary energy prices (e.g., the 1973 oil crisis), when government and industry were investing in clean energy technologies. Some of the best and brightest maintained their enthusiasm for high quality, low energy building design--even as government and industry support slowed--and worked tirelessly toward making sustainable design viable in the marketplace.

  9. PASSIVE SMOKING ON COMMERCIAL AIRLINE FLIGHTS

    EPA Science Inventory

    Inflight exposure to nicotine, urinary cotinine and symptom self reports were assessed in a study of 9 subjects (5 passengers and 4 attendants) on four routine commercial flights each of approximately 4 hours duration. rine samples were collected for 72 hours following each fligh...

  10. Passive and Hybrid Solar Energy Program

    SciTech Connect

    Not Available

    1980-11-01

    The background and scope of the program is presented in general terms. The Program Plan is summarized describing how individual projects are categorized into mission-oriented tasks according to market sector categories. The individual projects funded by DOE are presented as follows: residential buildings, commercial buildings, solar products, solar cities and towns, and agricultural buildings. A summary list of projects by institution (contractors) and indexed by market application area is included. (MHR)

  11. User participation in passive solar housing design

    SciTech Connect

    McLain-Kark, J.H.

    1985-01-01

    A field study was conducted in 1984 in order to compare the characteristics, lifestyle, attitudes, and behavioral adaptations of two groups of passive solar homeowners, those with high or low levels of participation in the design and/or building process. Forty-one Virginia passive solar homeowners were surveyed and interviewed in their home. Photographic slides and floor plans with furniture layout were also analyzed. The results indicate that the owner-built homeowners or those with high participation in design and/or building were older, more educated, and were more involved in community affairs than the low participation homeowners. They also were more involved in maintenance tasks, more likely to engage in a voluntary simplicity lifestyle, and more energy conserving. The owner-builders too had a higher level of satisfaction with their home. The majority of the homeowners expressed dissatisfaction with the flexibility of arranging furniture in the open plan. An analysis of the floor plans revealed that three factors were contributing to the problems: zones, circulation/furniture arrangement, and passive elements.

  12. Passive solar progress: a simplified guide to the 3rd national passive solar conference

    SciTech Connect

    Miller, H.; Howell, Y.; Richards, D.

    1980-10-01

    Some of the concepts and practices that have come to be known as passive solar heating and cooling are introduced, and a current picture of the field is presented. Much of the material presented is derived from papers given at the 3rd National Passive Solar Conference held in San Jose, California in January 1979 and sponsored by the US Department of Energy. Extracts and data from these papers have been integrated in the text with explanatory and descriptive material. In this way, it is attempted to present technical information in an introductory context. Topics include design considerations, passive and hybrid systems and applications, sizing methods and performance prediction, and implementation issues. A glossary is included. (WHK)

  13. SOLCOST-PASSIVE solar energy design program: User's Guide

    SciTech Connect

    Not Available

    1980-09-01

    The SOLCOST-PASSIVE solar energy design program is a public domain interactive computer design tool intended for use by non-thermal specialists to size passive solar systems with a methodology based on the Los Alamos Solar Load Ratio method. A life cycle savings analysis is included in the program. An overview of SOLCOST-PASSIVE capabilities and the Solar Load Ratio method which it is based on is presented. A detailed guide to the SOLCOST-PASSIVE input parameters is given. Sample problems showing typical execution sessions and the resulting SOLCOST-PASSIVE output are included. Appendices A thru D provide details on the SLR method and the life cycle savings methodology of SOLCOST-PASSIVE. (MHR)

  14. Passive solar sunset: Predicting our own demise

    SciTech Connect

    Milne, M.

    1986-01-01

    Phrases like solar heating, passive cooling, or energy-conserving design should be eliminated as quickly as possible from the vocabularies of all practicing architects. Such phrases should be replaced by the phrase ''competent design'' and simply taken for granted. Every client has a right to expect these features from a qualified professional just as they expect a structurally sound, fire-safe, and weather-tight building. In times past, indigenous builders knew very well how to design thermally efficient and energy-conserving buildings. They may not have understood the theory behind their designs, but the rituals, traditions, and cultural taboos governing their work embodied wisdom gained over the centuries. The elegance and thermal ingenuity of these buildings are still admired by even the most high-tech, post-modern architects of today.

  15. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  16. Passive solar technology aids biogas digesters

    SciTech Connect

    Not Available

    1988-07-01

    Farming communities throughout China rely on biogas generators as a primary source of light and heat, as well as using the sludge as a nitrogen-rich fertilizer. Now researchers at Beijing's Solar Energy Laboratory have improved efficiency by building a rectangular tank out of concrete slabs, with one slanted surface painted black and covered with glass. According to a report in New Scientist, this passive solar panel generates heat in the same way as a greenhouse, raising inside temperatures by 10{degree}C and increasing biogas production by 50%. Another advantage of the new tanks is easy access, since the tank's lid sites in wells of water which form a seal against oxygen. (Old biogas tanks were made of soil, sand and a little concrete, prone to developing severe cracks which would allow oxygen to enter thus slowing down anaerobic reaction). Explains Debora MacKenzie of New Scientist: with the new tank, the farmer can simply remove the lid and attack the contents with a spade. This means that the mixture can comprise more than 10% solids. Greater density allows smaller tanks. Rural families need one cubic meter of biogas daily for light and heat; instead of the former 8 cm biogas generator, the new tanks need only be 1 cm. The prediction is that the smaller size could make biogas more popular in China's crowded towns. The biogas department is headed by He Shao Qi, who is also investigating ways to reduce production costs for the tanks.

  17. Solar technology assessment project. Volume 4: Solar air conditioning: Active, hybrid and passive

    NASA Astrophysics Data System (ADS)

    Yellott, J. I.

    1981-04-01

    The status of absorption cycle solar air conditioning and the Rankine cycle solar cooling system is reviewed. Vapor jet ejector chillers, solar pond based cooling, and photovoltaic compression air conditioning are also briefly discussed. Hybrid solar cooling by direct and indirect evaporative cooling, and dehumidification by desiccation are described and discussed. Passive solar cooling by convective and radiative processes, evaporative cooling by passive processes, and cooling with roof ponds and movable insulation are reviewed. Federal and state involvement in solar cooling is discussed.

  18. Passive solar design: final evaluation, the Passive Studio

    SciTech Connect

    Bremer, Duncan S.; Rose, Stuart

    1980-08-01

    The further evaluation of the workshops in passive design for practicing architects and engineers through delayed interviews with a sample of the participants is reported with particular emphasis on the extent to which the participants have practiced passive design in the three-four months since attending. Also discussed is an unsuccessful attempt to conduct a lower-cost version of the program outside of normal office hours. Finally, the follow-on programs and improvements that the interviews indicated are needed are identified. (MHR)

  19. Window structure for passivating solar cells based on gallium arsenide

    NASA Technical Reports Server (NTRS)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  20. Enhanced Charge Collection with Passivation Layers in Perovskite Solar Cells.

    PubMed

    Lee, Yong Hui; Luo, Jingshan; Son, Min-Kyu; Gao, Peng; Cho, Kyung Taek; Seo, Jiyoun; Zakeeruddin, Shaik M; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2016-05-01

    The Al2 O3 passivation layer is beneficial for mesoporous TiO2 -based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of the perovskite layer during post-annealing. PMID:26928481

  1. Commercializing solar for industry in California

    NASA Astrophysics Data System (ADS)

    Yudelson, J.

    1980-10-01

    The State of California has begun a commercialization program for increasing the rate of solar applications in industry. The components of this program include low interest loans, tax credits, revenue bonds and educational efforts. Many California industries appear to be likely candidates for solar systems, but as yet only a few companies have elected to install them. The various barriers to solar use by industry are primarily perceptual and financial. The emphasis of the state program for commercialization is turning increasingly towards educational seminars for industry groups and development of creative financial tools and arrangements. There are a few remaining legislative changes at state and federal levels, primarily involving leasing and tax laws which, if enacted, would overcome all of the remaining financial barriers to widespread adoption of solar applications by industry.

  2. 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

  3. Passive-solar design manual for the United States Navy

    SciTech Connect

    Wray, W.O.; Biehl, F.A.; Kosiewicz, C.R.; Miles, C.R. Durlak, E.R.

    1982-01-01

    A passive solar design manual for single-family detached residences and dormitory-type buildings is being developed. The design procedure employed in the manual is a simplification of the original monthly solar load ratio (SLR) method. The new SLR correlations involve a single constant for each system. The correlation constant appears as a scale factor permitting the use of a universal performance curve for all passive systems. Furthermore, by providing location-dependent correlations between the annual solar heating fraction (SHF)* and the minimum monthly SHF, we have eliminated the need to perform an SLR calculation for each month of the heating season.

  4. Illinois solar '80: how to build 18 passive solar homes for less than $30,000

    SciTech Connect

    Donahue, P.; Dean, K.

    1981-01-01

    Illinois Solar '80, a residential passive solar construction program targeted at Illinois vocational schools traditionally involved in home building projects, is discussed. Conducted by the Illinois Institute of Natural Resources (INR), the first round of this program has resulted in the construction of 18 energy efficient passive solar homes by 17 vocational schools throughout the state. The major program components of Illinois Solar '80 are: (1) an open solicitation process, (2) professional training in passive design and construction, (3) $1000 grant award to each school, (4) technical assistance, (5) promotional support, and (6) site visits. A total agency investment of $29,000 in direct costs has resulted in training over 650 building trades students in passive solar design through construction of 18 solar homes.

  5. Locally contacted rear surface passivated solar cells by inkjet printing

    NASA Astrophysics Data System (ADS)

    Phiwpha, N.; Fangsuwannarak, T.; Sopitpan, S.

    2014-06-01

    Inkjet printing of photoresist material may provide a new route for low-cost fabrication of patterned oxide passivation layer of solar cells that require fine patterning and simple process. However, printing by liquid-based, environmentally friendly ink and printing device required development efforts aimed at achieving a fine patterning and long used inkjet nozzles under corrosive influence. This work was demonstrated a concept for grooved silicon oxide patterning for rear localized contact of p-n junction solar cells by chemical etching after photoresist patterning obtained. This article reviews the silicon dioxide fabrication on p-Si substrate from sol-gel technique for oxide passivation layer of solar cells. The aluminium was deposited on the patterned oxide layer and then heated at its Al-Si eutectic temperature. Finally, an aluminium-induced solid-phase epitaxial growth of p+ forming into the openings of the oxide passivation layer was presented. The sheet resistance of n-emitter layer, carrier life-time and surface recombination velocity values are investigated. Photoconductive measurements were performed on the prepared samples after each thermal process to measure the effective lifetime of the minority carriers. Carrier lifetime up to 60 microseconds has been measured on c-Si wafer passivated by the opened SiO2 layer. It was shown that the patterned SiO2 passivation has obtained high passivation quality making by the proposed inkjet printing method.

  6. Front surface passivation of silicon solar cells with antireflection coating

    NASA Technical Reports Server (NTRS)

    Crotty, G.; Daud, T.; Kachare, R.

    1987-01-01

    It is demonstrated that the deposition and postdeposition sintering of an antireflection (AR) coating in hydrogen acts to passivate silicon solar cells. Cells with and without an SiO2 passivating layer, coated with a TiO(x)/Al2O3 AR coating, showed comparable enhancements in short-wavelength spectral response and in open-circuit voltage Voc after sintering at 400 C for 5 min in a hydrogen ambient. The improvement in Voc of cells without SiO2 is attributed to front-surface passivation by the AR coating during processing.

  7. Passive-solar retrofit study for the United States Navy

    SciTech Connect

    Wray, W.O.; Miles, C.R.

    1981-01-01

    A passive solar retrofit study has been conducted for the United States Navy at the Los Alamos National Laboratory. The purpose of the study was to determine the energy savings obtainable in concrete block buildings from several passive solar heating strategies. A procedure involving the use of test cell data and computer simulation was employed to assess the merits of six retrofit options. The six strategies selected were chosen on the basis of providing a series of options that will deliver increasing energy savings at the cost of correspondingly increased levels of commitment.

  8. Passive-solar-retrofit study for the United States Navy

    SciTech Connect

    Wray, W.O.; Miles, C.R.

    1981-01-01

    A passive solar retrofit study has been conducted for the United States Navy at the Los Alamos National Laboratory. The purpose of the study was to determine the energy savings obtainable in concrete block buildings from several passive solar heating strategies. A procedure involving the use of test cell data and computer simulation was employed to assess the merits of six retrofit options. The six strategies selected were chosen on the basis of providing a series of options that will deliver increasing energy savings at the cost of correspondingly increased levels of commitment.

  9. Progress in passive solar energy systems. Volume 8. Part 1

    SciTech Connect

    Hayes, J.; Andrejko, D.A.

    1983-01-01

    This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.

  10. Commercial dissemination approaches for solar home systems

    SciTech Connect

    Terrado, E.

    1997-12-01

    The author discusses the issue of providing solar home systems to primarily rural areas from the perspective of how to commercialize the process. He considers two different approaches, one an open market approach and the other an exclusive market approach. He describes examples of the exclusive market approach which are in process in Argentina and Brazil. Coming from a banking background, the business aspects are discussed in detail. He points out the strengths and weaknesses of both approaches toward developing such systems.

  11. Passive solar array orientation devices for terrestrial application.

    NASA Technical Reports Server (NTRS)

    Fairbanks, J. W.; Morse, F. H.

    1972-01-01

    A passive solar array orientation device, called a thermal heliotrope, is described, and several terrestrial applications are illustrated. The thermal heliotrope consists of a bimetallic helical coil that serves as the motor element, producing torque and angular displacement. A control mechanism in the form of one or more shades completes the basic device. In comparison with electromechanical tracking systems, the thermal heliotrope is electrically passive, has relatively few parts, and is low cost. After describing the principle of operation and several models built for space applications, the design considerations for several terrestrial thermal heliotrope units are presented. It is suggested that the use of the thermal heliotrope for solar array orientation could significantly reduce array cost, thereby increasing the competitive economic posture of solar arrays for terrestrial applications. The thermal heliotrope modified for terrestrial use is readily adaptable to orient solar energy concentrators, such as furnaces and stills.

  12. Passive Solar Design: Technology Fact Sheet; Office of Building Technology, State and Community Programs (BTS)

    SciTech Connect

    Southern Energy Institute

    2000-12-14

    Fact sheet for homeowners and contractors on using passive solar design features in homes can increase energy efficiency and comfort. Topics include design techniques, cost, and passive solar design tools.

  13. Vocational-Technical Instructors Passive-Solar Training Workshop

    NASA Astrophysics Data System (ADS)

    1981-07-01

    The successful efforts to provide training to instructors who teach residential design and construction at vocational-technical (vo-tech) schools are described. The training was directed toward those techniques one must consider when designing and/or constructing an energy efficient passive solar home.

  14. Simple procedure for schematic design of passive solar buildings

    SciTech Connect

    Wray, W.O.; Kosiewicz, C.E.

    1984-01-01

    A simple procedure for use during the schematic phase of passive solar building design is presented in this article. The procedure is quantitative and accurate enough to insure that designs based on the provided starting point values of the primary building parameters will be cost effective.

  15. Passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

    1985-01-01

    Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

  16. Vocational-technical instructors passive-solar training workshop

    SciTech Connect

    Not Available

    1981-07-01

    The successful efforts to provide training to instructors who teach residential design and construction at vocational-technical (vo-tech) schools are described. The training was directed toward those techniques one must consider when designing and/or constructing an energy efficient passive solar home.

  17. Passive solar house in Skillman, NJ: Case study

    SciTech Connect

    Kendig, J.

    1999-07-01

    This study traces the history of a single family residence in Skillman, NJ designed by Harrison Fraker. The house, built in 1978, was conceived as primarily passive solar house intended to rely on solar energy for most of its heating needs. Solar features include direct gain windows, water walls and sunspace. The study documents original solar features, identifies changes over time and evaluates performance of the house. The owners have removed movable insulation and significantly reduced the amount of thermal mass over the life of the building. The owner reported comfort level changes intuitively consistent with those modifications. The owner is contemplating further changes to make the house more marketable, changes likely to further alter the remaining passive solar features. Builders Guide software was used to calculate changes in solar performance of the house related to building modifications. Calculations of solar performance generally correspond to anecdotal information from the owner. The author's attempts with Energy 10 program showed some promise, but are as yet inconclusive. At this time BG appears to be more useful and user friendly to the average practitioner with limited time and design resources. As a practicing architect the author is most interested in lessons to be learned from the past as they might contribute to future projects. Information gleaned from this study did confirm intuitively expected and currently disseminated thinking regarding passive solar design. The thermal mass proved to be vulnerable to change. Features which required daily manual adjustment were quickly discarded. Desire for comfort was driving force in changing the house and took precedence over the need to save energy or money.

  18. Efficient passivated phthalocyanine-quantum dot solar cells.

    PubMed

    Blas-Ferrando, Vicente M; Ortiz, Javier; González-Pedro, Victoria; Sánchez, Rafael S; Mora-Seró, Iván; Fernández-Lázaro, Fernando; Sastre-Santos, Ángela

    2015-01-31

    The power conversion efficiency of CdSe and CdS quantum dot sensitized solar cells is enhanced by passivation with asymmetrically substituted phthalocyanines. The introduction of the phthalocyanine dye increases the efficiency up to 45% for CdSe and 104% for CdS. The main mechanism causing this improvement is the quantum dot passivation. This study highlights the possibilities of a new generation of dyes designed to be directly linked to QDs instead of the TiO2 electrodes. PMID:25519050

  19. Analysis of thermal comfort in a passive solar heated residence

    NASA Astrophysics Data System (ADS)

    Liu, S. T.

    1981-11-01

    The thermal comfort conditions in a passive solar heated residence of the popular Trombe Wall configuration were investigated. The indoor thermal environment of an actual passive solar residence, using the typical meteorological year (TMY) weather data tape as input as three locations of different climatic conditions was simulated. The relevant thermal comfort parameters such as the space air temperature, mean radiant temperatures, operative temperatures, radiant temperature asymmetry, and temperature drifts of the occupied zone, were computed for a prime heating month, a transition month and a prime cooling month of a typical weather year at the three locations. It is found that for the specific passive solar residence analyzed, the upper boundary of the comfort envelope can be exceeded (overheating) during a typical clear day in the transition month of April unless a change of clothing to summer wear is made during the daytime high solar radiation house. The upper boundary will be exceeded during a typical clear day in the prime cooling month of August for a person in typical summer clothing at all three locations unless the average air movement in the occupied zone is increased above the level of natural circulation, or the thermostat setting is reduced to a lower level, or both.

  20. Passive-solar-cooling system concepts for small office buildings. Final report

    SciTech Connect

    Whiddon, W.I.; Hart, G.K.

    1983-02-01

    This report summarizes the efforts of a small group of building design professionals and energy analysis experts to develop passive solar cooling concepts including first cost estimates for small office buildings. Two design teams were brought together at each of two workshops held in the fall of 1982. Each team included an architect, mechanical engineer, structural engineer, and energy analysis expert. This report presents the passive cooling system concepts resulting from the workshops. It summarizes the design problems, solutions and first-cost estimates relating to each technology considered, and documents the research needs identified by the participants in attempting to implement the various technologies in an actual building design. Each design problem presented at the workshops was based on the reference (base case) small office building analyzed as part of LBL's Cooling Assessment. Chapter II summarizes the thermal performance, physical specifications and estimated first-costs of the base case design developed for this work. Chapters III - VI describe the passive cooling system concepts developed for each technology: beam daylighting; mass with night ventilation; evaporative cooling; and integrated passive cooling systems. The final Chapters, VII and VIII present the preliminary implications for economics of passive cooling technologies (based on review of the design concepts) and recommendations of workshop participants for future research in passive cooling for commercial buildings. Appendices provide backup information on each chapter as indicated.

  1. Surface passivation of high efficiency silicon solar cells

    NASA Astrophysics Data System (ADS)

    Aberle, A.; Warta, W.; Knobloch, J.; Voss, B.

    Theoretically and experimentally determined design guides for significantly reducing recombination at the emitter and rear surfaces of full-area Al-BSF (back-surface region) and oxide-passivated bifacial cells are given. The impact of emitter thickness and surface dopant concentration on emitter saturation current and solar cell efficiency is outlined. A modified emitter structure (locally deep diffused below the metal contacts) is predicted to have superior performance. Measured Voc values reveal the potential of deep emitter cells to achieve efficiencies above 20 percent in spite of high metallization factors. Experimentally, a strong dependence of passivation quality on oxide thickness and base doping concentration is found. The BSF quality of a diffused aluminum layer decreases strongly with increasing drive-in time. For SiO2-passivated rear surfaces of bifacial cells, measurements of the dependence of the surface recombination velocity on the excess carrier concentration are presented.

  2. Environmentally friendly education: A passive solar, straw-bale school

    SciTech Connect

    Stone, L.; Dickinson, J.

    1999-07-01

    The Waldorf students in the Roaring Fork Valley of western Colorado are learning their reading, writing and arithmetic in the cozy confines of a solar heated, naturally lit, straw-bale school. The Waldorf education system, founded in 1919 by Austrian Rudolph Steiner, stresses what's appropriate for the kids, not what's easiest to teach. In constructing a new school, the Waldorf community wanted a building that would reflect their philosophy. There was a long list of requirements: natural, energy efficient, light, warm, alive, and earthy. Passive solar straw-bale construction brought together all those qualities.

  3. Novel Passivating/Antireflective Coatings for Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Bailey, S. G.; Flood, D. J.; Faur, H. M.; Mateescu, C. G.; Alterovitz, S. A.; Scheiman, D.; Jenkins, P. P.; Brinker, D. J.

    2005-01-01

    We are developing a novel process to grow passivating/antireflective (AR) coatings for terrestrial and space solar cells. Our approach involves a Room Temperature Wet Chemical Growth (RTWCG) process, which was pioneered, and is under development at SPECMAT, Inc., under a Reimbursable Space Act Agreement with NASA Glenn Research Center. The RTWCG passivating/AR coatings with graded index of refraction are applied in one easy step on finished (bare) cells. The RTWCG coatings grown on planar, textured and porous Si, as well as on poly-Si, CuInSe2, and III-V substrates, show excellent uniformity irrespective of surface topography, crystal orientation, size and shape. In this paper we present some preliminary results of the RTWCG coatings on Si and III-V substrates that show very good potential for use as a passivation/AR coating for space solar cell applications. Compared to coatings grown using conventional techniques, the RTWCG coatings have the potential to reduce reflection losses and improve current collection near the illuminated surface of space solar cells, while reducing the fabrication costs.

  4. National Passive Solar Conference, 4th, Kansas City, MO, October 3-5, 1979, Proceedings. Volume 4

    NASA Astrophysics Data System (ADS)

    Franta, G.

    1981-10-01

    Papers concern recent experience in the research, development and application of passive solar technology. Specific topics include the legislative barriers and incentives to passive solar systems, coupled thermal and lighting simulations for evaluating daylighting design effectiveness, passive solar applications in inner city housing, radiative cooling in a desert climate, salinity gradient solar ponds, the retrofit of a masonry home for passive space heating, the performances of active and passive solar domestic hot water systems, builder experience with passive solar home construction, the use of solar energy installations on farm buildings, and a method of determining the thermal performance of passive storage walls.

  5. Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

    SciTech Connect

    Salyer, I.O.; Sircar, A.K.; Dantiki, S.

    1988-01-01

    During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

  6. Ion Implanted Passivated Contacts for Interdigitated Back Contacted Solar Cells

    SciTech Connect

    Young, David L.; Nemeth, William; LaSalvia, Vincenzo; Reedy, Robert; Bateman, Nicholas; Stradins, Pauls

    2015-06-14

    We describe work towards an interdigitated back contacted (IBC) solar cell utilizing ion implanted, passivated contacts. Formation of electron and hole passivated contacts to n-type CZ wafers using tunneling SiO2 and ion implanted amorphous silicon (a-Si) are described. P and B were ion implanted into intrinsic amorphous Si films at several doses and energies. A series of post-implant anneals showed that the passivation quality improved with increasing annealing temperatures up to 900 degrees C. The recombination parameter, Jo, as measured by a Sinton lifetime tester, was Jo ~ 14 fA/cm2 for Si:P, and Jo ~ 56 fA/cm2 for Si:B contacts. The contact resistivity for the passivated contacts, as measured by TLM patterns, was 14 milliohm-cm2 for the n-type contact and 0.6 milliohm-cm2 for the p-type contact. These Jo and pcontact values are encouraging for forming IBC cells using ion implantation to spatially define dopants.

  7. Simulation of a passive solar energy system. Master's thesis

    SciTech Connect

    Slate, M.P.

    1982-12-01

    A simple lumped capacitance-resistance model is used to simulate heat flow in a residential size structure heated passively by the sun. The model takes the form of an analogous electrical circuit. A computer program was written to analyse the circuit. By altering the input parameters of the program, the thermal performance of a wide variety of passive solar designs can be investigated for any geographical location. By comparing program generated data to data taken from experimental test cells in Los Alamos, New Mexico, it was found that the simulation program predicted energy use to within 4 percent of measured values. Also, the computer program predicted temperature swings to within 16 percent of measured swings. Correlation with empirical methods of calculating monthly and annual savings in fuel use for heating was poor. Using the simulation calculations as a base, the predictions of anual savings differed by as much as 76 percent.

  8. The role of surface passivation for efficient and photostable PbS quantum dot solar cells

    NASA Astrophysics Data System (ADS)

    Cao, Yiming; Stavrinadis, Alexandros; Lasanta, Tania; So, David; Konstantatos, Gerasimos

    2016-04-01

    For any emerging photovoltaic technology to become commercially relevant, both its power conversion efficiency and photostability are key parameters to be fulfilled. Colloidal quantum dot solar cells are a solution-processed, low-cost technology that has reached an efficiency of about 9% by judiciously controlling the surface of the quantum dots to enable surface passivation and tune energy levels. However, the role of the quantum dot surface on the stability of these solar cells has remained elusive. Here we report on highly efficient and photostable quantum dot solar cells with efficiencies of 9.6% (and independently certificated values of 8.7%). As a result of optimized surface passivation and the suppression of hydroxyl ligands—which are found to be detrimental for both efficiency and photostability—the efficiency remains within 80% of its initial value after 1,000 h of continuous illumination at AM1.5G. Our findings provide insights into the role of the quantum dot surface in both the stability and efficiency of quantum dot solar cells.

  9. Optimization of storage in passive solar heating systems. Final report

    SciTech Connect

    Bahm, R.J.

    1980-05-01

    The search for a simple method of estimating the optimum amount of storage for passive solar space heating system designs and the results of that search are described. The project goals, and why the project is important are described. The major project results are presented in the order of their importance with respect to meeting the project goal. A narrative description of the project is given. Here the various approaches attempted are described, giving the reasons for failure in those areas that were not successful. The Appendices contain the bulk of data generated by this project. Most of the data is presented in graphical form. (MHR)

  10. Thermal and cost goal analysis for passive solar heating designs

    SciTech Connect

    Noll, S.A.; Kirschner, C.

    1980-01-01

    Economic methodologies developed over the past several years for the design of residential solar systems have been based on life cycle cost (LCC) minimization. Because of uncertainties involving future economic conditions and the varied decision making processes of home designers, builders, and owners, LCC design approaches are not always appropriate. To deal with some of the constraints that enter the design process, and to narrow the number of variables to those that do not depend on future economic conditions, a simplified thermal and cost goal approach for passive designs is presented. Arithmetic and graphical approaches are presented with examples given for each. Goals discussed include simple payback, solar savings fraction, collection area, maximum allowable construction budget, variable cost goals, and Btu savings.

  11. Nanoporous Anodic Edge Passivation of Si Solar Cells.

    PubMed

    Choi, Jaeho; Palei, Srikanta; Parida, Bhaskar; Ko, Seuk Yong; Kim, Keunjoo

    2015-11-01

    We investigated the anodization effect on edge passivation of Si solar cells. The Si anodization allowed SiO2 formation on the edges of the cell for electrical passivation. The edge passivated cell showed enhanced conversion efficiency with reduced carrier recombination which was observed from photoluminescence and electroluminescence images. The luminescences were reduced at the edges indicating prevention of edge current leakage. However, when the rear Al paste layer of a sample was contacted to the solution during the anodization process, the conversion efficiency of the cell was reduced. We characterized oxide thin films by performing the anodization process for front Al thin film layer deposited by evaporation and rear Al paste layer. The front anodic aluminum oxide covering the Si emitter layer showed the excellent phototransmission with small photoreflectance lower than 5% and the anodization of Al paste showed the formation of a thin SiO2 film as well as nanoporous Al2O3 layer originating from the microspherical Al paste. The rear Al paste anodization allowed the Al microspheres to be filled with the nanopores in the inner empty space. PMID:26726608

  12. Economic analysis of commercial solar water-heating systems

    SciTech Connect

    1980-09-23

    A brief description is given of a typical commercial solar water heating system, outlining typical cost and performance levels. The economic performance of solar energy systems is described through the use of Cash Flow Diagrams. The economic performance of solar energy systems is described through the calculation of equivalent Return-On-Investment (ROI). Appendices are included that enable one to calculate the ROI for any particular solar hot water system investment. (MHR)

  13. A passive solar system for downward heat transport

    SciTech Connect

    Stacy, W.D.

    1982-01-01

    This paper discusses the development and testing of a unique passive solar DHW system employing roof mounted conventional flat plate collectors and a conventional coil-in-tank hot water heater located 20 feet below the collectors. The system operates as an intermittent heat pipe in a two stroke cycle involving day time boil down/night time condensate return. System concept, construction details, and test results are presented for the 40 ft/sup 2/, 40 gpd workhorse prototype DHW system. Passive system cycling was experimentally confirmed to be completely reliable under both design and off-design conditions of usage, isolation, and weather. Day long system efficiency averaged 35% to 40% between July and December in northern New England and reached 45% under favorable ambient conditions. System attributes regarding performance, reliability, and site/installation flexibility are described and discussed. Key advantages of boiling/condensing fluid systems in solar applications are noted, and the need for further development of appropriate working fluids is discussed in the context of evolving codes.

  14. Alternative Architecture for Commercial Space Solar Power

    NASA Technical Reports Server (NTRS)

    Potter, Seth

    2000-01-01

    This presentation discuss the space solar power (SSP) concept. It takes us step by step through the process: the use of sunlight and solar cells to create power, the conversion of the sunlight into electricity, the conversion of electricity to microwaves, and finally the from microwaves back to electricity by the Rectennas on Earth.

  15. NATURAL CONVECTION IN PASSIVE SOLAR BUILDINGS: EXPERIMENTS, ANALYSIS AND RESULTS

    SciTech Connect

    Gadgil, A.; Bauman, F.; Kammerud, R.

    1981-04-01

    Computer programs have been developed to numerically simulate natural convection in two- and three-dimensional room geometries. The programs have been validated using published data from the literature, results from a full-scale experiment performed at the Massachusetts Institute of Technology, and results from a small-scale experiment performed at LBL. One of the computer programs has been used to study the influence of natural convection on the thermal performance of a single zone in a direct-gain passive solar building. It is found that the convective heat transfer coefficients between the air and the enclosure surfaces can be substantially different from the values assumed in the standard building energy analysis methods, and can exhibit significant variations across a given surface. This study implies that the building heating loads calculated by standard building energy analysis methods may have substantial errors as a result of their use of common assumptions regarding the convection processes which occur in an enclosure.

  16. Wallboard with Latent Heat Storage for Passive Solar Applications

    SciTech Connect

    Kedl, R.J.

    2001-05-31

    Conventional wallboard impregnated with octadecane paraffin [melting point-23 C (73.5 F)] is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM (melting point, melting range, and heat of fusion), as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. The confirmed computer model may now be used in conjunction with a building heating and cooling code to evaluate design parameters and operational characteristics of latent heat storage wallboard for passive solar applications.

  17. A passive, sun-pointing, millimeter-scale solar sail

    NASA Astrophysics Data System (ADS)

    Atchison, Justin A.; Peck, Mason A.

    2010-07-01

    Taking inspiration from the orbital dynamics of dust, we find that spacecraft length scaling is a means of enabling infinite-impulse orbits that require no feedback control. Our candidate spacecraft is a 25 μm thick, 1 cm square silicon chip equipped with signal transmitting circuitry. This design reduces the total mass to less than 7.5 mg and enables the spacecraft bus itself to serve as a solar sail with characteristic acceleration on the order of 0.1 mm/s 2. It is passive in that it maneuvers with no closed-loop actuation of orbital or attitude states. The unforced dynamics that result from an insertion orbit and a launch-vehicle separation determine its subsequent state evolution. We have developed a system architecture that uses solar radiation torques to maintain a sun-pointing heading and can be fabricated with standard microfabrication processes. This architecture has potential applications in heliocentric, geocentric, and three-body orbits.

  18. Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling

    SciTech Connect

    Schneider, A.R.

    1980-01-01

    The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

  19. Passive solar design strategies: Remodeling guidelines for conserving energy at home. [Final report

    SciTech Connect

    Not Available

    1991-12-31

    The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler`s typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house`s need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

  20. Passive solar design strategies: Remodeling guidelines for conserving energy at home

    SciTech Connect

    Not Available

    1991-01-01

    The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler's typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house's need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

  1. DOE passive solar commercial buildings program: project summaries

    SciTech Connect

    Not Available

    1982-01-01

    The 23 projects participating in this program comprise a wide range of building types including offices, retail establishments, educational facilities, public service facilities, community and visitor centers, and private specialized-use facilities, located throughout the United States. Summary data and drawings are presented for each project. (MHR)

  2. Energy-conserving passive solar multi-family retrofit projects. Cycle 5, category 1: HUD Solar Heating and Cooling Demonstration Program

    NASA Astrophysics Data System (ADS)

    1981-10-01

    A total of 14 passive solar retrofit buildings are described. The concept of passive solar energy and the various types of passive systems found in the Cycle 5 projects are discussed. Each of the 14 solar designs is described, and some of the key points raised in the discussion of passive concepts are illustrated. Each project description cites the location of the passive solar home and presents the following information: grantee/builder, designer, solar designer, price, number of units, net heated area, heat load, degree days, solar fraction of the total heat load, and auxiliary heat required. Project descriptions also include data on recognition factors (the five passive elements necessary for a complete passive system), the type of auxiliary heating system used in the building, the solar water heating system (if any), and the passive cooling techniques used (if any).

  3. Concentrating Solar Power Commercial Application Study

    SciTech Connect

    none,

    2009-10-01

    This report has been prepared in response to section 603(b) of the Energy Independence and Security Act of 2007, (Pub. L. No. 110-140), which states that “…the Secretary of Energy shall transmit to Congress a report on the results of a study on methods to reduce the amount of water consumed by concentrating solar power systems.”

  4. Solar heating for a commercial broiler house

    SciTech Connect

    Rokeby, T.R.C.; Pitts, D.J.; Redfern, J.M.

    1981-01-01

    A solar air heater with rock storage has been used to provide heated ventilating air to an 8000-bird broiler chicken house. The system has operated successfully for four years. Fuel savings of 71% were recorded. Feed conversion and live weight were better than average. Overall system efficiency was 28.5% for a two week period in January 1981.

  5. Solar heating for a commercial broiler house

    SciTech Connect

    Rokeby, T.R.C.; Pitts, D.J.; Redfern, J.M.

    1981-01-01

    A solar air heater with rock storage has been used to provide heated ventilating air to an 8000-bird broiler chicken house. The system has operated successfully for four years. Fuel savings of 71% were recorded. Feed conversion and live weight were better than average. Overall system efficiency was 28.5% for a two week period in January, 1981. 7 refs.

  6. Low-cost passive solar-retrofit options for mobile homes

    SciTech Connect

    Brant, S.; Holtz, M.; Tasker, M.

    1981-03-01

    Passive solar heating and cooling retrofit options can significantly reduce the energy consumption of new and existing mobile homes. The initial efforts of the Solar Energy Research Institute to explore the solar potential for the existing stock of mobile homes and those in the production stage are described.

  7. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    ERIC Educational Resources Information Center

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

  8. Passivating Window/First Layer AR Coating for Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Bailey, S. G.; Flood, D. J.; Brinker, D. J.; Alterovitz, S. A.; Wheeler, D. R.; Matesscu, G.; Goradia, C.; Goradia, M.

    2004-01-01

    Chemically grown oxides, if well designed, offer excellent surface passivation of the emitter surface of space solar cells and can be used as effective passivating window/first layer AR coating. In this paper, we demonstrate the effectiveness of using a simple room temperature wet chemical technique to grow cost effective passivating layers on solar cell front surfaces after the front grid metallization step. These passivating layers can be grown both on planar and porous surfaces. Our results show that these oxide layers: (i) can effectively passivate the from the surface, (ii) can serve as an effective optical window/first layer AR coating, (iii) are chemically, thermally and UV stable, and (iv) have the potential of improving the BOL and especially the EOL efficiency of space solar cells. The potential of using this concept to simplify the III-V based space cell heterostructures while increasing their BOL and EOL efficiency is also discussed.

  9. Effect of Organic and Inorganic Passivation in Quantum-Dot-Sensitized Solar Cells.

    PubMed

    de la Fuente, Mauricio Solis; Sánchez, Rafael S; González-Pedro, Victoria; Boix, Pablo P; Mhaisalkar, S G; Rincón, Marina E; Bisquert, Juan; Mora-Seró, Iván

    2013-05-01

    The effect of semiconductor passivation on quantum-dot-sensitized solar cells (QDSCs) has been systematically characterized for CdS and CdS/ZnS. We have found that passivation strongly depends on the passivation agent, obtaining an enhancement of the solar cell efficiency for compounds containing amine and thiol groups and, in contrast, a decrease in performance for passivating agents with acid groups. Passivation can induce a change in the position of TiO2 conduction band and also in the recombination rate and nature, reflected in a change in the β parameter. Especially interesting is the finding that β, and consequently the fill factor can be increased with the passivation treatment. Applying this strategy, record cells of 4.65% efficiency for PbS-based QDSCs have been produced. PMID:26282308

  10. Light-induced anodisation of silicon for solar cell passivation

    NASA Astrophysics Data System (ADS)

    Cui, J.; Wang, X.; Opila, R.; Lennon, A.

    2013-11-01

    This paper reports a new method for forming anodic oxides on silicon surfaces using the light-induced current of pn-junction solar cells to make p-type silicon surfaces anodic. The light-induced anodisation process enables anodic oxide layers as thick as 79 nm to be formed at room temperature in a faster, more uniform, and controllable manner compared to previously reported clip-based anodisation methods. Although the effective minority carrier lifetime decreased immediately after light-induced anodisation from initial values measured with an 17 nm thermally grown oxide on both wafer surfaces, the 1-sun implied open circuit voltage of wafers on which the thermally grown oxide on the p-type surface was replaced by an anodic oxide of the same thickness could be returned to its initial value of ˜635 mV (for 3-5 Ω-cm Cz silicon wafers) after a 400 °C anneal in oxygen and then forming gas. The passivation of the formed anodic oxide layers was stable for a period of 50 days providing the oxide was protected by a 75 nm thick silicon nitride capping layer.

  11. Conventional wallboard with latent heat storage for passive solar applications

    SciTech Connect

    Kedl, R.J.

    1990-01-01

    Conventional wallboard impregnated with octadecane paraffin (Melting Point -- 73.5{degree}F) is being developed as a building material with latent heat storage for passive solar applications. Impregnation was accomplished simply by soaking the wallboard in molten paraffin. Concentrations of paraffin in the combined product as high as 35{percent} by weight were achieved. In support of this concept, a computer model was developed to describe thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions where the PCM melts at a specific melting point. However, agreement between the model and an experimentally produced thermal transient involving impregnated wallboard was only good after the model was modified to allow the paraffin to melt over a temperature range. This was accomplished by replacing the heat of fusion with a triangular heat capacity relationship that mimics the triangular melt curve found through differential scanning calorimetry. When this change was made, agreement between the model and the experimental transient was very good. 4 refs., 8 figs.

  12. Wallboard with latent heat storage for passive solar applications

    SciTech Connect

    Kedl, R.J.

    1991-05-01

    Conventional wallboard impregnated with octadecane paraffin is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM, as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. 11 refs., 25 figs., 2 tabs.

  13. Economic analysis of a passive solar multiple-family dwelling for upstate New York

    SciTech Connect

    Laquatra, J. Jr.

    1982-02-01

    The objective of this study was to examine the economic feasibility of passive solar energy as applied to a multiple-family dwelling in three upstate New York cities: Buffalo, Rochester, and Syracuse. Specifically, two passive solar applications - a Trombe wall and a direct-gain system - for a nine-unit structure designed by Total Environmental Action, Inc. were analyzed through the use of a solar economic performance code. City-specific data, including climatological information, building construction costs, utility rates, and property taxes were used, as were various economic parameters to reflect economic conditions in general and specifically those of the solar systems' owners.

  14. Daily radiation model for use in the simulation of passive solar buildings

    SciTech Connect

    Sillman, S.; Wortman, D.

    1981-04-01

    A model is presented to characterize solar radiation with just three input parameters for each day. This compressed daily radiation data may be used in place of hourly data in simulations of passive solar buildings. This method is tested with the SUNCAT passive simulation. Global horizontal and direct normal radiation data are input using the compressed daily form instead of by hour. Simulation results are found to be comparable to results based on hourly radiation data.

  15. Solar photocatalytic mineralization of commercial pesticides: acrinathrin.

    PubMed

    Malato, S; Blanco, J; Fernández-Alba, A R; Agüera, A

    2000-02-01

    A comparative study of the degradation of commercial acrinathrin spiked in water using TiO2 photocatalysis and photolysis under sunlight was performed. Samples were analysed by liquid chromatography-diode array detector (HPLC-DAD) and gas chromatography-ion trap-mass spectrometric detector (GC-ITMS). Additional total organic carbon (TOC) analyses were carried out to evaluate the mineralisation rates. One photoproduct, 2-phenoxy benzaldehyde, was unequivocally identified and evaluated by GC-ITMS during the processes. Although acrinathrin is almost destroyed when exposed to irradiation for more than 400 h, photocatalysis with TiO2 noticeably reduced degradation to a few hours. In this case, with the additional presence of peroxydisulphate, in less than 2 h acrinathrin is completely destroyed. Mineralisation of acrinathrin, without catalyst, was only around 50% after 400 h of irradiation. PMID:10665406

  16. Demonstration of a commercial solar greenhouse. Final report

    SciTech Connect

    Figueras, A.

    1982-03-31

    The greenhouse is located in the town of Russell, in St. Lawrence County, New York. It was built to demonstrate the economics of using the solar greenhouse design as a commercial greenhouse growing vegetables for local sale. The design and construction of the greenhouse are briefly described. Records of temperatures monitored and produce grown and sold are included. (BCS)

  17. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul; Hermle, Martin; Glunz, Stefan W.

    2015-11-01

    Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm-2 to 1 × 1016 cm-2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  18. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  19. Financial study of commercialization of solar central receiver power systems

    NASA Astrophysics Data System (ADS)

    1981-03-01

    Commercialization requires that central receiver (CR) systems meet the economic criteria used by industry to select systems for capital ventures. Quantitative estimates are given of the investment required by government, utilities, and the manufacturing sector to meet the energy displacement goals for central receiver technology. Initial solar repowering and stand-alone electric utility plants will not have economic comparability with competitive energy sources. A major factor for this is that initial (first of a kind) heliostat costs will be high. As heliostat costs are reduced due to automated manufacturing economies, learning, and high volume production, central receiver technology will become more competitive. Under this task, several scenarios (0.1, 0.5, and 1.0 quad/y) were evaluated to determine the effect on commercial attractiveness and to determine the cost to government to bring about commercialization of solar central receivers.

  20. Passive solar addition to therapeutic pre-school. Final technical report

    SciTech Connect

    Not Available

    1983-10-01

    This project consisted of designing and constructing a passive solar system on a new classroom addition to the Peanut Butter and Jelly Therapeutic Pre-School in Albuquerque, NM. The purpose of this project was to demonstrate the applicability of solar space heating systems to large institutional buildings, and to demonstrate the energy and cost savings available through the use of such systems. Preliminary estimates indicated that the passive solar systems will provide about 90 percent of the heating and cooling needs for the new classroom addition to the school.

  1. Terrestrial Solar Thermal Power Plants: On the Verge of Commercialization

    NASA Astrophysics Data System (ADS)

    Romero, M.; Martinez, D.; Zarza, E.

    2004-12-01

    Solar Thermal Power Plants (STPP) with optical concentration technologies are important candidates for providing the bulk solar electricity needed within the next few decades, even though they still suffer from lack of dissemination and confidence among citizens, scientists and decision makers. Concentrating solar power is represented nowadays at pilot-scale and demonstration-scale by four technologies, parabolic troughs, linear Fresnel reflector systems, power towers or central receiver systems, and dish/engine systems, which are ready to start up in early commercial/demonstration plants. Even though, at present those technologies are still three times more expensive than intermediate-load fossil thermal power plants, in ten years from now, STPP may already have reduced production costs to ranges competitive. An important portion of this reduction (up to 42%) will be obtained by R&D and technology advances in materials and components, efficient integration schemes with thermodynamic cycles, highly automated control and low-cost heat storage systems.

  2. Amorphous/crystalline silicon interface passivation: Ambient-temperature dependence and implications for solar cell performance

    DOE PAGESBeta

    Seif, Johannes P.; Krishnamani, Gopal; Demaurex, Benedicte; Ballif, Christophe; Wolf, Stefaan De

    2015-03-02

    Silicon heterojunction (SHJ) solar cells feature amorphous silicon passivation films, which enable very high voltages. We report how such passivation increases with operating temperature for amorphous silicon stacks involving doped layers and decreases for intrinsic-layer-only passivation. We discuss the implications of this phenomenon on the solar cell's temperature coefficient, which represents an important figure-of-merit for the energy yield of devices deployed in the field. We show evidence that both open-circuit voltage (Voc) and fill factor (FF) are affected by these variations in passivation and quantify these temperature-mediated effects, compared with those expected from standard diode equations. We confirm that devicesmore » with high Voc values at 25°C show better high-temperature performance. Thus, we also argue that the precise device architecture, such as the presence of charge-transport barriers, may affect the temperature-dependent device performance as well.« less

  3. Amorphous/crystalline silicon interface passivation: Ambient-temperature dependence and implications for solar cell performance

    SciTech Connect

    Seif, Johannes P.; Krishnamani, Gopal; Demaurex, Benedicte; Ballif, Christophe; Wolf, Stefaan De

    2015-03-02

    Silicon heterojunction (SHJ) solar cells feature amorphous silicon passivation films, which enable very high voltages. We report how such passivation increases with operating temperature for amorphous silicon stacks involving doped layers and decreases for intrinsic-layer-only passivation. We discuss the implications of this phenomenon on the solar cell's temperature coefficient, which represents an important figure-of-merit for the energy yield of devices deployed in the field. We show evidence that both open-circuit voltage (Voc) and fill factor (FF) are affected by these variations in passivation and quantify these temperature-mediated effects, compared with those expected from standard diode equations. We confirm that devices with high Voc values at 25°C show better high-temperature performance. Thus, we also argue that the precise device architecture, such as the presence of charge-transport barriers, may affect the temperature-dependent device performance as well.

  4. Application of PECVD for bulk and surface passivation of high efficiency silicon solar cells

    SciTech Connect

    Krygowski, T.; Doshi, P.; Cai, L.; Doolittle, A.; Rohatgi, A.

    1995-08-01

    Plasma enhanced chemical vapor deposition (PECVD) passivation of bulk and surface defects has been shown to be an important technique to improve the performance of multicrystalline silicon (mc-Si) and single crystalline silicon solar cells. In this paper, we report the status of our on-going investigation into the bulk and surface passivation properties of PECVD insulators for photovoltaic applications. The objective of this paper is to demonstrate the ability of PECVD films to passivate the front (emitter) surface, bulk, and back surface by proper tailoring of deposition and post-PECVD annealing conditions.

  5. Positioning Your Library for Solar (and Financial) Gain. Improving Energy Efficiency, Lighting, and Ventilation with Primarily Passive Techniques

    ERIC Educational Resources Information Center

    Shane, Jackie

    2012-01-01

    This article stresses the importance of building design above technology as a relatively inexpensive way to reduce energy costs for a library. Emphasis is placed on passive solar design for heat and daylighting, but also examines passive ventilation and cooling, green roofs, and building materials. Passive design is weighed against technologies…

  6. A commercially viable solar wood drying kiln system

    SciTech Connect

    Vore, J.B. de; Denny, G.S.; Harper, T.S.

    1999-01-01

    The purpose of the study was to create a totally passive solar wood drying kiln that would dry lumber to 9% moisture content in a reasonable amount of time. A series of modifications led to a kiln design that dried freshly-cut lumber to 8% in a 29-day period with no case hardening or cracking. Air speed, internal and external temperatures and relative humidity levels were measured at 5-minute intervals. The average temperature inside the kiln was 12% higher with relative humidity levels 19% lower than outside the kiln. It is hypothesized that the daily cycles of heating and cooling permitted the interior moisture of the wood to reach the surface through diffusion, thus lessening stress and speeding drying of the lumber.

  7. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    SciTech Connect

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-11-28

    Passivated contacts (poly-Si/SiO{sub x}/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF{sub 2}), the ion implantation dose (5 × 10{sup 14 }cm{sup −2} to 1 × 10{sup 16 }cm{sup −2}), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV{sub oc}) of 725 and 720 mV, respectively. For p-type passivated contacts, BF{sub 2} implantations into intrinsic a-Si yield well passivated contacts and allow for iV{sub oc} of 690 mV, whereas implanted B gives poor passivation with iV{sub oc} of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V{sub oc} of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF{sub 2} implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V{sub oc} of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  8. A passive cooling system of residential and commercial buildings in summer or hot season

    NASA Astrophysics Data System (ADS)

    Rahman, M. M.; Mashud, M.; Chu, C. M.; Misaran, M. S. bin; Sarker, M.; Kumaresen, S.

    2015-12-01

    The increasing number of high rise buildings may contribute to lack of natural ventilation in modern buildings. Generally, fans and air conditioning are used in the modern building for cooling and air ventilation. Most of the energy in tropical regions are consumed by heating, cooling and ventilation appliances. Therefore, solar power appliances for cooling, heating and ventilation will be a suitable option for saving energy from the household sector. A modified-structure building is designed and constructed with solar chimney to enhance ventilation rate that increases cooling performance and ensure thermal comfort. An evaporative cooler is introduced with a newly designed room to enhance the temperature reduction capacity. The room temperature is compared with a non-modified room as well as with ambient temperature. The results show that passive cooling system with evaporative cooler was able to reduce temperature by 5°C compared to the ambient temperature and about 2°C to 3°C below the reference room temperature.

  9. Passive solar space heating and cooling. (Latest citations from the NTIS Bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning the passive use of solar energy for space heating and cooling in buildings, houses, and homes. Citations discuss the design, performance, models, and economic analysis of heating and cooling systems. Topics include solar architecture, energy consumption analysis, energy conservation, and heat recovery. Also included are thermal comfort, quality of life, and housing for the elderly. (Contains a minimum of 209 citations and includes a subject term index and title list.)

  10. Commercialization of dish-Stirling solar terrestrial systems

    NASA Technical Reports Server (NTRS)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    1990-01-01

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  11. Commercialization of dish-Stirling solar terrestrial systems

    NASA Astrophysics Data System (ADS)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  12. Low temperature front surface passivation of interdigitated back contact silicon heterojunction solar cell

    SciTech Connect

    Shu, Brent; Das, Ujjwal; Jani, Omkar; Hegedus, Steve; Birkmire, Robert

    2009-06-08

    The interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell requires a low temperature front surface passivation/anti-reflection structure. Conventional silicon surface passivation using SiO2 or a-SiNx is performed at temperature higher than 400°C, which is not suitable for the IBC-SHJ cell. In this paper, we propose a PECVD a-Si:H/a-SiNx:H/a-SiC:H stack structure to passivate the front surface of crystalline silicon at low temperature. The optical properties and passivation quality of this structure are characterized and solar cells using this structure are fabricated. With 2 nm a-Si:H layer, the stack structure exhibits stable passivation with effective minority carrier lifetime higher than 2 ms, and compatible with IBC-SHJ solar cell processing. A critical advantage of this structure is that the SiC allows it to be HF resistant, thus it can be deposited as the first step in the process. This protects the a-Si/c-Si interface and maintains a low surface recombination velocity.

  13. CVD-Based Valence-Mending Passivation for Crystalline-Si Solar Cells

    SciTech Connect

    Tao, Meng

    2015-03-01

    The objective of this project is to investigate a new surface passivation technique, valence-mending passivation, for its applications in crystalline-Si solar cells to achieve significant efficiency improvement and cost reduction. As the enabling technique, the project includes the development of chemical vapor deposition recipes to passivate textured Si(100) and multicrystalline-Si surfaces by sulfur and the characterization of the passivated Si surfaces, including thermal stability, Schottky barrier height, contact resistance and surface recombination. One important application is to replace the Ag finger electrode in Si cells with Al to reduce cost, by ~$0.1/Wp, and allow terawatt-scale deployment of crystalline-Si solar cells. These all-Al Si cells require a low-temperature metallization process for the Al electrode, to be compatible with valence-mending passivation and to prevent Al diffusion into n-type Si. Another application is to explore valence-mending passivation of grain boundaries in multicrystalline Si by diffusing sulfur into grain boundaries, to reduce the efficiency gas between monocrystalline-Si solar cells and multicrystalline-Si cells. The major accomplishments of this project include: 1) Demonstration of chemical vapor deposition processes for valence-mending passivation of both monocrystalline Si(100) and multicrystalline Si surfaces. Record Schottky barriers have been demonstrated, with the new record-low barrier of less than 0.08 eV between Al and sulfur-passivated n-type Si(100) and the new record-high barrier of 1.14 eV between Al and sulfur-passivated p-type Si(100). On the textured p-type monocrystalline Si(100) surface, the highest barrier with Al is 0.85 eV by valence-mending passivation. 2) Demonstration of a low-temperature metallization process for Al in crystalline-Si solar cells. The new metallization process is based on electroplating of Al in a room-temperature ionic liquid. The resistivity of the electroplated Al is ~7×10–6

  14. 10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation.

    PubMed

    Lan, Xinzheng; Voznyy, Oleksandr; García de Arquer, F Pelayo; Liu, Mengxia; Xu, Jixian; Proppe, Andrew H; Walters, Grant; Fan, Fengjia; Tan, Hairen; Liu, Min; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H

    2016-07-13

    Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics. PMID:27351104

  15. The effect of microscopic texture on the direct plasma surface passivation of Si solar cells

    NASA Astrophysics Data System (ADS)

    Mehrabian, S.; Xu, S.; Qaemi, A. A.; Shokri, B.; Chan, C. S.; Ostrikov, K.

    2013-04-01

    Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 105 H+ ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.

  16. The effect of microscopic texture on the direct plasma surface passivation of Si solar cells

    SciTech Connect

    Mehrabian, S.; Xu, S.; Qaemi, A. A.; Shokri, B.; Chan, C. S.; Ostrikov, K.

    2013-04-15

    Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 10{sup 5} H{sup +} ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.

  17. Study of novel chemical surface passivation techniques on GaAs pn junction solar cells

    SciTech Connect

    Mauk, M.G.; Xu, S.; Arent, D.J.; Mertens, R.P.; Borghs, G.

    1989-01-16

    Novel methods of GaAs surface passivation are investigated. Passivation is acheived by simple chemical treatments using aqueous solutions of Na/sub 2/S, KOH, RuCl/sub 3/, and K/sub 2/Se. GaAs pn homojunction solar cells are used to evaluate the effectiveness of these passivation techniques. A significant reduction in minority-carrier surface recombination velocity is demonstrated. In the best case, the surface recombination velocity decreased from 5 x 10/sup 6/ cm/s (untreated surface) to 10/sup 3/ cm/s. In addition, we observe improvements in solar cell photogenerated current, short wavelength spectral response, open-circuit voltage, and junction ''dark'' current.

  18. Solar Energy: Energy Conservation and Passive Design Concepts: Student Material. First Edition.

    ERIC Educational Resources Information Center

    Younger, Charles; Orsak, Charles G., Jr.

    Designed for student use in "Energy Conservation and Passive Design Concepts," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, bibliographies, and illustrations for seven course modules. The manual, which corresponds to an instructor guide for the same course, covers the following topics:…

  19. Past, present and future of passive homes in solar village 3, Athens

    NASA Astrophysics Data System (ADS)

    Kalogridis, Achilles

    Solar village 3 in Pefki, Athens, was part of an ambitious program for the promotion of solar technology, applied to a large scale social housing scheme, designed in mid 80's and firstly inhabited in the early 1990's. Among the aims of the project was the demonstration of the latest of technology in active solar systems and passive techniques, incorporated in a new settlement's layout and houses' building envelop, in order to create an energy saving, comfortable environment. More than fifteen years later, the housing complex remains the largest residential development of bioclimatic "solar" architecture in Athens, with the active and passive solar systems providing space and water heating for about 1750 inhabitants. The study focuses in the passive solar systems that have been applied to a number of the buildings of the settlement. The systems provide space heating with no need of any active mechanism, however with demand of the participation of the end users for their proper operation. The essay reviews various previous studies, monitoring reports and criticisms that have appeared throughout the past years, and identifies how the houses perform today, through a recent survey, sample monitoring and thermal comfort simulation. The report records things that have changed, features which worked well or others that did not and comments on the residents' behaviour. Interesting findings come into question, regarding the passive solar systems, their integration into the building's design, their current condition and their contribution to energy savings and thermal comfort conditions. Finally, current plans concerning the future of the settlement are highlighted, and considerations about the houses sustainability are suggested.

  20. Abrams Primary School passive solar design. Phase 1. Final report

    SciTech Connect

    1980-01-01

    The general project documentation and the design process documentation for the project are presented. The following are appended: analysis of thermal transfer and internal heat contributions to the heating and cooling loads for a typical four-classroom teaching module using bin-chart temperature data, trace simulation for the original building design, Teanet simulation of original building design for the month of January 1959, Teanet simulation of Solar 2 for the month of January 1959, incremental solar cost assessment, and diffuse radiation incident on the monitor glass. (MHR)

  1. Passivating boron silicate glasses for co-diffused high-efficiency n-type silicon solar cell application

    SciTech Connect

    Engelhardt, Josh Frey, Alexander; Gloger, Sebastian; Hahn, Giso; Terheiden, Barbara

    2015-07-27

    Doping layers commonly have but one function: supplying the dopants to form a doped region within a substrate. This work presents B doping layers/stacks, which at the same time supply dopant atoms, passivate the B-doped crystalline Si surface sufficiently well (j{sub 0E} < 50 fA/cm{sup 2}), and show optical properties suitable for anti-reflective coating. Furthermore, these boron silicate glasses can act as a barrier against parasitic P in-diffusion during a co-diffusion step. The boron emitters diffused from the inductively coupled plasma plasma-enhanced chemical vapor-deposited B containing SiO{sub x} layers are investigated and optimized concerning passivation quality and contact properties for high-efficiency n-type solar Si cell designs. It is shown that even 10 nm thin SiO{sub x}:B films already allow for suitable emitter sheet resistance for screen-printed contacts. Furthermore, SiO{sub x}:B layers presented here allow for iV{sub OC} values of 675 mV and contact resistivity of 1 mΩcm{sup 2} for commercial Ag instead of Ag/Al pastes on the diffused boron emitter passivated with the SiO{sub x}:B layer supporting the contact formation. All of these properties can be achieved within one single B doping layer/stack.

  2. Passivating boron silicate glasses for co-diffused high-efficiency n-type silicon solar cell application

    NASA Astrophysics Data System (ADS)

    Engelhardt, Josh; Frey, Alexander; Gloger, Sebastian; Hahn, Giso; Terheiden, Barbara

    2015-07-01

    Doping layers commonly have but one function: supplying the dopants to form a doped region within a substrate. This work presents B doping layers/stacks, which at the same time supply dopant atoms, passivate the B-doped crystalline Si surface sufficiently well (j0E < 50 fA/cm2), and show optical properties suitable for anti-reflective coating. Furthermore, these boron silicate glasses can act as a barrier against parasitic P in-diffusion during a co-diffusion step. The boron emitters diffused from the inductively coupled plasma plasma-enhanced chemical vapor-deposited B containing SiOx layers are investigated and optimized concerning passivation quality and contact properties for high-efficiency n-type solar Si cell designs. It is shown that even 10 nm thin SiOx:B films already allow for suitable emitter sheet resistance for screen-printed contacts. Furthermore, SiOx:B layers presented here allow for iVOC values of 675 mV and contact resistivity of 1 mΩcm2 for commercial Ag instead of Ag/Al pastes on the diffused boron emitter passivated with the SiOx:B layer supporting the contact formation. All of these properties can be achieved within one single B doping layer/stack.

  3. Passive solar system for maintaining and rearing marine organisms

    SciTech Connect

    Yuschak, P.; Richards, F.M.

    1987-04-01

    A solar-heated facility for maintaining and rearing marine organisms is described. Water from a shallow tidal bay is moved by a tide-regulated pumping system into settling tanks for removal of suspended silt and clay, from which the water drains by gravity flow to circular rearing tanks.

  4. Passive thermosyphon solar heating and cooling module with supplementary heating

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A collection of three quarterly reports from Sigma Research, Inc., covering progress and status from January through September 1977 are presented. Three heat exchangers are developed for use in a solar heating and cooling system for installation into single-family dwellings. Each exchanger consists of one heating and cooling module and one submerged electric water heating element.

  5. Active charge/passive discharge solar heating systems: Thermal analysis and performance comparisons and performance comparisons

    NASA Astrophysics Data System (ADS)

    Swisher, J.

    1981-06-01

    This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat exchanger efficiencies, storage capacity, and storage to room coupling. Performance simulation results are used for comparisons with active and passive solar designs.

  6. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    Amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300 °C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  7. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    DOE PAGESBeta

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphousmore » silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.« less

  8. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  9. A new structure for comparing surface passivation materials of GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Desalvo, Gregory C.; Barnett, Allen M.

    1989-01-01

    The surface recombination velocity (S sub rec) for bare GaAs is typically as high as 10 to the 6th power to 10 to the 7th power cm/sec, which dramatically lowers the efficiency of GaAs solar cells. Early attempts to circumvent this problem by making an ultra thin junction (xj less than .1 micron) proved unsuccessful when compared to lowering S sub rec by surface passivation. Present day GaAs solar cells use an GaAlAs window layer to passivate the top surface. The advantages of GaAlAs in surface passivation are its high bandgap energy and lattice matching to GaAs. Although GaAlAs is successful in reducing the surface recombination velocity, it has other inherent problems of chemical instability (Al readily oxidizes) and ohmic contact formation. The search for new, more stable window layer materials requires a means to compare their surface passivation ability. Therefore, a device structure is needed to easily test the performance of different passivating candidates. Such a test device is described.

  10. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-01

    Amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300 °C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  11. Solar-heated commercial-greenhouse demonstration. Final performance report

    SciTech Connect

    1983-01-01

    Poly Solar Company was formed to design and fabricate a demonstration of a solar heating system for commercial greenhouses in moderate climates. This system is built of readily available materials, and can be constructed using conventional techniques available to most builders and farmers. Construction began on the demonstration project in August 1981 and the system was placed into operation that winter. Energy savings were calculated by monitoring the running time on an oil furnace in a duplicate greenhouse with the same crop as the solar heated greenhouse with an oil backup furnace. The first monitoring period was before the Christmas season with poinsettias used as the comparison crop with 60/sup 0/ to 64/sup 0/F. During this period the 126 ton mass storage and waste heat recovery sections of the system were used. These trials showed energy savings over the 100% oil heated structure to be 23.4%. After the crops were removed from the greenhouse trials were ran which showed this portion of the system could maintain night time temperatures as high as 56/sup 0/F with no other heat source and an outside temperature of 26/sup 0/F. The 1860 sq ft solar collector/storage system was monitored with a winter-spring crop of geraniums at a night time temperature of 60/sup 0/ to 64/sup 0/F. In April 1982 a severe storm with wind gusts in excess of 50 mph destroyed a section of duct that feeds heated air from the collector to the rock storage bed and caused light damage to the collector itself.

  12. Advanced Passivation Technology and Loss Factor Minimization for High Efficiency Solar Cells.

    PubMed

    Park, Cheolmin; Balaji, Nagarajan; Jung, Sungwook; Choi, Jaewoo; Ju, Minkyu; Lee, Seunghwan; Kim, Jungmo; Bong, Sungjae; Chung, Sungyoun; Lee, Youn-Jung; Yi, Junsin

    2015-10-01

    High-efficiency Si solar cells have attracted great attention from researchers, scientists, photovoltaic (PV) industry engineers for the past few decades. With thin wafers, surface passivation becomes necessary to increase the solar cells efficiency by overcoming several induced effects due to associated crystal defects and impurities of c-Si. This paper discusses suitable passivation schemes and optimization techniques to achieve high efficiency at low cost. SiNx film was optimized with higher transmittance and reduced recombination for using as an effective antireflection and passivation layer to attain higher solar cell efficiencies. The higher band gap increased the transmittance with reduced defect states that persisted at 1.68 and 1.80 eV in SiNx films. The thermal stability of SiN (Si-rich)/SiN (N-rich) stacks was also studied. Si-rich SiN with a refractive index of 2.7 was used as a passivation layer and N-rich SiN with a refractive index of 2.1 was used for thermal stability. An implied Voc of 720 mV with a stable lifetime of 1.5 ms was obtained for the stack layer after firing. Si-N and Si-H bonding concentration was analyzed by FTIR for the correlation of thermally stable passivation mechanism. The passivation property of spin coated Al2O3 films was also investigated. An effective surface recombination velocity of 55 cm/s with a high density of negative fixed charges (Qf) on the order of 9 x 10(11) cm(-2) was detected in Al2O3 films. PMID:26726397

  13. Silicon diffusion in aluminum for rear passivated solar cells

    SciTech Connect

    Urrejola, Elias; Peter, Kristian; Plagwitz, Heiko; Schubert, Gunnar

    2011-04-11

    We show that the lateral spread of silicon in a screen-printed aluminum layer increases by (1.50{+-}0.06) {mu}m/ deg. C, when increasing the peak firing temperature within an industrially applicable range. In this way, the maximum spread limit of diffused silicon in aluminum is predictable and does not depend on the contact area size but on the firing temperature. Therefore, the geometry of the rear side pattern can influence not only series resistance losses within the solar cell but the process of contact formation itself. In addition, too fast cooling lead to Kirkendall void formations instead of an eutectic layer.

  14. Effect of plants on sunspace passive solar heating

    SciTech Connect

    Best, E.D.; McFarland, R.D.

    1985-01-01

    The effect of plants on sunspace thermal performance is investigated, based on experiments done in Los Alamos using two test rooms with attached sunspaces, which were essentially identical except for the presence of plants in one. Performance is related to plant transpiration, evaporation from the soil, condensation on the glazing and the absorbtance of solar energy by the lightweight leaves. Performance effects have been quantified by measurements of auxiliary heat consumption in the test rooms and analyzed by means of energy balance calculations. A method for estimating the transpiration rate is presented.

  15. Development and Commercialization of the Lunar Solar Power System

    NASA Astrophysics Data System (ADS)

    Criswell, D. R.

    2002-01-01

    The proposed Lunar Solar Power (LSP) System consists of pairs of power bases located on opposite limbs of the Moon as seen from Earth. The power bases collect the solar energy and convert it to beams of microwaves. The microwaves are delivered directly to moonward-facing receivers on Earth or indirectly through relay satellites in orbit about Earth (1, 2, 3, 4). The LSP System may be the only reasonable method for establishing sustainable global energy prosperity within two generations. Commercial power prosperity requires at least 2 kWe/person. For ten billion people this implies 20 TWe and 2,000 TWe-y of electric energy or ~6,000 TWt-y of thermal energy per century (5, 6, 7, 8). A brief overview is presented of a reference LSP System that supplies 20 TWe by 2050. The engineering scales and the cost and benefits of this system are described. In order to provide low cost commercial electric energy, the power bases are made primarily of local lunar materials by machines, facilities, and people deployed from Earth (1, 2, 3). In addition, lunar production machinery can be made primarily from lunar materials. Advantages of this approach, versus the reference LSP System, are discussed. Full-scale production of a LSP System will certainly be proceeded by terrestrial and lunar operation of the production machinery and a small-scale demonstration of the operational system (1). Using government funds to establishing a permanent lunar base and the associated transportation system would significantly reduce the upfront cost for the demonstration of a commercial LSP System (2). The government program would provide a legal framework for commercial development of the LSP System (3, 9). The LSP System offers the opportunity to establish a materials industry on the Moon that can produce a growing mass and variety of goods and enable new services of benefit on the Earth and the Moon (10). New priorities are suggested for civilian space programs that can accelerate the establishment

  16. Commercial Development Of Ovonic Thin Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Ovshinsky, Stanford R.

    1983-09-01

    One square foot Ovonic amorphous photovoltaic devices are already in commercial production and are manufactured through a continuous web process. The next levels of commercialization required to achieve a large-volume power market will be discussed, and the device specifications correlated with the chemical and electronic properties of the materials that we are developing to achieve even higher efficiencies. It has been long considered a utopian dream to harness the energy of the sun to create electricity that would be competitive in cost to that produced from the conventional sources of energy such as oil, gas, and uranium. The impact on our society of stand-alone power generators without moving parts using the continually available, ubiquitous energy of the sun could certainly lead to a new age with consequences comparable to the first introduction of electricity which greatly accelerated the Industrial Revolution. Low cost, nonpolluting energy not dependent upon or limited by transmission costs could again make DC electricity a realistic option. The relatively young field of photovoltaics suffers from certain dogmas that are just now being questioned. For example, it is thought by many that solar cells utilizing crys-talline materials have inherently higher efficiencies than those using amorphous materials, and that somehow crystalline solar cells, whether fabricated from single crystals or polycrystalline material, in round or rectangular geometries, grown from the melt or by a rib-bon process, can be reduced in cost sufficiently that the economics become attractive enough for large-scale terrestrial generation of power. In this paper, we shall show that amorphous materials can have much higher efficiencies than do crystalline and that the answer to our power generation needs lies not in crystalline but in amorphous technology. At Energy Conversion Devices, Inc. (ECD), we have designed and built a production machine (described by my colleague, Dr. Izu, in a

  17. Sulfur passivation and contact methods for GaAs nanowire solar cells

    NASA Astrophysics Data System (ADS)

    Tajik, N.; Peng, Z.; Kuyanov, P.; LaPierre, R. R.

    2011-06-01

    The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements.

  18. Sulfur passivation and contact methods for GaAs nanowire solar cells.

    PubMed

    Tajik, N; Peng, Z; Kuyanov, P; LaPierre, R R

    2011-06-01

    The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements. PMID:21454946

  19. Silicon Heterojunction Solar Cells: Temperature Impact on Passivation and Performance

    SciTech Connect

    Seif, J.; Krishnamani, G.; Demaurex, B.; Martin de Nicholas, S.; Holm, N.; Ballif, C.; De Wolf, S.

    2015-03-23

    Photovoltaic devices deployed in the field can reach operation temperatures (T) as high as 90 °C [1]. Hence, their temperature coefficients (TC1) are of great practical importance as they determine their energy yield. In this study we concentrate on T-related lifetime variations of amorphous/crystalline interfaces and study their influence on the TCs of the individual solar cell parameters. We find that both the open-circuit voltage (Voc) and fill factor (FF) are influenced by these lifetime variations. However, this is only a minor effect compared to the dominant increase of the intrinsic carrier density and the related increase in dark saturation current density. Additionally, in this paper we will show that the TCVoc does not depend solely on the initial value of the Voc [2, 3], but that the structure of the device has to be considered as well.

  20. Performance of passive Q-switched solar-pumped high-power Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Noter, Yoram; Naftali, Nir; Pe'er, Idit L.; Yogev, Amnon; Lando, Mordechai; Shimony, Yehoshua

    1997-09-01

    Q-switched, solar-pumped, high power Nd:YAG lasers are attractive for a variety of applications requiring high instantaneous peak power density. The Q-switching can be obtained by an acousto-optic, electro-optic or passive device. Passive Q-switching seems an excellent choice for space as well as for other applications since it neither requires an external driver nor an electrical power supply. In recent years Cr+4:YAG single crystals were extensively used as passive Q-switches for flashlamp-pumped high power Nd:YAG lasers, demonstrating their superior thermal superior thermal characteristics and durability. In this work we report the first operation of passive Q- switched, solar-pumped, high power Nd:YAG lasers. The concentrated solar energy for he optical pumping of the laser was obtained by a 3-stage combination of imaging and non-imaging optics. It included: i) Weizmann Institute solar tower heliostats, ii) 3D compound parabolic concentrator, and iii) 2D compound parabolic concentrator in which the laser rod was placed. 72 mm long laser rods with either 3 mm or 4 mm diameter were used. The passive Q-switch was made from a Cr$=+4):YAG single crystal having a low- intensity transmission of 72 percent at 1.06 (mu) . Its rear surface was coated by a high reflectivity coating, serving as the rear mirror of the cavity. Output coupling mirrors with various reflectivities were used. The passive Q-switch demonstrated excellent durability and reliability during all the experiments. Repetition rates of 6-39 kHz were measured, showing higher repetition rates at higher laser power levels. The pulses demonstrated shorter full width at half maximum (FWHM) time for higher laser power elves, and the FWHM time range was 190-310 nsec. The maximal measured average power was 14 W. Thermal lensing was measured as a function of the absorbed solar power in the laser rod. It is estimated that laser peak power densities of approximately 100 kW/cm2 were achieved in the experiments. It is

  1. Enhanced Conversion Efficiency of Cu(In,Ga)Se2 Solar Cells via Electrochemical Passivation Treatment.

    PubMed

    Tsai, Hung-Wei; Thomas, Stuart R; Chen, Chia-Wei; Wang, Yi-Chung; Tsai, Hsu-Sheng; Yen, Yu-Ting; Hsu, Cheng-Hung; Tsai, Wen-Chi; Wang, Zhiming M; Chueh, Yu-Lun

    2016-03-30

    Defect control in Cu(In,Ga)Se2 (CIGS) materials, no matter what the defect type or density, is a significant issue, correlating directly to PV performance. These defects act as recombination centers and can be briefly categorized into interface recombination and Shockley-Read-Hall (SRH) recombination, both of which can lead to reduced PV performance. Here, we introduce an electrochemical passivation treatment for CIGS films that can lower the oxygen concentration at the CIGS surface as observed by X-ray photoelectron spectrometer analysis. Temperature-dependent J-V characteristics of CIGS solar cells reveal that interface recombination is suppressed and an improved rollover condition can be achieved following our electrochemical treatment. As a result, the surface defects are passivated, and the power conversion efficiency performance of the solar cell devices can be enhanced from 4.73 to 7.75%. PMID:26815164

  2. Cooling-load implications for residential passive-solar-heating systems

    SciTech Connect

    Jones, R.W.; McFarland, R.D.

    1983-01-01

    Ongoing research on quantifying the cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described, along with the computer simulation model used for calculating cooling loads. A sample of interim results is also presented. The objective of the research is to develop a simple analysis method, useful early in design, to estimate the annual cooling energy requirement of a given building.

  3. Passive and hybrid solar manufactured housing and buildings. [Includes architectural drawings

    SciTech Connect

    Scholz, D; Bowling, C; Winter, S; Levy, E; Marks, R; Zgolinski, A

    1980-01-01

    The final design work on a passive solar two story modular home to be built by Unibilt Industries is summarized. After reviewing alternative insulation, glazing, and water wall schemes, five options were identified for detailed energy use and life cycle cost analysis. Using the PASCALC/SLR analysis procedure, the performance of the base case home and each of the energy conservation options was calculated. (MHR)

  4. Economic analysis of commercial solar combined space-heating and hot-water systems

    SciTech Connect

    1980-09-23

    Typical commercial solar energy systems are described, outlining typical cost and performance lvels. The economic performance of solar energy systems are described through the use of Cash Flow Diagrams. These diagrams indicate the cumulative cash situation of a solar investment over the life of the investment. The economic performance of solar energy systems is described through the calculation of equivalent Return-on-Investment (ROI). Appendices are included that enable one to calculate the ROI for any particular solar energy system investment. (MHR)

  5. Large resource development projects as markets for passive solar technologies. Final report

    SciTech Connect

    Roze-Benson, R V

    1980-12-01

    A basic premise of this study is that large resource development projects provide a major market opportunity for passive solar manufactured buildings. The primary objectives of the work are to document selected resource development projects and identify their potential housing needs and development schedules, to contact resource industry representatives and assess some of the processes and motivations behind their involvement in housing decisions, and to provide passive solar manufactured buildings producers with results of these steps as early initial market intelligence. The intent is to identify not only the industries, location of their planned projects, and their likely worker housing needs, but also the individuals involved in making housing-related decisions. The 56 identified projects are located within 18 states and cover 11 types of resources. The report documents individual projects, provides protections of total worker-related housing needs, and presents overviews of resource development company involvement in the new construction market. In addition, the report profiles three organizations that expressed a strong interest in implementing the use of low-cost passive solar manufactured buildings in resource-development-related activities.

  6. Solar thermal central receiver integrated commercialization analysis. Volume 2. Appendices. Final report

    SciTech Connect

    Doyle, J.F.; Bos, P.B.; Weingart, J.M.

    1986-03-01

    The report presents brief discussions on the following topics: (1) value analysis computer program; (2) levelized busbar energy cost computation; (3) electric utility avoided cost; and (4) commercial solar tax credits. Each topic is in reference to the integrated commercialization of solar thermal central receivers. (BCS)

  7. Diffusion-free back contact solar cells on sulfur-passivated silicon(100) substrates

    NASA Astrophysics Data System (ADS)

    Song, Guanghua

    A diffusion-free back contact solar cell is proposed in this work. The textured front-side of this cell is coated with ˜100 nm thermal SiO2 to enhance the light trapping meanwhile reduce the surface recombination velocity (SRV). The back-side of this cell is finger-patterned, using a diffusion-free junction as its emitter region and Al-Si alloy as its base contact. The diffusion-free junction is made by a Schottky contact between low work-function metal aluminum (Al) and sulfur (S)-passivated p-type Si(100) surface. Solution-based S passivation is one of the experimental realizations of the "valence-mending concept". Previously developed MBE (molecular bean epitaxy) selenium (Se) passivation is not used due to its time-consuming process and high energy input. Following the concept, passivation of Si(100) surface by Group VI elements such as S and Se terminates the dangling bonds and releases the strained bonds and dimer bonds, thus significantly reduces the surface states. Quantification of surface states or interface states is introduced through the nano-CMOS devices. Removal of surface states enables an almost ideal barrier height after metal contact. This is one of the methods achieving the high Schottky barrier. Al on S-passivated p-type Si(100) surface yields an extremely high Schottky barrier of 1.1 eV, about 0.2 eV higher than the corresponding ideal barrier height. This discrepancy is accounted by S-Si dipole moment on the surface. Calculations using Fermi statistics discloses that the barrier height of 1.1 eV causes the degenerate inversion on Si surface, making this Schottky junction electrically behave like a diffused p-n junction. Eventually this junction as a field-induced junction free of any diffusion is integrated in the fabrication of the proposed back contact solar cells. High work-function metal Platinum (Pt) and nickel (Ni) on S-passivated n-type Si(100) are also investigated, but the yielding barrier heights are not high enough to create

  8. Aluminum oxide passivated radial junction sub-micrometre pillar array textured silicon solar cells

    NASA Astrophysics Data System (ADS)

    Pudasaini, Pushpa Raj; Elam, David; Ayon, Arturo A.

    2013-06-01

    We report radial, p-n junction, sub-micrometre, pillar array textured solar cells, fabricated on an n-type Czochralski silicon wafer. Relatively simple processing schemes such as metal-assisted chemical etching and spin on dopant techniques were employed for the fabrication of the proposed solar cells. Atomic layer deposition (ALD) grown aluminum oxide (Al2O3) was employed as a surface passivation layer on the B-doped emitter surface. In spite of the fact that the sub-micrometre pillar array textured surface has a relatively high surface-to-volume ratio, we observed an open circuit voltage (VOC) and a short circuit current density (JSC) as high as 572 mV and 29.9 mA cm-2, respectively, which leads to a power conversion efficiency in excess of 11.30%, for the optimized structure of the solar cell described herein. Broadband omnidirectional antireflection effects along with the light trapping property of the sub-micrometre, pillar array textured surface and the excellent passivation quality of the ALD-grown Al2O3 on the B-doped emitter surface were responsible for the enhanced electrical performance of the proposed solar cells.

  9. The Role of Education and Training Programs in the Commercialization and Diffusion of Solar Energy Technologies.

    ERIC Educational Resources Information Center

    Burns, Barbara; And Others

    The solar energy labor force is analyzed by identifying the importance of education and training in the commercialization and diffusion of solar technologies, discussing issues for planning and analysis of solar education and training efforts, and illustrating the range of programs and courses presently available. Four general perspectives are…

  10. Improved performance in GaInNAs solar cells by hydrogen passivation

    SciTech Connect

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

    2015-04-06

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells.

  11. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    SciTech Connect

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solar cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.

  12. Bifacial MIS inversion layer solar cells based on low temperature silicon surface passivation

    NASA Astrophysics Data System (ADS)

    Jaeger, K.; Hezel, R.

    A novel bifacial silicon solar cell fabricated by a simple low-temperature process is introduced. The front side is characterized by an MIS contact grid and a charged plasma silicon nitride layer. The rear side is made up of ohmic grid lines in combination with silicon nitride for surface passivation. This appears to be the first bifacial solar cell without any highly doped region and completely processed at temperatures below 500 C. An AM1 efficiency of 15 and 13.2 percent was achieved for front and back illumination, respectively. The dependence of the solar cell data on cell thickness was experimentally investigated in the range from 80 microns to 330 microns. This thickness dependence was confirmed by theoretical one-dimensional calculations.

  13. Layered insulator hexagonal boron nitride for surface passivation in quantum dot solar cell

    SciTech Connect

    Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin; Xu, Yang

    2013-12-09

    Single crystalline, two dimensional (2D) layered insulator hexagonal boron nitride (h-BN), is demonstrated as an emerging material candidate for surface passivation on mesoporous TiO{sub 2}. Cadmium selenide (CdSe) quantum dot based bulk heterojunction (BHJ) solar cell employed h-BN passivated TiO{sub 2} as an electron acceptor exhibits photoconversion efficiency ∼46% more than BHJ employed unpassivated TiO{sub 2}. Dominant interfacial recombination pathways such as electron capture by TiO{sub 2} surface states and recombination with hole at valence band of CdSe are efficiently controlled by h-BN enabled surface passivation, leading to improved photovoltaic performance. Highly crystalline, confirmed by transmission electron microscopy, dangling bond-free 2D layered h-BN with self-terminated atomic planes, achieved by chemical exfoliation, enables efficient passivation on TiO{sub 2}, allowing electronic transport at TiO{sub 2}/h-BN/CdSe interface with much lower recombination rate compared to an unpassivated TiO{sub 2}/CdSe interface.

  14. Control system analysis for off-peak auxiliary heating of passive solar systems

    SciTech Connect

    Murray, H.S.; Melsa, J.L.; Balcomb, J.D.

    1980-01-01

    A computer simulation method is presented for the design of an electrical auxiliary energy system for passive solar heated structures. The system consists of electrical mats buried in the ground underneath the structure. Energy is stored in the ground during utility off-peak hours and released passively to the heated enclosure. An optimal control strategy is used to determine the system design parameters of depth of mat placement and minimum instaled electrical heating capacity. The optimal control applies combinations of fixed duration energy pulses to the heater, which minimize the room temperature error-squared for each day, assuming advance knowledge of the day's weather. Various realizable control schemes are investigated in an attempt to find a system that approaches the performance of the optimal control system.

  15. Proposal of leak path passivation for InGaN solar cells to reduce the leakage current

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Imai, Daichi; Kusakabe, Kazuhide; Yoshikawa, Akihiko

    2016-01-01

    We propose some general ways to passivate the leak paths in InGaN solar cells and report some experimental evidences of its effectiveness. By adopting an AlOx passivation process, the photovoltaic performances of GaN pn-junctions and InGaN solar cells, grown by molecular beam epitaxy, have been significantly improved. The open circuit voltage under 1 sun illumination increases from 1.46 to 2.26 V for a GaN pn junction, and from 0.95 to 1.27 V for an InGaN solar cell, demonstrating evidence of leak path passivation (LPP) by AlOx. The proposed LPP is expected to be a realistic way to exploit the potential of thick and relaxed but defective InGaN for solar cell applications.

  16. Antireflection and SiO2 Surface Passivation by Liquid-Phase Chemistry for Efficient Black Silicon Solar Cells: Preprint

    SciTech Connect

    Yuan, H. C.; Oh, J.; Zhang, Y.; Kuznetsov, O. A.; Flood, D. J.; Branz, H. M.

    2012-06-01

    We report solar cells with both black Si antireflection and SiO2 surface passivation provided by inexpensive liquid-phase chemistry, rather than by conventional vacuum-based techniques. Preliminary cell efficiency has reached 16.4%. Nanoporous black Si antireflection on crystalline Si by aqueous etching promises low surface reflection for high photon utilization, together with lower manufacturing cost compared to vacuum-based antireflection coating. Ag-nanoparticle-assisted black Si etching and post-etching chemical treatment recently developed at NREL enables excellent control over the pore diameter and pore separation. Performance of black Si solar cells, including open-circuit voltage, short-circuit current density, and blue response, has benefited from these improvements. Prior to this study, our black Si solar cells were all passivated by thermal SiO2 produced in tube furnaces. Although this passivation is effective, it is not yet ideal for ultra-low-cost manufacturing. In this study, we report, for the first time, the integration of black Si with a proprietary liquid-phase deposition (LPD) passivation from Natcore Technology. The Natcore LPD forms a layer of <10-nm SiO2 on top of the black Si surface in a relatively mild chemical bath at room temperature. We demonstrate black Si solar cells with LPD SiO2 with a spectrum-weighted average reflection lower than 5%, similar to the more costly thermally grown SiO2 approach. However, LPD SiO2 provides somewhat better surface-passivation quality according to the lifetime analysis by the photo-conductivity decay measurement. Moreover, black Si solar cells with LPD SiO2 passivation exhibit higher spectral response at short wavelength compared to those passivated by thermally grown SiO2. With further optimization, the combination of aqueous black Si etching and LPD could provide a pathway for low-cost, high-efficiency crystalline Si solar cells.

  17. Passive solar-heating retrofit of a maintenance facility: First-year performance

    NASA Astrophysics Data System (ADS)

    Jackson, D. R.; Callahan, J. M.

    1982-09-01

    A 12,000 sf maintenance facility in Connecticut was retrofitted with a 1,500 sf passive solar Trombe wall, 2 in. of foam roof insulation and a new control system that allows night/weekend temperature setback. A new separate boiler was installed to heat an office/locker wing of the facility. An energy-consumption monitoring system was installed and collected data for 11/2 years before the retrofit and one complete year after the retrofit. Actual energy consumption for the facility was very close to that predicted using simple analytic methods. After the solar wall was installed and other energy-conservation measures implemented the yearly oil consumption was reduced to 2744 gallons/year.

  18. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    DOE PAGESBeta

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; et al

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solarmore » cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.« less

  19. The Pyramid House: A ten-day thermal time constant passive solar home

    SciTech Connect

    Ellison, T.

    1999-07-01

    The Pyramid House is a passive solar home being designed and built to operate without back-up heating. Having told people this, the fear that someday the author might have to swallow his pride and seek the warmth of a neighbor's cozy wood-heated cabin has encouraged him to analyze the Pyramid House's projected winter performance. This performance is easy to visualize when described in terms of the home's thermal time constant, {tau}--an easily calculated measure of the time it takes the house to reach equilibrium with the ambient temperature. The Pyramid House obtains its long time constant using conventional insulation, and a very high degree of thermal mass via a radiant heat flooring system and water storage. After presenting the time constant concept, it is employed to analyze building materials and then the Pyramid House. The analyses show the ineffectuality of adding solar gain to homes with low time constants, such as typical US homes.

  20. Amorphous Silicon Carbide Passivating Layers to Enable Higher Processing Temperature in Crystalline Silicon Heterojunction Solar Cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary

    2015-04-06

    "Very efficient crystalline silicon (c-Si) solar cells have been demonstrated when thin layers of intrinsic and doped hydrogenated amorphous silicon (a-Si:H) are used for passivation and carrier selectivity in a heterojunction device. One limitation of this device structure is the (parasitic) absorption in the front passivation/collection a-Si:H layers; another is the degradation of the a-Si:H-based passivation upon temperature, limiting the post-processes to approximately 200°C thus restricting the contacting possibilities and potential tandem device fabrication. To alleviate these two limitations, we explore the potential of amorphous silicon carbide (a-SiC:H), a widely studied material in use in standard a-Si:H thin-film solar cells, which is known for its wider bandgap, increased hydrogen content and stronger hydrogen bonding compared to a-Si:H. We study the surface passivation of solar-grade textured n-type c-Si wafers for symmetrical stacks of 10-nm-thick intrinsic a-SiC:H with various carbon content followed by either p-doped or n-doped a-Si:H (referred to as i/p or i/n stacks). For both doping types, passivation (assessed through carrier lifetime measurements) is degraded by increasing the carbon content in the intrinsic a-SiC:H layer. Yet, this hierarchy is reversed after annealing at 350°C or more due to drastic passivation improvements upon annealing when an a-SiC:H layer is used. After annealing at 350°C, lifetimes of 0.4 ms and 2.0 ms are reported for i/p and i/n stacks, respectively, when using an intrinsic a-SiC:H layer with approximately 10% of carbon (initial lifetimes of 0.3 ms and 0.1 ms, respectively, corresponding to a 30% and 20-fold increase, respectively). For stacks of pure a-Si:H material the lifetimes degrade from 1.2 ms and 2.0 ms for i/p and i/n stacks, respectively, to less than 0.1 ms and 1.1 ms (12-fold and 2-fold decrease, respectively). For complete solar cells using pure a-Si:H i/p and i/n stacks, the open-circuit voltage (Voc

  1. Role of hydrogen plasma pretreatment in improving passivation of the silicon surface for solar cells applications.

    PubMed

    Wang, Fengyou; Zhang, Xiaodan; Wang, Liguo; Jiang, Yanjian; Wei, Changchun; Sun, Jian; Zhao, Ying

    2014-09-10

    We have investigated the role of hydrogen plasma pretreatment in promoting silicon surface passivation, in particular examining its effects on modifying the microstructure of the subsequently deposited thin hydrogenated amorphous silicon (a-Si:H) passivation film. We demonstrate that pretreating the silicon surface with hydrogen plasma for 40 s improves the homogeneity and compactness of the a-Si:H film by enhancing precursor diffusion and thus increasing the minority carrier lifetime (τ(eff)). However, excessive pretreatment also increases the density of dangling bond defects on the surface due to etching effects of the hydrogen plasma. By varying the duration of hydrogen plasma pretreatment in fabricating silicon heterojunction solar cells based on textured substrates, we also demonstrate that, although the performance of the solar cells shows a similar tendency to that of the τ(eff) on polished wafers, the optimal duration is prolonged owing to the differences in the surface morphology of the substrates. These results suggest that the hydrogen plasma condition must be carefully regulated to achieve the optimal level of surface atomic hydrogen coverage and avoid the generation of defects on the silicon wafer. PMID:25141300

  2. Comal County MHMR Center passive solar demonstration program. Operation and evaluation final report

    SciTech Connect

    Svedeman, S.J.; Stubblefield, J.; Wyatt, R.

    1983-10-01

    A stone school building, built in New Braunfels, Texas in 1934, was renovated for use as a mental health facility. Included in the renovation of the 4805 ft/sup 2/ building were cost effective passive solar and conservation options. The total cost for building renovation was $125,000 with the cost of the energy related options totaling $14,000. The passive solar and conservation options included in building construction were ceiling insulation, weather proofing, fluorescent lighting, roof evaporative spray cooling systems, awnings, and ceiling fans. Natural ventilation and night cooling are used to reduce the cooling load. Natural daylighting is utilized to replace the dependence on artificial lighting. The yearly space heating energy consumption at the MHMR Center was 16,000 Btu/ft/sup 2//year. The energy usage for lighting (including ceiling fans), water heating, and air conditioning was 7380 Btu/ft/sup 2//year, 2070 Btu/ft/sup 2//year, and 3700 Btu/ft/sup 2//year, respectively. Approximately 23% of the lighting load was for external night lighting. The average monthly utility bill, including natural gas and electric, for the 4805 ft/sup 2/ building was $171.

  3. Materials research for passive solar systems: solid-state phase-change materials

    SciTech Connect

    Benson, D.K.; Webb, J.D.; Burrows, R.W.; McFadden, J.D.O.; Christensen, C.

    1985-03-01

    A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C/sub 5/H/sub 12/O/sub 4/), pentaglycerinve (C/sub 5/H/sub 12/O/sub 3/), and neopentyl glycol (C/sub 5/H/sub 12/O/sub 2/). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature betweeen 25/sup 0/C and 188/sup 0/C, and have latent heats of transformation between 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier. Nevertheless, a higher cost of the phase-change materials (approx. =$0.70 per pound) is likely to limit their applicability in passive solar systems unless their performance can be significantly improved through further research.

  4. Site-Selective Passivation of Defects in NiO Solar Photocathodes by Targeted Atomic Deposition.

    PubMed

    Flynn, Cory J; McCullough, Shannon M; Oh, EunBi; Li, Lesheng; Mercado, Candy C; Farnum, Byron H; Li, Wentao; Donley, Carrie L; You, Wei; Nozik, Arthur J; McBride, James R; Meyer, Thomas J; Kanai, Yosuke; Cahoon, James F

    2016-02-01

    For nanomaterials, surface chemistry can dictate fundamental material properties, including charge-carrier lifetimes, doping levels, and electrical mobilities. In devices, surface defects are usually the key limiting factor for performance, particularly in solar-energy applications. Here, we develop a strategy to uniformly and selectively passivate defect sites in semiconductor nanomaterials using a vapor-phase process termed targeted atomic deposition (TAD). Because defects often consist of atomic vacancies and dangling bonds with heightened reactivity, we observe-for the widely used p-type cathode nickel oxide-that a volatile precursor such as trimethylaluminum can undergo a kinetically limited selective reaction with these sites. The TAD process eliminates all measurable defects in NiO, leading to a nearly 3-fold improvement in the performance of dye-sensitized solar cells. Our results suggest that TAD could be implemented with a range of vapor-phase precursors and be developed into a general strategy to passivate defects in zero-, one-, and two-dimensional nanomaterials. PMID:26821265

  5. Temperature resolution enhancing of commercially available THz passive cameras due to computer processing of images

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.

    2014-06-01

    As it is well-known, application of the passive THz camera for the security problems is very promising way. It allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. Efficiency of using the passive THz camera depends on its temperature resolution. This characteristic specifies possibilities of the detection of concealed object: minimal size of the object, maximal distance of the detection, image detail. One of probable ways for a quality image enhancing consists in computer processing of image. Using computer processing of the THz image of objects concealed on the human body, one may improve it many times. Consequently, the instrumental resolution of such device may be increased without any additional engineering efforts. We demonstrate new possibilities for seeing the clothes details, which raw images, produced by the THz cameras, do not allow to see. We achieve good quality of the image due to applying various spatial filters with the aim to demonstrate independence of processed images on math operations. This result demonstrates a feasibility of objects seeing. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp., and Capital Normal University (Beijing, China).

  6. Ultrathin flexible planar crystalline-silicon/polymer hybrid solar cell with 5.68% efficiency by effective passivation

    NASA Astrophysics Data System (ADS)

    Li, Yingfeng; Fu, Pengfei; Li, Ruike; Li, Meicheng; Luo, Younan; Song, Dandan

    2016-03-01

    Ultrathin silicon based solar cells provide a viable way to reduce the material usage and diversify their applications. However, complex light-trapping structures are always needed to be fabricated to enhance light absorption, which will lead to exacerbation of carrier collection and expensive fabrication cost. Here, we report very simple planar flexible crystalline silicon-polymer hybrid solar cell with thickness about 18 μm, whose power conversion efficiency (PCE) reaches 5.68%. By introducing the amorphous silicon layer to passivate the Silicon/Polymer interface in our device, with accuracy control of the thickness of 2 nm to balance the passivation effect and the deterioration of internal electric field, the short current density reaches 83.0% of the theoretical limit. Additionally, we found that the average PCE of solar cells passivated by such technology is 5.8% and 7.1% enhanced compared with those without passivation (H-terminated) and passivated by native oxide approaches. The simple device structure provided in this study has great practicability, and the passivation processes can be duplicated for other silicon based photovoltaic devices.

  7. High-Efficiency, Commercial Ready CdTe Solar Cells

    SciTech Connect

    Sites, James R.

    2015-11-19

    Colorado State’s F-PACE project explored several ways to increase the efficiency of CdTe solar cells and to better understand the device physics of those cells under study. Increases in voltage, current, and fill factor resulted in efficiencies above 17%. The three project tasks and additional studies are described in detail in the final report. Most cells studied were fabricated at Colorado State using an industry-compatible single-vacuum closed-space-sublimation (CSS) chamber for deposition of the key semiconductor layers. Additionally, some cells were supplied by First Solar for comparison purposes, and a small number of modules were supplied by Abound Solar.

  8. Commercially available black chrome is an effective solar collector coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1974-01-01

    Black chrome, electroplated decorative finish, which absorbs and retains solar energy is readily available, easily applied, and low cost. It is indistinguishable from black nickel and is equally feasible on aluminum or steel.

  9. Properties of dye-sensitized solar cells with TiO2 passivating layers prepared by electron-beam evaporation.

    PubMed

    Jin, Young Sam; Choi, Hyung Wook

    2012-01-01

    The aim of this work is to prevent back transfer of electrons due to direct contact between the electrolyte and the FTO glass substrate using a TiO2 passivating layer. The TiO2 passivating layer was deposited on FTO glass by e-beam evaporation. The TiO2 film was prepared with different deposition rates. The specific surface area was reduced with increasing deposition rate. The nanoporous TiO2 upper layer was coated by screen-printing on the TiO2 passivating layer prepared by e-beam evaporation. The optical transmittance and absorbance of the TiO2 films depend on the morphology of the TiO2 passivating layer. The dye-sensitized solar cells influenced the surface morphology of the TiO2 passivating layer. The dye-sensitized solar cell using the TiO2 passivating layer recorded a maximum conversion efficiency of 4.93% due to effective prevention of the electron recombination to the electrolyte. PMID:22524036

  10. Hodges residence: performance of a direct gain passive solar home in Iowa

    SciTech Connect

    Hodges, L.

    1980-01-01

    Results are presented for the performance of the Hodges Residence, a 2200-square-foot earth-sheltered direct gain passive solar home in Ames, Iowa, during the 1979-80 heating season, its first occupied season. No night insulation was used on its 500 square feet of double-pane glass. Total auxiliary heat required was 43 GJ (41 MBTU) gross and 26 GJ (25 MBTU) net, amounting, respectively, to 60 and 36 kJ/C/sup 0/-day-m/sup 2/ (2.9 and 1.8 BTU/F/sup 0/-day-ft/sup 2/). The heating season was unusually cloudy and included the cloudiest January in the 21 years of Ames insolation measurements. Results are also presented for the performance of the hollow-core floor which serves as the main storage mass and for the comfort range in the house.

  11. Hydrogen passivation of electrically active defects in crystalline silicon solar cells

    SciTech Connect

    Milstein, J B; Tsuo, Y S; Osterwald, C R; White, C W

    1984-06-01

    We have observed significant improvements in the efficiencies of dendritic web and edge-supported-pulling (ESP) silicon sheet solar cells after hydrogen ion beam passivation for a period of ten minutes or less. We have studied the effects of the hydrogen ion beam treatment with respect to silicon material damage, silicon sputter rate, introduction of impurities, and changes in reflectance. We have determined that the silicon sputter rate for a constant ion beam flux of 0.60 +- 0.05 mA/cm/sup 2/ exhibits a maximum at approximately 1400 eV ion beam energy. We have observed that hydrogen ion beam treatment can result in a reduced fill factor, which is caused by damage to the front metallization of the cell rather than by damage to the p-n junction.

  12. Development of an exterior insulating mechanism for passive solar walls. Final report

    SciTech Connect

    Christianson, L.

    1984-01-01

    A movable, mechanically operated, insulated cover for insulating and protecting the exterior side of south-facing window walls typical of passive solar homes was designed, built and tested. The shutter, which covers an 8 ft by 32 ft glass wall on a house near Brookings, South Dakota, is constructed of 4 in. of styrofoam insulation sandwiched between 3/8 in. plywood. The shutter consists of two 4-1/3 ft by 33 ft sections which are raised or lowered by cables. Each section is attached to a mechanical drive operated by a 1/2 HP electric motor coupled to a worm gear box which automatically locks in position whenever re-energized. Major problems encountered were (1) selection of a motor and gear box combination which locked in position when de-energized to avoid problems which could occur during a power outage, (2) design of the door guide system to minimize possibilities of the door sections binding or catching while moving up or down, and (3) minimizing the door system cost to enhance the economic feasibility of insulating passive window walls at night. Energy consumption can be reduced by approximately 80,000 to 90,000 Btu/ft/sup 2/-y by using this window cover device. Material costs for the cover are approximately $8.00/ft/sup 2/.

  13. Hydrogen passivation of defects and rapid thermal processing for high-efficiency silicon ribbon solar cells

    NASA Astrophysics Data System (ADS)

    Jeong, Ji-Weon

    2002-01-01

    The use of photovoltaic (PV) system offers a unique opportunity to solve the energy and the environmental problems simultaneously because solar energy is free and can be directly converted into electrical energy by solar cells without any undesirable impact on the environment. In spite of the many advantages, PV still accounts for less than 0.05% of the current U.S. energy portfolio. This is mainly because PV is 2-4 times more expensive than traditional energy sources. PV modules should cost about $1/W to produce electricity at a rate of 6¢/kWh and to compete with fossil fuels. Since Si material accounts for ˜40% of the cost of current Si PV modules, the use of low-cost Si substrate is critical for cost reduction. Edge-defined film-fed grown (EFG) Si ribbon is the focus as substrate materials for this research because it is one of the most promising for low-cost PV. However, as-grown EFG Si has a lot of impurities and crystal defects resulted from the Si feedstock and its growth system, which reduce the bulk lifetime of less than 3 ms. In this research, first, the requirements for achieving 16% efficiency have been established using computer model simulations. To improve the bulk lifetime, manufacturable P and Al gettering techniques are developed to remove the lifetime-killing impurities from the active to inactive device regions. PECVD SiN-induced hydrogen defect passivation is investigated and maximized through the fundamental understanding of the role of Al, the impact of RTP firing, and the difference between two PECVD SiN films. For low-cost contact formation, a novel RTP firing process is developed for high-quality screen-printed contacts and Al-BSF. Finally, a complete process sequence that involves the optimal conditions for defect passivation and contacts is developed to produce ˜16% efficiency on screen-printed EFG Si solar cells, which is the highest efficiency for any screen-printed Si ribbon solar cells to date.

  14. New three-layer antireflection/surface passivating coating for high efficiency III-V compound solar cells

    SciTech Connect

    Moulot, J.; Faur, M.; Goradia, C.; Goradia, M.; Faur, M.; Alterovitz, S.; Bailey, S.

    1996-12-31

    By using a chemically grown In(PO{sub 3}){sub 3}-rich oxide layer as the first layer of a 3-layer AR coating, with Al{sub 2}O{sub 3} and MgF{sub 2} as the second and third layers, the authors have addressed the problem of surface passivation and AR coating on InP solar cells. They have designed a 3-layer optimized AR coating for p{sup +}n InP solar cell, which reduces the average reflectance on the surface of cell from about 40% (bare) to less than 2%. At the same time the AR coating significantly improves the J{sub SC} and V{sub OC} by passivating the top surface of the emitter. The authors believe that the significant front surface passivation is to a large extent responsible for their achieving the record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused p{sup +}n InP(Cd,S) solar cell. This concept of using a passivating chemically grown oxide as the first layer of a multilayer AR coating can be beneficial to other III-V compound solar cells as well.

  15. Passive cooling with solar updraft and evaporative downdraft chimneys. Interim report, June 15, 1984--March 1, 1985

    SciTech Connect

    Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

    1985-12-31

    Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

  16. Development of high-efficiency solar cells on thin silicon through design optimization and defect passivation

    NASA Astrophysics Data System (ADS)

    Sheoran, Manav

    The focus of this research is to investigate the potential of lower quality cast multicrystalline Si (mc-Si) as well as thin single and mc-Si cells. The overall goal of this research is to improve fundamental understanding of the hydrogen passivation of defects in low-cost Si and the fabrication of high-efficiency solar cells on thin crystalline silicon through low-cost technology development. This is addressed by a combination of five research tasks. The key results of these tasks are summarized below. A novel method was developed to determine the concentration and flux of H diffusing into the Si. The understanding of defect passivation acquired in task 1 was used to fabricate high-efficiency solar cells on cast mc-Si wafers. An optimized co-firing process was developed, which resulted in ˜17% efficient 4 cm2 screen-printed solar cells with single-layer AR coating, and no surface texturing or selective emitter. The HEM mc-Si wafer gave an average efficiency of 16.5%, with a maximum of 16.9%. The identical process applied to the un-textured Float zone (FZ) wafers gave an efficiency of 17.2%. These cells were fabricated using the same simple, manufacturable process involving POCl3 diffusion for a 45 O/sq emitter, PECVD SiNx:H deposition for single-layer antireflection coating and rapid co-firing of a Ag grid, an Al back contact, and Al-BSF formation in a belt furnace. A high-efficiency of 17.1% was achieved on high sheet-resistance HEM mc-Si with good quality contacts. The effects of changing several device parameters on the efficiency of the solar cells was modeled with PC1D and guidelines were established to improve the efficiency from ˜17% to over 20% cells on low lifetime (100 mus), thin (140 mum) silicon wafers. The understanding of enhanced defect hydrogenation and the optimized fabrication sequence was applied to fabricate high-efficiency solar cells on top, middle, and bottom regions of several mc-Si ingots. Screen-printed solar cells were fabricated on

  17. Commercial solar/load management experiment: New mechanical engineering building

    NASA Astrophysics Data System (ADS)

    Noble, J. M.

    1981-01-01

    The effects of load management heat recovery, thermal storage, and solar systems on energy usage and power demand profiles in the University of New Mexico's Mechanical Engineering Building are presented. Results were obtained from a year monitoring of the building's heating and cooling systems and recording of sensor signals by a computer based data acquisition system. A modified AXCESS Energy Analysis Program to simulate energy usage is detailed, and the development of perferred strategies for maximizing the building's load management capabilities is outlined.

  18. Progress toward achieving a commercially viable solar reflective material

    SciTech Connect

    Kennedy, C.E.; Smilgys, R.V. |

    1998-06-01

    Solar thermal technologies use large mirrors to concentrate sunlight for renewable power generation. The development of advanced reflector materials is important to the viability of electricity production by solar thermal energy systems. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. Production processes associated with candidate materials must be scalable to mass production techniques. A promising low-cost construction uses a stainless steel foil substrate with a silver reflective layer protected by an optically transparent oxide topcoat. Thick (2 to 4 micron), dense alumina coatings provide durable protective layers. The excellent performance of alumina-coated reflector materials in outdoor and accelerated testing suggests that a larger field trial of the material is warranted. The key to producing a greater quantity of material for field deployment and testing without incurring substantial capital is the use of a chilled drum coater. An existing chamber is being modified, and the deposition rate will be increased prior to the installation of a drum coater to produce 1-ft wide by 10-ft long strips of solar reflector material. The production and performance of these materials are discussed.

  19. Passive-solar-heating project for a single-family residence. Final report

    SciTech Connect

    Starkey, V.J.

    1982-05-01

    This project was a passive home heating system utilizing solar collectors that are part of the roof structure of a 15' x 30' greenhouse. The design utilized solar air collectors constructed on site that are actually part of the roof of the greenhouse. The flow of air is from the storage to the collectors then back to the storage. The storage bin consists of a 5' x 19' concrete insulated bin built into the floor of the greenhouse. The storage mass was gallon plastic jugs. The plastic jugs did not work properly, so they are being replaced by salt rods. This replacement will be an after the fact project by the owner. The concrete storage bin was insulated with 2'' plastic foam insulation, applied to the 8'' concrete wall. The ducts entering and leaving the storage bin have low voltage (12 volt) electric dampers. A cross flow system was used. The heated air circulates from the collectors to storage via ducts in the walls of the lean-to design. The removal of heat from the storage bin was from end to end via the ducts to the central air system for the house. In addition, the greenhouse is connected to the house with a doorway that can be opened to circulate air into the house, a shuttled exhaust fan 1/3H.P. motor has aided in the circulation of air from the storage bin to the collectors and back.

  20. Tuning semiconductor band edge energies for solar photocatalysis via surface ligand passivation.

    PubMed

    Yang, Shenyuan; Prendergast, David; Neaton, Jeffrey B

    2012-01-11

    Semiconductor photocatalysts capable of broadband solar photon absorption may be nonetheless precluded from use in driving water splitting and other solar-to-fuel related reactions due to unfavorable band edge energy alignment. Using first-principles density functional theory and beyond, we calculate the electronic structure of passivated CdSe surfaces and explore the opportunity to tune band edge energies of this and related semiconductors via electrostatic dipoles associated with chemisorbed ligands. We predict substantial shifts in band edge energies originating from both the induced dipole at the ligand/CdSe interface and the intrinsic dipole of the ligand. Building on important induced dipole contributions, we further show that, by changing the size and orientation of the ligand's intrinsic dipole moment via functionalization, we can control the direction and magnitude of the shifts of CdSe electronic levels. Our calculations suggest a general strategy for enabling new active semiconductor photocatalysts with both optimal opto-electronic, and photo- and electrochemical properties. PMID:22192078

  1. High reduction of interfacial charge recombination in colloidal quantum dot solar cells by metal oxide surface passivation

    NASA Astrophysics Data System (ADS)

    Chang, Jin; Kuga, Yuki; Mora-Seró, Iván; Toyoda, Taro; Ogomi, Yuhei; Hayase, Shuzi; Bisquert, Juan; Shen, Qing

    2015-03-01

    Bulk heterojunction (BHJ) solar cells based on colloidal QDs and metal oxide nanowires (NWs) possess unique and outstanding advantages in enhancing light harvesting and charge collection in comparison to planar architectures. However, the high surface area of the NW structure often brings about a large amount of recombination (especially interfacial recombination) and limits the open-circuit voltage in BHJ solar cells. This problem is solved here by passivating the surface of the metal oxide component in PbS colloidal quantum dot solar cells (CQDSCs). By coating thin TiO2 layers onto ZnO-NW surfaces, the open-circuit voltage and power conversion efficiency have been improved by over 40% in PbS CQDSCs. Characterization by transient photovoltage decay and impedance spectroscopy indicated that the interfacial recombination was significantly reduced by the surface passivation strategy. An efficiency as high as 6.13% was achieved through the passivation approach and optimization for the length of the ZnO-NW arrays (device active area: 16 mm2). All solar cells were tested in air, and exhibited excellent air storage stability (without any performance decline over more than 130 days). This work highlights the significance of metal oxide passivation in achieving high performance BHJ solar cells. The charge recombination mechanism uncovered in this work could shed light on the further improvement of PbS CQDSCs and/or other types of solar cells.Bulk heterojunction (BHJ) solar cells based on colloidal QDs and metal oxide nanowires (NWs) possess unique and outstanding advantages in enhancing light harvesting and charge collection in comparison to planar architectures. However, the high surface area of the NW structure often brings about a large amount of recombination (especially interfacial recombination) and limits the open-circuit voltage in BHJ solar cells. This problem is solved here by passivating the surface of the metal oxide component in PbS colloidal quantum dot solar

  2. Economic Recovery Act of 1981 and tax policies for commercial solar-energy applications

    SciTech Connect

    Ball, D. E.

    1981-12-01

    Key tax policies relevant to commercial solar energy applications are outlined. Included are certain changes in depreciation rules and small business federal income tax percentages that were part of the recently enacted Economic Recovery Tax Act of 1981. Also, the regulations for business investment and energy tax credits are explained. An example of the effects of the new depreciation schedule on a solar industrial process heat system is given.

  3. Commercialization of a thick-film solar cell

    NASA Astrophysics Data System (ADS)

    McDonald, G. D.

    1980-12-01

    The use of screen printing as a technique for producing large area solar cells was evaluated with emphasis on the preparation and improvement in performance of screen printed CdS cells. Thermal gravimetric analysis of the CdS inks used to print CdS films confirm that all the fugitive binders and flux are removed under firing conditions used to prepare the CdS films. Warpage of the Nesatron glass substrates makes their use questionable. Multiple layers of CdS appear to resolve a pin hole problem previously encountered.

  4. Black chrome on commercially electroplated tin as a solar selecting coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1977-01-01

    The reflectance properties of black chrome electroplated on commercially electroplated tin were measured for various black chrome plating times for both the solar and infrared spectrum. The values of absorptance and emittance were calculated from the measured reflectance values. The results indicate that the optimum combination of the highest absorptance in the solar region and the lowest emittance in the infrared of the black chrome plated on commercially electroplated tin is obtained for a black chrome plating time of between one and two minutes.

  5. Long-lasting FR-4 surface hydrophilisation towards commercial PCB passive microfluidics

    NASA Astrophysics Data System (ADS)

    Vasilakis, Nikolaos; Moschou, Despina; Carta, Daniela; Morgan, Hywel; Prodromakis, Themistoklis

    2016-04-01

    Printed circuit boards (PCB) technologies are an attractive system for simple sensing and microfluidic systems. Controlling the surface properties of PCB material is an important part of this technology and to date there has been no study on long-term hydrophilisation stability of these materials. In this work, the effect of different oxygen plasma input power and treatment duration times on the wetting properties of FR-4 surfaces was investigated by sessile droplet contact angle measurements. Super and weakly hydrophilic behaviour was achieved and the retention time of these properties was studied, with the hydrophilic nature being retained for at least 26 days. To demonstrate the applicability of this treatment method, a commercially manufactured microfluidic structure made from a multilayer PCB (3-layer FR-4 stack) was exposed to oxygen plasma at the optimum conditions. The structures could be filled with deionised (DI) water under capillary flow unlike the virgin devices.

  6. International solar commercialization study of the market potential of solar products in Latin America: Jamaica. Final report

    SciTech Connect

    Not Available

    1981-12-01

    The current and forecasted economic situations in Jamaica are reviewed. The logistics of doing business is reviewed, including finance, labor, investment and import policy. Market penetration strategy is presented, with emphasis on the Kingston free zone analysis. A Market Potential for US Renewable Energy Products in Jamaica included government, agricultural, tourism, manufacturing, and mining sectors. Conclusions and recommendations are given. The market readiness of the following renewable technologies was analyzed: photovoltaics; industrial process heat; active and passive solar; biomass; wind; small-scale hydro; ocean thermal; geothermal; and conservation. When appropriate, the foreign competition was also analyzed.

  7. Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

    SciTech Connect

    Wan, Yimao Bullock, James; Cuevas, Andres

    2015-05-18

    This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negative fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.

  8. Enhanced Lifetime of Polymer Solar Cells by Surface Passivation of Metal Oxide Buffer Layers.

    PubMed

    Venkatesan, Swaminathan; Ngo, Evan; Khatiwada, Devendra; Zhang, Cheng; Qiao, Qiquan

    2015-07-29

    The role of electron selective interfaces on the performance and lifetime of polymer solar cells were compared and analyzed. Bilayer interfaces consisting of metal oxide films with cationic polymer modification namely poly ethylenimine ethoxylated (PEIE) were found to enhance device lifetime compared to bare metal oxide films when used as an electron selective cathode interface. Devices utilizing surface-modified metal oxide layers showed enhanced lifetimes, retaining up to 85% of their original efficiency when stored in ambient atmosphere for 180 days without any encapsulation. The work function and surface potential of zinc oxide (ZnO) and ZnO/PEIE interlayers were evaluated using Kelvin probe and Kelvin probe force microscopy (KPFM) respectively. Kelvin probe measurements showed a smaller reduction in work function of ZnO/PEIE films compared to bare ZnO films when aged in atmospheric conditions. KPFM measurements showed that the surface potential of the ZnO surface drastically reduces when stored in ambient air for 7 days because of surface oxidation. Surface oxidation of the interface led to a substantial decrease in the performance in aged devices. The enhancement in the lifetime of devices with a bilayer interface was correlated to the suppressed surface oxidation of the metal oxide layers. The PEIE passivated surface retained a lower Fermi level when aged, which led to lower trap-assisted recombination at the polymer-cathode interface. Further photocharge extraction by linearly increasing voltage (Photo-CELIV) measurements were performed on fresh and aged samples to evaluate the field required to extract maximum charges. Fresh devices with a bare ZnO cathode interlayer required a lower field than devices with ZnO/PEIE cathode interface. However, aged devices with ZnO required a much higher field to extract charges while aged devices with ZnO/PEIE showed a minor increase compared to the fresh devices. Results indicate that surface modification can act as a

  9. Photovoltaic commercialization: an analysis of legal issues affecting a government-accelerated solar industry

    SciTech Connect

    Lamm, D.

    1980-06-01

    The Photovoltaics Research, Development, and Demonstration Act of 1978 is discussed. Legal issues, including solar access, the need for performance standards, the effects of building codes on photovoltaic system use and commercialization, and manufacturer and installer performance guarantees, are examined. Electric utility policies are examined, including interconnection, and rates and legal issues affecting them. (LEW)

  10. Interim Policy Options for Commercialization of Solar Heating and Cooling Systems.

    ERIC Educational Resources Information Center

    Bezdek, Roger

    This interim report reviews the major incentive policy options available to accelerate market penetration of solar heating and cooling (SHAC) systems. Feasible policy options designed to overcome existing barriers to commercial acceptance and market penetration are identified and evaluated. The report is divided into seven sections, each dealing…

  11. Solar-Energy System for a Commercial Building--Topeka, Kansas

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Report describes a solar-energy system for space heating, cooling and domestic hot water at a 5,600 square-foot (520-square-meter) Topeka, Kansas, commercial building. System is expected to provide 74% of annual cooling load, 47% of heating load, and 95% of domestic hot-water load. System was included in building design to maximize energy conservation.

  12. Passivated Tunneling Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint

    SciTech Connect

    Stradins, P.; Essig, S.; Nemeth, W.; Lee, B. G.; Young, D.; Norman, A.; Liu, Y.; Luo, J.-W.; Warren, E.; Dameron, A.; LaSalvia, V.; Page, M.; Rohatgi, A.; Upadhyaya, A.; Rounsaville, B.; Ok, Y.-W.; Glunz, S.; Benick, J.; Feldmann, F.; Hermle, M.

    2014-12-01

    We present a case that passivated contacts based on a thin tunneling oxide layer, combined with a transport layer with properly selected work function and band offsets, can lead to high efficiency c-Si solar cells. Passivated contacts contribute to cell efficiency as well as design flexibility, process robustness, and a simplified process flow. Material choices for the transport layer are examined, including transparent n-type oxides and n+-doped poly-Si. SiO2/n+-poly-Si full-area, induced-junction back surface field contacts to n-FZ and n-Cz Si are incorporated into high efficiency cells with deep, passivated boron emitters.

  13. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    SciTech Connect

    Wagner, Hannes; Ohrdes, Tobias; Dastgheib-Shirazi, Amir; Puthen-Veettil, Binesh; König, Dirk; Altermatt, Pietro P.

    2014-01-28

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl{sub 3} diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)–(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher V{sub oc}. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  14. Nationwide Analysis of U.S. Commercial Building Solar Photovoltaic (PV) Breakeven Conditions

    SciTech Connect

    Davidson, Carolyn; Gagnon, Pieter; Denholm, Paul; Margolis, Robert

    2015-10-01

    The commercial sector offers strong potential for solar photovoltaics (PV) owing to abundant available roof space suitable for PV and the opportunity to offset the sector's substantial retail electricity purchases. This report evaluated the breakeven price of PV for 15 different building types and various financing options by calculating electricity savings based on detailed rate structures for most U.S. utility territories (representing approximately two thirds of U.S. commercial customers). We find that at current capital costs, an estimated 1/3 of U.S. commercial customers break even in the cash scenario and approximately 2/3 break even in the loan scenario. Variation in retail rates is a stronger driver of breakeven prices than is variation in building load or solar generation profiles. At the building level, variation in the average breakeven price is largely driven by the ability for a PV system to reduce demand charges.

  15. Comal County Mental Health and Mental Retardation Center Passive Solar Demonstration Program. Final report

    SciTech Connect

    Risner, P. S.; Stubblefield, J.; Deffenbaugh, D. M.; Stevenson, J.

    1980-07-31

    An extensive energy analysis was performed on an existing schoolhouse built in New Braunfels, Texas, in the 1930's. The purpose of the analysis was to evaluate the potentials for passive solar retrofitting concepts and energy conservation techniques which could be applied to the structure on an economically justifiable basis. The energy analysis was performed by the Bin methodology, and a life cycle cost analysis was utilized in determining the economics of the alternatives under consideration. The alternatives which were considered were analyzed on an individual basis as to the percentage improvement in the existing structure's yearly energy loads which each option could be expected to provide. The life cycle cost analysis was based on the assumed useful life of the option; the estimated fuel savings the option provided; the initial investment required to incorporate the option into the retrofitted structure; and discount and fuel escalation rates of 10 and 12%, respectively. If the option provided a positive annual real savings over its assumed life, then the selection of the option was considered to be economically feasible. The selected options were subsequently combined into a revised construction package, and an energy/economic analysis was performed to estimate the annual savings which could be expected by the revisions. A conservative building temperature control strategy which consisted of turning off the mechanical equipment during unoccupied hours, and utilizing natural ventilation when applicable was also investigated. The options which were selected and the relative annual savings are given.

  16. Starting a local conservation and passive solar retrofit program: an energy planning sourcebook

    SciTech Connect

    Barber, V; Mathews, R

    1982-02-01

    A city planner or a neighborhood activist may wish to initiate a local conservation and passive solar retrofit program but may not have previous experience in doing so. This sourcebook is designed to assist interested individuals with their energy planning efforts, from determining retrofit potential, to financing and implementing the program. An approach or methodology is provided which can be applied to determine retrofit potential in single-family residences, mobile homes, multifamily residences, and nonresidential buildings. Case studies in Albuquerque, New Mexico, are given as examples. Guidelines are provided for evaluating the economic benefits of a retrofit program through benefit-cost analysis and economic base studies at the city and neighborhood levels. Also included are approaches to community outreach, detailing how to get started, how to gain local support, and examples of successful programs throughout the US. The need for financing, the development of a local strategy, public and private financing techniques, and community energy service organizations are examined. In addition to the Albuquerque case studies, a brief technology characterization, heat-loss calculations, economic tools, and a list of resources are appended.

  17. Early commercial demonstration of space solar power using ultra-lightweight arrays

    NASA Astrophysics Data System (ADS)

    Reed, Kevin; Willenberg, Harvey J.

    2009-11-01

    Space solar power shows great promise for future energy sources worldwide. Most central power stations operate with power capacity of 1000 MW or greater. Due to launch size limitations and specific power of current, rigid solar arrays, the largest solar arrays that have flown in space are around 50 kW. Thin-film arrays offer the promise of much higher specific power and deployment of array sizes up to several MW with current launch vehicles. An approach to early commercial applications for space solar power to distribute power to charge hand-held, mobile battery systems by wireless power transmission (WPT) from thin-film solar arrays in quasi-stationary orbits will be presented. Four key elements to this prototype will be discussed: (1) Space and near-space testing of prototype wireless power transmission by laser and microwave components including WPT space to space and WPT space to near-space HAA transmission demonstrations; (2) distributed power source for recharging hand-held batteries by wireless power transmission from MW space solar power systems; (3) use of quasi-geostationary satellites to generate electricity and distribute it to targeted areas; and (4) architecture and technology for ultra-lightweight thin-film solar arrays with specific energy exceeding 1 kW/kg. This approach would yield flight demonstration of space solar power and wireless power transmission of 1.2 MW. This prototype system will be described, and a roadmap will be presented that will lead to still higher power levels.

  18. Remote trap passivation in colloidal quantum dot bulk nano-heterojunctions and its effect in solution-processed solar cells.

    PubMed

    Rath, Arup K; Pelayo Garcia de Arquer, F; Stavrinadis, Alexandros; Lasanta, Tania; Bernechea, Maria; Diedenhofen, Silke L; Konstantatos, Gerasimos

    2014-07-16

    More-efficient charge collection and suppressed trap recombination in colloidal quantum dot (CQD) solar cells is achieved by means of a bulk nano-heterojunction (BNH) structure, in which p-type and n-type materials are blended on the nanometer scale. The improved performance of the BNH devices, compared with that of bilayer devices, is displayed in higher photocurrents and higher open-circuit voltages (resulting from a trap passivation mechanism). PMID:24895324

  19. Shellfish mariculture facility which employs passive solar heating and heat pump systems. Performance and cost analysis study. Final report

    SciTech Connect

    Zoto, G.A.; Krabach, M.H.

    1984-06-01

    This report incorporates operations data such as clam growth rates, clam biomass buildup, water volume, and algal food requirements compiled while developing a year-round production schedule for production of hard clam seed. The facility includes a passive solar hatchery and heat pump. Three major areas which affect development of energy-efficient mariculture are addressed: biological operation parameters, energy requirements, and system economics. (LEW)

  20. Preliminary energy sector assessments of Jamaica. Volume III: renewable energy. Part I: solar energy - commercial and industrial

    SciTech Connect

    Not Available

    1980-01-01

    This study concerns commercial and industrial solar applications, specifically solar water heating and solar air cooling. The study finds that solar domestic water heating and boiler make-up water preheating are technically feasible and, depending on the displaced energy source (electrical or various fuel types), economically justified; and that solar hot water installations could displace the equivalent of 189,842 barrels of fuel oil per year. However, solar cooling requires high performance collectors not currently manufactured in Jamaica, and feasibility studies indicate that solar cooling in the near term is not economically justified.

  1. Passive solar in Milton Keynes, England. A description of some of the more numerical aspects of the design of an estate of low energy houses

    NASA Astrophysics Data System (ADS)

    Everett, R.

    1980-07-01

    The numerical aspects of the design of low energy consumption houses using passive solar energy collection and high levels of insulation are described. Two housing energy conservation projects were begun, one involving the construction of 177 low energy houses on a cost-effective basis, and the other involving the detailed monitoring of eight highly insulated passive solar houses. Both experimental data and theoretical analysis are presented, and the relative effectiveness of the various design alternatives are discussed.

  2. Endurance testing of first generation (Block 1) commercial solar cell modules

    NASA Technical Reports Server (NTRS)

    Anagnostou, E.; Forestieri, A. F.

    1978-01-01

    To determine lifetimes of the first generation (Block 1) commercial solar cell modules used in solar cell arrays, a program was initiated to expose these modules to a range of environments. The conditions endured by these modules encompassed hot and dry, hot and humid, tropical rain forests, sea-air, urban industrial and urban clean. Exposures were for periods up to 1 year. The effect of outdoor exposure on the performance of the modules was determined using current-voltage curves. Short-circuit current (I sub sc) and maximum power (P sub max) were the parameters monitored. In all cases, there was a loss of performance of the modules with outdoor exposure.

  3. Passive solar commercial buildings project. Project status report, November 1-December 31, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Additional work on the Security State BLAST input file has resulted in better agreement between measured and estimated conditions. Although agreement is not complete, additional sources of error have been identified and some original problems corrected. A third visit has been made to the Security State Bank and data on the modified building operation obtained. The planned continuous infiltration test using equipment supplied by Lawrence Berkeley Laboratories was cancelled. It was found that the complexity of the test was beyond the scope of this project. The data acquisition system installed by ESG in the Security State Bank has been turned over to representatives of Architectural Energy Corporation (AEC) for long term data retrieval. Further monitoring of this site by ESG is not expected. A data acquisition system has been installed in the Salt Lake City Johnson Controls building. The necessary one time measurements were made on the building. Hourly data from the building is to be provided to ESG by AEC over telecommunication lines. No data has been made available yet from this site. The final data from the building modifications is not expected before the end of January, 1984.

  4. Endurance testing of first generation /Block I/ commercial solar cell modules

    NASA Technical Reports Server (NTRS)

    Anagnostou, E.; Forestieri, A. F.

    1978-01-01

    NASA-LeRC has conducted outdoor endurance tests on modules commercially produced as part of the 46-kW purchase of first generation (Block I) modules by the JPL Low Cost Silicon Solar Array Project. Block I modules from four manufacturers were installed at commercial testing sites in Florida, Puerto Rico, and Arizona and at noncommercial sites in Cleveland, Ohio. The conditions endured by these modules included hot and dry, hot and humid, tropical rain forest, sea-air, urban industrial and urban clean; exposures were for periods up to one year. Test results are presented and discussed.

  5. Dish/Stirling systems: Overview of an emerging commercial solar thermal electric technology

    SciTech Connect

    Strachan, J.W.; Diver, R.B.; Estrada, C.

    1995-11-01

    Dish/Stirling is a solar thermal electric technology which couples parabolic, point-focusing solar collectors and heat engines which employ the Stirling thermodynamic cycle. Since the late 1970s, the development of Dish/Stirling systems intended for commercial use has been in progress in Germany, Japan, and the US. In the next several years it is expected that one or more commercial systems will enter the market place. This paper provides a general overview of this emerging technology, including: a description of the fundamental principles of operation of Dish/Stirling systems; a presentation of the major components of the systems (concentrator, receiver, engine/alternator, and controls); an overview of the actual systems under development around the world, with a discussion of some of the technical issues and challenges facing the Dish/Stirling developers. A brief discussion is also presented of potential applications for small Dish/Stirling systems in northern Mexico.

  6. Investigation of positive roles of hydrogen plasma treatment for interface passivation based on silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Liping; Guo, Wanwu; Liu, Wenzhu; Bao, Jian; Liu, Jinning; Shi, Jianhua; Meng, Fanying; Liu, Zhengxin

    2016-04-01

    The positive roles of H2-plasma treatment (HPT) have been investigated by using different treatment procedures in view of the distinctly improved passivation performance of amorphous-crystalline silicon heterojunctions (SHJs). It has been found that a hydrogenated amorphous silicon thin film and crystalline silicon (a-Si:H/c-Si) interface with a high stretching mode (HSM) is detrimental to passivation. A moderate pre-HPT introduces atomic H, which plays an effective tuning role in decreasing the interfacial HSM; unfortunately, an epitaxial layer is formed. Further improvement in passivation can be achieved in terms of increasing the HSM of a-Si:H film treated by appropriate post-HPT based on the a-Si:H thickness. The minority carrier lifetime of crystalline wafers can be improved by treated films containing a certain quantity of crystallites. The microstructure factor R and the maximum intensity of the dielectric function ε 2max have been found to be critical microstructure parameters that describe high-quality a-Si:H passivation layers, which are associated with the amorphous-to-microcrystalline transition phase induced by multi-step HPT. Finally, the open circuit voltage and conversion efficiency of the SHJ solar cell can be improved by implementing an effective HPT process.

  7. Solar Design Workbook

    SciTech Connect

    Franta, G.; Baylin, F.; Crowther, R.; Dubin, F.; Grace, A., Griffith, J.W.; Holtz, M.; Kutscher, C.; Nordham, D.; Selkowitz, S.; Villecco, M.

    1981-06-01

    This Solar Design Workbook presents solar building design applications for commercial buildir^s. The book is divided into four sections. The first section describes the variety of solar applications in buildings including conservation aspects, solar fundamentals, passive systems, active systems, daylighting, and other solar options. Solar system design evaluation techniques including considerations for building energy requirements, passive systems, active systems, and economics are presented in Section II. The third section attempts to assist the designer in the building design process for energy conservation and solar applications including options and considerations for pre-design, design, and post-design phases. The information required for the solar design proee^ has not been fully developed at this time. Therefore, Section III is incomplete, but an overview of the considerations with some of the design proces elements is presented. Section IV illustrates ease studies that utilize solar applications in the building design.

  8. Estimating the economic and demographic impacts of solar technology commercialization on US regions

    SciTech Connect

    Kort, J.R.

    1980-12-01

    The purpose of this study is to develop a framework through which these regional economic and demographic impacts of solar technology commercialization can be analyzed. Two models comprise the basis of this framework - a national input/output model and an interregional econometric model, the National-Regional Impact Evaluation System (NRIES). These models are used to convert projected sales of solar energy systems to gross output concepts, and to evaluate the impacts associated with these sales. Analysis is provided for the nine census regions and 50 states and the District of Columbia for the years 1980 through 1990. Impacts on major economic aggregates such as output, employment, income, and population are described. The methodology used in this study is described. The economic and demographic impacts of solar technology commercialization on US regions and states are presented. The major conclusions of the study are summarized, and direction is provided for further research. Detailed tables of regional and state solar energy expenditures and their impacts appear in the Appendix.

  9. A correction factor to f-chart predictions of active solar fraction in active-passive heating systems

    NASA Astrophysics Data System (ADS)

    Evans, B. L.; Beckman, W. A.; Duffie, J. A.; Mitchell, J. W.; Klein, S. A.

    1983-11-01

    The extent to which a passive system degrades the performance of an active solar space heating system was investigated, and a correction factor to account for these interactions was developed. The transient system simulation program TRNSYS is used to simulate the hour-by-hour performance of combined active-passive (hybrid) space heating systems in order to compare the active system performance with simplified design method predictions. The TRNSYS simulations were compared to results obtained using the simplified design calculations of the f-Chart method. Comparisons of TRNSYS and f-Chart were used to establish the accuracy of the f-Charts for active systems. A correlation was then developed to correct the monthly loads input into the f-Chart method to account for controller deadbands in both hybrid and active only buildings. A general correction factor was generated to be applied to the f-Chart method to produce more accurate and useful results for hybrid systems.

  10. SiC formation for a solar cell passivation layer using an RF magnetron co-sputtering system.

    PubMed

    Joung, Yeun-Ho; Kang, Hyun Il; Kim, Jung Hyun; Lee, Hae-Seok; Lee, Jaehyung; Choi, Won Seok

    2012-01-01

    In this paper, we describe a method of amorphous silicon carbide film formation for a solar cell passivation layer. The film was deposited on p-type silicon (100) and glass substrates by an RF magnetron co-sputtering system using a Si target and a C target at a room-temperature condition. Several different SiC [Si1-xCx] film compositions were achieved by controlling the Si target power with a fixed C target power at 150 W. Then, structural, optical, and electrical properties of the Si1-xCx films were studied. The structural properties were investigated by transmission electron microscopy and secondary ion mass spectrometry. The optical properties were achieved by UV-visible spectroscopy and ellipsometry. The performance of Si1-xCx passivation was explored by carrier lifetime measurement. PMID:22221730

  11. Alphabus Solar Array- Versatile and Powerful Solar Arrays for Tomorrow's Commercial Telecom Satellites

    NASA Astrophysics Data System (ADS)

    Pfefferkorn, T.; Oxynos, C.; Greff, P.; Gerlach, L.

    2008-09-01

    After the successful series of Eurostar 3000 and Spacebus 4000 satellites and due to the demand of satellite operators for even larger and more powerful satellites, ESA decided to co-fund the development of a new satellite platform which covers the market segment beyond the upper limits of both satellite families.The new satellite bus family Alphabus is developed in the frame of ARTES 8 project by a joint project team of ASTRIUM and TAS, whereas the solar array is developed by ASTRIUM GmbH.The main approaches in this design phase for the Alphabus solar array were to find a standardized and scaleable design to production and to use qualification heritage from former projects, especially Eurostar 3000, as far as possible. The main challenges for the solar array design and test philosophy were the usage of lateral deployment and related sequential deployment and the bus voltage of 102,5V and related ESD precautions.This paper provides an overview of the different configurations, their main design features and performance parameters. In addition it summarizes the development and verification approach and shows the actual qualification status.

  12. Performance of commercially available Passive Integrated Transponder (PIT) tag systems used for fish identification and interjurisdictional fisheries management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passive integrated transponder (PIT) tag systems are commonly used for identification and monitoring programs with fisheries applications. Transponders of different frequencies, sizes, and code formats are available from numerous manufacturers, and there is an increasing concern regarding the need ...

  13. Economic analysis of solar assisted absorption chiller for a commercial building

    NASA Astrophysics Data System (ADS)

    Antonyraj, Gnananesan

    Dwindling fossil fuels coupled with changes in global climate intensified the drive to make use of renewable energy resources that have negligible impact on the environment. In this attempt, the industrial community produced various devices and systems to make use of solar energy for heating and cooling of building space as well as generate electric power. The most common components employed for collection of solar energy are the flat plate and evacuated tube collectors that produce hot water that can be employed for heating the building space. In order to cool the building, the absorption chiller is commonly employed that requires hot water at high temperatures for its operation. This thesis deals with economic analysis of solar collector and absorption cooling system to meet the building loads of a commercial building located in Chattanooga, Tennessee. Computer simulations are employed to predict the hourly building loads and performance of the flat plate and evacuated tube solar collectors using the hourly weather data. The key variables affecting the economic evaluation of such system are identified and the influence of these parameters is presented. The results of this investigation show that the flat plate solar collectors yield lower payback period compared to the evacuated tube collectors and economic incentives offered by the local and federal agencies play a major role in lowering the payback period.

  14. Building with passive solar: an application guide for the southern homeowner and builder

    SciTech Connect

    1981-03-01

    This instructional material was prepared for training workshops for builders and home designers. It includes: fundamental definitions and equations, climate and site studies, building components, passive systems and techniques, and design tools. (MHR)

  15. Passive solar heating and natural cooling of an earth-integrated design

    SciTech Connect

    Barnes, P.R.; Shapira, H.B.

    1980-01-01

    The Joint Institute for Heavy Ion Research is being designed with innovative features that will greatly reduce its energy consumption for heating, cooling, and lighting. A reference design has been studied and the effects of extending the overhang during summer and fall, varying glazing area, employing RIB, and reducing internal heat by natural lighting have been considered. The use of RIB and the extendable overhang increases the optimum window glazing area and the solar heating fraction. A mass-storage wall which will likely be included in the final design has also been considered. A figure of merit for commercial buildings is the total annual energy consumption per unit area of floor space. A highly efficient office building in the Oak Ridge area typically uses 120 to 160 kWhr/m/sup 2/. The Joint Institute reference design with natural lighting, an annual average heat pump coefficient of performance (COP) equal to 1.8, RIB, and the extendable overhang uses 71 kWhr/m/sup 2/. This figure was determined from NBSLD simulations corrected for the saving from RIB. The internal heat energy from lighting and equipment used in the simulation was 1653 kWhrs/month (high natural lighting case) which is much lower than conventional office buildings. This value was adopted because only a portion of the building will be used as office space and efforts will be made to keep internal heat generation low. The mass-storage wall and ambient air cooling will reduce energy consumption still further. The combined savings of the innovative features in the Joint Institute building are expected to result in a very energy efficient design. The building will be instrumented to monitor its performance and the measured data will provide a means of evaluating the energy-saving features. The efficiency of the design will be experimentally verified over the next several years.

  16. Toward a national plan for the accelerated commercialization of solar energy: the implications of a national commitment

    SciTech Connect

    Bennington, G.; Bohannon, M.; Gerstein, R.; Hartzler, R.; Kannan, N.; Miller, G.; Rebibo, K.; Shulman, M.; Spewak, P.; Taul, J.

    1980-01-01

    This report analyzes the expected benefits, costs, and implications of three levels of federal commitment and subsidy for the accelerated commercialization of solar energy. It includes estimates of potential solar use representing 16 to 23 percent of the nation's energy supply in the year 2000. Projections are based on data available as of early 1979.

  17. Improvement of the SiOx passivation layer for high-efficiency Si/PEDOT:PSS heterojunction solar cells.

    PubMed

    Sheng, Jiang; Fan, Ke; Wang, Dan; Han, Can; Fang, Junfeng; Gao, Pingqi; Ye, Jichun

    2014-09-24

    Interfacial properties currently hinder the performance of Si/organic heterojunction solar cells for an alternative to high-efficiency and low-cost photovoltaics. Here, we present a simple and repeatable wet oxidation method for developing the surface passivation layer, SiOx, on the Si surface for the fabrication of high-efficiency Si/poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) heterojunction solar cells. The uniform and dense SiOx thin layer introduced by the oxidizing aqueous solution of H2O2 or HNO3 provided the better surface passivation and stronger wettability of the Si surface, compared to those in the native oxide case. These two types of progress helped create a lower defect density at the Si/PEDOT:PSS interface and thus a high-quality p-n junction with a lower interface recombination velocity. As a result, the HNO3-oxidized device displayed better performance with a power conversion efficiency (PCE) of 11%, representing a 28.96% enhancement from the PCE of 8.53% in the native oxide case. The effects on the performance of the Si/PEDOT:PSS hybrid solar cells of the wet oxidation treatment procedure, including the differences in surface roughness and wettability of the Si substrate, the quality and thickness of the SiOx, etc., were explored extensively. Such a simple and controllable oxidizing treatment could be an effective way to promote the interfacial properties that are an important cornerstone for more efficient Si/organic hybrid solar cells. PMID:25157634

  18. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber for laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Carson, Cantwell G.; Goueguel, Christian L.; Sanghapi, Hervé; Jain, Jinesh; McIntyre, Dustin

    2016-05-01

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV-vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  19. Study of surface passivation as a function of InP closed-ampoule solar cell fabrication processing variables

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Jenkins, Phillip; Goradia, Manju; Goradia, Chandra; Bailey, Sheila; Weinberg, Irving; Jayne, Douglas

    1990-01-01

    The effects of various surface preparation procedures, including chemical treatment and anodic or chemical oxidation, closed-ampoule diffusion conditions, and post-diffusion surface preparation and annealing conditions, on the passivating properties of InP have been investigated in order to optimize the fabrication procedures of n(+)p InP solar cells made by closed-ampoule diffusion of sulfur into p-type InP. The InP substrates used were p-type Cd-doped to a level of 1.7 x 10 to the 16th/cu cm, Zn-doped to levels of 2.2 x 10 to the 16th and 1.2 x 10 to the 18th/cu cm, and n-type S-doped to 4.4 x 10 to the 18th/cu cm. The passivating properties have been evaluated from photoluminescence (PL) and conductance-voltage (G-V) data. Good agreement was found between the level of surface passivation and the composition of different surface layers as revealed by X-ray photoelectron spectroscopy (XPS) analysis.

  20. Barriers to commercialization of large-scale solar electricity: Lessions learned from the LUZ experience

    SciTech Connect

    Lotker, M. , Westlake Village, CA )

    1991-11-01

    This report discusses the economic and policy factors leading to the initial successful introduction of Luz International Limited's Solar Electric Generating Systems (SEGS). It then addresses the wide range of barriers to continued SEGS commercialization, including state and federal tax policy, avoided cost energy pricing, artificial size limitations under the Public Utility Regulatory Policies Act (PURPA), the loss of effectiveness of PURPA itself, the lack of incentives available to utilities as owners of solar electric plants, and the limited ways in which the environmental benefits of this technology have been recognized. The way in which each of these barriers contributed to the suspension of new LUZ projects is highlighted. In addition, mitigation approaches to each of these barriers are suggested.

  1. Barriers to commercialization of large-scale solar electricity: Lessions learned from the LUZ experience

    SciTech Connect

    Lotker, M.

    1991-11-01

    This report discusses the economic and policy factors leading to the initial successful introduction of Luz International Limited`s Solar Electric Generating Systems (SEGS). It then addresses the wide range of barriers to continued SEGS commercialization, including state and federal tax policy, avoided cost energy pricing, artificial size limitations under the Public Utility Regulatory Policies Act (PURPA), the loss of effectiveness of PURPA itself, the lack of incentives available to utilities as owners of solar electric plants, and the limited ways in which the environmental benefits of this technology have been recognized. The way in which each of these barriers contributed to the suspension of new LUZ projects is highlighted. In addition, mitigation approaches to each of these barriers are suggested.

  2. Benefits of the integrated solar upper stage (ISUS) to commercial space systems

    NASA Astrophysics Data System (ADS)

    Malloy, John; Miles, Barry

    1997-01-01

    The Integrated Solar Upper Stage (ISUS) is a solar thermal system that provides both propulsion and electric power. Using hydrogen as the propellant, ISUS can provide average specific impulses between 750 and 800 seconds. Once in final orbit, the stage uses thermionic diodes to produce electricity for the satellite payload throughout its operating lifetime. Because of its high specific impulse, ISUS can increase the total mass delivered to GEO by any launch vehicle by up to 250%. ISUS can provide benefits to commercial system in lower orbits as well. These orbits are particularly demanding on battery system because of the short orbit periods and the resulting number of battery cycles. Thermal storage in the ISUS receiver can accommodate these cycles without increasing system mass. ISUS also provide more efficient propulsion for station keeping and for separation of satellites when multiple satellites are launched for a single launch vehicle.

  3. LiBr treated porous silicon used for efficient surface passivation of crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Zarroug, Ahmed; Haddadi, Ikbel; Derbali, Lotfi; Ezzaouia, Hatem

    2015-04-01

    A simple but effective passivation method of both front and rear surfaces using porous silicon (PS) has been developed. This paper investigates the effect of LiBr on the passivation of PS. The immersion of as-etched PS in dilute LiBr solution followed by an annealing in an infrared furnace, under a controlled atmosphere at different temperatures, led to the passivation of the PS layer and the improvement of the electronic properties of the crystalline silicon substrates. The influence of substrate temperature was investigated, since the processed wafers were found to be sensitive to heat, which in turn was optimized to have a gettering effect. The bromide of lithium can effectively saturate dangling bonds and hence contributed to the formation of a stable passivation film, at both front and back surfaces. Such a reaction was found to have a beneficial effect on the passivation process of the PS layer grown on both sides. The obtained results exhibited a significant improvement of the minority carrier lifetime, which is an important parameter that defines the quality of crystalline silicon substrates, and an apparent enhancement of its photoluminescence (PL). The internal quantum efficiency was investigated and found to be significantly improved. The qualitative effect of the above-mentioned procedure proved a significant enhancement of the electronic quality of the treated substrates.

  4. Carrier Selective, Passivated Contacts for High Efficiency Silicon Solar Cells based on Transparent Conducting Oxides

    DOE PAGESBeta

    Young, David L.; Nemeth, William; Grover, Sachit; Norman, Andrew; Yuan, Hao-Chih; Lee, Benjamin G.; LaSalvia, Vincenzo; Stradins, Paul

    2014-01-01

    We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO2 and transparent conducting oxide layers. High temperature silicon dioxide is grown on both surfaces of an n-type wafer to a thickness <50 Å, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high J0,contact, and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter of the contact (J0,contact) and the specificmore » contact resistivity (ρcontact) using a TLM pattern. The best ITO/SiO2 passivated contact in this study has J0,contact = 92.5 fA/cm2 and ρcontact = 11.5 mOhm-cm2. These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J0,contact, ρcontact) values. The ITO/SiO2 contacts are found to have a higher J0,contact, but a similar ρcontact compared to the best reported passivated contacts.« less

  5. Evaluating the Performance and Economics of Transpired Solar Collectors for Commercial Applications: Preprint

    SciTech Connect

    Kozubal, E.; Deru, M.; Slayzak, S.; Norton, P.; Barker, G.; McClendon, J,

    2008-07-01

    Using transpired solar collectors to preheat ventilation air has recently become recognized as an economic alternative for integrating renewable energy into commercial buildings in heating climates. The collectors have relatively low installed costs and operate on simple principles. Theory and performance testing have shown that solar collection efficiency can exceed 70% of incident solar. However, implementation and current absorber designs have adversely affected the efficiency and associated economics from this initial analysis. The National Renewable Energy Laboratory has actively studied this technology and monitored performance at several installations. A calibrated model that uses typical meteorological weather data to determine absorber plate efficiency resulted from this work. With this model, an economic analysis across heating climates was done to show the effects of collector size, tilt, azimuth, and absorptivity. The analysis relates the internal rate of return of a system based on the cost of the installed absorber area. In general, colder and higher latitude climates return a higher rate of return because the heating season extends into months with good solar resource.

  6. Long-term measurement of indoor thermal environment and energy performance in a detached wooden house with passive solar systems

    SciTech Connect

    Ishikawa, Yoshimi; Yoshino, Hiroshi; Sasaki, Chikashi

    1998-07-01

    The indoor thermal environment, energy performance and energy consumption for a detached wooden house equipped with two passive solar systems, were investigated over a period of three years. The house with a floor area of 188 m{sup 2} was constructed in the autumn of 1993 in Sendai, Japan; and was well insulated and very airtight compared with other houses in Japan. There are six occupants. Heating equipment is comprises of a thermal storage space heater using night-time electricity and a vented firewood furnace on the first floor. Each room is ventilated all day by a central ventilation system. Two passive solar systems were incorporated: a concrete floor in the southern perimeter of the living room as a direct gain system, and an earth tube embedded around the circumference of the house to supply fresh air. The principal results obtained are as follows: (1) The indoor environment during the heating season was more thermally comfortable, compared with that or ordinary houses in Japan. (2) The concrete floor played a role of thermal storage, which absorbed and released heat for decreasing the fluctuation of room temperature. (3) The earth tube supplied air with lower temperature in the summer and higher temperature in the winter to the room, that the outdoor air temperature. This thermal performance did not decrease in spite of the long-term use. (4) The annual amount of energy consumption of this house was less than that of ordinary houses in the northern part of Japan.

  7. Commercial-scale process design for thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Russell, T. W. F.; Baron, B. N.; Rocheleau, R. E.

    Process and manufacturing costs for commercial-scale production of thin-film solar cells are examined from the viewpoint of the chemical process industry, with emphasis on CdS/Cu2S cells. The cells comprise opaque contact, collector/converter, absorber/generator, transparent contact, and encapsulation/antireflective coating layers. Each layer is deposited as a separate unit operation, through either continuous or batch processing methods. The scale-up of laboratory-verified cell manufacturing steps to commercial processing is detailed from the choice of a Zn-plated copper foil substrate to the bonding of a 1/16 in. tempered glass protective layer with polyvinyl butyral. The total product cost is calculated as a sum of raw materials, utilities, labor, and capital investment costs, using a cost/W for a 1 GW plant. Continuous processing results in a $0.50/W cell with raw materials accounting for 38% of the total product cost.

  8. On the performance limiting behavior of defect clusters in commercial silicon solar cells

    SciTech Connect

    Sopori, B.L.; Chen, W.; Jones, K.; Gee, J.

    1998-09-01

    The authors report the observation of defect clusters in high-quality, commercial silicon solar cell substrates. The nature of the defect clusters, their mechanism of formation, and precipitation of metallic impurities at the defect clusters are discussed. This defect configuration influences the device performance in a unique way--by primarily degrading the voltage-related parameters. Network modeling is used to show that, in an N/P junction device, these regions act as shunts that dissipate power generated within the cell.

  9. Module greenhouse with high efficiency of transformation of solar energy, utilizing active and passive glass optical rasters

    SciTech Connect

    Korecko, J.; Jirka, V.; Sourek, B.; Cerveny, J.

    2010-10-15

    Since the eighties of the 20th century, various types of linear glass rasters for architectural usage have been developed in the Czech Republic made by the continuous melting technology. The development was focused on two main groups of rasters - active rasters with linear Fresnel lenses in fixed installation and with movable photo-thermal and/or photo-thermal/photo-voltaic absorbers. The second group are passive rasters based on total reflection of rays on an optical prism. During the last years we have been working on their standardization, exact measuring of their optical and thermal-technical characteristics and on creation of a final product that could be applied in solar architecture. With the project supported by the Ministry of Environment of the Czech Republic we were able to build an experimental greenhouse using these active and passive optical glass rasters. The project followed the growing number of technical objectives. The concept of the greenhouse consisted of interdependence construction - structural design of the greenhouse with its technological equipment securing the required temperature and humidity conditions in the interior of the greenhouse. This article aims to show the merits of the proposed scheme and presents the results of the mathematical model in the TRNSYS environment through which we could predict the future energy balance carried out similar works, thus optimizing the investment and operating costs. In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved. (author)

  10. Si surface passivation by SiOx : H films deposited by a low-frequency ICP for solar cell applications

    NASA Astrophysics Data System (ADS)

    Zhou, H. P.; Wei, D. Y.; Xu, S.; Xiao, S. Q.; Xu, L. X.; Huang, S. Y.; Guo, Y. N.; Khan, S.; Xu, M.

    2012-10-01

    Hydrogenated silicon suboxide (SiOx : H) thin films are fabricated by a low-frequency inductively coupled plasma of hydrogen-diluted SiH4 + CO2 at a low temperature (100 °C). Introduction of a small amount of oxygen into the film results in a predominantly amorphous structure, wider optical bandgap, increased H content, lower conductivity and higher activation energy. The minority carrier lifetime in the SiOx : H-passivated p-type Si substrate is up to 428 µs with a reduced incubation layer at the interface. The associated surface recombination velocity is as low as 70 cm s-1. The passivation behaviour dominantly originates from the H-related chemical passivation. The passivation effect is also demonstrated by the excellent photovoltaic performance of the heterojunction solar cell with the SiOx : H-based passivation and emitter layers.

  11. Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint

    SciTech Connect

    Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

    2012-06-01

    A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

  12. Interface engineering for the passivation of c-Si with O3-based atomic layer deposited AlOx for solar cell application

    NASA Astrophysics Data System (ADS)

    Lee, Hyunju; Tachibana, Tomihisa; Ikeno, Norihiro; Hashiguchi, Hiroki; Arafune, Koji; Yoshida, Haruhiko; Satoh, Shin-ichi; Chikyow, Toyohiro; Ogura, Atsushi

    2012-04-01

    We have investigated the effects of deposition temperature and post-annealing on the passivation performance of AlOx films deposited by O3-based atomic layer deposition for crystalline Si. We found that the dramatic enhancement in the passivation performance of room-temperature deposited AlOx films by post-annealing is due to the phase transformation of aluminum silicate to mullite in an AlOx interlayer and the resulting self-aligned AlOx/SiOx interface. This result is interesting for the fabrication of high-performance silicon solar cells with AlOx passivation layers.

  13. Solar paint of ZnO/CdS and ZnO/CdSe based on commercial ZnO

    NASA Astrophysics Data System (ADS)

    Guo, Yi; Zhang, Xiang; Li, Yanhong; Li, Yanmei; Hu, Chunli; Zhou, Xingfu

    2016-03-01

    We report a facile and cheap route to the fabrication of ZnO/CdS and ZnO/CdSe based on commercial ZnO particles. The obtained product can be directly brush printed as solar paint. The results show that the solar cell based on the mixture of ZnO/CdS and ZnO/CdSe have a better light absorption and electron transport ability, and a high power conversion efficiency (PCE) of 1.36% was obtained, which is the highest PCE reported for inorganic paint-based solar cells to date. This method greatly simplifies the process of the solar cell fabrication and opens a door toward the cheap and printable solar paint based on commercial available materials.

  14. Carrier Selective, Passivated Contacts for High Efficiency Silicon Solar Cells based on Transparent Conducting Oxides

    SciTech Connect

    Young, David L.; Nemeth, William; Grover, Sachit; Norman, Andrew; Yuan, Hao-Chih; Lee, Benjamin G.; LaSalvia, Vincenzo; Stradins, Paul

    2014-01-01

    We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO2 and transparent conducting oxide layers. High temperature silicon dioxide is grown on both surfaces of an n-type wafer to a thickness <50 Å, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high J0,contact, and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter of the contact (J0,contact) and the specific contact resistivity (ρcontact) using a TLM pattern. The best ITO/SiO2 passivated contact in this study has J0,contact = 92.5 fA/cm2 and ρcontact = 11.5 mOhm-cm2. These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J0,contact, ρcontact) values. The ITO/SiO2 contacts are found to have a higher J0,contact, but a similar ρcontact compared to the best reported passivated contacts.

  15. Enhanced photovoltaic performance of inverted pyramid-based nanostructured black-silicon solar cells passivated by an atomic-layer-deposited Al2O3 layer.

    PubMed

    Chen, Hong-Yan; Lu, Hong-Liang; Ren, Qing-Hua; Zhang, Yuan; Yang, Xiao-Feng; Ding, Shi-Jin; Zhang, David Wei

    2015-10-01

    Inverted pyramid-based nanostructured black-silicon (BS) solar cells with an Al2O3 passivation layer grown by atomic layer deposition (ALD) have been demonstrated. A multi-scale textured BS surface combining silicon nanowires (SiNWs) and inverted pyramids was obtained for the first time by lithography and metal catalyzed wet etching. The reflectance of the as-prepared BS surface was about 2% lower than that of the more commonly reported upright pyramid-based SiNW BS surface over the whole of the visible light spectrum, which led to a 1.7 mA cm(-2) increase in short circuit current density. Moreover, the as-prepared solar cells were further passivated by an ALD-Al2O3 layer. The effect of annealing temperature on the photovoltaic performance of the solar cells was investigated. It was found that the values of all solar cell parameters including short circuit current, open circuit voltage, and fill factor exhibit a further increase under an optimized annealing temperature. Minority carrier lifetime measurements indicate that the enhanced cell performance is due to the improved passivation quality of the Al2O3 layer after thermal annealing treatments. By combining these two refinements, the optimized SiNW BS solar cells achieved a maximum conversion efficiency enhancement of 7.6% compared to the cells with an upright pyramid-based SiNWs surface and conventional SiNx passivation. PMID:26243694

  16. The design of a solar energy collection system to augment heating and cooling for a commercial office building

    NASA Technical Reports Server (NTRS)

    Basford, R. C.

    1977-01-01

    Analytical studies supported by experimental testing indicate that solar energy can be utilized to heat and cool commercial buildings. In a 50,000 square foot one-story office building at the Langley Research Center, 15,000 square feet of solar collectors are designed to provide the energy required to supply 79 percent of the building heating needs and 52 percent of its cooling needs. The experience gained from the space program is providing the technology base for this project. Included are some of the analytical studies made to make the building design changes necessary to utilize solar energy, the basic solar collector design, collector efficiencies, and the integrated system design.

  17. Electromagnetic Fields Associated with Commercial Solar Photovoltaic Electric Power Generating Facilities.

    PubMed

    Tell, R A; Hooper, H C; Sias, G G; Mezei, G; Hung, P; Kavet, R

    2015-01-01

    The southwest region of the United States is expected to experience an expansion of commercial solar photovoltaic generation facilities over the next 25 years. A solar facility converts direct current generated by the solar panels to three-phase 60-Hz power that is fed to the grid. This conversion involves sequential processing of the direct current through an inverter that produces low-voltage three-phase power, which is stepped up to distribution voltage (∼12 kV) through a transformer. This study characterized magnetic and electric fields between the frequencies of 0 Hz and 3 GHz at two facilities operated by the Southern California Edison Company in Porterville, CA and San Bernardino, CA. Static magnetic fields were very small compared to exposure limits established by IEEE and ICNIRP. The highest 60-Hz magnetic fields were measured adjacent to transformers and inverters, and radiofrequency fields from 5-100 kHz were associated with the inverters. The fields measured complied in every case with IEEE controlled and ICNIRP occupational exposure limits. In all cases, electric fields were negligible compared to IEEE and ICNIRP limits across the spectrum measured and when compared to the FCC limits (≥0.3 MHz). PMID:26023811

  18. Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields: Preprint

    SciTech Connect

    Kearney, D.; Mehos, M.

    2010-12-01

    Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the EPC contractor or owners. In lieu of the present absence of engineering code developed for this purpose, NREL has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The fundamental differences between acceptance of a solar power plant and a conventional fossil-fired plant are the transient nature of the energy source and the necessity to utilize an analytical performance model in the acceptance process. These factors bring into play the need to establish methods to measure steady state performance, potential impacts of transient processes, comparison to performance model results, and the possible requirement to test, or model, multi-day performance within the scope of the acceptance test procedure. The power block and BOP are not within the boundaries of this guideline. The current guideline is restricted to the solar thermal performance of parabolic trough systems and has been critiqued by a broad range of stakeholders in CSP development and technology.

  19. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  20. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  1. Hydrogen passivation of n+p and p+n heteroepitaxial InP solar cell structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, B.; Ringel, S. A.; Hoffman, R., Jr.

    1995-01-01

    High-efficiency, heteroepitaxial (HE) InP solar cells, grown on GaAs, Si or Ge substrates, are desirable for their mechanically strong, light-weight and radiation-hard properties. However, dislocations, caused by lattice mismatch, currently limit the performance of the HE cells. This occurs through shunting paths across the active photovoltaic junction and by the formation of deep levels. In previous work we have demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of dislocations in specially designed HE InP test structures. In this work, we present the first report of successful hydrogen passivation in actual InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in HE n+n InP cell structures from as-grown values of approximately 10(exp 15)/cm(exp -3), down to 1-2 x 10(exp 13)/cm(exp -3). The deep levels in the p-type base region of the cell structure match those of our earlier p-type test structures, which were attributed to dislocations or related point defect complexes. All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. I-V analysis indicated a subsequent approximately 10 fold decrease in reverse leakage current at -1 volt reverse bias, and no change in the forward biased series resistance of the cell structure which indicates complete reactivation of the n+ emitter. Furthermore, electrochemical C-V profiling indicates greatly enhanced passivation depth, and hence hydrogen diffusion, for heteroepitaxial structures when compared with identically processed homoepitaxial n+p InP structures. An analysis of hydrogen diffusion in dislocated InP will be discussed, along with comparisons of passivation effectiveness for n+p versus p+n heteroepitaxial cell configurations. Preliminary hydrogen-passivated

  2. Design and application of ion-implanted polySi passivating contacts for interdigitated back contact c-Si solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Guangtao; Ingenito, Andrea; van Hameren, Nienke; Isabella, Olindo; Zeman, Miro

    2016-01-01

    Ion-implanted passivating contacts based on poly-crystalline silicon (polySi) are enabled by tunneling oxide, optimized, and used to fabricate interdigitated back contact (IBC) solar cells. Both n-type (phosphorous doped) and p-type (boron doped) passivating contacts are fabricated by ion-implantation of intrinsic polySi layers deposited via low-pressure chemical vapor deposition and subsequently annealed. The impact of doping profile on the passivation quality of the polySi doped contacts is studied for both polarities. It was found that an excellent surface passivation could be obtained by confining as much as possible the implanted-and-activated dopants within the polySi layers. The doping profile in the polySi was controlled by modifying the polySi thickness, the energy and dose of ion-implantation, and the temperature and time of annealing. An implied open-circuit voltage of 721 mV for n-type and 692 mV for p-type passivating contacts was achieved. Besides the high passivating quality, the developed passivating contacts exhibit reasonable high conductivity (Rsh n-type = 95 Ω/□ and Rsh p-type = 120 Ω/□). An efficiency of 19.2% (Voc = 673 mV, Jsc = 38.0 mA/cm2, FF = 75.2%, and pseudo-FF = 83.2%) was achieved on a front-textured IBC solar cell with polySi passivating contacts as both back surface field and emitter. By improving the front-side passivation, a VOC of 696 mV was also measured.

  3. Grain Boundary Passivation of Multicrystalline Silicon Using Hydrogen Sulfide as a Sulfur Source

    NASA Astrophysics Data System (ADS)

    Saha, Arunodoy

    Hydrogen sulfide (H2S) has been identified as a potential ingredient for grain boundary passivation of multicrystalline silicon. Sulfur is already established as a good surface passivation material for crystalline silicon (c-Si). Sulfur can be used both from solution and hydrogen sulfide gas. For multicrystalline silicon (mc-Si) solar cells, increasing efficiency is a major challenge because passivation of mc-Si wafers is more difficult due to its randomly orientated crystal grains and the principal source of recombination is contributed by the defects in the bulk of the wafer and surface. In this work, a new technique for grain boundary passivation for multicrystalline silicon using hydrogen sulfide has been developed which is accompanied by a compatible Aluminum oxide (Al2O3) surface passivation. Minority carrier lifetime measurement of the passivated samples has been performed and the analysis shows that success has been achieved in terms of passivation and compared to already existing hydrogen passivation, hydrogen sulfide passivation is actually better. Also the surface passivation by Al 2O3 helps to increase the lifetime even more after post-annealing and this helps to attain stability for the bulk passivated samples. Minority carrier lifetime is directly related to the internal quantum efficiency of solar cells. Incorporation of this technique in making mc-Si solar cells is supposed to result in higher efficiency cells. Additional research is required in this field for the use of this technique in commercial solar cells.

  4. Metal insulator semiconductor solar cell devices based on a Cu{sub 2}O substrate utilizing h-BN as an insulating and passivating layer

    SciTech Connect

    Ergen, Onur; Gibb, Ashley; Vazquez-Mena, Oscar; Zettl, Alex; Regan, William Raymond

    2015-03-09

    We demonstrate cuprous oxide (Cu{sub 2}O) based metal insulator semiconductor Schottky (MIS-Schottky) solar cells with efficiency exceeding 3%. A unique direct growth technique is employed in the fabrication, and hexagonal boron nitride (h-BN) serves simultaneously as a passivation and insulation layer on the active Cu{sub 2}O layer. The devices are the most efficient of any Cu{sub 2}O based MIS-Schottky solar cells reported to date.

  5. Process heat in California: Applications and potential for solar energy in the industrial, agricultural and commercial sectors

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Bartera, R. E.; Davis, E. S.; Hlavka, G. E.; Pivirotto, D. S.; Yanow, G.

    1978-01-01

    A summary of the results of a survey of potential applications of solar energy for supplying process heat requirements in the industrial, agricultural, and commercial sectors of California is presented. Technical, economic, and institutional characteristics of the three sectors are examined. Specific applications for solar energy are then discussed. Finally, implications for California energy policy are discussed along with recommendations for possible actions by the State of California.

  6. Low-cost foil metallization using arc discharge for passivated emitter and rear solar cells

    NASA Astrophysics Data System (ADS)

    Kurimoto, Yuji; Yamasaki, Ichiro

    2016-04-01

    For the cost reduction of passivated emitter and rear cells (PERC), we propose a new rear contact formation method, in which an aluminum foil and an arc discharge system are used. The arc discharge system consists of inexpensive parts and does not contain any sophisticated part such as a laser ablation apparatus. Therefore, this system can save the cost of the rear contact forming process. We applied this technique to a test production of PERC. It is found that the arc discharge system can provide a similar performance to that attained by a conventional PERC production method.

  7. Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.

    1986-01-01

    At the present time all experimental towers (chimneys) are completed and operating. This consists of both a solar updraft and a natural-evaporative downdraft tower retrofitted to an existing residence structure and a greenhouse. The residential, experimental, natural-draft cooling system was completed in May, 1985, and five months of summer data on a Hewlet Packard 85 data acquisition computer with a digital voltmeter were acquired. The cooling tower and solar chimney on the experimental greenhouse became operational in September of 1985. A conceptual drawing of both the greenhouse and the residence natural-draft towers is included in the appendix along with the September 85 progress report.

  8. Back-side hydrogenation technique for defect passivation in silicon solar cells

    DOEpatents

    Sopori, Bhushan L.

    1994-01-01

    A two-step back-side hydrogenation process includes the steps of first bombarding the back side of the silicon substrate with hydrogen ions with intensities and for a time sufficient to implant enough hydrogen atoms into the silicon substrate to potentially passivate substantially all of the defects and impurities in the silicon substrate, and then illuminating the silicon substrate with electromagnetic radiation to activate the implanted hydrogen, so that it can passivate the defects and impurities in the substrate. The illumination step also annihilates the hydrogen-induced defects. The illumination step is carried out according to a two-stage illumination schedule, the first or low-power stage of which subjects the substrate to electromagnetic radiation that has sufficient intensity to activate the implanted hydrogen, yet not drive the hydrogen from the substrate. The second or high-power illumination stage subjects the substrate to higher intensity electromagnetic radiation, which is sufficient to annihilate the hydrogen-induced defects and sinter/alloy the metal contacts.

  9. Back-side hydrogenation technique for defect passivation in silicon solar cells

    DOEpatents

    Sopori, B.L.

    1994-04-19

    A two-step back-side hydrogenation process includes the steps of first bombarding the back side of the silicon substrate with hydrogen ions with intensities and for a time sufficient to implant enough hydrogen atoms into the silicon substrate to potentially passivate substantially all of the defects and impurities in the silicon substrate, and then illuminating the silicon substrate with electromagnetic radiation to activate the implanted hydrogen, so that it can passivate the defects and impurities in the substrate. The illumination step also annihilates the hydrogen-induced defects. The illumination step is carried out according to a two-stage illumination schedule, the first or low-power stage of which subjects the substrate to electromagnetic radiation that has sufficient intensity to activate the implanted hydrogen, yet not drive the hydrogen from the substrate. The second or high-power illumination stage subjects the substrate to higher intensity electromagnetic radiation, which is sufficient to annihilate the hydrogen-induced defects and sinter/alloy the metal contacts. 3 figures.

  10. Passivation properties of aluminum oxide films deposited by mist chemical vapor deposition for solar cell applications

    NASA Astrophysics Data System (ADS)

    Miki, Shohei; Iguchi, Koji; Kitano, Sho; Hayakashi, Koki; Hotta, Yasushi; Yoshida, Haruhiko; Ogura, Atsushi; Satoh, Shin-ichi; Arafune, Koji

    2015-08-01

    Aluminum oxide (AlOx) films were deposited by mist chemical vapor deposition (MCVD) in air for p-type crystalline silicon, and the effects of the deposition temperature (Tdep) and AlOx film thickness on the maximum surface recombination velocities (Smax) were evaluated. It was found that Smax was improved with increasing Tdep. The AlOx film deposited at 400 °C exhibited the best Smax value of 2.8 cm/s, and the passivation quality was comparable to that of AlOx deposited by other vacuum-based techniques. Smax was also improved with increasing film thickness. When the film thickness was above 10 nm, Smax was approximately 10 cm/s. From the Fourier transform infrared spectra, it was found that the AlOx films deposited by MCVD consisted of an AlOx layer and a Si-diffused AlOx layer. In addition, it is important for the layers to be thick enough to obtain high-quality passivation.

  11. Progress In The Commercialization Of A Carbonaceous Solar Selective Absorber On A Glass Substrate

    NASA Astrophysics Data System (ADS)

    Garrison, John D.; Haiad, J. Carlos; Averett, Anthony J.

    1987-11-01

    A carbonaceous solar selective absorber is formed on a glass substrate by coating the glass with a silver infrared reflecting layer, electroplating a thin nickel catalyst coating on the silver using very special plating conditions, and then exposing the nickel coated, silvered glass substrate to acetylene at a temperature of about 400 - 500°C for about five minutes. A fairly large plater and conveyor oven have been constructed and operated for the formation of these solar selective absorbers in order to study the formation of this absorber by a process which might be used commercially. Samples of this selective absorber on a glass substrate have been formed using the plater and conveyor oven. The samples, which have the best optical properties, have an absorptance of about 0.9 and an emittance of about 0.03. Excessive decomposition of the acetylene by the walls of the oven at higher temperatures with certain wall materials and oven geometries can prevent the formation of good selective absorbers. Procedures for preventing excessive decomposition of the acetylene and the knowledge gained so far by these studies is discussed.

  12. Inorganic compounds for passive solar energy storage: Solid-state dehydration materials and high specific heat materials

    NASA Astrophysics Data System (ADS)

    Struble, L. J.; Brown, P. W.

    1986-04-01

    Two classes of hydrated inorganic salts have been studied to assess their potential as materials for passive solar energy storage. The materials are part of the quaternary system CaO-Al2O3-SO3-H2O and related chemical systems, and the two classes are typified by ettringite, a trisubstituted salt, and Friedel's salt, a monosubstituted salt. The trisubstituted salts were studied for their possible application in latent heat storage, utilizing a low-temperature dehydration reaction, and both classes were studies for their application in sensible heat storage. In order to assess their potential for energy storage, the salts have been synthesized, characterized by several analytical techniques, and thermal properties measured. The dehydration data of that the trisubstituted salts vary somewhat with chemical composition, with the temperature of the onset of dehydration ranging from 6(0)C to 33(0)C, and enthalpy changes on dehydration ranging from 60 to 200 cal/g. Heat capacity is less variable with composition; values for the trisubstituted phases are 30 cal/g/(0)C and for the monosubstituted phases between 0.23 and 0.28 cal/g/(0)C. Preliminary experiments indicate that the dehydration is reversible, and suggest that the materials might have additional potential as solar desiccant materials. These thermal data demonstrate the trisubstituted salts have potential as latent heat storage materials, and that both classes of salts have potential as sensible heat storage materials.

  13. Origin and elimination of photocurrent hysteresis by fullerene passivation in CH3NH3PbI3 planar heterojunction solar cells

    DOE PAGESBeta

    Shao, Yuchuan; Xiao, Zhengguo; Bi, Cheng; Yuan, Yongbo; Huang, Jinsong

    2014-12-15

    The large photocurrent hysteresis observed in many organometal trihalide perovskite solar cells has become a major hindrance impairing the ultimate performance and stability of these devices, while its origin was unknown. Here we demonstrate the trap states on the surface and grain boundaries of the perovskite materials to be the origin of photocurrent hysteresis and that the fullerene layers deposited on perovskites can effectively passivate these charge trap states and eliminate the notorious photocurrent hysteresis. Fullerenes deposited on the top of the perovskites reduce the trap density by two orders of magnitude and double the power conversion efficiency of CH3NH3PbI3more » solar cells. As a result, the elucidation of the origin of photocurrent hysteresis and its elimination by trap passivation in perovskite solar cells provides important directions for future enhancements to device efficiency.« less

  14. The Solar Heating and Cooling Commercial Demonstration Program at Marshall Space Flight Center - Some problems and conclusions

    NASA Technical Reports Server (NTRS)

    Middleton, R. L.

    1978-01-01

    The origin and evolution of the Solar Heating and Cooling Commercial Demonstration Program by the Department of Energy and the Marshall Space Flight Center activities supporting this program from its conception are defined and discussed. Problems are summarized in the design and financial areas. It is concluded that the program has significantly assisted the creation of a viable solar testing and cooling industry. The cost effective procedures evolving from the program are expected to make a major contribution to reducing the effective life cycle cost of solar installation.

  15. SOLCOST. Solar Hot Water Handbook. A Simplified Design Method for Sizing and Costing Residential and Commercial Solar Service Hot Water Systems. Second Edition.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet offers a preview of information services available from Solcost, a research and development project. The first section explains that Solcost calculates system and costs performance for solar heated and cooled new and retrofit constructions, such as residential buildings and single zone commercial buildings. For a typical analysis,…

  16. Implementation of Tunneling Passivated Contacts into Industrially Relevant n-Cz Si Solar Cells

    SciTech Connect

    Nemeth, William; LaSalvia, Vincenzo; Page, Matthew R.; Warren, Emily L.; Dameron, Arrelaine; Norman, Andrew G.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-06-14

    We identify bottlenecks, and propose solutions, to implement a B-diffused front emitter and a backside pc-Si/SiO2 pasivated tunneling contact into high efficiency n-Cz Si cells in an industrially relevant way. We apply an O-precipitate dissolution treatment to make n-Cz wafers immune to bulk lifetime process degradation, enabling robust, passivated B front emitters with J0 <; 20fA/cm2. Adding ultralow recombination n+ pc-Si/SiO2 back contacts enables pre-metallized cells with iVoc=720 mV and J0=8.6 fA/cm2. However, metallization significantly degrades performance of these contacts due to pinholes and possibly, grain boundary diffusion of primary metal and source contaminates such as Cu. An intermediate, doped a-Si:H capping layer is found to significantly block the harmful metal penetration into pc-Si.

  17. Surface passivation of InP solar cells with InAlAs layers

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.; Landis, Geoffrey A.

    1993-01-01

    The efficiency of indium phosphide solar cells is limited by high values of surface recombination. The effect of a lattice-matched In(0.52)Al(0.48)As window layer material for InP solar cells, using the numerical code PC-1D is investigated. It was found that the use of InAlAs layer significantly enhances the p(+)n cell efficiency, while no appreciable improvement is seen for n(+)p cells. The conduction band energy discontinuity at the heterojunction helps in improving the surface recombination. An optimally designed InP cell efficiency improves from 15.4 percent to 23 percent AMO for a 10 nm thick InAlAs layer. The efficiency improvement reduces with increase in InAlAs layer thickness, due to light absorption in the window layer.

  18. Thermal control system and method for a passive solar storage wall

    SciTech Connect

    Ortega, J.K.E.

    1981-07-10

    A system and method are provided for controlling the storing and release of thermal energy from a thermal storage wall wherein said wall is capable of storing thermal energy from insolation. The system and method includes a device such as a plurality of louvers spaced a predetermined distance from the thermal wall for regulating the release of thermal energy from the thermal wall. This regulating device is made from a material which is substantially transparent to the incoming solar radiation so that when it is in any operative position, the thermal storage wall substantially receives all of the impacting solar radiation. The material in the regulating device is further capable of being substantially opaque to thermal energy so that when the device is substantially closed, thermal release of energy from the storage wall is substantially minimized. An adjustment device is interconnected with the regulating mechanism for selectively opening and closing it in order to regulate the release of thermal energy from the wall.

  19. Beneficial surface passivation of hydrothermally grown TiO2 nanowires for solar water oxidation

    NASA Astrophysics Data System (ADS)

    Yun, Gun; Song, Gwang Yeom; Ahn, Bo-Eun; Lee, Sang-Kwon; Heo, Jaeyeong; Ahn, Kwang-Soon; Kang, Soon Hyung

    2016-03-01

    Rutile TiO2 nanowires (TONWs) with a length of 2.0 μm were synthesized using a facile hydrothermal method in a strong acid solution. To investigate the effect of surface passivation of TONW arrays, a TiO2 layer with a thickness varying from 5 to 20 nm on TONW arrays was applied by atomic layer deposition (ALD). No distinct morphological modification was observed in all prepared TONW arrays in the environment where the diameter of the TONW arrays was systematically increased from 10 to 40 nm. In this study, Mott-Schottky analysis revealed that 10 nm TiO2-coated TONW (denoted as TiO2(10 nm)/TONW) arrays showed the highest electronic conductivity, followed by the 5 nm, 20 nm, and 0 nm TiO2/TONW arrays. The photoelectrochemical (PEC) performance was assessed in 0.1 M KOH, which revealed that TiO2(10 nm)/TONW arrays displayed a photocurrent density (3.92 mA/cm2 at 0.5 VNHE) higher than that (2.72 mA/cm2) of TONW arrays. This may be ascribed to the surface passivation of trap or defect sites by the thin TiO2 surface coating, leading to the increased electron densities and improving the PEC performance. For a more definitive examination, photovoltage decay measurement was performed to calculate the decay lifetime, which is closely correlated to the electron-hole recombination reaction. In this study, TiO2(10 nm)/TONW arrays exhibited a decay lifetime (0.7 s) shorter than that (1.1 s) of TONW arrays, proving the suppressed charge recombination in the thin TiO2/TONW arrays.

  20. Program to monitor and evaluate a passive solar greenhouse/aquaculture system. Final report

    SciTech Connect

    Not Available

    1982-01-01

    A temperature monitoring program of Amity's solar greenhouse demonstrated that air, soil, and water temperatures can be maintained at optimal levels without supplemental heat. A foil reflector placed in front of the greenhouse glazing at an angle of between 0 and 5/sup 0/ above horizontal enhanced direct light entering the greenhouse by as much as 22%. Aquaculture in the water heat storage of a solar greenhouse has been a success. Fish reached harvest size in about seven months. The two species that were received the best by the public were African perch (Tilapia mossambica) and channel catfish (Ictalurus punctatus). Although carp (Cyprinus carpio) were the fastest growers they were not well received by the public. Linking hydroponics to greenhouse aquaculture shows a lot of promise. Different support medias were examined and tomatoes and European cucumbers were raised successfully. A savonius windmill was successfully linked to an aquaculture aeration system but because of the wind pattern in the Willamette valley the windmill system did not provide air in the evening when it was needed most. Alternate designs are discussed. Locally grown fish diets were evaluated for their ability to promote fish growth. Diets such as water hyacinth, duckweed, earthworms, beans, and comfrey were raised on the Amity site, pelleted with a hand grinder and solar dried. Duckweed and earthworms appear to hold promise for a nutritous, easy to grow and pelletize, food source. Amity's solar greenhouse, three coldframe designs and a PVC tunnel cloche were compared in a vegetable growing trial. Most impressive was the cloche design because it provided adequate protection, was inexpensive and very easy to build.

  1. Thermal control system and method for a passive solar storage wall

    DOEpatents

    Ortega, Joseph K. E.

    1984-01-01

    The invention provides a system and method for controlling the storing and elease of thermal energy from a thermal storage wall wherein said wall is capable of storing thermal energy from insolation of solar radiation. The system and method includes a device such as a plurality of louvers spaced a predetermined distance from the thermal wall for regulating the release of thermal energy from the thermal wall. This regulating device is made from a material which is substantially transparent to the incoming solar radiation so that when it is in any operative position, the thermal storage wall substantially receives all of the impacting solar radiation. The material in the regulating device is further capable of being substantially opaque to thermal energy so that when the device is substantially closed, thermal release of energy from the storage wall is substantially minimized. An adjustment device is interconnected with the regulating mechanism for selectively opening and closing it in order to regulate the release of thermal energy from the wall.

  2. National Program for Solar Heating and Cooling of Buildings. Project Date Summaries. Vol. I: Commercial and Residential Demonstrations.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    Three volumes present brief abstracts of projects funded by the Energy Research and Development Administration (ERDA) and conducted under the National Program for Solar Heating and Cooling of Buildings through July 1976. The overall federal program includes demonstrations of heating and/or combined cooling for residential and commercial buildings…

  3. Impact of interstitial oxygen trapped in silicon during plasma growth of silicon oxy-nitride films for silicon solar cell passivation

    NASA Astrophysics Data System (ADS)

    Saseendran, Sandeep S.; Saravanan, S.; Raval, Mehul C.; Kottantharayil, Anil

    2016-03-01

    Low temperature oxidation of silicon in plasma ambient is a potential candidate for replacing thermally grown SiO2 films for surface passivation of crystalline silicon solar cells. In this work, we report the growth of silicon oxy-nitride (SiOxNy) film in N2O plasma ambient at 380 °C. However, this process results in trapping of interstitial oxygen within silicon. The impact of this trapped interstitial oxygen on the surface passivation quality is investigated. The interstitial oxygen trapped in silicon was seen to decrease for larger SiOxNy film thickness. Effective minority carrier lifetime (τeff) measurements on n-type float zone silicon wafers passivated by SiOxNy/silicon nitride (SiNv:H) stack showed a decrease in τeff from 347 μs to 68 μs, for larger SiOxNy film thickness due to degradation in interface properties. From high frequency capacitance-voltage measurements, it was concluded that the surface passivation quality was governed by the interface parameters (fixed charge density and interface state density). High temperature firing of the SiOxNy/SiNv:H stack resulted in a severe degradation in τeff due to migration of oxygen across the interface into silicon. However, on using the SiOxNy/SiNv:H stack for emitter surface passivation in screen printed p-type Si solar cells, an improvement in short wavelength response was observed in comparison to the passivation by SiNv:H alone, indicating an improvement in emitter surface passivation quality.

  4. Passivation of PbS Quantum Dot Surface with l-Glutathione in Solid-State Quantum-Dot-Sensitized Solar Cells.

    PubMed

    Jumabekov, Askhat N; Cordes, Niklas; Siegler, Timothy D; Docampo, Pablo; Ivanova, Alesja; Fominykh, Ksenia; Medina, Dana D; Peter, Laurence M; Bein, Thomas

    2016-02-24

    Surface oxidation of quantum dots (QDs) is one of the biggest challenges in quantum dot-sensitized solar cells (QDSCs), because it introduces surface states that enhance electron-hole recombination and degrade device performance. Protection of QDs from surface oxidation by passivating the surface with organic or inorganic layers can be one way to overcome this issue. In this study, solid-state QDSCs with a PbS QD absorber layer were prepared from thin mesoporous TiO2 layers by the successive ionic layer adsorption/reaction (SILAR) method. Spiro-OMeTAD was used as the organic p-type hole transporting material (HTM). The effects on the solar cell performance of passivating the surface of the PbS QDs with the tripeptide l-glutathione (GSH) were investigated. Current-voltage characteristics and external quantum efficiency measurements of the solar cell devices showed that GSH-treatment of the QD-sensitized TiO2 electrodes more than doubled the short circuit current and conversion efficiency. Impedance spectroscopy, intensity-modulated photovoltage and photocurrent spectroscopy analysis of the devices revealed that the enhancement in solar cell performance of the GSH-treated cells originates from improved charge injection from PbS QDs into the conduction band of TiO2. Time-resolved photoluminescence decay measurements show that passivation of the surface of QDs with GSH ligands increases the exciton lifetime in the QDs. PMID:26771519

  5. Proof-of-Concept Testing of the Passive Cooling System (T-CLIP™) for Solar Thermal Applications at an Elevated Temperature

    SciTech Connect

    Kim, Seung Jun; Quintana, Donald L.; Vigil, Gabrielle M.; Perraglio, Martin Juan; Farley, Cory Wayne; Tafoya, Jose I.; Martinez, Adam L.

    2015-11-30

    The Applied Engineering and Technology-1 group (AET-1) at Los Alamos National Laboratory (LANL) conducted the proof-of-concept tests of SolarSPOT LLC’s solar thermal Temperature- Clipper, or T-CLIP™ under controlled thermal conditions using a thermal conditioning unit (TCU) and a custom made environmental chamber. The passive T-CLIP™ is a plumbing apparatus that attaches to a solar thermal collector to limit working fluid temperature and to prevent overheating, since overheating may lead to various accident scenarios. The goal of the current research was to evaluate the ability of the T-CLIP™ to control the working fluid temperature by using its passive cooling mechanism (i.e. thermosiphon, or natural circulation) in a small-scale solar thermal system. The assembled environmental chamber that is thermally controlled with the TCU allows one to simulate the various possible weather conditions, which the solar system will encounter. The performance of the T-CLIP™ was tested at two different target temperatures: 1) room temperature (70 °F) and 2) an elevated temperature (130 °F). The current test campaign demonstrated that the T-CLIP™ was able to prevent overheating by thermosiphon induced cooling in a small-scale solar thermal system. This is an important safety feature in situations where the pump is turned off due to malfunction or power outages.

  6. Site handbook: data acquisition system information, passive solar retrofit Automobile Maintenance Facility, City of Philadelphia

    SciTech Connect

    Not Available

    1985-01-01

    Data were collected at the City of Philadelphia's Auto Maintenance Facility using an Aeoloan Kinetics PDL-24 data acquisition system. Instantaneous data readings were recorded each 15 seconds by the microprocessor. These channel readings were then averaged to produce hourly values which were then stored on an audio cassette. The energy saving strategies include: styrofoam and concrete roof coverings; weatherstripping; replacement of north windows with combination insulation and view glazing; PVC strips between heated and unheated areas; gas fired radiant heaters at individual work stations; reduction of the number of light fixtures; and the installation of retrofit window units for radiant solar heating, daylighting, ventilation, glare control and vandalism protection.

  7. Energy efficiency and comfort conditions in passive solar buildings: Effect of thermal mass at equatorial high altitudes

    NASA Astrophysics Data System (ADS)

    Ogoli, David Mwale

    This dissertation is based on the philosophy that architectural design should not just be a function of aesthetics, but also of energy-efficiency, advanced technologies and passive solar strategies. A lot of published literature is silent regarding buildings in equatorial highland regions. This dissertation is part of the body of knowledge that attempts to provide a study of energy in buildings using thermal mass. The objectives were to establish (1) effect of equatorial high-altitude climate on thermal mass, (2) effect of thermal mass on moderating indoor temperatures, (3) effect of thermal mass in reducing heating and cooling energy, and (4) the amount of time lag and decrement factor of thermal mass. Evidence to analyze the effect of thermal mass issues came from three sources. First, experimental physical models involving four houses were parametrically conducted in Nairobi, Kenya. Second, energy computations were made using variations in thermal mass for determining annual energy usage and costs. Third, the data gathered were observed, evaluated, and compared with currently published research. The findings showed that: (1) Equatorial high-altitude climates that have diurnal temperature ranging about 10--15°C allow thermal mass to moderate indoor temperatures; (2) Several equations were established that indicate that indoor mean radiant temperatures can be predicted from outdoor temperatures; (3) Thermal mass can reduce annual energy for heating and cooling by about 71%; (4) Time lag and decrement of 200mm thick stone and concrete thermal mass can be predicted by a new formula; (5) All windows on a building should be shaded. East and west windows when shaded save 51% of the cooling energy. North and south windows when fully shaded account for a further 26% of the cooling energy; (6) Insulation on the outside of a wall reduces energy use by about 19.6% below the levels with insulation on the inside. The basic premise of this dissertation is that decisions that

  8. GaAs nanopillar-array solar cells employing in situ surface passivation

    PubMed Central

    Mariani, Giacomo; Scofield, Adam C.; Hung, Chung-Hong; Huffaker, Diana L.

    2013-01-01

    Arrays of III–V direct-bandgap semiconductor nanopillars represent promising photovoltaic candidates due to their inherent high optical absorption coefficients and minimized reflection arising from light trapping, efficient charge collection in the radial direction and the ability to synthesize them on low-cost platforms. However, the increased surface area results in surface states that hamper the power conversion efficiency. Here, we report the first demonstration of GaAs nanopillar-array photovoltaics employing epitaxial passivation with air mass 1.5 global power conversion efficiencies of 6.63%. High-bandgap epitaxial InGaP shells are grown in situ and cap the radial p–n junctions to alleviate surface-state effects. Under light, the photovoltaic devices exhibit open-circuit voltages of 0.44 V, short-circuit current densities of 24.3 mA cm−2 and fill factors of 62% with high external quantum efficiencies >70% across the spectral regime of interest. A novel titanium/indium tin oxide annealed alloy is exploited as transparent ohmic anode. PMID:23422665

  9. Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Maksudur Rahman, Mohammad; Higo, Akio; Sekhar, Halubai; Erman Syazwan, Mohd; Hoshi, Yusuke; Usami, Noritaka; Samukawa, Seiji

    2016-03-01

    The effect of passivation films on a Si quantum dot superlattice (QDSL) was investigated to generate high photocurrent in solar-cell applications. Three types of passivation films, sputter-grown amorphous silicon carbide (a-SiC), hydrogenated a-SiC (a-SiC:H), and atomic-layer-deposited aluminum oxide (ALD-Al2O3), were used to passivate the Si QDSLs containing a stack of four 4 nm Si nanodisks (NDs) and 2 nm silicon carbide (SiC) films fabricated by neutral beam etching (NBE). Because of the high surface-to-volume ratio typically present in quantum Si-NDs formed in the top-down NBE process, there is a tendency to form larger surface dangling bonds on untreated Si-ND surfaces as well as to have short distance (<10 nm) between high-aspect-ratio nanopillars of stacked 4 nm Si-NDs/2 nm SiC films, which conventionally sputter SiC films cannot uniformly cover. Therefore, we optimized the passivation techniques with an ALD-Al2O3 film. Scanning electron microscopy (SEM) analysis helped to explain the surface morphology before and after the passivation of the QDSLs. After the completion of the passivation process, the quality of the top surface films of the QDSLs was analyzed from the surface roughness by atomic force microscopy (AFM) analysis, which revealed that ALD-Al2O3 passivated films had the smallest roughness (RMS) of 1.09 nm with respect to sputter-grown a-SiC (RMS: 1.75 nm) and a-SiC:H (RMS: 1.54 nm) films. Conductive atomic force microscopy (CAFM) revealed that ALD-Al2O3 passivation decreased the surface-leakage current as a result of proper passivation of side-wall surface defects in the QDSLs. The carrier transport characteristics were extracted from the QDSLs using the photovoltaic (PV) properties of p++/i/n+ solar cells, where the QDSLs consisted of different passivation layers acting as intermediate layers (i-layers) between the high-doping-density p++ Si (1 × 1020 cm-3) and n+ Si (1 × 1019 cm-3) substrates. High-doping-density p++ Si acted as a hole

  10. A passive satellite deorbiting strategy for medium earth orbit using solar radiation pressure and the J2 effect

    NASA Astrophysics Data System (ADS)

    Lücking, Charlotte; Colombo, Camilla; McInnes, Colin R.

    2012-08-01

    The growing population of space debris poses a serious risk to the future of space flight. To effectively manage the increase of debris in orbit, end-of life disposal has become a key requirement for future missions. This poses a challenge for Medium Earth Orbit (MEO) spacecraft which require a large Δv to re-enter the atmosphere or reach the geostationary graveyard orbit. This paper further explores a passive strategy based on the joint effects of solar radiation pressure and the Earth's oblateness acting on a high area-to-mass-ratio object. The concept was previously presented as an analytical planar model. This paper uses a full 3D model to validate the analytical results numerically for equatorial circular orbits first, then investigating higher inclinations. It is shown that for higher inclinations the initial position of the Sun and right ascension of the ascending node become increasingly important. A region of very low required area-to-mass-ratio is identified in the parameter space of semi-major axis and inclination which occurs for altitudes below 10,000 km.

  11. Use of radiometer to reform and repair an old living house to passive solar one

    SciTech Connect

    Okamoto, Yoshizo; Inagaki, Terumi; Suzuki, Takakazu; Kurokawa, Takashi

    1994-12-31

    Japanese houses consist mainly of wooden elements under high-temperature and moist condition. To modify the hot and humid environment of the living room of one house, a conventional house was revamped and partially repaired. Especially for the winter season, a diagnostic thermographic test was used to detect deteriorated and leaking parts of interior and exterior walls. Macroscopic deteriorated parts were checked again in detail. The deteriorated element was replaced with a new one. During the reconstruction process, a new solar heat and air conditioning system using a silica-gel adsorber and underground water was installed to cool and warm up the living room. Thermography tests of this revamped house shows that room temperature is always constant and comfortable to human beings, especially in the winter. Temperature and heat flow distribution of flowing air in the living room was measured using thermal net and wire methods. Leaking thermal streak flow of the gap was locally visualized by the infrared radiometer and high-sensitive video camera. It was verified that the IR thermography is a useful measuring instrument to check thermal defects of the homes.

  12. Comprehensive analytical model for locally contacted rear surface passivated solar cells

    NASA Astrophysics Data System (ADS)

    Wolf, Andreas; Biro, Daniel; Nekarda, Jan; Stumpp, Stefan; Kimmerle, Achim; Mack, Sebastian; Preu, Ralf

    2010-12-01

    For optimum performance of solar cells featuring a locally contacted rear surface, the metallization fraction as well as the size and distribution of the local contacts are crucial, since Ohmic and recombination losses have to be balanced. In this work we present a set of equations which enable to calculate this trade off without the need of numerical simulations. Our model combines established analytical and empirical equations to predict the energy conversion efficiency of a locally contacted device. For experimental verification, we fabricate devices from float zone silicon wafers of different resistivity using the laser fired contact technology for forming the local rear contacts. The detailed characterization of test structures enables the determination of important physical parameters, such as the surface recombination velocity at the contacted area and the spreading resistance of the contacts. Our analytical model reproduces the experimental results very well and correctly predicts the optimum contact spacing without the use of free fitting parameters. We use our model to estimate the optimum bulk resistivity for locally contacted devices fabricated from conventional Czochralski-grown silicon material. These calculations use literature values for the stable minority carrier lifetime to account for the bulk recombination caused by the formation of boron-oxygen complexes under carrier injection.

  13. Photovoltaics for commercial solar power applications; Proceedings of the Meeting, Cambridge, MA, Sept. 18, 19, 1986

    NASA Astrophysics Data System (ADS)

    Adler, David

    1986-01-01

    Papers are presented on efficient multijunction monolithic cascade solar cells, high efficiency silicon solar cells, point contact silicon cells, and space solar cell research. Also considered are photovoltaic power plants, the reliability of photovoltaic modules, the continuous fabrication of amorphous silicon solar cells on polymer substrates, and the density of states of amorphous silicon. Other topics include breaking the efficiency-stability-production barrier in amorphous photovoltaics, the development of flexible a-SiC/a-Si heterojunction solar cells and stable a-SiC/a-Si tandem cells with blocking barriers, and performance aspects for thin-film-silicon-hydrogen solar cells.

  14. Development of Commercial Technology for Thin Film Silicon Solar Cells on Glass: Cooperative Research and Development Final Report, CRADA Number CRD-07-209

    SciTech Connect

    Sopori, B.

    2013-03-01

    NREL has conducted basic research relating to high efficiency, low cost, thin film silicon solar cell design and the method of making solar cells. Two patents have been issued to NREL in the above field. In addition, specific process and metrology tools have been developed by NREL. Applied Optical Sciences Corp. (AOS) has expertise in the manufacture of solar cells and has developed its own unique concentrator technology. AOS wants to complement its solar cell expertise and its concentrator technology by manufacturing flat panel thin film silicon solar cell panels. AOS wants to take NREL's research to the next level, using it to develop commercially viable flat pane, thin film silicon solar cell panels. Such a development in equipment, process, and metrology will likely produce the lowest cost solar cell technology for both commercial and residential use. NREL's fundamental research capability and AOS's technology and industrial background are complementary to achieve this product development.

  15. The Impact of Neighbourhood Density on the Energy Demand of Passive Houses and on Potential Energy Sources from the Waste Flows and Solar Energy

    NASA Astrophysics Data System (ADS)

    Stupka, Robert

    This study demonstrates how the density of a neighbourhood affects its energy demand, metabolism (energy and material flows) and its ability to produce its own energy. Single-family detached houses and row townhouses were each modeled using passive solar housing guidelines with the DesignBuilder building energy simulation software. Energy demand is then modeled within neighbourhoods at two densities based on south facing windows fully un-shaded at 9:00 am, and 12:00 pm solar time on Dec. 21. The neighbourhood metabolisms were then calculated based on location and density. The potential energy supply was evaluated from the spatial characteristics of the neighbourhood (for solar) and the metabolism (municipal solid waste and wastewater flows.) The potential energy demand and supply are then compared for the varying building types and densities to determine the sensitivity of the energy supply and demand relationships.

  16. Rear-Sided Passivation by SiNx:H Dielectric Layer for Improved Si/PEDOT:PSS Hybrid Heterojunction Solar Cells

    NASA Astrophysics Data System (ADS)

    Sun, Yiling; Gao, Pingqi; He, Jian; Zhou, Suqiong; Ying, Zhiqin; Yang, Xi; Xiang, Yong; Ye, Jichun

    2016-06-01

    Silicon/organic hybrid solar cells have recently attracted great attention because they combine the advantages of silicon (Si) and the organic cells. In this study, we added a patterned passivation layer of silicon nitride (SiNx:H) onto the rear surface of the Si substrate in a Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hybrid solar cell, enabling an improvement of 0.6 % in the power conversion efficiency (PCE). The addition of the SiNx:H layer boosted the open circuit voltage ( V oc) from 0.523 to 0.557 V, suggesting the well-passivation property of the patterned SiNx:H thin layer that was created by plasma-enhanced chemical vapor deposition and lithography processes. The passivation properties that stemmed from front PEDOT:PSS, rear-SiNx:H, front PEDOT:PSS/rear-SiNx:H, etc. are thoroughly investigated, in consideration of the process-related variations.

  17. Development and Evaluation of Solar Tunnel Dryer for Commercial Fish Drying

    NASA Astrophysics Data System (ADS)

    Mohod, A. G.; Khandetod, Y. P.; Shrirame, H. Y.

    2014-01-01

    The local practice of drying fish in open sun drying poses problems such as high moisture content, uncontrolled drying and contamination. These problems can be avoided by proper use of improved methods such as the solar tunnel dryer, which results in faster drying of fish. The semi cylindrical walk-in type natural convection solar tunnel dryer, having drying area of 37.5 m2 was developed and evaluated for the drying of fish products in comparison with the conventional method of open sun drying. The experiments were conducted without fish and with fish to evaluate the performance of solar tunnel dryer. The average rise in temperature inside the solar tunnel dryer was found to be 11.24 °C and 18.29 °C over the ambient temperature during no load test in winter and summer respectively. The average 28 % saving in time was observed for selected fish drying using solar tunnel dryer over open sun drying method with average drying efficiency of 19 %. The economics was calculated for drying of prawns ( Parapaeneopsis stylifera) by solar tunnel dryer and open sun drying system on the basis of business as a whole. The economics of the solar tunnel dryer is presented in term of Net present worth, Benefit-Cost Ratio, Payback period, Profitability index and Internal rate of return. The pay back period for solar tunnel dryer was found to be 2.84 years.

  18. Solar Access to Public Capital (SAPC) Working Group: Best Practices in Commercial and Industrial (C&I) Solar Photovoltaic System Installation; Period of Performance: November 28, 2014-September 1, 2015

    SciTech Connect

    Doyle, Chris; Loomans, Len; Truitt, Andrew; Lockhart, Robert; Golden, Matt; Dabbagh, Kareem; Lawrence, Richard

    2015-12-29

    This Best Practices in Commercial and Industrial Solar Photovoltaic System Installation Guide is the second of a series of guides designed to standardize and improve solar asset transparency for investors and rating agencies, provide an industry framework for quality management, and reduce transaction costs in the solar asset securitization process. The Best Practices in C&I PV System Installation Guide is intended to outline the minimum requirements for commercial and industrial solar project developments. Adherence to the guide is voluntary. Providers that adhere to the guide are responsible for self-certifying that they have fulfilled the guide requirements. Investors and rating agencies should verify compliance.

  19. A comparison of fuel savings in the residential and commercial sectors generated by the installation of solar heating and cooling systems under three tax credit scenarios

    NASA Astrophysics Data System (ADS)

    Moden, R.

    An analysis of expected energy savings between 1977 and 1980 under three different solar tax credit scenarios is presented. The results were obtained through the solar heating and cooling of buildings (SHACOB) commercialization model. This simulation provides projected savings of conventional fuels through the installation of solar heating and cooling systems on buildings in the residential and commercial sectors. The three scenarios analyzed considered the tax credits contained in the Windfall Profits Tax of April 1980, the National Tax Act of November 1978, and a case where no tax credit is in effect.

  20. Silicon surface passivation by silicon nitride deposition

    NASA Technical Reports Server (NTRS)

    Olsen, L. C.

    1984-01-01

    Silicon nitride deposition was studied as a method of passivation for silicon solar cell surfaces. The following three objectives were the thrust of the research: (1) the use of pecvd silicon nitride for passivation of silicon surfaces; (2) measurement techniques for surface recombination velocity; and (3) the importance of surface passivation to high efficiency solar cells.

  1. Leak path passivation by in situ Al-N for InGaN solar cells operating at wavelengths up to 570 nm

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Imai, Daichi; Kusakabe, Kazuhide; Yoshikawa, Akihiko

    2016-02-01

    A leak path passivation (LPP) technology for InGaN solar cells with photo-response up to 570 nm was developed by inserting in situ monolayers of Al-N into active layers. The InGaN layer in the passivated sample is partially relaxed and incorporates more than 23.5% In. By adopting in situ Al-N LPP, the open circuit voltage increases from 0.96 V to 1.35 V under one sun illumination (1.45-1.68 V under 72 suns), and the dark shunt resistance increases from 3.6 kΩ cm2 to 12.6 kΩ cm2, leading to an increase in power conversion efficiency by a factor of 2.0-2.26 (1-72 suns). This in situ Al-N LPP approach paves a way to exploit the full potential of InGaN for high efficiency solar cell application, accepting the reality of defective high-In-content thick and relaxed InGaN.

  2. Usefulness of a commercial equine IgG test and serum protein concentration as indicators of failure of transfer of passive immunity in hospitalized foals.

    PubMed

    Metzger, Nadine; Hinchcliff, Kenneth W; Hardy, Joanne; Schwarzwald, Colin C; Wittum, Thomas

    2006-01-01

    Detection of failure of transfer of passive immunity (FTPI) is important in reducing morbidity and mortality in neonatal foals. We investigated the performance of a commercial equine IgG test (SNAP Foal IgG Test Kit) to diagnose FTPI in hospitalized foals. Furthermore, we evaluated the usefulness of serum total protein (STP) and serum globulin (SG) concentrations as indicators of FTPI. Serum IgG concentration was measured by means of the SNAP test and single radial immunodiffusion, and SG and STP concentrations were determined by means of a clinical chemistry analyzer. Subjects were 67 hospitalized foals <19 days old. The SNAP test was repeated on 37 samples from 29 foals, with identical results for 24 samples (kappa statistic, 0.64; 95% confidence interval [CI], 0.46-0.82). The sensitivity of the SNAP test to detect serum IgG concentration [IgG] < or =400 and < or =800 mg/dl was 90% (95% CI, 71-98%) and 95% (85-99%), respectively, and the specificity was 79% (71-82%) and 52% (39-57%), respectively. Sensitivity for detection of [IgG] < or =400 mg/dl was not affected (P > .05) by plasma fibrinogen concentration, sepsis score, or bacteremia. Specificity for detection of [IgG] < or = 800 mg/dl was lower (P < .05) in foals with sepsis score < or =11 (50% [31-60%] versus 100% [8-100%]) and bacteremia (25% [5-56%] versus 62% [45-62%]). Sensitivity and specificity of [STP] < or = 5.0 g/dl for [IgG] < or =800 mg/dl was 94% (83-99%) and 47% (30-56%), respectively. Performance of the SNAP test in hospitalized foals is impaired because of low specificity, but can have usefulness provided that the properties of the test and characteristics of the foal being examined are considered when interpreting the results. The STP and SG concentrations are poor sole indicators of FTPI in hospitalized foals, but may be useful adjunctive tests. PMID:16594598

  3. Commercialization of BNL design solar collector in India: Phase 1 report

    SciTech Connect

    Wilhelm, W.G.; Mubayi, V.

    1985-09-01

    The present market for solar thermal energy technologies in India is almost completely restricted to solar hot water and, in a smaller number, hot air systems. A few projects utilizing concentrating systems for producing steam and/or thermally generated electric power have been carried out but these are restricted to the R and D stage. Similarly, a few projects employing solar space heating have also been done in remote, mountainous areas but these are also at the R and D level. Based on interviews with knowledgeable observers, including officials of DNES/STEC, state ''nodal'' agencies responsible for implementing solar energy projects in different states, and flat plate collector/hot water systems manufacturers, it has been roughly estimated that between 90 to 95% of the hot water systems installed or under installation have been funded by government programs. This includes systems funded under Central Government programs by DNES and systems installed under State Government projects. The remaining 5 to 10% of the installations are in the private sector and are believed to be mostly small, domestic systems (100 liters per day of hot water at 60/sup 0/C).

  4. Development of a commercial aquaculture system utilizing solar energy and recycled waste. Final report

    SciTech Connect

    Westbrook, D.

    1982-09-27

    Successfully designed and constructed was a hot air solar heated structure to house a pool for the freshwater shrimp which were expected to grow on feed composed of chicken waste products. The main pool and a series of smaller test pools were installed and were conducted on manures, algal growth, and water conditions.

  5. Randomized clinical trial of a customized electronic alert requiring an affirmative response compared to a control group receiving a commercial passive CPOE alert: NSAID–warfarin co-prescribing as a test case

    PubMed Central

    Schinnar, Rita; Bilker, Warren; Hennessy, Sean; Leonard, Charles E; Pifer, Eric

    2010-01-01

    Background Studies that have looked at the effectiveness of computerized decision support systems to prevent drug–drug interactions have reported modest results because of low response by the providers to the automated alerts. Objective To evaluate, within an inpatient computerized physician order entry (CPOE) system, the incremental effectiveness of an alert that required a response from the provider, intended as a stronger intervention to prevent concurrent orders of warfarin and non-steroidal anti-inflammatory drugs (NSAIDs). Design Randomized clinical trial of 1963 clinicians assigned to either an intervention group receiving a customized electronic alert requiring affirmative response or a control group receiving a commercially available passive alert as part of the CPOE. The study duration was 2 August 2006 to 15 December 2007. Measurements Alert adherence was compared between study groups. Results The proportion of desired ordering responses (ie, not reordering the alert-triggering drug after firing) was lower in the intervention group (114/464 (25%) customized alerts issued) than in the control group (154/560 (28%) passive alerts firing). The adjusted OR of inappropriate ordering was 1.22 (95% CI 0.69 to 2.16). Conclusion A customized CPOE alert that required a provider response had no effect in reducing concomitant prescribing of NSAIDs and warfarin beyond that of the commercially available passive alert received by the control group. New CPOE alerts cannot be assumed to be effective in improving prescribing, and need evaluation. PMID:20595308

  6. Commercialization strategy for the Department of Energy's Solar Buildings Demonstration Program

    SciTech Connect

    Not Available

    1981-01-01

    Efforts reported include: conducting a survey of existing commercial demonstration projects, categorizing these projects, determining criteria for evaluating the feasibility of continuing/aborting demonstration projects, and applying the criteria and making recommendations for which projects to continue and abort. It is recommended to refurbish 114 of the projects examined and to abandon 41. (LEW)

  7. Design, experimental and economic evaluation of a commercial-type solar dryer for production of high-quality hay

    SciTech Connect

    Arinze, E.A.; Sokhansanj, S.; Schoenau, G.J.; Crerar, B.; Opoku, A.

    1998-03-01

    Design features, development, experimental functional performance and economic evaluation of an energy efficient solar energy dryer for commercial production of high-quality hay and processed forage products are presented. The solar hay dryer consists of an improved solar collector with selective coated aluminum absorber plate and spaced fins, and a drying shed connected to the collector by an insulated duct and having a perforated metal grate floor, swing-away plywood frames and polyethylene curtains for effectively sealing the hay stack, and a crawl space below the floor where a 3-hp in-line centrifugal fan is housed for air circulation by suction. In late August and in early September, 1996, 160 small rectangular bales of alfalfa hay with about 25% bromegrass were successfully dried from 33% initial moisture content to 13%, and from 25% to 11% moisture in 4 and 3 days, respectively, under average weather conditions in Saskatoon, Saskatchewan, Canada. With about 18 m{sup 3}/min per tonne airflow, 10--15 C temperature rise above ambient was obtained during peak bright sunshine hours. Relatively high daily average collector efficiency of 76%, high drying effectiveness, drying uniformity, uniform air distribution and tight sealing of the stack were achieved which resulted in an attractive green color of hay, no mold growth on hay, and an overall system drying efficiency of about 79%. Compared to a conventional natural gas drying system or field-drying method, the payback period on extra investment costs recovered through drying cost savings of $3/t to $6/t or through over two times higher prices for high-quality hay produced by the solar drying system may be just one or two years, respectively.

  8. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF:F-2 saturable absorber for laser-induced breakdown spectroscopy

    SciTech Connect

    Carson, Cantwell; Goueguel, Christian; Sanghapi, Herve; Jinesh, Jain; McIntyre, Dustin

    2015-12-11

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV–vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  9. Thermal refuge designs for seawater solar ponds in commercial mariculture operations

    SciTech Connect

    Li, H.; Kleis, S.J.

    1996-12-31

    Thermal refuge areas for protecting fish from winter kills in commercial mariculture operations using large outdoor ponds are experimentally investigated. A double curtain arrangement is introduced and is shown to be both practical and effective as a thermal barrier. The sea water thermal refuge concept is shown to be viable for the pond sizes of over 26,000 m{sup 2} tested. Comparisons based on thermal performance are made among three barrier arrangements.

  10. Hydrogen Passivation of N(+)P and P(+)N Heteroepitaxial InP Solar Cell Structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, B.; Davis, W. C.; Ringel, S. A.; Hoffman, R., Jr.

    1995-01-01

    Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n(+)p and p(+)n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)p and p(+)n heteroepitaxial InP cell structures from as-grown values of 5 - 7 x 10(exp 14)/cc, down to 3 - 5 x 10(exp 12)/cc. All dopants were successfully reactivated by a 400 C, 5 minute anneal With no detectable activation of deep levels. I-V analysis indicated a subsequent approx. 100 fold decrease In reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)n structures. ln addition to being passivated,dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

  11. Hydrogen passivation of N(+)-P and P(+)-N heteroepitaxial InP solar cell structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, Basab; Davis, William C.; Ringel, Steve A.; Hoffman, Richard, Jr.

    1996-01-01

    Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n-p and p-n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)-p and p(+)-n heteroepitaxial InP cell structures from as-grown values of 5-7 x 10(exp 14) cm(exp -3), down to 3-5 x 10(exp 12) cm(exp -3). All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. One to five analysis indicated a subsequent approximately 100 fold decrease in reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)-n structures. In addition to being passivated, dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

  12. To Own or Lease Solar: Understanding Commercial Retailers' Decisions to Use Alternative Financing Models

    SciTech Connect

    Feldman, D.; Margolis, R.

    2014-12-01

    This report examines the tradeoffs among financing methods for businesses installing onsite photovoltaics (PV). We present case studies of PV financing strategies used by two large commercial retailers that have deployed substantial U.S. PV capacity: IKEA, which owns its PV, and Staples, which purchases power generated from onsite PV systems through power purchase agreements (PPAs). We also analyze the financial considerations that influence any company's choice of PV financing strategy. Our goal in this report is to clarify the financial and institutional costs and benefits of financing strategies and to inform other companies that are considering launching or expanding similar PV programs.

  13. Simultaneous P and B diffusion, in-situ surface passivation, impurity filtering and gettering for high-efficiency silicon solar cells

    SciTech Connect

    Krygowski, T.; Rohatgi, A.; Ruby, D.

    1997-11-01

    A technique is presented to simultaneously diffuse boron and phosphorus in silicon, and grow an in-situ passivating oxide in a single furnace step. It is shown that limited solid doping sources made from P and B Spin-On Dopant (SOD) films can produce optimal n{sup +} and p{sup +} profiles simultaneously without the deleterious effects of cross doping. A high quality passivating oxide is grown in-situ beneath the thin ({approximately} 60 {angstrom}) diffusion glass, resulting in low J{sub o} values below 100 fA/cm{sup 2} for transparent ({approximately} 100 {Omega}/{open_square}) phosphorus and boron diffusions. For the first time it is shown that impurities present in the boron SOD film can be effectively filtered out by employing separate source wafers, resulting in bulk lifetimes in excess of 1 ms for the sample wafers. The degree of lifetime degradation in the sources is related to the gettering efficiency of boron in silicon. This novel simultaneous diffusion, in-situ oxidation, impurity filtering and gettering technique was successfully used to produce 20.3% Fz, and 19.1% Cz solar cells, in one furnace step.

  14. Research on the Hydrogen Passivation of Defects and Impurities in Si Relevant to Crystalline Si Solar Cell Materials: Final Report, 16 February 2000 -- 15 April 2003

    SciTech Connect

    Stavola, M.

    2003-09-01

    The goal of this experimental research program is to increase the understanding, at a microscopic level, of hydrogenation processes and passivation mechanisms for crystalline-Si photovoltaics. In our experiments, vibrational spectroscopy was used to study the properties of the interstitial H2 molecule in Si and the transition-metal-hydrogen complexes in Si. The interstitial H2 molecule is formed readily in Si when hydrogen is introduced. Our studies establish that interstitial H2 in Si behaves as a nearly free rotator, solving puzzles about the behavior of this defect that have persisted since the discovery of its vibrational spectrum. The transition metals are common impurities in Si that decrease the minority-carrier lifetime and degrade the efficiencies of solar cells. Therefore, the possibility that transition-metal impurities in Si might be passivated by hydrogen has long been of interest. Our studies of transition-metal-H complexes in Si help to establish the structural and electrical properties of a family of Pt-H complexes in Si, and have made the Pt-H complexes a model system for understanding the interaction of hydrogen with transition-metal impurities in Si.

  15. Real-Time and Accelerated Solar Weathering of Commercial PV Modules: Preprint

    SciTech Connect

    Osterwald, C. R.; Pruett, J.; Myers, D. R.; Rummel, S.; Anderberg, A.; Ottoson, L.; Basso, T.

    2001-10-01

    Presented at the 2001 NCPV Program Review Meeting: We report the observed degradation in 6 different types of PV modules as a function of total UV exposure and give a number of recommendations for future weathering tests. Since 1997, using existing ASTM standards for weathering of materials, we have been conducting a solar weathering program on a group of six different types of photovoltaic (PV) modules. The methods used include real-time outdoor, accelerated outdoor, and accelerated indoor weathering. We have employed the technique specified in these standards that quantifies exposure totals by the time integral of the ultraviolet (UV) irradiance. In this paper, we report the observed degradation in the test modules as a function of total UV exposure, and give a number of recommendations for future weathering tests that resulted from our first attempt at a formal test program.

  16. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 4: Commercial System Definition. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. The operational reliability, the minimum risk of failure, and the maintenance and repair characteristics are determined and the commercial system design is defined.

  17. Halarchaeum acidiphilum gen. nov., sp. nov., a moderately acidophilic haloarchaeon isolated from commercial solar salt.

    PubMed

    Minegishi, Hiroaki; Echigo, Akinobu; Nagaoka, Shuhei; Kamekura, Masahiro; Usami, Ron

    2010-11-01

    A novel halophilic archaeon, strain MH1-52-1(T), was isolated from solar salt imported from Australia. Cells were pleomorphic, non-motile and Gram-negative. Strain MH1-52-1(T) required at least 3.0 M NaCl and 1 mM Mg(2+) for growth. Strain MH1-52-1(T) was able to grow at pH 4.0-6.0 (optimum, pH 4.4-4.5) and 15-45 °C (optimum, 37 °C). The diether phospholipids phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, derived from both C(20)C(20) and C(20)C(25) archaeol, were present. Four unidentified glycolipids were also detected. The 16S rRNA gene sequence showed the highest similarity to that of Halobacterium noricense A1(T) (91.7%); there were lower levels of similarity to other members of the family Halobacteriaceae. The G+C content of its DNA was 61.4 mol%. Based on our phenotypic, genotypic and phylogenetic analyses, it is proposed that the isolate should be classified as a representative of a new genus and species, for which the name Halarchaeum acidiphilum gen. nov., sp. nov. is proposed. The type strain of Halarchaeum acidiphilum is MH1-52-1(T) (=JCM 16109(T) =DSM 22442(T) =CECT 7534(T)). PMID:19965997

  18. Room temperature surface passivation of silicon for screen printed c-Si solar cells by HiTUS reactive sputter deposition

    NASA Astrophysics Data System (ADS)

    Kaminski, P. M.; Bass, K.; Claudio, G.; Walls, J. M.

    2014-05-01

    The dielectric coatings used on silicon solar cells serve a dual purpose: a surface passivation layer and as an antireflection coating. Silicon nitride films were deposited by sputtering, using a HiTUS technology, on crystalline silicon wafers. Films were deposited without substrate heating, which simplifies the deposition process, from a polycrystalline silicon target in a mixed ambient of argon, nitrogen and hydrogen gasses. After the deposition, the minority carrier lifetime, refractive index and deposition rate were measured. Photo conductance decay measurements show that the minority carrier lifetime increased up to 26 μs on a 40 Ω/□ doped 1 Ω cm p-type <1 0 0> Cz-Si pseudo square wafer (compared to 1 μs measured for bare wafer) and up to 984 μs for a double-side polished 3 Ω cm Cz-Si wafer (from ˜70 μs measured for uncoated wafer). Spectroscopic ellipsometry measurements showed that the refractive index of the deposited films was 2.05 at λ = 632.8 nm; deposition rate was measured at 22.4 nm/min. The films were used to prepare screen-printed c-Si solar cells. The resultant cells showed an efficiency of 15.14% with silicon nitride films grown without the use of silane or substrate heating.

  19. Origin and elimination of photocurrent hysteresis by fullerene passivation in CH3NH3PbI3 planar heterojunction solar cells

    SciTech Connect

    Shao, Yuchuan; Xiao, Zhengguo; Bi, Cheng; Yuan, Yongbo; Huang, Jinsong

    2014-12-15

    The large photocurrent hysteresis observed in many organometal trihalide perovskite solar cells has become a major hindrance impairing the ultimate performance and stability of these devices, while its origin was unknown. Here we demonstrate the trap states on the surface and grain boundaries of the perovskite materials to be the origin of photocurrent hysteresis and that the fullerene layers deposited on perovskites can effectively passivate these charge trap states and eliminate the notorious photocurrent hysteresis. Fullerenes deposited on the top of the perovskites reduce the trap density by two orders of magnitude and double the power conversion efficiency of CH3NH3PbI3 solar cells. As a result, the elucidation of the origin of photocurrent hysteresis and its elimination by trap passivation in perovskite solar cells provides important directions for future enhancements to device efficiency.

  20. Solar explosion

    NASA Astrophysics Data System (ADS)

    Baccei, B. C.

    1981-04-01

    The Solar Energy Research Institute (SERI) and the Department of Energy (DOE) Passive Solar Manufactured Buildings and Solar Home Builders Programs are developing much needed cost and performance data on solar buildings produced by large-volume home builders. These programs also serve as a model on how government can work effectively with industry.

  1. Dynamic optimization for commercialization of renewable energy: an example for solar photovoltaics

    SciTech Connect

    Richards, Kenneth, R.; Ashton, W. Bradley; McVeigh, James

    2000-04-21

    There are several studies of optimal allocation of research and development resources over the time horizon of a project. The primary result of the basic noncompetitive models in this literature is that the optimal strategy is to choose a research intensity and ending date for the project such that the marginal costs of accelerating the project equals the marginal benefits of introducing the product sooner. This literature provides useful insights for the government planner who must allocate R&D resources for renewable energy development. However, several characteristics distinguish the process from the typical R&D planning problem. Specifically, with PV development, where the goal is to maximize the net present value of activities leading to cost reduction in commercial modules, there are (1) significant lag-times between investment in laboratory research and resulting effects in the marketplace, (2) a learning curve associated with the manufacturing process that also reduces the cost s of PV modules, (3) interim benefits from technical advances, (4) no clear end point to the R&D process, but rather a tapering off of the value of advances in technical efficiency, (5) significant uncertainty in the R&D process, (6) a family of products rather than an individual technology, (7) a co-mingling of government and private resources with implications for efficient management. A dynamic model is developed to characterize the optimal intensity and timing of government and private resource allocation for basic research in improving the technical efficiency of cells and subsidies to the manufacturing process to encourage progress on the learning curve. A series of propositions regarding optimal paths for each are examined. While the research is purely analytical, the results are useful for conceptualizing the R&D planning process. They also provide a basis for a numerical study that can address whether current levels and historic patterns of funding are optimal.

  2. A Facile Surface Passivation of Hematite Photoanodes with TiO2 Overlayers for Efficient Solar Water Splitting.

    PubMed

    Ahmed, Mahmoud G; Kretschmer, Imme E; Kandiel, Tarek A; Ahmed, Amira Y; Rashwan, Farouk A; Bahnemann, Detlef W

    2015-11-01

    The surface modification of semiconductor photoelectrodes with passivation overlayers has recently attracted great attention as an effective strategy to improve the charge-separation and charge-transfer processes across semiconductor-liquid interfaces. It is usually carried out by employing the sophisticated atomic layer deposition technique, which relies on reactive and expensive metalorganic compounds and vacuum processing, both of which are significant obstacles toward large-scale applications. In this paper, a facile water-based solution method has been developed for the modification of nanostructured hematite photoanode with TiO2 overlayers using a water-soluble titanium complex (i.e., titanium bis(ammonium lactate) dihydroxide, TALH). The thus-fabricated nanostructured hematite photoanodes have been characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Photoelectrochemical measurements indicated that a nanostructured hematite photoanodes modified with a TiO2 overlayer exhibited a photocurrent response ca. 4.5 times higher (i.e., 1.2 mA cm(-2) vs RHE) than that obtained on the bare hematite photoanode (i.e., 0.27 mA cm(-2) vs RHE) measured under standard illumination conditions. Moreover, a cathodic shift of ca. 190 mV in the water oxidation onset potential was achieved. These results are discussed and explored on the basis of steady-state polarization, transient photocurrent response, open-circuit potential, intensity-modulated photocurrent spectroscopy, and impedance spectroscopy measurements. It is concluded that the TiO2 overlayer passivates the surface states and suppresses the surface electron-hole recombination, thus increasing the generated photovoltage and the band bending. The present method for the hematite electrode modification with a TiO2 overlayer is effective and simple and might find broad applications in the development of stable and high-performance photoelectrodes. PMID:26488924

  3. Application of solar energy; Proceedings of the Third Southeastern Conference, Huntsville, Ala., April 17-19, 1978

    NASA Technical Reports Server (NTRS)

    Wu, S. T. (Editor); Christensen, D. L.; Head, R. R.

    1978-01-01

    Demonstration projects, systems-subsystems simulation programs, applications (heating, cooling, agricultural, industrial), and climatic data testing (standards, economics, institutional) are the topics of the book. Economics of preheating water for commercial use and collecting, processing, and dissemination of data for the national demonstration program are discussed. Computer simulation of a solar energy system and graphical representation of solar collector performance are considered. Attention is given to solar driven heat pumps, solar cooling equipment, hybrid passive/active solar systems, and solar farm buildings. Evaluation of a thermographic scanning device for solar energy and conservation applications, use of meteorological data in system evaluation, and biomass conversion potential are presented.

  4. Manned exploration and exploitation of solar system: Passive and active shielding for protecting astronauts from ionizing radiation-A short overview

    NASA Astrophysics Data System (ADS)

    Spillantini, Piero

    2014-11-01

    In deep space manned missions for the exploration and exploitation of celestial bodies of Solar System astronauts are not shielded by the terrestrial magnetic field and must be protected against the action of Solar Cosmic Rays (SCRs) and Galactic Cosmic Rays (GCRs). SCRs are sporadically emitted, and in very rare but possible events, their fluence can be so high to be lethal to a unprotected crew. Their relatively low energy allows us to conceive fully passive shields, also if active systems can somewhat reduce the needed mass penalty. GCRs continuously flow without intensity peaks, and are dangerous to the health and operability of the crew in long duration (>1year) missions. Their very high energy excludes the possible use of passive systems, so that recourse must be made to electromagnetic fields for preventing ionizing particles to reach the habitat where astronauts spend most of their living and working time. A short overview is presented of the many ideas developed in last decades of last century; ideas are mainly based on very intense electrostatic shields, flowing plasma bubbles, or enormous superconducting coil systems for producing high magnetic fields. In the first decade of this century the problem began to be afforded in more realistic scenarios, taking into account the present and foreseeable possibilities of launchers (payload mass, diameter and length of the shroud of the rocket, etc.) and of assembling and/or inflating structures in space. Driving parameters are the volume of the habitat to be protected and the level of mitigation of the radiation dose to be guaranteed to the crew. Superconducting magnet systems based on multi-solenoid complexes or on one huge magnetic torus surrounding the habitat are being evaluated for defining the needed parameters: masses, mechanical structures for supporting the huge magnetic forces, needed equipments and safety systems. Technological tests are in preparation or planned for improving density of the current

  5. Cost effectiveness of solar DHW systems: results of side-by-side tests of active and passive systems

    SciTech Connect

    Athoe, J.; Beach, C.; Gleman, S.

    1981-01-01

    Four solar domestic hot water systems were assembled at the Florida Solar Energy Systems Test Facility and run side-by-side for 6 months in the Florida sunshine. The systems included (1) a 40 ft/sup 2/, 80 gal pumped direct system with differential control, (2) a 40 ft/sup 2/, 80 gal pumped direct system with snap switch control, (3) a 24 ft/sup 2/, 40 gal thermosiphon system, and (4) a bread-box water heater (originally a Baer-type or horizontal tank system with about 20 ft/sup 2/ aperture and 66 gallon tank, later changed to a tilted tank, 24 ft/sup 2/, 40 gallon system). These systems were run without backup power and under a draw of 63 gallons per day for each system. The installed costs of these systems were estimated on a consistent basis. Results of the tests are presented, including thermal efficiency (heat delivered to load divided by sunshine incident upon collector), water draw temperature, and cost effectiveness (heat per day per dollar system cost) of the system. Based on data for the colder half of the year in Florida, it is concluded: (1) differential and snap switch controls perform about equally well, (2) the thermosiphon is the most cost-effective, (3) the more costly the system, the higher the temperature of the water it delivers, and (4) the less costly systems are adequate for some purposes, and about as cost-effective as the more expensive systems.

  6. Nano Ag-enhanced energy conversion efficiency in standard commercial pc-Si solar cells and numerical simulations with finite difference time domain method

    NASA Astrophysics Data System (ADS)

    Yu, Jing; Shao, Weijia; Zhou, Yao; Wang, Huijie; Liu, Xiao; Xu, Xiaoliang

    2013-11-01

    Nano Ag-enhanced energy conversion efficiency (ECE) in one standard commercial pc-Si solar cell utilizing the forward scattering by Ag nanoparticles on surface has been researched experimentally and simulatively in this paper. Directly assembling Ag nanoparticles (with size about 100 nm) on the surface, it is found when the particle surface coverage is 10%, the ECE and the short circuit current density are increased by 2.8% and 1.4%, respectively. Without changing any existing structure of the ready-made solar cell, this facile and efficient method has huger applications than other methods.

  7. Enhanced Carrier Collection from CdS Passivated Grains in Solution-Processed Cu2ZnSn(S,Se)4 Solar Cells.

    PubMed

    Werner, Melanie; Keller, Debora; Haass, Stefan G; Gretener, Christina; Bissig, Benjamin; Fuchs, Peter; La Mattina, Fabio; Erni, Rolf; Romanyuk, Yaroslav E; Tiwari, Ayodhya N

    2015-06-10

    Solution processing of Cu2ZnSn(S,Se)4 (CZTSSe)-kesterite solar cells is attractive because of easy manufacturing using readily available metal salts. The solution-processed CZTSSe absorbers, however, often suffer from poor morphology with a bilayer structure, exhibiting a dense top crust and a porous bottom layer, albeit yielding efficiencies of over 10%. To understand whether the cell performance is limited by this porous layer, a systematic compositional study using (scanning) transmission electron microscopy ((S)TEM) and energy-dispersive X-ray spectroscopy of the dimethyl sulfoxide processed CZTSSe absorbers is presented. TEM investigation revealed a thin layer of CdS that is formed around the small CZTSSe grains in the porous bottom layer during the chemical bath deposition step. This CdS passivation is found to be beneficial for the cell performance as it increases the carrier collection and facilitates the electron transport. Electron-beam-induced current measurements reveal an enhanced carrier collection for this buried region as compared to reference cells with evaporated CdS. PMID:25985349

  8. Commercialization of New Lattice-Matched Multi-Junction Solar Cells Based on Dilute Nitrides: July 8, 2010 - March 7, 2012

    SciTech Connect

    Herb, J.

    2012-04-01

    Final Technical Progress Report for PV Incubator subcontract NAT-0-99013-03. The overall objective of this Incubator subcontract was to complete the work necessary to make commercial ready solar cells using the dilute nitride technology. The specific objectives of this program were aimed at completing the development of a triple-junction solar cell that incorporates a GaInNAs {approx}1eV subcell to the point of commercial readiness, and determining the cell reliability and, if necessary, identifying and eliminating process or material related issues that lead to early-life cell failures. There were three major objectives for Phase 1, each of which focuses on a key element of the solar cell that determines its performance in a commercial CPV system. One objective was to optimize the quality and performance of the key individual components making up the solar cell structure and then to optimize the integration of these components into a complete triple-junction cell. A second objective was to design and test anti-reflective coating that maximizes the light coupled into a 3J cell with a {approx}1 eV bottom cell bandgap. The third objective was to develop Highly Accelerated Life Tests (HALT) protocols and tools for identifying and correcting potential reliability problems. The Phase 2 objectives were a continuation of the work begun in Phase 1 but aimed at optimizing cell performance for commercial requirements. Phase 2 had four primary objectives: (1) develop a glass-matched anti-reflective coating (ARC) and optimize the cell/ARC to give good performance at 60C operating temperature, (2) optimize the cell for good operation at 60C and high concentration, and (3) complete the light biased HALT system and use it to determine what, if any, failures are observed, and (4) determine the reliability limits of the optimized cell.

  9. Quaternary Cu2ZnSnS4 quantum dot-sensitized solar cells: Synthesis, passivation and ligand exchange

    NASA Astrophysics Data System (ADS)

    Bai, Bing; Kou, Dongxing; Zhou, Wenhui; Zhou, Zhengji; Tian, Qingwen; Meng, Yuena; Wu, Sixin

    2016-06-01

    The quaternary Cu2ZnSnS4 (CZTS) QDs had been successfully introduced into quantum dot-sensitized solar cells (QDSC) via hydrolysis approach in our previous work [Green Chem. 2015, vol. 17, p. 4377], but the obtained cell efficiency was still limited by low open-circuit voltage and fill factor. Herein, we use 1-dodecanethiol (DDT) as capping ligand for fairly small-sized CZTS QDs synthesis to improve their intrinsic properties. Since this strong bonded capping ligand can not be replaced by 3-mercaptopropionic acid (MPA) directly, the nature cation (Cu, Zn or Sn)-DDT units of QDs are first exchanged by the preconjugated Cd-oleate via successive ionic layer adsorption and reaction (SILAR) procedure accompanied with the formation of a core/shell structure. The weak bonded oleic acid (OA) can be finally replaced by MPA and the constructed water soluble CZTS/CdSe QDSC achieves an impressive conversion efficiency of 4.70%. The electron transport and recombination dynamic processes are confirmed by intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS) measurements. It is found that the removal of long alkyl chain is conducive to improve the electron transport process and the type-II core/shell structure is beneficial to accelerate electron transport and retard charge recombination. This effective ligand removal strategy is proved to be more convenient for the applying of quaternary QDs in QDSC and would boost a more powerful efficiency in the future work.

  10. Solar Energy and You.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    This booklet provides an introduction to solar energy by discussing: (1) how a home is heated; (2) how solar energy can help in the heating process; (3) the characteristics of passive solar houses; (4) the characteristics of active solar houses; (5) how solar heat is stored; and (6) other uses of solar energy. Also provided are 10 questions to…

  11. Computer Program for Assessing the Economic Feasibility of Solar Energy for Single Family Residences and Light Commercial Applications

    NASA Technical Reports Server (NTRS)

    Forney, J. A.; Walker, D.; Lanier, M.

    1979-01-01

    Computer program, SHCOST, was used to perform economic analyses of operational test sites. The program allows consideration of the economic parameters which are important to the solar system user. A life cycle cost and cash flow comparison is made between a solar heating system and a conventional system. The program assists in sizing the solar heating system. A sensitivity study and plot capability allow the user to select the most cost effective system configuration.

  12. Photocatalytic mineralization of commercial herbicides in a pilot-scale solar CPC reactor: photoreactor modeling and reaction kinetics constants independent of radiation field.

    PubMed

    Colina-Márquez, Jose; Machuca-Martínez, Fiderman; Li Puma, Gianluca

    2009-12-01

    The six-flux absorption-scattering model (SFM) of the radiation field in the photoreactor, combined with reaction kinetics and fluid-dynamic models, has proved to be suitable to describe the degradation of water pollutants in heterogeneous photocatalytic reactors, combining simplicity and accuracy. In this study, the above approach was extended to model the photocatalytic mineralization of a commercial herbicides mixture (2,4-D, diuron, and ametryne used in Colombian sugar cane crops) in a solar, pilot-scale, compound parabolic collector (CPC) photoreactor using a slurry suspension of TiO(2). The ray-tracing technique was used jointly with the SFM to determine the direction of both the direct and diffuse solar photon fluxes and the spatial profile of the local volumetric rate of photon absorption (LVRPA) in the CPC reactor. Herbicides mineralization kinetics with explicit photon absorption effects were utilized to remove the dependence of the observed rate constants from the reactor geometry and radiation field in the photoreactor. The results showed that the overall model fitted the experimental data of herbicides mineralization in the solar CPC reactor satisfactorily for both cloudy and sunny days. Using the above approach kinetic parameters independent of the radiation field in the reactor can be estimated directly from the results of experiments carried out in a solar CPC reactor. The SFM combined with reaction kinetics and fluid-dynamic models proved to be a simple, but reliable model, for solar photocatalytic applications. PMID:19943672

  13. Evaluation of Alternate Surface Passivation Methods (U)

    SciTech Connect

    Clark, E

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  14. Lunar Solar Power System and Minimization of Carbon Dioxide Emissions in the Production of Commercial Power for a Prosperous Global Economy

    NASA Astrophysics Data System (ADS)

    Criswell, D. R.

    2001-12-01

    A prosperous world requires at least 6.7 kWt/person of thermal energy or the equivalent of 2.5 - 3 kWe/person of electric energy (1, 2). Thus, a prosperous world of 10 billion people requires approximately 67 TWt or 25 to 30 TWe of commercial power that is low in cost, globally safe, and capable of providing 6,700 TWt-y/century to Earth for many centuries. These requirements preclude conventional terrestrial fossil-fuel, nuclear, and renewable systems. Cost-effective access of solar energy is required. The Moon intercepts 13,000 TWs of solar power. The proposed Lunar Solar Power (LSP) System collects a small portion of this solar power at bases located near the Earthward limbs of the Moon, converts the power to low-intensity microwave power beams (less than 20 percent the intensity of sunlight), and delivers the microwave power to receivers on Earth. The LSP lunar components are manufactured on the Moon using lunar materials. The receivers on Earth output utility-scale power. By 2050 the LSP System can provide abundant, clean, and low-cost commercial electric power to Earth that is independent of the biosphere. LSP energy can decouple physical and most service industry from the biosphere, stimulate healthy net growth of the global economy, and establish a two-planet (Earth-Moon) economy. 1. World Energy Council (2000) Energy for Tomorrow's World - Acting Now!,175pp., Atalink Projects Ltd., London. 2. Criswell, D. R. 1998 (13 - 18 September) Lunar solar power for energy prosperity within the 21st century, 17th Congress of the World Energy Council, Division 4: Concepts for a sustainable future - issues session, 4.1.23, 277-289, Houston, TX (Also on WEC'98 web site. Search for lunar.)

  15. Commercialization of High-Temperature Solar Selective Coating: Cooperative Research and Development Final Report, CRADA Number CRD-08-300

    SciTech Connect

    Gray, M. H.

    2014-01-01

    The goal for Concentrating Solar Power (CSP) technologies is to produce electricity at 15 cents/kilowatt-hour (kWh) with six hours of thermal storage in 2015 (intermediate power) and close to 10 cents/kWh with 12-17 hours of thermal storage in 2020 (baseload power). Cost reductions of up to 50% to the solar concentrator are targeted through technology advances. The overall solar-to-electric efficiency of parabolic-trough solar power plants can be improved and the cost of solar electricity can be reduced by improving the properties of the selective coating on the receiver and increasing the solar-field operating temperature to >450 degrees C. New, more-efficient selective coatings will be needed that have both high solar absorptance and low thermal emittance at elevated temperatures. Conduction and convection losses from the hot absorber surface are usually negligible for parabolic trough receivers. The objective is to develop new, more-efficient selective coatings with both high solar absorptance (..alpha.. > 0.95) and low thermal emittance (..epsilon.. < 0.08 @ 450 degrees C) that are thermally stable above 450 degrees C, ideally in air, with improved durability and manufacturability, and reduced cost.

  16. Solar engineering - 1981; Proceedings of the Third Annual Conference on Systems Simulation, Economic Analysis/Solar Heating and Cooling Operational Results, Reno, NV, April 27-May 1, 1981

    NASA Astrophysics Data System (ADS)

    Reid, R. L.; Murphy, L. M.; Ward, D. S.

    Progress made toward the commercialization of solar energy technologies as of 1981 is assessed, and attention is given to the future uses and impacts of solar energy. Attention is given to the results of several years of monitoring and modifying solar heating and cooling on residential and commercial structures. Solar system simulation and analysis methods are reviewed, covering the performance and operations of passive and active systems, thermosyphon systems, heat pumps and phase change systems. Simulations of system components are discussed, as are means to validate existing computer simulation codes, particularly the TRNSYS program. Control systems and logic for collector systems are explored, including analyses of building loads and climates, and numerical models of the economics of solar heating systems are presented. Performance simulations and economic analyses are also outlined for wind and photovoltaic systems, and for industrial solar heating systems. Finally, fundamental studies of corrosion, steam flow, wind loading, and scaling in solar systems are described.

  17. Analysis of radiation induced effects in high-density commercial memories on-board Alsat-1: The impact of extreme solar particle events

    NASA Astrophysics Data System (ADS)

    Bentoutou, Youcef; Bensikaddour, El-Habib

    2015-06-01

    This paper presents a long-term study on radiation effects in non-hardened high density memory devices operating within the main on-board computer system of the Algerian microsatellite Alsat-1 in Low Earth Orbit (LEO). A statistical analysis of single-event upset (SEU) activity is presented for commercial SRAM devices, and their response to extreme solar events shows SEU rate significant increases correlated with high-energy protons (E > 100 MeV). Ground based neutron monitor data are used to illustrate the long-term correlation between galactic cosmic rays and Alsat-1 upsets. The short-term effects of energetic solar particles are illustrated with space environment data from GOES-11. The Alsat-1 observed SEU rates are compared to the predicted rates based on ground test data and environment models. The prediction results are in good agreement with in-flight data.

  18. Hood River Passive House

    SciTech Connect

    Hales, D.

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  19. Hood River Passive House

    SciTech Connect

    Hales, David

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  20. Observation of solar particle event on board a commercial flight from Los Angeles to New York on 29 October 2003

    NASA Astrophysics Data System (ADS)

    Getley, Ian L.

    2004-05-01

    The enhanced radiation associated with solar particle events and in particular the secondary ionization doses created by the neutron flux in the upper atmosphere resulting from both cosmic ray and solar particle interaction with constituents of the atmosphere, pose an additional significant risk to both aircrew and passengers at aircraft altitude. Whilst the elevated x-ray component from a solar flare or coronal mass ejection (CME) can be significant, the effects of large particle events to the secondary radiation environment at jet aircraft cruising altitudes, can have consequences for both people and micro electronics used in modern generation aircraft. It has been shown that dose rates increase with higher latitudes and altitudes, and due to the geomagnetic field effect that deflects incoming solar and galactic cosmic rays, we get greater shielding closer to the equator. Generally increasing latitude appears to have a greater effect on increasing secondary radiation than altitude alone and this is certainly so during a solar flare or solar particle event.

  1. The Radiation Dose at Commercial Aircraft Altitudes During the January 2005 High-Energy Solar Cosmic ray Event and the Effects of the Solar Cosmic ray Anisotropy

    NASA Astrophysics Data System (ADS)

    Smart, D. F.; Shea, M. A.; Friedberg, W.; Copeland, K.; Sauer, H. H.

    2005-12-01

    The radiation dose to aircrews and passengers is a phenomenon of societal interest. There is a requirement to provide alerts whenever the radiation dose exceeds 20 micro-sieverts per hour at flight altitudes. The possibility that this might occur during a large high-energy solar cosmic ray event has resulted in much speculation. During the 20 January 2005 ground-level event the FAA Solar Radiation Alert System would have issued such an alert for aircraft at high latitudes for flight altitudes above 40,000 feet. Analysis of the GOES high-energy proton data results in a predicted dose rate of 23 micro Sv per hour at 60,000 feet for the first hour of the event. We also predict that the maximum peak dose rate would have been higher at the geographical position corresponding to the peak anisotropic flux intensity and would be correspondingly lower at geographical positions receiving a lower high energy solar cosmic ray flux. The solar high-energy flux anisotropy is extremely variable among the observed solar cosmic ray ground-level events. The 20 January 2005 event had one of the most extreme anisotropies yet observed by ground-level cosmic ray neutron monitors. We discuss the effects of this anisotropy with respect to aircraft radiation dose.

  2. Commercial/industrial photovoltaic module and array requirement study. Low-cost solar array project engineering area

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Design requirements for photovoltaic modules and arrays used in commercial and industrial applications were identified. Building codes and referenced standards were reviewed for their applicability to commercial and industrial photovoltaic array installation. Four general installation types were identified - integral (replaces roofing), direct (mounted on top of roofing), stand-off (mounted away from roofing), and rack (for flat or low slope roofs, or ground mounted). Each of the generic mounting types can be used in vertical wall mounting systems. This implies eight mounting types exist in the commercial/industrial sector. Installation costs were developed for these mounting types as a function of panel/module size. Cost drivers were identified. Studies were performed to identify optimum module shapes and sizes and operating voltage cost drivers. The general conclusion is that there are no perceived major obstacles to the use of photovoltaic modules in commercial/industrial arrays.

  3. Passive Accelerometer

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J.; Baugher, Charles; Alexander, Iwan

    1992-01-01

    Motion of ball in liquid indicates acceleration. Passive accelerometer measures small accelerations along cylindrical axis. Principle of operation based on Stokes' law. Provides accurate measurements of small quasi-steady accelerations. Additional advantage, automatically integrates out unwanted higher-frequency components of acceleration.

  4. Small- Geo Solar Array: New Generation Of Solar Arrays For Commercial Telecom Satellites For Power Ranges Between 2,5 KW And 7,5 KW

    NASA Astrophysics Data System (ADS)

    Paarmann, Carola; Muller, Jens; Mende, Thomas; Borner, Carsten; Mascher, Rolf

    2011-10-01

    In the frame of the ESA supported Artes 11 program a new generation of GEO telecommunication satellites is under development. This platform will cover the power range from 2 to 5 kW. ASTRIUM GmbH is contracted to develop and design the Solar Array for this platform. Furthermore the manufacturing and the qualification of a PFM wing for the first flight model is foreseen. The satellite platform, called Small-GEO, is developed under the responsibility of OHB System. This first Small-GEO satellite is designated to be delivered to HISPASAT for operation. The concept of ASTRIUM GmbH is to use all the experiences from the very successful EUROSTAR 2000+, EUROSTAR-3000 and the ALPHABUS platform and to adapt the technologies to the Small- GEO Solar Array. With the benefit of the huge in-orbit heritage of these programs, the remaining risks for the Small-GEO Solar Array can be minimized. The development of the Small-GEO Solar Array extends the ASTRIUM GmbH product portfolio by covering now the complete power range between 2 kW and 31 kW. This paper provides an overview of the different configurations, their main design features and parameters.

  5. Passive fluorescence measurements during SIFLEX

    NASA Astrophysics Data System (ADS)

    Moya, I.; Ounis, A.; Louis, J.; Evain, S.; Ducruet, J.-M.

    band. It was used to complete the measurements of the PMFD instrument. It was installed on a tripod at 2 m above the ground and focused on a small tree in the vicinity of the tower. The instrument was used to explore fluorescence fluxes in correlation with a small lidar (LASERPAM) which measured the stationary fluorescence on the same footprint. In addition to the instrumentation for passive fluorescence measurements two lidar systems (FIPAM &LASERPAM) to better characterise the diurnal cycle of the sun induced fluorescence of the Scott pine forest (see accompanying presentation of Ounis et al. this meeting). A commercial LICOR 6400 IRGA system was also operated for punctual gas exchange measurements. More than 1 Gb of data as been collected which would require several months of work to be correctly evaluated. One original aspect of the campaign was the nature of the target constituted of the crowns of several Scott pines in different planes. The low density of the trees and the distribution of the needles on the volume of the target generated a situation very far for the usual approximation of the "big leaf" of a dense canopy. As a consequence the 760 nm radiation, which is well transmitted and well reflected generated unpredictable variations upon changes of solar radiation. More reliable results seems to be obtained using the 687 nm channel, as a consequence of the strong absorption of this wavelength. A rough examination of the PRI data showed interesting correlation, along the time series with the maximum electron flow of the photosystem II determined by variable fluorescence measurements.

  6. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  7. A commercial hydrogen maser: Progress report

    NASA Technical Reports Server (NTRS)

    Dials, M. A.; Wert, L.

    1983-01-01

    The design of the new small passive hydrogen maser prototype and some anticipated design changes between the version reported and the commercial versions are discussed. Specifications of the commercial hydrogen maser and performance data of the prototype are given.

  8. Impact of Sn(S,Se) secondary phases in Cu2ZnSn(S,Se)4 solar cells: a chemical route for their selective removal and absorber surface passivation.

    PubMed

    Xie, Haibing; Sánchez, Yudania; López-Marino, Simón; Espíndola-Rodríguez, Moisés; Neuschitzer, Markus; Sylla, Diouldé; Fairbrother, Andrew; Izquierdo-Roca, Victor; Pérez-Rodríguez, Alejandro; Saucedo, Edgardo

    2014-08-13

    The control and removal of secondary phases is one of the major challenges for the development of Cu2ZnSn(S,Se)4 (CZTSSe)-based solar cells. Although etching processes have been developed for Cu(S,Se), Zn(S,Se), and CuSn(S,Se) secondary phases, so far very little attention has been given to the role of Sn(S,Se). In this paper, we report a chemical route using a yellow (NH4)2S solution to effectively remove Sn(S,Se). We found that Sn(S,Se) can form on the surface either because of stoichiometric deviation or by condensation. After etching, the efficiency of devices typically increases between 20 and 65% relative to the before etch efficiencies. We achieved a maximum 5.9% efficiency in Se-rich CZTSSe-based devices. It is confirmed that this feature is related not only to the removal of Sn(S,Se) but also to the unexpected passivation of the surface. We propose a phenomenological model for this passivation, which may open new perspectives for the development of CZTSSe-based solar cells. PMID:25033026

  9. Solar flair.

    PubMed Central

    Manuel, John S

    2003-01-01

    Design innovations and government-sponsored financial incentives are making solar energy increasingly attractive to homeowners and institutional customers such as school districts. In particular, the passive solar design concept of daylighting is gaining favor among educators due to evidence of improved performance by students working in daylit classrooms. Electricity-generating photovoltaic systems are also becoming more popular, especially in states such as California that have high electric rates and frequent power shortages. To help spread the word about solar power, the U.S. Department of Energy staged its first-ever Solar Decathlon in October 2002. This event featured solar-savvy homes designed by 14 college teams. PMID:12573926

  10. Solar flair.

    PubMed

    Manuel, John S

    2003-02-01

    Design innovations and government-sponsored financial incentives are making solar energy increasingly attractive to homeowners and institutional customers such as school districts. In particular, the passive solar design concept of daylighting is gaining favor among educators due to evidence of improved performance by students working in daylit classrooms. Electricity-generating photovoltaic systems are also becoming more popular, especially in states such as California that have high electric rates and frequent power shortages. To help spread the word about solar power, the U.S. Department of Energy staged its first-ever Solar Decathlon in October 2002. This event featured solar-savvy homes designed by 14 college teams. PMID:12573926

  11. Investigation of the stability and 1.0 MeV proton radiation resistance of commercially produced hydrogenated amorphous silicon alloy solar cells

    NASA Technical Reports Server (NTRS)

    Lord, Kenneth R., II; Walters, Michael R.; Woodyard, James R.

    1994-01-01

    The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys is reported. A number of different device structures were irradiated with 1.0 MeV protons. The cells were annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters or fluences below 1(exp 14) cm(exp -2); fluences above 1(exp 14) cm(exp -2) require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed in dark I-V measurements. The current mechanisms were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

  12. Investigation of the Stability and 1.0 MeV Proton Radiation Resistance of Commercially Produced Hydrogenated Amorphous Silicon Alloy Solar Cells

    NASA Technical Reports Server (NTRS)

    Lord, Kenneth R., II; Walters, Michael R.; Woodyard, James R.

    1994-01-01

    The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys is reported. A number of different device structures were irradiated with 1.0 MeV protons. The cells were insensitive to proton fluences below 1E12 sq cm. The parameters of the irradiated cells were restored with annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters for fluences below 1E14 sq cm fluences above 1E14 sq cm require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed In dark I-V measurements. The current mechanism were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

  13. Solar still. Final report

    SciTech Connect

    Adams, W.D.

    1983-07-20

    Passive solar heating was used in a still in which a packed column packed with popped popcorn separates the alcohol and water vapors. The still's performance was not satisfactory, and it is concluded that passive solar heating could have been better used to preheat makeup water for the fermentation process and to maintain proper fermentation temperatures during the winter. (LEW)

  14. Removal of arsenic from contaminated groundwater by solar-driven membrane distillation using three different commercial membranes.

    PubMed

    Pal, Parimal; Manna, Ajay K

    2010-11-01

    Investigations on solar-driven membrane distillation (SDMD) were carried out for removal of arsenic from contaminated groundwater. Three different types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polypropylene (PP) with surface area of 120 × 10(-4)m(2) were used as flat sheet in a direct contact membrane distillation (DCMD) set up in a cross flow module. Effects of initial arsenic concentration in the feed, feed velocity, feed temperature and distillate inlet temperature on arsenic removal efficiency and flux were studied where temperatures of feed and distillate were found to have significant effect on the flux. Almost 100% arsenic separation was achieved without wetting membrane pore even after 120 h of operation. The PTFE membrane with a flux of 49.80 kg/m(2)h was found to the best one out of the tested membranes. The study shows that solar-driven DCMD can effectively separate arsenic from groundwater using a cross flow membrane module with PTFE hydrophobic membrane. PMID:20579681

  15. Non-Hardware ("Soft") Cost-Reduction Roadmap for Residential and Small Commercial Solar Photovoltaics, 2013-2020

    SciTech Connect

    Ardani, K.; Seif, D.; Margolis, R.; Morris, J.; Davidson, C.; Truitt, S.; Torbert, R.

    2013-08-01

    The objective of this analysis is to roadmap the cost reductions and innovations necessary to achieve the U.S. Department of Energy (DOE) SunShot Initiative's total soft-cost targets by 2020. The roadmap focuses on advances in four soft-cost areas: (1) customer acquisition; (2) permitting, inspection, and interconnection (PII); (3) installation labor; and (4) financing. Financing cost reductions are in terms of the weighted average cost of capital (WACC) for financing PV system installations, with real-percent targets of 3.0% (residential) and 3.4% (commercial).

  16. Environmental and Economic Performance of Commercial-scale Solar Photovoltaic Systems: A Field Study of Complex Energy Systems at the Desert Research Institute (DRI)

    NASA Astrophysics Data System (ADS)

    Liu, X.

    2014-12-01

    Solar photovoltaic (PV) systems are being aggressively deployed at residential, commercial, and utility scales to complement power generation from conventional sources. This is motivated both by the desire to reduce carbon footprints and by policy-driven financial incentives. Although several life cycle analyses (LCA) have investigated environmental impacts and energy payback times of solar PV systems, most results are based on hypothetical systems rather than actual, deployed systems that can provide measured performance data. Over the past five years, Desert Research Institute (DRI) in Nevada has installed eight solar PV systems of scales from 3 to 1000 kW, the sum of which supply approximately 40% of the total power use at DRI's Reno and Las Vegas campuses. The goal of this work is to explore greenhouse gas (GHG) impacts and examine the economic performance of DRI's PV systems by developing and applying a comprehensive LCA and techno-economic (TEA) model. This model is built using data appropriate for each type of panel used in the DRI systems. Power output is modeled using the National Renewable Energy Laboratory (NREL) model PVWatts. The performance of PVWatts is verified by the actual measurements from DRI's PV systems. Several environmental and economic metrics are quantified for the DRI systems, including life cycle GHG emissions and energy return. GHG results are compared with Nevada grid-based electricity. Initial results indicate that DRI's solar-derived electricity offers clear GHG benefits compared to conventional grid electricity. DRI's eight systems have GHG intensity values of 29-56 gCO2e/kWh, as compared to the GHG intensity of 212 gCO2e/kWh of national average grid power. The major source of impacts (82-92% of the total) is the upstream life cycle burden of manufacturing PV panels, which are made of either mono-crystalline or multi-crystalline silicon. Given the same type of PV panel, GHG intensity decreases as the scale of the system increases

  17. The Trade-off between Solar Reflectance and Above-Sheathing Ventilation for Metal Roofs on Residential and Commercial Buildings

    SciTech Connect

    Desjarlais, Andre Omer; Kriner, Scott; Miller, William A

    2013-01-01

    An alternative to white and cool-color roofs that meets prescriptive requirements for steep-slope (residential and non-residential) and low-slope (non-residential) roofing has been documented. Roofs fitted with an inclined air space above the sheathing (herein termed above-sheathing ventilation, or ASV), performed as well as if not better than high-reflectance, high-emittance roofs fastened directly to the deck. Field measurements demonstrated the benefit of roofs designed with ASV. A computer tool was benchmarked against the field data. Testing and benchmarks were conducted at roofs inclined at 18.34 ; the roof span from soffit to ridge was 18.7 ft (5.7 m). The tool was then exercised to compute the solar reflectance needed by a roof equipped with ASV to exhibit the same annual cooling load as that for a direct-to-deck cool-color roof. A painted metal roof with an air space height of 0.75 in. (0.019 m) and spanning 18.7 ft (5.7 m) up the roof incline of 18.34 needed only a 0.10 solar reflectance to exhibit the same annual cooling load as a direct-to-deck cool-color metal roof (solar reflectance of 0.25). This held for all eight ASHRAE climate zones complying with ASHRAE 90.1 (2007a). A dark heat-absorbing roof fitted with 1.5 in. (0.038 m) air space spanning 18.7 ft (5.7 m) and inclined at 18.34 was shown to have a seasonal cooling load equivalent to that of a conventional direct-to-deck cool-color metal roof. Computations for retrofit application based on ASHRAE 90.1 (1980) showed that ASV air spaces of either 0.75 or 1.5 in. (0.019 and 0.038 m) would permit black roofs to have annual cooling loads equivalent to the direct-to-deck cool roof. Results are encouraging, and a parametric study of roof slope and ASV aspect ratio is needed for developing guidelines applicable to all steep- and low-slope roof applications.

  18. Solar home on the range

    SciTech Connect

    Wainwright, K.

    1999-10-01

    Solar technologies and indigenous materials are used in this remote Texas ranch house. Passive solar, thermal mass of adobe walls, photovoltaics, wood stoves, native stone, a ventilated roof, reflective barrier, and porch overhangs surrounding the house combine to keep the house comfortable all summer. The PV system used a passive solar tracking system that increased the electrical output by an overall 29 percent.

  19. Low temperature solar furnace and method

    SciTech Connect

    Keller, R.R.

    1982-07-13

    This disclosure generally relates to a technique and apparatus for solar heating which may be adapted for heating residential, commercial or industrial buildings, and in which the functions of solar energy collection, storage and heat-exchange are combined in the same passive structure generally consisting of a plurality of cylindrical tubes preferably fabricated of glass-fiber reinforced polyester resin which are filled with a stationary heat absorbing medium, such as water, with their surfaces preferably coated with a high absorptance material on to which solar rays are directed through a solar ''transmittor'' or window , and which surfaces serve as heat-exchange elements from which heat may be extracted in a variety of ways, including passage of air and thermal siphoning, and with the tubes enclosed within an appropriate insulated chamber. Cooperative action with domestic or similar hot water systems may also be achieved.

  20. Low temperature solar furnace and method

    SciTech Connect

    Keller, R.R.

    1982-10-12

    This disclosure generally relates to a technique and apparatus for solar heating which may be adapted for heating residential, commercial or industrial buildings, and in which the functions of solar energy collection, storage and heat-exchange are combined in the same passive structure generally consisting of a plurality of cylindrical tubes preferably fabricated of glass-fiber reinforced polyester resin which are filled with a stationary heat absorbing medium, such as water, with their surfaces preferably coated with a high absorbtance material on to which solar rays are directed through a solar ''transmittor'' or window , and which surfaces serve as heat-exchange elements from which heat may be extracted in a variety of ways, including passage of air and thermal siphoning, and with the tubes enclosed within an appropriate insulated chamber. Cooperative action with domestic or similar hot water systems may also be achieved.

  1. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Final report, June 15, 1984--December 31, 1987

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-12-31

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  2. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys. Final report, June 15, 1984--December 31, 1987

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-12-31

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  3. Sunspot Time Series: Passive and Active Intervals

    NASA Astrophysics Data System (ADS)

    Zięba, S.; Nieckarz, Z.

    2014-07-01

    Solar activity slowly and irregularly decreases from the first spotless day (FSD) in the declining phase of the old sunspot cycle and systematically, but also in an irregular way, increases to the new cycle maximum after the last spotless day (LSD). The time interval between the first and the last spotless day can be called the passive interval (PI), while the time interval from the last spotless day to the first one after the new cycle maximum is the related active interval (AI). Minima of solar cycles are inside PIs, while maxima are inside AIs. In this article, we study the properties of passive and active intervals to determine the relation between them. We have found that some properties of PIs, and related AIs, differ significantly between two group of solar cycles; this has allowed us to classify Cycles 8 - 15 as passive cycles, and Cycles 17 - 23 as active ones. We conclude that the solar activity in the PI declining phase (a descending phase of the previous cycle) determines the strength of the approaching maximum in the case of active cycles, while the activity of the PI rising phase (a phase of the ongoing cycle early growth) determines the strength of passive cycles. This can have implications for solar dynamo models. Our approach indicates the important role of solar activity during the declining and the rising phases of the solar-cycle minimum.

  4. Improvement in passivation quality and open-circuit voltage in silicon heterojunction solar cells by the catalytic doping of phosphorus atoms

    NASA Astrophysics Data System (ADS)

    Tsuzaki, Shogo; Ohdaira, Keisuke; Oikawa, Takafumi; Koyama, Koichi; Matsumura, Hideki

    2015-07-01

    We apply phosphorus (P) doping to amorphous silicon (a-Si)/crystalline silicon (c-Si) heterojunction solar cells realized by exposing c-Si to P-related radicals generated by the catalytic cracking of PH3 molecules (Cat-doping). An ultrathin n+-layer formed by P Cat-doping acts to improve the effective minority carrier lifetime (τeff) and implied open-circuit voltage (implied Voc) owing to its field effect by which minority holes are sent back from an a-Si/c-Si interface. An a-Si/c-Si heterojunction solar cell with a P Cat-doped layer shows better solar cell performance, particularly in Voc, than the cell without P Cat-doping. This result demonstrates the feasibility of applying Cat-doping to a-Si/c-Si heterojunction solar cells, owing to the advantage of the low-temperature (<200 °C) process of Cat-doping.

  5. Trade-off between Zr Passivation and Sn Doping on Hematite Nanorod Photoanodes for Efficient Solar Water Oxidation: Effects of a ZrO2 Underlayer and FTO Deformation.

    PubMed

    Subramanian, Arunprabaharan; Annamalai, Alagappan; Lee, Hyun Hwi; Choi, Sun Hee; Ryu, Jungho; Park, Jung Hee; Jang, Jum Suk

    2016-08-01

    Herein we report the influence of a ZrO2 underlayer on the PEC (photoelectrochemical) behavior of hematite nanorod photoanodes for efficient solar water splitting. Particular attention was given to the cathodic shift in onset potential and photocurrent enhancement. Akaganite (β-FeOOH) nanorods were grown on ZrO2-coated FTO (fluorine-doped tin oxide) substrates. Sintering at 800 °C transformed akaganite to the hematite (α-Fe2O3) phase and induced Sn diffusion into the crystal structure of hematite nanorods from the FTO substrates and surface migration, shallow doping of Zr atoms from the ZrO2 underlayer. The ZrO2 underlayer-treated photoanode showed better water oxidation performance compared to the pristine (α-Fe2O3) photoanode. A cathodic shift in the onset potential and photocurrent enhancement was achieved by surface passivation and shallow doping of Zr from the ZrO2 underlayer, along with Sn doping from the FTO substrate to the crystal lattice of hematite nanorods. The Zr based hematite nanorod photoanode achieved 1 mA/cm(2) at 1.23 VRHE with a low turn-on voltage of 0.80 VRHE. Sn doping and Zr passivation, as well as shallow doping, were confirmed by XPS, Iph, and M-S plot analyses. Electrochemical impedance spectroscopy revealed that the presence of a ZrO2 underlayer decreased the deformation of FTO substrate, improved electron transfer at the hematite/FTO interface and increased charge-transfer resistance at the electrolyte/hematite interface. This is the first systematic investigation of the effects of Zr passivation, shallow doping, and Sn doping on hematite nanorod photoanodes through application of a ZrO2 underlayer on the FTO substrate. PMID:27420603

  6. Passive field reflectance measurements

    NASA Astrophysics Data System (ADS)

    Weber, Christian; Schinca, Daniel C.; Tocho, Jorge O.; Videla, Fabian

    2008-10-01

    The results of reflectance measurements performed with a three-band passive radiometer with independent channels for solar irradiance reference are presented. Comparative operation between the traditional method that uses downward-looking field and reference white panel measurements and the new approach involving duplicated downward- and upward-looking spectral channels (each latter one with its own diffuser) is analyzed. The results indicate that the latter method performs in very good agreement with the standard method and is more suitable for passive sensors under rapidly changing atmospheric conditions (such as clouds, dust, mist, smog and other scatterers), since a more reliable synchronous recording of reference and incident light is achieved. Besides, having separate channels for the reference and the signal allows a better balancing of gains in the amplifiers for each spectral channel. We show the results obtained in the determination of the normalized difference vegetation index (NDVI) corresponding to the period 2004-2007 field experiments concerning weed detection in soybean stubbles and fertilizer level assessment in wheat. The method may be used to refine sensor-based nitrogen fertilizer rate recommendations and to determine suitable zones for herbicide applications.

  7. Passivation of defect states in surface and edge regions on pn-junction Si solar cells by use of hydrogen cyanide solutions

    NASA Astrophysics Data System (ADS)

    Takahashi, Masao; Shishido, Takeru; Iwasa, Hitoo; Kobayashi, Hikaru

    2009-06-01

    The local photovoltage of the pn-junction single-crystalline silicon solar cells observed by spot light scanning gradually decreases in the vicinity of edges. The energy conversion efficiency is increased by shadowing the edge regions where the local photovoltage is lower, showing that the defect density is high in the edge regions. From the analysis of the local photovoltage, the spacial distribution of defect states is obtained. The cyanide method, i. e., immersion of solar cells in HCN solutions at room temperature, increases the local photovoltage and increases the energy conversion efficiency.

  8. Design, testing, and commercialization plans for the SAIC/STM 20 kW{sub e} solar dish/Stirling system

    SciTech Connect

    Beninga, K.J.; Davenport, R.L.; Johansson, S.N.

    1995-12-31

    As a part of the US Department of Energy`s (DOE) Utility-Scale Joint-Venture Program, Science Applications International Corporation (SAIC) and Stirling Thermal Motors (STM) have teamed to produce a solar dish/Stirling system for utility electricity generation. The 90 m{sup 2} dish concentrator consists of 16 stretched membrane mirror facets on a truss structure with an azimuth/elevation gear drive. The design modifies a faceted stretched membrane dish design developed previously by SAIC and WGA, Inc. in order to simplify the structure and reduce manufacturing costs, The Stirling engine used in the system is the STM 4-120 kinematic Stirling engine. It features variable swash plate control and a direct absorption solar receiver with hydrogen as the operating fluid. A prototype dish/Stirling system has been installed at a test site near Golden, Colorado and is now undergoing tests. The optical and thermal performance of the dish is being characterized using a Coldwater calorimeter and the optical Beam Characterization System (BCS) developed by Sandia National Labs in Albuquerque, New Mexico. After completion of the dish characterization tests, the STM engine will be installed on the dish and system power generation and efficiency will be measured. This paper presents a summary of the SAIC/STM dish/Stirling system design and gives results from initial testing of the system. Also described are SAIC`s plans for manufacturing and commercialization of the dish/Stirling system to utilities and other markets in the US and abroad.

  9. Hydrogen passivation of silicon nanowire structures

    NASA Astrophysics Data System (ADS)

    Aouida, S.; Benabderrahmane Zaghouani, R.; Bachtouli, N.; Bessais, B.

    2016-05-01

    In this work, we focus on hydrogen passivation of silicon nanowire structures (SiNWs) obtained by metal assisted chemical etching (MACE) intended to be used in silicon-based solar cells. SiNWs present high surface defects density causing the minority carrier lifetime reduction. Our results show that hydrogen passivation of SiNWs ameliorates minority carrier lifetime by reducing the dangling bonds and then the surface recombination velocity. This enhancement is limited by SiNWs distribution.

  10. Evaluation of Alternate Stainless Steel Surface Passivation Methods

    SciTech Connect

    Clark, Elliot A.

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  11. The Class C Passive Performance Evaluation Program

    NASA Astrophysics Data System (ADS)

    1981-09-01

    The Class-C performance which provides information on qualities of passive solar features which make them attractive to buyers was evaluated. The following topics are discussed: design of an audit form; design of regionally specific audit addenda; determination of site selection criteria; identification of sites; selection, training, and management of auditors; and packaging of materials of subcontractors for evaluation. Results and findings are presented as follows: demographic profile, passive solar home profile, cost, financing, and payback considerations, expectations, realizations, and satisfaction, and decisionmaking.

  12. Investigation of anodic and chemical oxides grown on p-type InP with applications to surface passivation for n(+)-p solar cell fabrication

    NASA Technical Reports Server (NTRS)

    Faur, Maria; Faur, Mircea; Goradia, Manju; Goradia, Chandra; Jenkins, Phillip; Jayne, Douglas; Weinberg, Irving

    1991-01-01

    Most of the previously reported InP anodic oxides were grown on a n-type InP with applications to fabrication of MISFET structures and were described as a mixture of In2O3 and P2O5 stoichiometric compounds or nonstoichiometric phases which have properties similar to crystalline compounds In(OH)3, InPO4, and In(PO3)3. Details of the compositional change of the anodic oxides grown under different anodization conditions were previously reported. The use of P-rich oxides grown either by anodic or chemical oxidation are investigated for surface passivation of p-type InP and as a protective cap during junction formation by closed-ampoule sulfur diffusion. The investigation is based on but not limited to correlations between PL intensity and X-ray photoelectron spectroscopy (XPS) chemical composition data.

  13. Fundamental studies of passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed point defects models'' (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies.

  14. Active-passive airborne ocean color measurement. II - Applications

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.; Yungel, J. K.

    1986-01-01

    Reported here for the first time is the use of a single airborne instrument to make concurrent measurements of oceanic chlorophyll concentration by (1) laser-induced fluorescence, (2) passive upwelling radiance, and (3) solar-induced chlorophyll fluorescence. Results from field experiments conducted with the NASA airborne oceanographic lidar (AOL) in the New York Bight demonstrate the capability of a single active-passive instrument to perform new and potentially important ocean color studies related to (1) active lidar validation of passive ocean color in-water algorithms, (2) chlorophyll a in vivo fluorescence yield variability, (3) calibration of active multichannel lidar systems, (4) effect of sea state on passive and active ocean color measurements, (5) laser/solar-induced chlorophyll fluorescence investigations, and (6) subsequent improvement of satellite-borne ocean color scanners. For validation and comparison purposes a separate passive ocean color sensor was also flown along with the new active-passive sensor during these initial field trials.

  15. Damp and dry heat degradation of thermal oxide passivation of p+ silicon

    NASA Astrophysics Data System (ADS)

    Thomson, Andrew; Gardner, Matthew; McIntosh, Keith; Shalav, Avi; Bullock, James

    2014-03-01

    Thermal SiO2 passivates both moderately and heavily doped silicon surfaces irrespective of the dopant type, which is advantageous in high-efficiency solar cell designs. Commercial photovoltaic cells are submitted to accelerated ageing tests, such as damp-heat exposure, to ensure they maintain their performance for at least 20 yr. We find damp-heat exposure causes a severe and rapid degradation of thermal SiO2 passivation on p+ silicon surfaces. The reaction is so severe that the diffused-region recombination in the degraded state is limited by the diffusion of minority carriers to the Si-SiO2 interface not the density of interface defects Dit. Certainly, this effect renders the thermal-oxide passivation useless if employed on a solar cell. To study the cause of the degradation, we also test the effects of storage in dry heat and room ambient conditions. Examination of the rate of degradation in the tested storage conditions in comparison with modelled diffusion of moisture in SiO2, we find a significant correlation between the time dependent J0e and moisture supplied to the interface, leading us to the conclusion that moisture ingression and subsequent reaction at the SiO2-Si interface are the cause of both damp-heat and room- ambient degradation.

  16. Solar Meter

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The instrument pictured is an inexpensive solar meter which is finding wide acceptance among architects, engineers and others engaged in construction of solar energy facilities. It detects the amount of solar energy available at a building site, information necessary to design the most efficient type of solar system for a particular location. Incorporating technology developed by NASA's Lewis Research Center, the device is based upon the solar cell, which provides power for spacecraft by converting the sun's energy to electricity. The meter is produced by Dodge Products, Inc., Houston, Texas, a company formed to bring the technology to the commercial marketplace.

  17. Land use and environmental impacts of decentralized solar energy use

    SciTech Connect

    Twiss, R.H.; Smith, P.L.; Gatzke, A.E.; McCreary, S.T.

    1980-01-01

    The physical, spatial and land-use impacts of decentralized solar technologies applied at the community level by the year 2000 are examined. The results of the study are intended to provide a basis for evaluating the way in which a shift toward reliance on decentralized energy technologies may eventually alter community form. Six land-use types representative of those found in most US cities are analyzed according to solar penetration levels identified in the maximum solar scenario for the year 2000. The scenario is translated into shares of end use demand in the residential, commercial and industrial sectors. These proportions become the scenario goals to be met by the use of decentralized solar energy systems. The percentage of total energy demand is assumed to be 36.5 percent, 18.8 percent and 22.6 percent in the residential, commercial and industrial sectors respectively. The community level scenario stipulated that a certain percentage of the total demand be met by on-site solar collection, i.e. photovoltaic and thermal collectors, and by passive design. This on-site solar goal is 31.9 percent (residential), 16.8 percent (commercial) and 13.1 percent (industrial).

  18. Fundamental studies on passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1993-06-01

    Using photoelectrochemical impedance and admittance spectroscopies, a fundamental and quantitative understanding of the mechanisms for the growth and breakdown of passive films on metal and alloy surfaces in contact with aqueous environments is being developed. A point defect model has been extended to explain the breakdown of passive films, leading to pitting and crack growth and thus development of damage due to localized corrosion.

  19. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    ERIC Educational Resources Information Center

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  20. Cooling by means of passively grown ice

    SciTech Connect

    Gorski, A.; Schertz, W.; Wantroba, A.; Rush, R.; Falkenberg, J.

    1981-01-01

    A solar cooling technique is described that uses ice passively-grown the previous winter. Using heat pipes (thermal syphons), ice is grown and stored in the same container ready for the coming cooling season. This modern adaption of an old cooling technique may have side application both in this country as well as in more northern regions.

  1. Credible evidence for the passivation effect of remnant PbI2 in CH3NH3PbI3 films in improving the performance of perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Shimao; Dong, Weiwei; Fang, Xiaodong; Zhang, Qingli; Zhou, Shu; Deng, Zanhong; Tao, Ruhua; Shao, Jingzhen; Xia, Rui; Song, Chao; Hu, Linhua; Zhu, Jun

    2016-03-01

    The role of remnant PbI2 in CH3NH3PbI3 films is still controversial, some investigations have revealed that the remnant PbI2 plays a passivation role, reduces the charge recombination in perovskite solar cells (PSCs), and improves the performance of PSCs, but the opposing views state that remnant PbI2 has no passivation effect and it would deteriorate the stability of the devices. In our investigation, the CH3NH3PbI3 films have been prepared by a two-step spin-coating method and the content of the remnant PbI2 in CH3NH3PbI3 films has been tuned by varying the preparation temperature. It has been found that increasing the heating temperature could increase the coverage of spin-coated PbI2 films, which has led to high coverage CH3NH3PbI3 films and more remnant PbI2 in CH3NH3PbI3 films, and as a result, the performance of PSCs was enhanced obviously and the maximum power conversion efficiency of 14.32 +/- 0.28% was achieved by the PSCs prepared at 130/120 °C (PbI2 films were heated at 130 °C and CH3NH3PbI3 films were heated at 120 °C). Furthermore, the dark current, electrochemical impedance spectroscopy and time-resolved fluorescence emission decay measurements revealed that the charge recombination in PSCs has been gradually suppressed and the fluorescence emission lifetime has gradually increased with the content of remnant PbI2 increasing. Thus, the passivation effects of the unreacted and decomposed PbI2 in improving the performance of PSCs have been confirmed unquestionably.The role of remnant PbI2 in CH3NH3PbI3 films is still controversial, some investigations have revealed that the remnant PbI2 plays a passivation role, reduces the charge recombination in perovskite solar cells (PSCs), and improves the performance of PSCs, but the opposing views state that remnant PbI2 has no passivation effect and it would deteriorate the stability of the devices. In our investigation, the CH3NH3PbI3 films have been prepared by a two-step spin-coating method and the

  2. Passive Safety Features for Small Modular Reactors

    SciTech Connect

    Ingersoll, Daniel T

    2010-01-01

    The rapid growth in the size and complexity of commercial nuclear power plants in the 1970s spawned an interest in smaller, simpler designs that are inherently or intrinsically safe through the use of passive design features. Several designs were developed, but none were ever built, although some of their passive safety features were incorporated into large commercial plant designs that are being planned or built today. In recent years, several reactor vendors are actively redeveloping small modular reactor (SMR) designs with even greater use of passive features. Several designs incorporate the ultimate in passive safety they completely eliminate specific accident initiators from the design. Other design features help to reduce the likelihood of an accident or help to mitigate the accident s consequences, should one occur. While some passive safety features are common to most SMR designs, irrespective of the coolant technology, other features are specific to water, gas, or liquid-metal cooled SMR designs. The extensive use of passive safety features in SMRs promise to make these plants highly robust, protecting both the general public and the owner/investor. Once demonstrated, these plants should allow nuclear power to be used confidently for a broader range of customers and applications than will be possible with large plants alone.

  3. Commercialization of parabolic dish systems

    NASA Technical Reports Server (NTRS)

    Washom, B.

    1982-01-01

    The impact of recent federal tax and regulatory legislation on the commercialization of parabolic solar reflector technology is assessed. Specific areas in need of technical or economic improvement are noted.

  4. Commercialization of parabolic dish systems

    NASA Astrophysics Data System (ADS)

    Washom, B.

    1982-07-01

    The impact of recent federal tax and regulatory legislation on the commercialization of parabolic solar reflector technology is assessed. Specific areas in need of technical or economic improvement are noted.

  5. Tropospheric Passive Remote Sensing

    NASA Technical Reports Server (NTRS)

    Keafer, L. S., Jr. (Editor)

    1982-01-01

    The long term role of airborne/spaceborne passive remote sensing systems for tropospheric air quality research and the identification of technology advances required to improve the performance of passive remote sensing systems were discussed.

  6. Passive storage technologies

    NASA Astrophysics Data System (ADS)

    Kittel, P.

    1984-04-01

    Advances in storage technology and how passive techniques could be applied to the storage of propellants at the space station are described. The devices considered are passive orbital disconnect struts, cooled shield optimization, liftweight shields and catalytic converters.

  7. Passive storage technologies

    NASA Technical Reports Server (NTRS)

    Kittel, P.

    1984-01-01

    Advances in storage technology and how passive techniques could be applied to the storage of propellants at the space station are described. The devices considered are passive orbital disconnect struts, cooled shield optimization, liftweight shields and catalytic converters.

  8. Interlanguage Passive Construction

    ERIC Educational Resources Information Center

    Simargool, Nirada

    2008-01-01

    Because the appearance of the passive construction varies cross linguistically, differences exist in the interlanguage (IL) passives attempted by learners of English. One such difference is the widely studied IL pseudo passive, as in "*new cars must keep inside" produced by Chinese speakers. The belief that this is a reflection of L1 language…

  9. Passive Baited Sequential Filth Fly Trap

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted cone design to passively confi...

  10. Cloud Liquid Water Path Comparisons from Passive Microwave and Solar Reflectance Satellite Measurements: Assessment of Sub-Field-of-View Cloud Effects in Microwave Retrievals

    NASA Technical Reports Server (NTRS)

    Greenwald, Thomas J.; Christopher, Sundar A.; Chou, Joyce

    1997-01-01

    Satellite observations of the cloud liquid water path (LWP) are compared from special sensor microwave imager (SSM/I) measurements and GOES 8 imager solar reflectance (SR) measurements to ascertain the impact of sub-field-of-view (FOV) cloud effects on SSM/I 37 GHz retrievals. The SR retrievals also incorporate estimates of the cloud droplet effective radius derived from the GOES 8 3.9-micron channel. The comparisons consist of simultaneous collocated and full-resolution measurements and are limited to nonprecipitating marine stratocumulus in the eastern Pacific for two days in October 1995. The retrievals from these independent methods are consistent for overcast SSM/I FOVS, with RMS differences as low as 0.030 kg/sq m, although biases exist for clouds with more open spatial structure, where the RMS differences increase to 0.039 kg/sq m. For broken cloudiness within the SSM/I FOV the average beam-filling error (BFE) in the microwave retrievals is found to be about 22% (average cloud amount of 73%). This systematic error is comparable with the average random errors in the microwave retrievals. However, even larger BFEs can be expected for individual FOVs and for regions with less cloudiness. By scaling the microwave retrievals by the cloud amount within the FOV, the systematic BFE can be significantly reduced but with increased RMS differences of O.046-0.058 kg/sq m when compared to the SR retrievals. The beam-filling effects reported here are significant and are expected to impact directly upon studies that use instantaneous SSM/I measurements of cloud LWP, such as cloud classification studies and validation studies involving surface-based or in situ data.

  11. Modeling the photocatalytic mineralization in water of commercial formulation of estrogens 17-β estradiol (E2) and nomegestrol acetate in contraceptive pills in a solar powered compound parabolic collector.

    PubMed

    Colina-Márquez, José; Machuca-Martínez, Fiderman; Li Puma, Gianluca

    2015-01-01

    Endocrine disruptors in water are contaminants of emerging concern due to the potential risks they pose to the environment and to the aquatic ecosystems. In this study, a solar photocatalytic treatment process in a pilot-scale compound parabolic collector (CPC) was used to remove commercial estradiol formulations (17-β estradiol and nomegestrol acetate) from water. Photolysis alone degraded up to 50% of estradiol and removed 11% of the total organic carbon (TOC). In contrast, solar photocatalysis degraded up to 57% of estrogens and the TOC removal was 31%, with 0.6 g/L of catalyst load (TiO2 Aeroxide P-25) and 213.6 ppm of TOC as initial concentration of the commercial estradiols formulation. The adsorption of estrogens over the catalyst was insignificant and was modeled by the Langmuir isotherm. The TOC removal via photocatalysis in the photoreactor was modeled considering the reactor fluid-dynamics, the radiation field, the estrogens mass balance, and a modified Langmuir-Hinshelwood rate law, that was expressed in terms of the rate of photon adsorption. The optimum removal of the estrogens and TOC was achieved at a catalyst concentration of 0.4 g/L in 29 mm diameter tubular CPC reactors which approached the optimum catalyst concentration and optical thickness determined from the modeling of the absorption of solar radiation in the CPC, by the six-flux absorption-scattering model (SFM). PMID:26205059

  12. Comparison Between Research-Grade and Commercially Available SnO2 for Thin-Film CdTe Solar Cells: Preprint

    SciTech Connect

    Li, X.; Pankow, J.; To, B.; Gessert, T.

    2008-05-01

    Compared to commercial SnO2 (with similar film thickness and sheet resistance), research-grade SnO2 has higher optical transmittance and higher electron mobility. Based on our study, changing the glass substrate and improving the SnO2 quality could improve the optical properties of commercial SnO2.

  13. Renewable energy technologies for federal facilities: Solar water heating

    SciTech Connect

    1996-05-01

    This sheet presents information on solar water heaters (passive and active), solar collectors (flat plate, evacuated tube, parabolic trough), lists opportunities for use of solar water heating, and describes what is required and the costs. Important terms are defined.

  14. Performance evaluation of a refrigerant-charged thermosyphon solar DHW system

    SciTech Connect

    Farrington, R.; DeAngelis, M.; Morrison, L.; Dougherty, D.

    1981-04-01

    Refrigerant-charged passive solar domestic hot water (SDHW) systems, which have recently become commercially available, are generating great interest in the solar community. These systems, which can be installed even in freezing climates, may achieve the high performance and reliability of direct thermosyphon systems. The Solar Energy Research Institute (SERI) is testing and analyzing a promixing prototype refrigerant-charged thermosyphon system; SERI also plans to evaluate a commercially available system. The prototype was installed in a single-family residence using a stabilized R-11 as the heat transfer fluid. A system analysis was performed based on measured data. The analysis method and preliminary results, which indicate that there is reason to be optimistic about this type of system are discussed.

  15. Solar Heating And Cooling (SHAC) simulation programs: Assessment and evaluation. Volume 1: Summary report

    NASA Astrophysics Data System (ADS)

    Merriam, R. L.

    1981-05-01

    Solar heating and cooling system simulation programs available to use by electric utilities was evaluated. A comprehensive reference manual describing the characteristics of computer programs and manual methods was developed. An analysis of the intended capabilities of 11 programs is carried out. The programs are described and ranked by application. Four programs (AXCESS, DEROB, EMPSS, TRNSYS) for three building types (residential, light commercial, and heavy commercial) and three heating and cooling system classes (conventional, active solar, passive solar are tested. The results are compared and related to the program analytical bases. The user experience encountered during the program testing is highlighted and the user related factors for the four programs are compared. The applicability of the 11 programs to utilities is explored. DOE

  16. Solar Energy: Uses for Your Home. The CIRcular: Consumer Information Report 15.

    ERIC Educational Resources Information Center

    Bank of America NT & SA, San Francisco, CA.

    This report defines active and passive solar energy systems, describes home uses for solar energy, and offers guidelines for choosing and installing a system. Much of the information is specific to the state of California. Uses for solar energy which are presented include passive space heating, passive cooling, active space heating, household…

  17. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F.

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  18. Passive environmental temperature control system

    DOEpatents

    Corliss, John M.; Stickford, George H.

    1981-01-01

    Passive environmental heating and cooling systems are described, which utilize heat pipes to transmit heat to or from a thermal reservoir. In a solar heating system, a heat pipe is utilized to carry heat from a solar heat absorber plate that receives sunlight, through a thermal insulation barrier, to a heat storage wall, with the outer end of the pipe which is in contact with the solar absorber being lower than the inner end. The inclining of the heat pipe assures that the portion of working fluid, such as Freon, which is in a liquid phase will fall by gravity to the outer end of the pipe, thereby assuring diode action that prevents the reverse transfer of heat from the reservoir to the outside on cool nights. In a cooling system, the outer end of the pipe which connects to a heat dissipator, is higher than the inner end that is coupled to a cold reservoir, to allow heat transfer only out of the reservoir to the heat dissipator, and not in the reverse direction.

  19. Heterojunction solar cell

    DOEpatents

    Olson, Jerry M.

    1994-01-01

    A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

  20. Heterojunction solar cell

    DOEpatents

    Olson, J.M.

    1994-08-30

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  1. Structure engineering of hole-conductor free perovskite-based solar cells with low-temperature-processed commercial carbon paste as cathode.

    PubMed

    Zhang, Fuguo; Yang, Xichuan; Wang, Haoxin; Cheng, Ming; Zhao, Jianghua; Sun, Licheng

    2014-09-24

    Low-temperature-processed (100 °C) carbon paste was developed as counter electrode material in hole-conductor free perovskite/TiO2 heterojunction solar cells to substitute noble metallic materials. Under optimized conditions, an impressive PCE value of 8.31% has been achieved with this carbon counter electrode fabricated by doctor-blading technique. Electrochemical impedance spectroscopy demonstrates good charge transport characteristics of low-temperature-processed carbon counter electrode. Moreover, this carbon counter electrode-based perovskite solar cell exhibits good stability over 800 h. PMID:25162717

  2. Ozark Mountain solar home

    SciTech Connect

    Miller, B.

    1998-03-01

    If seeing is believing, Kyle and Christine Sarratt are believers. The couple has been living in their passive solar custom home for almost two years, long enough to see a steady stream of eye-opening utility bills and to experience the quality and comfort of energy-efficient design. Skeptical of solar homes at first, the Sarratts found an energy-conscious designer that showed them how they could realize their home-building dreams and live in greater comfort while spending less money. As Kyle says, {open_quotes}We knew almost nothing about solar design and weren`t looking for it, but when we realized we could get everything we wanted in a home and more, we were sold.{close_quotes} Now the couple is enjoying the great feeling of solar and wood heat in the winter, natural cooling in the summer and heating/cooling bills that average less than $20/month. The Sarratts` home overlooks a large lake near the town of Rogers, tucked up in the northwest corner of Arkansas. It is one of three completed homes out of 29 planned for the South Sun Estates subdivision, where homes are required by covenant to incorporate passive solar design principles. Orlo Stitt, owner of Stitt Energy Systems and developer of the subdivision, has been designing passive solar, energy-efficient homes for twenty years. His passive solar custom home development is the first in Arkansas.

  3. Solar-terrestrial interactions

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The effects of solar radiation on man's environment are discussed. It is solar radiation that is the basic energy source driving the circulations of the earth's atmosphere and oceans. Solar radiation is responsible for the ionization of the earth's upper atmosphere to form the ionosphere, which is important to our understanding of the magnetosphere and its interaction with the solar wind. The solar wind, which is the continuous (but not steady) flow of the sun's coronal plasma and magnetic field into interplanetary space, plays both an active and passive role in its interaction with the earth's environment.

  4. Comparison Between Research-Grade SnO2 and Commercial Available SnO2 for Thin-Film CdTe Solar Cell (Poster)

    SciTech Connect

    Li, X.; Pankow, J.; To, B.; Gessert, T.

    2008-05-01

    A comparison between research-grade, tin-oxide (SnO{sub 2}) thin films and those available from commercial sources is performed. The research-grade SnO{sub 2} film is fabricated at NREL by low-pressure metal-organic chemical vapor deposition. The commercial SnO{sub 2} films are Pilkington Tec 8 and Tec 15 fabricated by atmospheric-pressure chemical vapor deposition. Optical, structural, and compositional analyses are performed. From the optical analysis, an estimation of the current losses due to the SnO{sub 2} layer and glass is provided. Our analysis indicates that the optical properties of commercial SnO{sub 2} could be improved for PV usage.

  5. Solar cell with back side contacts

    DOEpatents

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J; Wanlass, Mark Woodbury; Clews, Peggy J

    2013-12-24

    A III-V solar cell is described herein that includes all back side contacts. Additionally, the positive and negative electrical contacts contact compoud semiconductor layers of the solar cell other than the absorbing layer of the solar cell. That is, the positive and negative electrical contacts contact passivating layers of the solar cell.

  6. Passive tracking with sensors of opportunity using passive coherent location

    NASA Astrophysics Data System (ADS)

    Subramaniam, Mahes; Tharmarasa, R.; McDonald, Mike; Kirubarajan, T.

    2008-04-01

    Passive coherent location (PCL), which uses the commercial signals as illuminators of opportunity, is an emerging technology in air defense systems. The advantages of PCL are low cost, low vulnerability to electronic counter measures, early detection of stealthy targets and low-altitude detection. However, limitations of PCL include lack of control over illuminators, poor bearing accuracy, time-varying sensor parameters and limited observability. In this paper, multiple target tracking using PCL with high bearing error is considered. In this case, the challenge is to handle high nonlinearity due to high measurement error. In this paper, we implement the converted measurement Kalman filter, unscented Kalman filter and particle filter based PHD filter for PCL radar measurements and compare their performances.

  7. Conservation and solar energy program: congressional budget request, FY 1982

    SciTech Connect

    1981-01-01

    Funding summaries are presented for the Conservation and Solar Energy Program funding information and program overview on energy conservation (Volume 7 of 7, DOE/CR-0011/2) are included for the Buildings and Community Systems, Industrial, Transportation; State and Local, Multi-Sector, Energy Impact Assistance, and Residential/Commercial retrofit programs. Funding information and program overviews on solar technology (Volume 2 of 7, DOE/CR-011/2) are included for Active and Passive Solar Heating and Cooling, Photovoltaics Energy Systems, Solar Thermal Power Systems, Biomass Energy Systems, Wind Energy Conversion Systems, Ocean Systems, Solar International Activities, Solar Information Systems, SERI Facility, MX-RES, Program Direction, and Alcohol Fuels programs. Information and overviews on energy production, demonstration, and distribution (Volume 6 of 7, DOE/CR-0011/2) are given for the solar program. A funding summary and a program overview are included for electrochemical and physical and chemical storage systems as appearing in DOE/CR-0011/2, Volume 3 of 7. Relevant tabulated data from the FY 1981. Request to the Congress are presented for Supplementals, Rescissions, and Deferrals. (MCW)

  8. Passive Energy Building Design Tool

    Energy Science and Technology Software Center (ESTSC)

    1994-11-01

    SOLAR5 is a computer aided design tool to help architects design better, more energy efficient buildings. It is intended for use at the beginning of the design process. To get started, only four pieces of information are necessary to compute the energy needed: the square footage, the number of stories, the kind of building (such as school, home, hotel, or any one of 20 types), and its location (the program stores the temperature ranges formore » fourty major cities). Additional information may be given later to fine tune the design. An expert system using heuristics from a wide range of sources, automatically creates a passive solar baseline building from the four facts specified for that project. By modifying and adapting prior designs the user can create and work upon as many as nine schemes simultaneously. SOLAR5 can analyze the buildings thermal performance for each hour of each month and plot its total heat gain or loss as a three-dimensional surface. After reading the plot, the user can immediately redesign the building and rerun the analysis. Separate heat gain/loss surfaces can be plotted for each of the different parts of the building or schemes that add together to make up the total, including walls, roof, windows, skylights, floor, slab on grade, people, lights, equipment, and infiltration. Two different schemes can be instantly compared by asking for a three-dimensional plot showing only the difference in their performances. The objective of SOLAR5 is to allow the designer to make changes easily and quickly with detailed instantaneous pictorial feedback of the implications of the change.« less

  9. Commercial Crew

    NASA Video Gallery

    Phil McAlister delivers a presentation by the Commercial Crew (CC) study team on May 25, 2010, at the NASA Exploration Enterprise Workshop held in Galveston, TX. The purpose of this workshop was to...

  10. Immunizations: Active vs. Passive

    MedlinePlus

    ... they’ve been exposed. For example, the passive rabies immunization (rabies immune globulin) is commonly used after a certain ... of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual ...

  11. Hood River Passive House

    SciTech Connect

    Hales, D.

    2013-03-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project.

  12. Space Commercialization

    NASA Technical Reports Server (NTRS)

    Martin, Gary L.

    2011-01-01

    A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

  13. Solar Schematic

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

  14. Solar Simulator Represents the Mars Surface Solar Environment

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; Dawson, Stephen F.; Mueller, Robert L.; Mardesich, Nick; Rapp, Donald

    2009-01-01

    A report discusses the development of a Mars surface, laboratory-based solar simulator to create solar cells that can function better on Mars. The Mars Optimized Solar cell Technology (MOST) required defining the surface incident spectrum, developing an appropriate laboratory solar simulator measurement capability, and developing and testing commercial cells modified for the Mars surface spectrum.

  15. Plants for passive cooling. A preliminary investigation of the use of plants for passive cooling in temperate humid climates

    SciTech Connect

    Spirn, A W; Santos, A N; Johnson, D A; Harder, L B; Rios, M W

    1981-04-01

    The potential of vegetation for cooling small, detached residential and commercial structures in temperate, humid climates is discussed. The results of the research are documented, a critical review of the literature is given, and a brief review of energy transfer processes is presented. A checklist of design objectives for passive cooling, a demonstration of design applications, and a palette of selected plant species suitable for passive cooling are included.

  16. Markets for concentrating solar power

    SciTech Connect

    Not Available

    1998-04-01

    The report describes the markets for concentrating solar power. As concentrating solar power technologies advance into the early stages of commercialization, their economic potential becomes more sharply defined and increasingly tangible.

  17. Manual for solar specialists

    SciTech Connect

    Not Available

    1982-07-01

    The objective of the manual is to meet the specific training needs of code enforcement personnel in connection with the examination of plans for and the inspection of solar energy installations. There is a brief historical review and discussion of geographical dependence of solar feasibility. The fundamentals of solar energy are presented to establish the quantity of solar energy which can be anticipated in a particular geographic location. The active, passive, and hybrid solar systems are described, telling how insolation is collected, stored, and distributed by various means. The physical and theoretical components of solar systems are related to specific code enforcement techniques. Also, the recommended requirements to code officials for solar heating, cooling, and hot water systems are reviewed and discussed. (LEW)

  18. Commercial Fishing.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee. Div. of Vocational Education.

    This document is a curriculum framework for a program in commercial fishing to be taught in Florida secondary and postsecondary institutions. This outline covers the major concepts/content of the program, which is designed to prepare students for employment in occupations with titles such as net fishers, pot fishers, line fishers, shrimp boat…

  19. Commercial applications

    NASA Technical Reports Server (NTRS)

    Togai, Masaki

    1990-01-01

    Viewgraphs on commercial applications of fuzzy logic in Japan are presented. Topics covered include: suitable application area of fuzzy theory; characteristics of fuzzy control; fuzzy closed-loop controller; Mitsubishi heavy air conditioner; predictive fuzzy control; the Sendai subway system; automatic transmission; fuzzy logic-based command system for antilock braking system; fuzzy feed-forward controller; and fuzzy auto-tuning system.

  20. Wireless passive radiation sensor

    SciTech Connect

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  1. Passive optical element with selective angular reflection

    SciTech Connect

    Tremblay, C.; Rheault, F.; Boulay, R.; Tremblay, R.

    1987-02-01

    This work is related to the development of passive selective transmission materials that will contribute to regularize the solar thermal gain. We propose an original solution to the problem of seasonal control of energetic input into buildings through windows. A passive optical element with selective angular reflection is used to solve this problem. This optical element allows sunlight to enter windows during the fall and winter, whereas, owing to the different astronomical path of the sun, it stops and rejects direct sunlight by means of the optical effect called total internal reflection (TIR) during the central spring-Summer period. The purpose of this paper is to describe the optical element in some detail, to develop the principal design equations, and give the results of the optimization of optical and geometrical parameters.

  2. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, M.W.

    1990-06-19

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  3. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  4. Solar Energy Research Institute Validation Test House Site Handbook

    SciTech Connect

    Burch, J.; Wortman, D.; Judkoff, R.; Hunn, B.

    1985-05-01

    The Validation Test House at the Solar Energy Research Institute in Golden, Colorado, is being used to collect performance data for analysis/design tool validation as part of the DOE Passive Solar Class A Performance Evaluation Program.

  5. Stability and self-passivation of copper vanadate photoanodes under chemical, electrochemical, and photoelectrochemical operation.

    PubMed

    Zhou, Lan; Yan, Qimin; Yu, Jie; Jones, Ryan J R; Becerra-Stasiewicz, Natalie; Suram, Santosh K; Shinde, Aniketa; Guevarra, Dan; Neaton, Jeffrey B; Persson, Kristin A; Gregoire, John M

    2016-04-14

    Deployment of solar fuels technology requires photoanodes with long term stability, which can be accomplished using light absorbers that self-passivate under operational conditions. Several copper vanadates have been recently reported as promising photoanode materials, and their stability and self-passivation is demonstrated through a combination of Pourbaix calculations and combinatorial experimentation. PMID:26997488

  6. Method for processing silicon solar cells

    DOEpatents

    Tsuo, Y.S.; Landry, M.D.; Pitts, J.R.

    1997-05-06

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystalline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation. 2 figs.

  7. Method for processing silicon solar cells

    DOEpatents

    Tsuo, Y. Simon; Landry, Marc D.; Pitts, John R.

    1997-01-01

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystallline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation.

  8. Simulation of Device Parameters of High Efficiency Multicrystalline Silicon Solar Cells

    SciTech Connect

    Budhraja, V.; Misra, D.; Ravindra, N. M.

    2011-11-01

    The results of the simulation of the reported experimental results of high efficiency multicrystalline silicon (mc-Si) solar cells, using PC1D software, are reported in this study. Results obtained by various groups have been incorporated and compared in this study. The highest efficiency reported so far for mc-Si solar cells is 20{center_dot}4% and 17-18% by research laboratories and commercial houses, respectively. The efficiency can be further enhanced if passivation characteristics on both the front and back surface are improved. The role of back surface recombination has become more significant in light of the use of thin mc-Si wafers by the solar cell industry. Based on the passivation characteristics and considering the understanding of the past three decades of studies, the authors have proposed and simulated a structure for mc-Si solar cells to improve the performance of the same. The results of our modeled structure of mc-Si solar cell show an efficiency of 21{center_dot}88% with short-circuit current density, J{sub sc} = 39{center_dot}39 mA/cm2, and open circuit voltage, V{sub oc} = 0{center_dot}666 V.

  9. Passive Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1983-01-01

    Magnetic bearing for limited rotation devices requires no feedback control system to sense and correct shaft position. Passive Magnetic Torsion Bearing requires no power supply and has no rubbing parts. Torsion wire restrains against axial instability. Magnetic flux geometry chosen to assure lateral stability with radial restoring force that maintains alignment.

  10. Central receiver solar thermal power system, Phase 1: CDRL Item 2, pilot plant preliminary design report. Volume VII. Pilot plant cost and commercial plant cost and performance

    SciTech Connect

    Hallet, Jr., R. W.; Gervais, R. L.

    1980-05-01

    Detailed cost and performance data for the proposed tower focus pilot plant and commercial plant are given. The baseline central receiver concept defined by the MDAC team consists of the following features: (A) an external receiver mounted on a tower, and located in a 360/sup 0/ array of sun-tracking heliostats which comprise the collector subsystem. (B) feedwater from the electrical power generation subsystem is pumped through a riser to the receiver, where the feedwater is converted to superheated steam in a single pass through the tubes of the receiver panels. (C) The steam from the receiver is routed through a downcomer to the ground and introduced to a turbine directly for expansion and generation of electricity, and/or to a thermal storage subsystem, where the steam is condensed in charging heat exchangers to heat a dual-medium oil and rock thermal storage unit (TSU). (D) Extended operation after daylight hours is facilitated by discharging the TSU to generate steam for feeding the admission port of the turbine. (E) Overall control of the system is provided by a master control unit, which handles the interactions between subsystems that take place during startup, shutdown, and transitions between operating modes. (WHK)

  11. Solar Glazing Tips for School Construction

    ERIC Educational Resources Information Center

    Smith, Jonathan

    2012-01-01

    Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and…

  12. Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

    NASA Astrophysics Data System (ADS)

    Mathe, Vikas L.; Varma, Vijay; Raut, Suyog; Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R. K.; Bhoraskar, Sudha V.; Das, Asoka K.

    2016-04-01

    Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

  13. Solar heated beehives

    SciTech Connect

    Hardin, B.

    1985-02-01

    A new translucent plastic cover for bee hives is described which will serve as a passive solar collector and insulator. Scientists at the USDA-ARS designed the cover to maintain bees in cold weather. It should be of interest to beekeepers in northern states who have had to destroy colonies to avoid overwintering costs.

  14. Solar Energy Now.

    ERIC Educational Resources Information Center

    Rose, Harvey, Ed.

    Twenty articles addressing different aspects of solar energy are compiled in this book. They represent the views of different governmental and non-governmental organizations, members of congress, and other individuals including, for example, Barry Commoner and Amory Lovins. Topics discussed include the need for federal support, passive solar…

  15. Commercial Capaciflector

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1991-01-01

    A capacitive proximity/tactile sensor with unique performance capabilities ('capaciflector' or capacitive reflector) is being developed by NASA/Goddard Space Flight Center (GSFC) for use on robots and payloads in space in the interests of safety, efficiency, and ease of operation. Specifically, this sensor will permit robots and their attached payloads to avoid collisions in space with humans and other objects and to dock these payloads in a cluttered environment. The sensor is simple, robust, and inexpensive to manufacture with obvious and recognized commercial possibilities. Accordingly, NASA/GSFC, in conjunction with industry, is embarking on an effort to 'spin' this technology off into the private sector. This effort includes prototypes aimed at commercial applications. The principles of operation of these prototypes are described along with hardware, software, modelling, and test results. The hardware description includes both the physical sensor in terms of a flexible printed circuit board and the electronic circuitry. The software description will include filtering and detection techniques. The modelling will involve finite element electric field analysis and will underline techniques used for design optimization.

  16. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  17. Passivated niobium cavities

    DOEpatents

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  18. Passive Baited Sequential Filth Fly Trap.

    PubMed

    Aldridge, Robert L; Britch, Seth C; Snelling, Melissa; Gutierez, Arturo; White, Gregory; Linthicum, Kenneth J

    2015-09-01

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted-cone design to passively confine flies in 8 modified collection bottles corresponding to 8 intervals. Efficacy trials in a hot-arid desert environment indicate no significant difference (P  =  0.896) between the modified sequential trap and a Rid-Max® fly trap. PMID:26375911

  19. The Economics of Solar Heating

    NASA Technical Reports Server (NTRS)

    Forney, J. A.

    1982-01-01

    SHCOST program assesses economic feasibility of solar energy for single-family residences and light commercial applications. Program analyzes life-cycle costs as well as sensitivity studies to aid designer in selecting most economically attractive solar system for single-family residence or light commercial application. SHCOST includes fairly comprehensive list of cost elements from which user may select.

  20. Passively actuated valve

    SciTech Connect

    Modro, S. Michael; Ougouag, Abderrafi M.

    2005-09-20

    A passively actuated valve for isolating a high pressure zone from a low pressure zone and discontinuing the isolation when the pressure in the high pressure zone drops below a preset threshold. If the pressure in the high pressure zone drops below the preset threshold, the valve opens and allows flow from the high pressure zone to the low pressure zone. The valve remains open allowing pressure equalization and back-flow should a pressure inversion between the two pressure zone occur.

  1. Passive fetal monitoring sensor

    NASA Astrophysics Data System (ADS)

    Zuckerwar, Allan J.; Hall, Earl T.; Baker, Donald A.; Bryant, Timothy D.

    1992-08-01

    An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

  2. Passive fetal monitoring sensor

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J. (Inventor); Hall, Earl T. (Inventor); Baker, Donald A. (Inventor); Bryant, Timothy D. (Inventor)

    1992-01-01

    An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

  3. Commercial LANDSAT?

    NASA Astrophysics Data System (ADS)

    Private industry should assume responsibility either for the United States' land satellite (LANDSAT) system or for both the land and the weather satellite systems, recommends the Land Remote Sensing Satellite Advisory Committee. The committee (Eos, June 29, 1982, p. 553), composed of representatives from academia, industry, and government, has a working group that is evaluating the potential for commercialization of remote sensing satellites.The recommendations call for industry ownership or operation of either or both of the remote sensing systems, but only up to and including the holding of raw, unprocessed data. The National Aeronautics and Space Administration (NASA) currently operates LANDSAT but will be relinquishing its responsibility to the National Oceanic and Atmospheric Administration (NOAA) on January 31. NOAA already operates the U.S. civilian weather satellite service, which includes the NOAA-5, NOAA-6, and the Geostationary Operational Environmental (GOES) satellites (Eos, June 2, 1981, p. 522).

  4. Solar power towers

    SciTech Connect

    Not Available

    1998-04-01

    The high desert near Barstow, California, has witnessed the development of this country`s first two solar power towers. Solar One operated successfully from 1982 to 1988 and proved that power towers work efficiently to produce utility-scale power from sunlight. Solar Two was connected to the utility grid in 1996 and is operating today. Like its predecessor, Solar Two is rated at 10 megawatts. An upgrade of the Solar One plant, Solar Two demonstrates how solar energy can be stored in the form of heat in molten salt for power generation on demand. The experience gained with these two pilot power towers has established a foundation on which industry can develop its first commercial plants. These systems produce electricity on a large scale. They are unique among solar technologies because they can store energy efficiently and cost effectively. They can operate whenever the customer needs power, even after dark or during cloudy weather.

  5. Passivation effects on quantum dots prepared by successive ionic layer adsorption and reaction

    NASA Astrophysics Data System (ADS)

    Dai, Qilin; Maloney, Scott; Chen, Weimin; Poudyal, Uma; Wang, Wenyong

    2016-06-01

    ZnS is typically used to passivate semiconductor quantum dots (QDs) prepared by the successive ionic layer adsorption and reaction (SILAR) method for solar cell applications, while for colloidal QDs, organic ligands are usually used for this passivation purpose. In this study we utilized oleylamine and oleic acid ligands, besides ZnS, to passivate QDs prepared by the SILAR approach, and investigated their effects on the incident photon-to-current efficiency (IPCE) performance of the solar cells. It was observed that oleylamine passivation decreased device performance, while oleic acid passivation improved the IPCE of the cells. Redshift of the IPCE onset wavelength was also observed after oleic acid coating, which was attributed to the delocalization of excitons in the CdS QDs.

  6. Passivation effects on quantum dots prepared by successive ionic layer adsorption and reaction.

    PubMed

    Dai, Qilin; Maloney, Scott; Chen, Weimin; Poudyal, Uma; Wang, Wenyong

    2016-06-01

    ZnS is typically used to passivate semiconductor quantum dots (QDs) prepared by the successive ionic layer adsorption and reaction (SILAR) method for solar cell applications, while for colloidal QDs, organic ligands are usually used for this passivation purpose. In this study we utilized oleylamine and oleic acid ligands, besides ZnS, to passivate QDs prepared by the SILAR approach, and investigated their effects on the incident photon-to-current efficiency (IPCE) performance of the solar cells. It was observed that oleylamine passivation decreased device performance, while oleic acid passivation improved the IPCE of the cells. Redshift of the IPCE onset wavelength was also observed after oleic acid coating, which was attributed to the delocalization of excitons in the CdS QDs. PMID:27103144

  7. 22. 8% efficient silicon solar cell

    SciTech Connect

    Blakers, A.W.; Wang, A.; Milne, A.M.; Zhao, J.; Green, M.A. )

    1989-09-25

    A new silicon solar cell structure, the passivated emitter and rear cell, is described. The cell structure has yielded independently confirmed efficiencies of up to 22.8%, the highest ever reported for a silicon cell.

  8. Fundamental Research and Development for Improved Crystalline Silicon Solar Cells: Final Subcontract Report, March 2002 - July 2006

    SciTech Connect

    Rohatgi, A.

    2007-11-01

    This report summarizes the progress made by Georgia Tech in the 2002-2006 period toward high-efficiency, low-cost crystalline silicon solar cells. This program emphasize fundamental and applied research on commercial substrates and manufacturable technologies. A combination of material characterization, device modeling, technology development, and complete cell fabrication were used to accomplish the goals of this program. This report is divided into five sections that summarize our work on i) PECVD SiN-induced defect passivation (Sections 1 and 2); ii) the effect of material inhomogeneity on the performance of mc-Si solar cells (Section 3); iii) a comparison of light-induced degradation in commercially grown Ga- and B-doped Czochralski Si ingots (Section 4); and iv) the understanding of the formation of high-quality thick-film Ag contacts on high sheet-resistance emitters (Section 5).

  9. Solar Water Heater Installation Package

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A 48-page report describes water-heating system, installation (covering collector orientation, mounting, plumbing and wiring), operating instructions and maintenance procedures. Commercial solar-powered water heater system consists of a solar collector, solar-heated-water tank, electrically heated water tank and controls. Analysis of possible hazards from pressure, electricity, toxicity, flammability, gas, hot water and steam are also included.

  10. Commercial applications

    NASA Astrophysics Data System (ADS)

    The near term (one to five year) needs of domestic and foreign commercial suppliers of radiochemicals and radiopharmaceuticals for electromagnetically separated stable isotopes are assessed. Only isotopes purchased to make products for sale and profit are considered. Radiopharmaceuticals produced from enriched stable isotopes supplied by the Calutron facility at ORNL are used in about 600,000 medical procedures each year in the United States. A temporary or permanent disruption of the supply of stable isotopes to the domestic radiopharmaceutical industry could curtail, if not eliminate, the use of such diagnostic procedures as the thallium heart scan, the gallium cancer scan, the gallium abscess scan, and the low radiation dose thyroid scan. An alternative source of enriched stable isotopes exist in the USSR. Alternative starting materials could, in theory, eventually be developed for both the thallium and gallium scans. The development of a new technology for these purposes, however, would take at least five years and would be expensive. Hence, any disruption of the supply of enriched isotopes from ORNL and the resulting unavailability of critical nuclear medicine procedures would have a dramatic negative effect on the level of health care in the United States.

  11. Passive Microwave Remote Sensing of Soil Moisture

    NASA Technical Reports Server (NTRS)

    Njoku, Eni G.; Entekhabi, Dara

    1996-01-01

    Microwave remote sensing provides a unique capability for direct observation of soil moisture. Remote measurements from space afford the possibility of obtaining frequent, global sampling of soil moisture over a large fraction of the Earth's land surface. Microwave measurements have the benefit of being largely unaffected by cloud cover and variable surface solar illumination, but accurate soil moisture estimates are limited to regions that have either bare soil or low to moderate amounts of vegetation cover. A particular advantage of passive microwave sensors is that in the absence of significant vegetation cover soil moisture is the dominant effect on the received signal. The spatial resolutions of passive Microwave soil moisture sensors currently considered for space operation are in the range 10-20 km. The most useful frequency range for soil moisture sensing is 1-5 GHz. System design considerations include optimum choice of frequencies, polarizations, and scanning configurations, based on trade-offs between requirements for high vegetation penetration capability, freedom from electromagnetic interference, manageable antenna size and complexity, and the requirement that a sufficient number of information channels be available to correct for perturbing geophysical effects. This paper outlines the basic principles of the passive microwave technique for soil moisture sensing, and reviews briefly the status of current retrieval methods. Particularly promising are methods for optimally assimilating passive microwave data into hydrologic models. Further studies are needed to investigate the effects on microwave observations of within-footprint spatial heterogeneity of vegetation cover and subsurface soil characteristics, and to assess the limitations imposed by heterogeneity on the retrievability of large-scale soil moisture information from remote observations.

  12. Fundamental studies of passivity and passivity breakdown. Final report

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed ``point defects models`` (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies.

  13. Passive propellant system

    NASA Technical Reports Server (NTRS)

    Hess, D. A.; Regnier, W. W.; Jacobs, V. L. (Inventor)

    1979-01-01

    A passive propellant acquisition and feed system is disclosed which acquires and feeds gas-free propellant in low or zero-g environments during orbital maneuvers and retains this propellant under high axially directed acceleration such as may be experienced during launch of a space vehicle and orbit-to-orbit transfer is described. The propellant system includes a dual compartment propellant tank with independent surface tension acquisition channels in each compartment to provide gas-free flow of pressurized liquid propellant from one compartment to the other in one direction only.

  14. Passive Immunization Against Poliomyelitis

    PubMed Central

    Rinaldo, Charles R.

    2005-01-01

    Poliomyelitis has gone from being one of the worst scourges of the 20th century to nearing eradication in the 21st. This success is well known to be attributable to the Salk inactivated and Sabin attenuated poliovirus vaccines. However, before introduction of these vaccines, William McDowall Hammon of the University of Pittsburgh Graduate School of Public Health led the first major breakthrough in prevention of the disease by using passive immunization in one of the earliest double-blind, placebo-controlled clinical trials. This study provided the first evidence that antibodies to poliovirus could prevent the disease in humans. PMID:15855454

  15. Improvement of passive THz camera images

    NASA Astrophysics Data System (ADS)

    Kowalski, Marcin; Piszczek, Marek; Palka, Norbert; Szustakowski, Mieczyslaw

    2012-10-01

    Terahertz technology is one of emerging technologies that has a potential to change our life. There are a lot of attractive applications in fields like security, astronomy, biology and medicine. Until recent years, terahertz (THz) waves were an undiscovered, or most importantly, an unexploited area of electromagnetic spectrum. The reasons of this fact were difficulties in generation and detection of THz waves. Recent advances in hardware technology have started to open up the field to new applications such as THz imaging. The THz waves can penetrate through various materials. However, automated processing of THz images can be challenging. The THz frequency band is specially suited for clothes penetration because this radiation does not point any harmful ionizing effects thus it is safe for human beings. Strong technology development in this band have sparked with few interesting devices. Even if the development of THz cameras is an emerging topic, commercially available passive cameras still offer images of poor quality mainly because of its low resolution and low detectors sensitivity. Therefore, THz image processing is very challenging and urgent topic. Digital THz image processing is a really promising and cost-effective way for demanding security and defense applications. In the article we demonstrate the results of image quality enhancement and image fusion of images captured by a commercially available passive THz camera by means of various combined methods. Our research is focused on dangerous objects detection - guns, knives and bombs hidden under some popular types of clothing.

  16. Fly ash carbon passivation

    DOEpatents

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  17. Mechanical passive logic module

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay; Caulfield, H. John

    2015-02-01

    Nothing from nothing gives simple simile, but something from nothing is an interesting and challenging task. Adolf Lohmann once proposed 'do nothing machine' in optics, which only copies input to output. Passive logic module (PALM) is a special type of 'do nothing machine' which can converts inputs into one of 16 possible binary outputs. This logic module is not like the conventional irreversible one. It is a simple type of reversible Turing machine. In this manuscript we discussed and demonstrated PALM using mechanical movement of plane mirrors. Also we discussed the theoretical model of micro electro mechanical system (MEMS) based PALM in this manuscript. It may have several valuable properties such as passive operation (no need for nonlinear elements as other logic device require) and modular logic (one device implementing any Boolean logic function with simple internal changes). The result is obtained from the demonstration by only looking up the output. No calculation is required to get the result. Not only that, PALM is a simple type of the famous 'billiard ball machine', which also discussed in this manuscript.

  18. Volcanic passive margins

    NASA Astrophysics Data System (ADS)

    Geoffroy, Laurent

    2005-12-01

    Compared to non-volcanic ones, volcanic passive margins mark continental break-up over a hotter mantle, probably subject to small-scale convection. They present distinctive genetic and structural features. High-rate extension of the lithosphere is associated with catastrophic mantle melting responsible for the accretion of a thick igneous crust. Distinctive structural features of volcanic margins are syn-magmatic and continentward-dipping crustal faults accommodating the seaward flexure of the igneous crust. Volcanic margins present along-axis a magmatic and tectonic segmentation with wavelength similar to adjacent slow-spreading ridges. Their 3D organisation suggests a connection between loci of mantle melting at depths and zones of strain concentration within the lithosphere. Break-up would start and propagate from localized thermally-softened lithospheric zones. These 'soft points' could be localized over small-scale convection cells found at the bottom of the lithosphere, where adiabatic mantle melting would specifically occur. The particular structure of the brittle crust at volcanic passive margins could be interpreted by active and sudden oceanward flow of both the unstable hot mantle and the ductile part of the lithosphere during the break-up stage. To cite this article: L. Geoffroy, C. R. Geoscience 337 (2005).

  19. Thiol passivation of MWIR type II superlattice photodetectors

    NASA Astrophysics Data System (ADS)

    Salihoglu, O.; Muti, A.; Aydinli, A.

    2013-06-01

    Poor passivation on photodetectors can result in catastrophic failure of the device. Abrupt termination of mesa side walls during pixel definition generates dangling bonds that lead to inversion layers and surface traps leading to surface leakage currents that short circuit diode action. Good passivation, therefore, is critical in the fabrication of high performance devices. Silicondioxide has been the main stay of passivation for commercial photodetectors, deposited at high temperatures and high RF powers using plasma deposition techniques. In photodetectors based on III-V compounds, sulphur passivation has been shown to replace oxygen and saturate the dangling bonds. Despite its effectiveness, it degrades over time. More effort is required to create passivation layers which eliminate surface leakage current. In this work, we propose the use of sulphur based octadecanethiol (ODT), CH3(CH2)17SH, as a passivation layer for the InAs/GaSb superlattice photodetectors that acts as a self assembled monolayer (SAM). ODT SAMs consist of a chain of 18 carbon atoms with a sulphur atom at its head. ODT Thiol coating is a simple process that consist of dipping the sample into the solution for a prescribed time. Excellent electrical performance of diodes tested confirm the effectiveness of the sulphur head stabilized by the intermolecular interaction due to van der Walls forces between the long chains of ODT SAM which results in highly stable ultrathin hydrocarbon layers without long term degradation.

  20. Laser doping for high-efficiency silicon solar cells

    NASA Astrophysics Data System (ADS)

    Jäger, Ulrich; Wolf, Andreas; Steinhauser, Bernd; Benick, Jan; Nekarda, Jan; Preu, Ralf

    2012-10-01

    Selective laser doping is a versatile tool for the local adaption of doping profiles in a silicon substrate. By adjusting the laser fluence as well as the pulse width the maximum melt depth in the silicon can be controlled. Longer pulses lead to lower temperatures in the material and can help to enlarge the process window as ablation sets in at higher fluencies. For the fabrication of highly efficient silicon solar cells, laser doping can be used for efficiency improvement and process simplification. In passivated emitter and rear cells (PERC), selective laser doping can be used for selective emitter formation. Employing such a process, an efficiency boost of Δ ƞ= 0.4%abs was observed on commercial Cz-Si material. Laser doping was also used for process simplification for the fabrication of locally doped point contacts at the rear of a solar cell. A simple approach employing a doped passivation layer and a laser doping process allows for efficiencies beyond 22% on high quality n-type silicon.

  1. Use of coupled passivants and consolidants on calcite mineral surfaces

    SciTech Connect

    Nagy, K.L.; Cygan, R.T.; Brinker, C.J.; Ashley, C.S.; Scotto, C.S.

    1997-02-01

    Deterioration of monuments, buildings, and works of art constructed of carbonate-based stone potentially can be arrested by applying a combination of chemical passivants and consolidants that prevent hydrolytic attack and mechanical weakening. The authors used molecular modeling and laboratory synthesis to develop an improved passivating agent for the calcite mineral surface based on binding strength and molecular packing density. The effectiveness of the passivating agent with and without a linked outer layer of consolidant against chemical weathering was determined through leaching tests conducted with a pH-stat apparatus at pH 5 and 25 C. For the range of molecules considered, modeling results indicate that the strongest-binding passivant is the trimethoxy dianionic form of silylalkylaminocarboxylate (SAAC). The same form of silylalkylphosphonate (SAP) is the second strongest binder and the trisilanol neutral form of aminoethylaminopropylsilane (AEAPS) is ranked third. Short-term leaching tests on calcite powders coated with the trisilanol derivative of SAAC, the triethoxy neutral form of SAP, and the trimethoxy neutral form of AEAPS show that the passivant alone does not significantly slow the dissolution rate. However, all passivants when linked to the sol consolidant result in decreased rates. Combined AEAPS plus consolidant results in a coating that performs better than the commercial product Conservare{reg_sign} OH and at least as well as Conservare{reg_sign} H. The modeling results indicate that there may be a threshold binding energy for the passivant above which the dissolution rate of calcite is actually enhanced. More strongly-binding passivants may aid in the dissolution mechanism or dissociate in aqueous solution exposing the calcite surface to water.

  2. Commentary on "Capturing the Evasive Passive"

    ERIC Educational Resources Information Center

    Lillo-Martin, Diane; Snyder, William

    2009-01-01

    Passives has been the focus of much research in language acquisition since the 1970s. It has been clear from this research that young children seldom produce passives spontaneously, particularly "long" or "full" passives with a by-phrase; and they usually perform poorly on experimental tests of the comprehension of passives, especially passives of…

  3. Passive magnetic bearing system

    DOEpatents

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  4. Passive containment cooling system

    DOEpatents

    Billig, P.F.; Cooke, F.E.; Fitch, J.R.

    1994-01-25

    A passive containment cooling system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel and is vented to the drywell. An isolation pool is disposed above the GDCS pool and includes an isolation condenser therein. The condenser has an inlet line disposed in flow communication with the drywell for receiving the non-condensable gas along with any steam released therein following a loss-of-coolant accident (LOCA). The condenser also has an outlet line disposed in flow communication with the drywell for returning to the drywell both liquid condensate produced upon cooling of the steam and the non-condensable gas for reducing pressure within the containment vessel following the LOCA. 1 figure.

  5. Passive Ball Capture Joint

    NASA Technical Reports Server (NTRS)

    Cloyd, Richard A. (Inventor); Bryan, Thomas C. (Inventor)

    2003-01-01

    A passive ball capture joint has a sleeve with a plurality of bores distributed about a circumference thereof and formed therethrough at an acute angle relative to the sleeve's longitudinal axis. A spring-loaded retainer is slidingly fitted in each bore and is biased such that, if allowed, will extend at least partially into the sleeve to retain a ball therein. A ring, rotatably mounted about the bores, has an interior wall defining a plurality of shaped races that bear against the spring-loaded retainers. A mechanized rotational force producer is coupled to the ring. The ring can be rotated from a first position (that presses the retainers into the sleeve to lock the ball in place) to a second position (that allows the retainers to springback out of the sleeve to release the ball).

  6. Passive containment cooling system

    DOEpatents

    Billig, Paul F.; Cooke, Franklin E.; Fitch, James R.

    1994-01-01

    A passive containment cooling system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel and is vented to the drywell. An isolation pool is disposed above the GDCS pool and includes an isolation condenser therein. The condenser has an inlet line disposed in flow communication with the drywell for receiving the non-condensable gas along with any steam released therein following a loss-of-coolant accident (LOCA). The condenser also has an outlet line disposed in flow communication with the drywell for returning to the drywell both liquid condensate produced upon cooling of the steam and the non-condensable gas for reducing pressure within the containment vessel following the LOCA.

  7. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, C.W.

    1994-11-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

  8. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, Charles W.

    1994-01-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

  9. Solar cells

    NASA Astrophysics Data System (ADS)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  10. Passive synthetic aperture radar imaging of ground moving targets

    NASA Astrophysics Data System (ADS)

    Wacks, Steven; Yazici, Birsen

    2012-05-01

    In this paper we present a method for imaging ground moving targets using passive synthetic aperture radar. A passive radar imaging system uses small, mobile receivers that do not radiate any energy. For these reasons, passive imaging systems result in signicant cost, manufacturing, and stealth advantages. The received signals are obtained by multiple airborne receivers collecting scattered waves due to illuminating sources of opportunity such as commercial television, radio, and cell phone towers. We describe a novel forward model and a corresponding ltered-backprojection type image reconstruction method combined with entropy optimization. Our method determines the location and velocity of multiple targets moving at dierent velocities. Furthermore, it can accommodate arbitrary imaging geometries. we present numerical simulations to verify the imaging method.

  11. EBIC Characterization and Hydrogen Passivation in Silicon Sheet

    NASA Technical Reports Server (NTRS)

    Hanoka, J. I.

    1985-01-01

    As a general qualitative tool, the electron beam induced current (EBIC) method can be very useful in imaging recombination in silicon sheet used for solar cells. Work using EBIC on EFG silicon ribbon is described. In particular, some efforts at making the technique more quantitative and hence more useful, some limitations of the method, and finally specific application to hydrogen passivation is treated. Some brief remarks are made regarding the technique itself.

  12. Antireflection/Passivation Step For Silicon Cell

    NASA Technical Reports Server (NTRS)

    Crotty, Gerald T.; Kachare, Akaram H.; Daud, Taher

    1988-01-01

    New process excludes usual silicon oxide passivation. Changes in principal electrical parameters during two kinds of processing suggest antireflection treatment almost as effective as oxide treatment in passivating cells. Does so without disadvantages of SiOx passivation.

  13. Commercial and Industrial Base Intermittent Resource Management Pilot

    SciTech Connect

    Kiliccote, Sila; Sporborg, Pamela; Sheik, Imran; Huffaker, Erich; Piette, Mary Ann

    2010-11-30

    This scoping study summarizes the challenges with integrating wind and solar generation into the California's electricity grid. These challenges include: Smoothing intra-hour variability; - Absorbing excess renewable energy during over-generation periods; - Addressing morning and evening ramping periods. In addition, there are technical challenges to integrating retail demand response (DR) triggered by the wholesale conditions into the CAISO markets. The study describes the DR programs available to the consumers through the utilities in California and CAISO's ancillary services market because an integration of the wholesale and retail DR requires an understanding of these different offerings and the costs associated with acquiring them. Demand-side active and passive storage systems are proposed as technologies that may be used to mitigate the effects of intermittence due to renewable generation. Commercial building technologies as well as industrial facilities with storage capability are identified as targets for the field tests. Two systems used for ancillary services communications are identified as providing the triggers for DR enablement. Through the field tests, issues related to communication, automation and flexibility of demand-side resources will be explored and the performance of technologies that participate in the field tests will be evaluated. The major outcome of this research is identifying and defining flexibility of DR resources and optimized use of these resources to respond to grid conditions.

  14. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  15. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J

    2014-05-20

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electricity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  16. Hot exhaust gases with passive FTIR emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Heland, Joerg; Schaefer, Klaus; Haus, Rainer

    1998-12-01

    Passive FTIR emission spectroscopy using a commercial medium resolution instrument with a telescope has been applied to analyze the hot exhaust gases of various combustion sources, such as industrial and building smoke stacks, aircraft engines, flares, and forest fires. To interpret the remotely measured spectra a multi-layer, line-by-line spectra retrieval software using the molecular spectral databases HITRAN and HITEMP has been developed, validated and successfully used to determine the exhaust gas temperatures and the concentrations of CO2, H2O, CO, N2O, CH4, NO, NO2, SO2, and HCl for different combustion conditions of the sources. In this paper the feasibility and the setup of passive IR measurements, the basic theory of radiative transfer and special features of the commercially available spectra analysis code are described. In addition, the results of the different measurement applications are summarized.

  17. NEDO Solar Technology Subcommittee

    NASA Astrophysics Data System (ADS)

    1991-10-01

    Five papers were reported in the 11th research report meeting held in October, 1991 in the Solar Technology Subcommittee of NEDO. Several themes as to development of the solar technology and development of commercialization technology of the industrial solar system which were forwarded in 1990 were explained including themes presented in these 5 papers. For example, the following items were developed for the photovoltaic power generation of the solar technology development: new type solar cells, practical use of amorphous solar cells, development of ultra-highly efficient solar cells, research and development of independent dispersion type as the utilization system, hybrid type photovoltaic power generation using solar light and heat, and the manufacturing equipment of compound type semi-conductors for solar cells, etc. As for the technical development to make the industrial solar system practical use, the following techniques such as the research of elementary techniques including the solar energy collector, the advanced heat process using new metal hydrides for refrigerating heat generation and chemical energy conversion technique are researched. In addition, the development of an MW class large wind power generation system is also advanced as a research object of this Subcommittee.

  18. Copper passivation of dislocations in silicon

    SciTech Connect

    Lee, J.; Morrison, S.R.

    1988-12-15

    The J-V characteristics of metal-insulator-semiconductor solar cells fabricated on Si samples which are damaged (lapped) with 1-..mu..m grit size of Al/sub 2/O/sub 3/ are substantially degraded. The introduction of copper at 250--400 /sup 0/C passivates the dislocations. The copper is diffused in from the surface. Anodic oxidation followed by etching in aqua regia and 48% HF was used to remove excess copper remaining on the damaged surface and to etch away controlled amounts of the silicon wafers. The experimental results are compared to the model of Divigalpitiya and Morrison (J. Appl. Phys. 60, 406 (1986)). It is concluded using the model that copper passivation reduces the product of the density of hole traps and the capture cross section of hole traps and may also increase the specific conductance of the dislocations. Results for samples lapped with finer-grit alumina (0.3 ..mu..m) seem qualitatively different from those with 1-..mu..m alumina. The variation in dislocation density as a function of depth into the surface is used to explain the difference qualitatively. The dislocation density decreases rapidly with distance from the damaged surface.

  19. Imparting passivity to vapor deposited magnesium alloys

    NASA Astrophysics Data System (ADS)

    Wolfe, Ryan C.

    electron microscope. The corrosion rate of the nonequilibrium sputtered alloys, as determined by polarization resistance, is significantly reduced compared to the most corrosion resistant commercial magnesium alloys. The open circuit potentials of the sputter deposited alloys are significantly more noble compared to commercial, equilibrium phase magnesium alloys. Galvanic corrosion susceptibility has also been considerably reduced. Nonequilibrium magnesium-yttrium-titanium alloys have been shown to achieve passivity autonomously by alteration of the composition chemistry of the surface oxide/hydroxide layer. Self-healing properties are also evident, as corrosion propagation can be arrested after initial pitting of the material. A clear relationship exists between the corrosion resistance of sputter vapor deposited magnesium alloys and the amount of ion bombardment incurred by the alloy during deposition. Argon pressure, the distance between the source and the substrate, and alloy morphology play important roles in determining the ability of the alloy to develop a passive film. Thermal effects, both during and after alloy deposition, alter the stress state of the alloys, precipitation of second phases, and the mechanical stability of the passive film. An optimal thermal treatment has been developed in order to maximize the corrosion resistance of the magnesium-yttrium-titanium alloys. The significance of the results includes the acquisition of electrochemical data for these novel materials, as well as expanding the utilization of magnesium alloys by the improvement in their corrosion resistance. The magnesium alloys developed in this work are more corrosion resistant than any commercial magnesium alloy. Structural components comprised of these alloys would therefore exhibit unprecedented corrosion performance. Coatings of these alloys on magnesium components would provide a corrosion resistant yet galvanically-compatible coating. The broad impact of these contributions is

  20. Imparting passivity to vapor deposited magnesium alloys

    NASA Astrophysics Data System (ADS)

    Wolfe, Ryan C.

    electron microscope. The corrosion rate of the nonequilibrium sputtered alloys, as determined by polarization resistance, is significantly reduced compared to the most corrosion resistant commercial magnesium alloys. The open circuit potentials of the sputter deposited alloys are significantly more noble compared to commercial, equilibrium phase magnesium alloys. Galvanic corrosion susceptibility has also been considerably reduced. Nonequilibrium magnesium-yttrium-titanium alloys have been shown to achieve passivity autonomously by alteration of the composition chemistry of the surface oxide/hydroxide layer. Self-healing properties are also evident, as corrosion propagation can be arrested after initial pitting of the material. A clear relationship exists between the corrosion resistance of sputter vapor deposited magnesium alloys and the amount of ion bombardment incurred by the alloy during deposition. Argon pressure, the distance between the source and the substrate, and alloy morphology play important roles in determining the ability of the alloy to develop a passive film. Thermal effects, both during and after alloy deposition, alter the stress state of the alloys, precipitation of second phases, and the mechanical stability of the passive film. An optimal thermal treatment has been developed in order to maximize the corrosion resistance of the magnesium-yttrium-titanium alloys. The significance of the results includes the acquisition of electrochemical data for these novel materials, as well as expanding the utilization of magnesium alloys by the improvement in their corrosion resistance. The magnesium alloys developed in this work are more corrosion resistant than any commercial magnesium alloy. Structural components comprised of these alloys would therefore exhibit unprecedented corrosion performance. Coatings of these alloys on magnesium components would provide a corrosion resistant yet galvanically-compatible coating. The broad impact of these contributions is

  1. Passive Vaporizing Heat Sink

    NASA Technical Reports Server (NTRS)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  2. Passive blast pressure sensor

    DOEpatents

    King, Michael J.; Sanchez, Roberto J.; Moss, William C.

    2013-03-19

    A passive blast pressure sensor for detecting blast overpressures of at least a predetermined minimum threshold pressure. The blast pressure sensor includes a piston-cylinder arrangement with one end of the piston having a detection surface exposed to a blast event monitored medium through one end of the cylinder and the other end of the piston having a striker surface positioned to impact a contact stress sensitive film that is positioned against a strike surface of a rigid body, such as a backing plate. The contact stress sensitive film is of a type which changes color in response to at least a predetermined minimum contact stress which is defined as a product of the predetermined minimum threshold pressure and an amplification factor of the piston. In this manner, a color change in the film arising from impact of the piston accelerated by a blast event provides visual indication that a blast overpressure encountered from the blast event was not less than the predetermined minimum threshold pressure.

  3. Active and passive multispectral scanner for earth resources applications: An advanced applications flight experiment

    NASA Technical Reports Server (NTRS)

    Hasell, P. G., Jr.; Peterson, L. M.; Thomson, F. J.; Work, E. A.; Kriegler, F. J.

    1977-01-01

    The development of an experimental airborne multispectral scanner to provide both active (laser illuminated) and passive (solar illuminated) data from a commonly registered surface scene is discussed. The system was constructed according to specifications derived in an initial programs design study. The system was installed in an aircraft and test flown to produce illustrative active and passive multi-spectral imagery. However, data was not collected nor analyzed for any specific application.

  4. Minority carrier device comprising a passivating layer including a Group 13 element and a chalcogenide component

    NASA Technical Reports Server (NTRS)

    Barron, Andrew R. (Inventor); Hepp, Aloysius F. (Inventor); Jenkins, Phillip P. (Inventor); MacInnes, Andrew N. (Inventor)

    1999-01-01

    A minority carrier device includes at least one junction of at least two dissimilar materials, at least one of which is a semiconductor, and a passivating layer on at least one surface of the device. The passivating layer includes a Group 13 element and a chalcogenide component. Embodiments of the minority carrier device include, for example, laser diodes, light emitting diodes, heterojunction bipolar transistors, and solar cells.

  5. Issues affecting advanced passive light-water reactor safety analysis

    SciTech Connect

    Beelman, R.J.; Fletcher, C.D.; Modro, S.M.

    1992-08-01

    Next generation commercial reactor designs emphasize enhanced safety through improved safety system reliability and performance by means of system simplification and reliance on immutable natural forces for system operation. Simulating the performance of these safety systems will be central to analytical safety evaluation of advanced passive reactor designs. Yet the characteristically small driving forces of these safety systems pose challenging computational problems to current thermal-hydraulic systems analysis codes. Additionally, the safety systems generally interact closely with one another, requiring accurate, integrated simulation of the nuclear steam supply system, engineered safeguards and containment. Furthermore, numerical safety analysis of these advanced passive reactor designs wig necessitate simulation of long-duration, slowly-developing transients compared with current reactor designs. The composite effects of small computational inaccuracies on induced system interactions and perturbations over long periods may well lead to predicted results which are significantly different than would otherwise be expected or might actually occur. Comparisons between the engineered safety features of competing US advanced light water reactor designs and analogous present day reactor designs are examined relative to the adequacy of existing thermal-hydraulic safety codes in predicting the mechanisms of passive safety. Areas where existing codes might require modification, extension or assessment relative to passive safety designs are identified. Conclusions concerning the applicability of these codes to advanced passive light water reactor safety analysis are presented.

  6. Issues affecting advanced passive light-water reactor safety analysis

    SciTech Connect

    Beelman, R.J.; Fletcher, C.D.; Modro, S.M.

    1992-01-01

    Next generation commercial reactor designs emphasize enhanced safety through improved safety system reliability and performance by means of system simplification and reliance on immutable natural forces for system operation. Simulating the performance of these safety systems will be central to analytical safety evaluation of advanced passive reactor designs. Yet the characteristically small driving forces of these safety systems pose challenging computational problems to current thermal-hydraulic systems analysis codes. Additionally, the safety systems generally interact closely with one another, requiring accurate, integrated simulation of the nuclear steam supply system, engineered safeguards and containment. Furthermore, numerical safety analysis of these advanced passive reactor designs wig necessitate simulation of long-duration, slowly-developing transients compared with current reactor designs. The composite effects of small computational inaccuracies on induced system interactions and perturbations over long periods may well lead to predicted results which are significantly different than would otherwise be expected or might actually occur. Comparisons between the engineered safety features of competing US advanced light water reactor designs and analogous present day reactor designs are examined relative to the adequacy of existing thermal-hydraulic safety codes in predicting the mechanisms of passive safety. Areas where existing codes might require modification, extension or assessment relative to passive safety designs are identified. Conclusions concerning the applicability of these codes to advanced passive light water reactor safety analysis are presented.

  7. Zinc recovery and waste sludge minimization from chromium passivation baths.

    PubMed

    Diban, Nazely; Mediavilla, Rosa; Urtiaga, Ane; Ortiz, Inmaculada

    2011-08-30

    This work reports the feasibility of applying emulsion pertraction technology (EPT) aiming at zinc recovery and waste minimization in the zinc electroplating processes that include Cr (III) passivation. The assessment consists of firstly the lifetime extension of the passivation baths by selective removal of the tramp ions zinc and iron, and secondly, the recovery of zinc for further reuse. Spent passivation baths from a local industry were tested, being the major metallic content: Cr(3+) 9000mg L(-1), Zn(2+) 12,000mg L(-1), Fe(3+) 100mg L(-1). Working in a Liqui-Cel hollow fiber membrane contactor and using the extractant bis(2,4,4-trimethylpentyl) phosphinic acid, reduction of zinc and iron concentrations below 60mg L(-1) and 2mg L(-1), respectively were obtained, while trivalent chromium, the active metal that generates the passivation layer, was retained in the baths. Zinc was selectively transferred to an acidic stripping phase that in the experimental time reached a concentration of 157,000mg L(-1). Zinc recovery by electrowinning from the acidic stripping phase without any pretreatment of the electrolyte solution provided a purity of 98.5%, matching the lower commercial zinc grade. As a result of the extension of the life time of the passivation bath, significant environmental advantages are derived such as minimization of the volume of hazardous wastes and savings in the consumption of raw materials. PMID:21704452

  8. Solar energy thermalization and storage device

    DOEpatents

    McClelland, John F.

    1981-09-01

    A passive solar thermalization and thermal energy storage assembly which is visually transparent. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  9. Solar energy thermalization and storage device

    DOEpatents

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  10. Solar Energy Education. Industrial arts: student activities. Field test edition

    SciTech Connect

    Not Available

    1981-02-01

    In this teaching manual several activities are presented to introduce students to information on solar energy through classroom instruction. Wind power is also included. Instructions for constructing demonstration models for passive solar systems, photovoltaic cells, solar collectors and water heaters, and a bicycle wheel wind turbine are provided. (BCS)

  11. Silicone wristbands as personal passive samplers.

    PubMed

    O'Connell, Steven G; Kincl, Laurel D; Anderson, Kim A

    2014-03-18

    Active-sampling approaches are commonly used for personal monitoring, but are limited by energy usage and data that may not represent an individual's exposure or bioavailable concentrations. Current passive techniques often involve extensive preparation, or are developed for only a small number of targeted compounds. In this work, we present a novel application for measuring bioavailable exposure with silicone wristbands as personal passive samplers. Laboratory methodology affecting precleaning, infusion, and extraction were developed from commercially available silicone, and chromatographic background interference was reduced after solvent cleanup with good extraction efficiency (>96%). After finalizing laboratory methods, 49 compounds were sequestered during an ambient deployment which encompassed a diverse set of compounds including polycyclic aromatic hydrocarbons (PAHs), consumer products, personal care products, pesticides, phthalates, and other industrial compounds ranging in log K(ow) from -0.07 (caffeine) to 9.49 (tris(2-ethylhexyl) phosphate). In two hot asphalt occupational settings, silicone personal samplers sequestered 25 PAHs during 8- and 40-h exposures, as well as 2 oxygenated-PAHs (benzofluorenone and fluorenone) suggesting temporal sensitivity over a single work day or week (p < 0.05, power =0.85). Additionally, the amount of PAH sequestered differed between worksites (p < 0.05, power = 0.99), suggesting spatial sensitivity using this novel application. PMID:24548134

  12. Silicone Wristbands as Personal Passive Samplers

    PubMed Central

    2014-01-01

    Active-sampling approaches are commonly used for personal monitoring, but are limited by energy usage and data that may not represent an individual’s exposure or bioavailable concentrations. Current passive techniques often involve extensive preparation, or are developed for only a small number of targeted compounds. In this work, we present a novel application for measuring bioavailable exposure with silicone wristbands as personal passive samplers. Laboratory methodology affecting precleaning, infusion, and extraction were developed from commercially available silicone, and chromatographic background interference was reduced after solvent cleanup with good extraction efficiency (>96%). After finalizing laboratory methods, 49 compounds were sequestered during an ambient deployment which encompassed a diverse set of compounds including polycyclic aromatic hydrocarbons (PAHs), consumer products, personal care products, pesticides, phthalates, and other industrial compounds ranging in log Kow from −0.07 (caffeine) to 9.49 (tris(2-ethylhexyl) phosphate). In two hot asphalt occupational settings, silicone personal samplers sequestered 25 PAHs during 8- and 40-h exposures, as well as 2 oxygenated-PAHs (benzofluorenone and fluorenone) suggesting temporal sensitivity over a single work day or week (p < 0.05, power =0.85). Additionally, the amount of PAH sequestered differed between worksites (p < 0.05, power = 0.99), suggesting spatial sensitivity using this novel application. PMID:24548134

  13. Solar astronomy

    NASA Technical Reports Server (NTRS)

    Rosner, Robert; Noyes, Robert; Antiochos, Spiro K.; Canfield, Richard C.; Chupp, Edward L.; Deming, Drake; Doschek, George A.; Dulk, George A.; Foukal, Peter V.; Gilliland, Ronald L.

    1991-01-01

    An overview is given of modern solar physics. Topics covered include the solar interior, the solar surface, the solar atmosphere, the Large Earth-based Solar Telescope (LEST), the Orbiting Solar Laboratory, the High Energy Solar Physics mission, the Space Exploration Initiative, solar-terrestrial physics, and adaptive optics. Policy and related programmatic recommendations are given for university research and education, facilitating solar research, and integrated support for solar research.

  14. Liquid flat plate collector and pump for solar heating and cooling systems: A collection of quarterly reports

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress in the development, fabrication, and delivery of solar subsystems consisting of a solar operated pump, and solar collectors which can be used in solar heating and cooling, or hot water, for single family, multifamily, or commercial applications is reported.

  15. Orion Passive Thermal: Control Overview

    NASA Technical Reports Server (NTRS)

    Alvarez-Hermandez, Angel; Miller, Stephen W.

    2009-01-01

    A general overview of the NASA Orion Passive Thermal Control System (PTCS) is presented. The topics include: 1) Orion in CxP Hierarchy; 2) General Orion Description/Orientation; and 3) Orion PTCS Overview.

  16. Passive vapor extraction feasibility study

    SciTech Connect

    Rohay, V.J.

    1994-06-30

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

  17. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  18. Smart, passive sun facing surfaces

    DOEpatents

    Hively, Lee M.

    1996-01-01

    An article adapted for selectively utilizing solar radiation comprises an absorptive surface and a reflective surface, the absorptive surface and the reflective surface oriented to absorb solar radiation when the sun is in a relatively low position, and to reflect solar radiation when the sun is in a relatively high position.

  19. Smart, passive sun facing surfaces

    DOEpatents

    Hively, L.M.

    1996-04-30

    An article adapted for selectively utilizing solar radiation comprises an absorptive surface and a reflective surface, the absorptive surface and the reflective surface oriented to absorb solar radiation when the sun is in a relatively low position, and to reflect solar radiation when the sun is in a relatively high position. 17 figs.

  20. Space Radiation Environmental Considerations for Commercial Space Flight

    NASA Technical Reports Server (NTRS)

    Johnson, Steve; Zapp, Neal

    2007-01-01

    This viewgraph presentation reviews basic environmental information regarding solar energetic particle events and includes some discussion slides regarding the operational impacts application as it may apply to commercial spaceflight.

  1. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    A major constraint to the evolution of solar thermal power systems is the need to provide continuous operation during periods of solar outage. A number of high temperature thermal energy storage technologies which have the potential to meet this need are currently under development. The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  2. Multistage Passive Cooler for Spaceborne Instruments

    NASA Technical Reports Server (NTRS)

    Rodriquez, Jose I.

    2007-01-01

    A document describes a three-stage passive radiative cooler for a cryogenic spectrometer to be launched into a low orbit around the Moon. This cooler is relatively lightweight and compact, and its basic design is scalable and otherwise adaptable to other applications in which there are requirements for cooling instrumentation in orbit about planets. The cooler includes multiple lightweight flat radiator blades alternating with cylindrical parabolic infrared reflectors. The radiator blades are oriented at an angle chosen to prevent infrared loading from the Moon limb at the intended orbital altitude and attitude. The reflectors are shaped and oriented to position their foci outside the radiator surfaces. There are six radiator-blade/reflector pairs - two pairs for each stage of cooling. The radiator blades and reflectors are coated on their front and back surfaces with materials having various infrared emissivities, infrared reflectivities, and solar reflectivities so as to maximize infrared radiation to cold outer space and minimize inadvertent solar heating. The radiator blades and reflectors are held in place by a lightweight support structure, the components of which are designed to satisfy a complex combination of thermal and mechanical requirements.

  3. Microgravity Passive Phase Separator

    NASA Technical Reports Server (NTRS)

    Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

    2012-01-01

    A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface

  4. Passive Wake Vortex Control

    SciTech Connect

    Ortega, J M

    2001-10-18

    works by placing shape memory alloy (SMA) control surfaces on the submarine's diving planes and periodically oscillating them. The modulated control vortices generated by these surfaces interact with the tip vortices on the diving planes, causing an instability to rapidly occur. Though several numerical simulations have been presented, experimental verification does not appear to be available in the open literature. The authors address this problem through a concept called passive wake vortex control (PWVC), which has been demonstrated to rapidly break apart a trailing vortex wake and render it incoherent. PWVC functions by introducing unequal strength, counter-rotating control vortices next to the tip vortices. The presence of these control vortices destabilizes the vortex wake and produces a rapidly growing wake instability.

  5. Passive dosimetry aboard the Mir Orbital Station: internal measurements

    NASA Technical Reports Server (NTRS)

    Benton, E. R.; Benton, E. V.; Frank, A. L.

    2002-01-01

    Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET infinity H2O > or = 5 keV/micrometers. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target

  6. Passive dosimetry aboard the Mir Orbital Station: internal measurements.

    PubMed

    Benton, E R; Benton, E V; Frank, A L

    2002-10-01

    Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET infinity H2O > or = 5 keV/micrometers. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target

  7. Passive acoustic detection of closed-circuit underwater breathing apparatus in an operational port environment.

    PubMed

    Fillinger, L; Hunter, A J; Zampolli, M; Clarijs, M C

    2012-10-01

    Divers constitute a potential threat to waterside infrastructures. Active diver detection sonars are available commercially but present some shortcomings, particularly in highly reverberant environments. This has led to research on passive sonar for diver detection. Passive detection of open-circuit UBA (underwater breathing apparatus) has been demonstrated. This letter reports on the detection of a diver wearing closed-circuit UBA (rebreather) in an operational harbor. Beamforming is applied to a passive array of 10 hydrophones in a pseudo-random linear arrangement. Experimental results are presented demonstrating detection of the rebreather at ranges up to 120 m and are validated by GPS ground truth. PMID:23039570

  8. 78 FR 45523 - Catalina Solar, LLC; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... Power Act over Catalina Solar because it will become the passive owner and lessor of a solar-powered... Energy Regulatory Commission Catalina Solar, LLC; Notice of Petition for Declaratory Order Take notice... (Commission) Rules of Practice and Procedure 18 CFR 385.207 and 385.212, Catalina Solar, LLC filed a...

  9. Passivation effects of atomic-layer-deposited aluminum oxide

    NASA Astrophysics Data System (ADS)

    Kotipalli, R.; Delamare, R.; Poncelet, O.; Tang, X.; Francis, L. A.; Flandre, D.

    2013-09-01

    Atomic-layer-deposited (ALD) aluminum oxide (Al2O3) has recently demonstrated an excellent surface passivation for both n- and p-type c-Si solar cells thanks to the presence of high negative fixed charges (Qf ~ 1012-1013 cm-2) in combination with a low density of interface states (Dit). This paper investigates the passivation quality of thin (15 nm) Al2O3 films deposited by two different techniques: plasma-enhanced atomic layer deposition (PE-ALD) and Thermal atomic layer deposition (T-ALD). Other dielectric materials taken into account for comparison include: thermally-grown silicon dioxide (SiO2) (20 nm), SiO2 (20 nm) deposited by plasma-enhanced chemical vapour deposition (PECVD) and hydrogenated amorphous silicon nitride (a-SiNx:H) (20 nm) also deposited by PECVD. With the above-mentioned dielectric layers, Metal Insulator Semiconductor (MIS) capacitors were fabricated for Qf and Dit extraction through Capacitance-Voltage-Conductance (C-V-G) measurements. In addition, lifetime measurements were carried out to evaluate the effective surface recombination velocity (SRV). The influence of extracted C-V-G parameters (Qf,Dit) on the injection dependent lifetime measurements τ(Δn), and the dominant passivation mechanism involved have been discussed. Furthermore we have also studied the influence of the SiO2 interfacial layer thickness between the Al2O3 and silicon surface on the field-effect passivation mechanism. It is shown that the field effect passivation in accumulation mode is more predominant when compared to surface defect passivation.

  10. Solar Water Heater

    NASA Technical Reports Server (NTRS)

    1993-01-01

    As a Jet Propulsion Laboratory (JPL) scientist Dr. Eldon Haines studied the solar energy source and solar water heating. He concluded he could build a superior solar water heating system using the geyser pumping principle. He resigned from JPL to develop his system and later form Sage Advance Corporation to market the technology. Haines' Copper Cricket residential system has no moving parts, is immune to freeze damage, needs no roof-mounted tanks, and features low maintenance. It provides 50-90 percent of average hot water requirements. A larger system, the Copper Dragon, has been developed for commercial installations.

  11. New steps for passive millimeter imaging

    NASA Astrophysics Data System (ADS)

    Pergande, Albert

    2007-04-01

    Passive imaging for security and other applications has reached an important level of development. Ka and W band imaging systems are now commercial products, thanks to cheap and stable amplifiers. While deployment numbers are still modest, improvements to these systems will come from engineering and algorithm development, and not fundamental research. What research should focus on are system volume reduction and resolution improvements. Fundamental research has several potential paths to solve these problems. Silicon Germanium CMOS can build acceptable millimeter wave amplifiers, and while SiGe noise figure is higher than GaAs, the ability to integrate RF and back end processing will push us closer to a CCD-like sensor. Antimony Arsenide features higher mobility than GaAs, with very low flicker noise and operation above 200 GHz which will reduce aperture size for equivalent resolution. More focus is needed in material characterization, particularly for clothing and common commercial materials. Finally, Sparse Array technology may build flat, conformal structures with high resolution and relatively low detector count. This paper will briefly discuss the time line of past innovations, and explore the advantages and challenges of the new technologies that will drive this field forward.

  12. Solar Energy Program: Chapter from the Energy and EnvironmentalDivision Annual Report 1980

    SciTech Connect

    Energy and Environment Division

    1981-03-01

    suitable for use with flat plate or higher-temperature collectors. Operation of the controls test facility and computer modeling of collector loop and building load dynamics are yielding quantitative evaluations of the performance of different control strategies for active solar-heating systems. Research is continuing on ''passive'' approaches to solar heating and cooling, where careful considerations of architectural design, construction materials, and the environment are used to moderate a building's interior climate. Computer models of passive concepts are being developed and incorporated into building energy analysis computer programs which are in the public domain. The resulting passive analysis capabilities are used in systems studies leading to design tools and in the design of commercial buildings on a case study basis. The investigation of specific passive cooling methods is an ongoing project; for example, a process is being studied in which heat-storage material would be cooled by radiation to the night sky, and would then provide ''coolness'' to the building. Laboratory personnel involved in the solar cooling, controls, and passive projects are also providing technical support to the Active Heating and Cooling Division and the Passive and Hybrid Division of DOE in developing program plans, evaluating proposals, and making technical reviews of projects at other institutions and in industry. Low-grade heat is a widespread energy resource that could make a significant contribution to energy needs if economical methods can be developed for converting it to useful work. Investigations continued this year on the feasibility of using the ''shape-memory'' alloy, Nitinol, as a basis for constructing heat engines that could operate from energy sources, such as solar-heated water, industrial waste heat, geothermal brines, and ocean thermal gradients. Several projects are investigating longer-term possibilities for utilizing solar energy. One project involves the

  13. Proposed solar two project Barstow, California

    SciTech Connect

    Not Available

    1994-01-01

    This Environmental Assessment (EA) evaluates the environmental consequences of the proposed conversion and operation of the existing Solar One Facility in Daggett, Ca, near the city of Barstow, to a nitrate salt based heat transfer system, Solar Two. The EA also addresses the alternatives of different solar conversion technologies and alternative sites and discusses a no action alternative. A primary objective of the Solar Two Project is to demonstrate the technical and economic feasibility of a solar central receiver power plant using molten salt as the thermal storage and transport fluid medium. If successful, the information gathered from the Solar Two Project could be used to design larger commercial solar power plants.

  14. Commercial Buildings Characteristics, 1992

    SciTech Connect

    Not Available

    1994-04-29

    Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

  15. Hood River Passive House, Hood River, Oregon (Fact Sheet)

    SciTech Connect

    Not Available

    2014-02-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50%" (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  16. Passivated ambipolar black phosphorus transistors.

    PubMed

    Yue, Dewu; Lee, Daeyeong; Jang, Young Dae; Choi, Min Sup; Nam, Hye Jin; Jung, Duk-Young; Yoo, Won Jong

    2016-07-01

    We report the first air-passivated ambipolar BP transistor formed by applying benzyl viologen, which serves as a surface charge transfer donor for BP flakes. The passivated BP devices exhibit excellent stability under both an ambient atmosphere and vacuum; their transistor performance is maintained semi-permanently. Unlike their intrinsic p-type properties, passivated BP devices present advantageous ambipolar properties with much higher electron mobility up to ∼83 cm(2) V(-1) s(-1) from 2-terminal measurement at 300 K, compared to other reported studies on n-type BP transistors. On the basis of the n-type doping effect that originated from benzyl viologen, we also systematically investigated the BP thickness dependence of our devices on electrical properties, in which we found the best electron transport performance to be attained when an ∼10 nm thick BP flake was used. PMID:27283027

  17. Efficient 'Optical Furnace': A Cheaper Way to Make Solar Cells is Reaching the Marketplace

    SciTech Connect

    von Kuegelgen, T.

    2008-10-01

    In Bhushan Sopori's laboratory, you'll find a series of optical furnaces he has developed for fabricating solar cells. When not in use, they sit there discreetly among the lab equipment. But when a solar silicon wafer is placed inside one for processing, Sopori walks over to a computer and types in a temperature profile. Almost immediately this fires up the furnace, which glows inside and selectively heats up the silicon wafer to 800 degrees centigrade by the intense light it produces. Sopori, a principal engineer at the National Renewable Energy Laboratory, has been researching and developing optical furnace technology for around 20 years. He says it's a challenging technology to develop because there are many issues to consider when you process a solar cell, especially in optics. Despite the challenges, Sopori and his research team have advanced the technology to the point where it will benefit all solar cell manufacturers. They are now developing a commercial version of the furnace in partnership with a manufacturer. 'This advanced optical furnace is highly energy efficient, and it can be used to manufacture any type of solar cell,' he says. Each type of solar cell or manufacturing process typically requires a different furnace configuration and temperature profile. With NREL's new optical furnace system, a solar cell manufacturer can ask the computer for any temperature profile needed for processing a solar cell, and the same type of furnace is suitable for several solar cell fabrication process steps. 'In the future, solar cell manufacturers will only need this one optical furnace because it can be used for any process, including diffusion, metallization and oxidation,' Sopori says. 'This helps reduce manufacturing costs.' One startup company, Applied Optical Systems, has recognized the furnace's potential for manufacturing thin-film silicon cells. 'We'd like to develop thin-film silicon cells with higher efficiencies, up to 15 to 18 percent, and we believe

  18. Estimating the sensitivity of passive surveillance for HPAI H5N1 in Bayelsa state, Nigeria.

    PubMed

    Ojimelukwe, Agatha E; Prakarnkamanant, Apisit; Rushton, Jonathan

    2016-07-01

    This study identified characteristics of poultry farming with a focus on practices that affect the detection of HPAI; and estimated the system sensitivity of passive surveillance for HPAI H5N1 in commercial and backyard chicken farms in Bayelsa-State, Nigeria. Field studies were carried out in Yenegoa and Ogbia local government areas in Bayelsa state. Willingness to report HPAI was highest in commercial poultry farms (13/13) than in Backyard farms (8/13). Poor means of dead bird disposal was common to both commercial and backyard farms. Administering some form of treatment to sick birds without prior consultation with a professional was higher in backyard farms (8/13) than in commercial farms (4/13). Consumption of sick birds was reported in 4/13 backyard farms and sale of dead birds was recorded in one commercial farm. The sensitivity of passive surveillance for HPAI was assessed using scenario tree modelling. A scenario tree model was developed and applied to estimate the sensitivity, i.e. the probability of detecting one or more infected chicken farms in Bayelsa state at different levels of disease prevalence. The model showed a median sensitivity of 100%, 67% and 23% for detecting HPAI by passive surveillance at a disease prevalence of 0.1%, a minimum of 10 and 3 infected poultry farms respectively. Passive surveillance system sensitivity at a design prevalence of 10 infected farms is increasable up to 86% when the disease detection in backyard chicken farms is enhanced. PMID:27317323

  19. Thermodynamic treatment of passive monitors

    SciTech Connect

    Posner, J.C.; Moore, G.

    1985-05-01

    Previous mathematical descriptions of sampling using passive monitors have used Fick's First Law of diffusion and the assumption that the concentration of adsorbate in the vapor phase above the sorbent is zero. This paper shows that by introducing a simplified expression for the equilibrium vapor pressure, behavior more nearly resembling that observed for passive monitors is predicted. The theory can also be applied to the case of loss of sample from a diffusive monitor. Experimental evidence is also provided which demonstrates that the theory adequately describes the observed results.

  20. Passivation of high temperature superconductors

    NASA Technical Reports Server (NTRS)

    Vasquez, Richard P. (Inventor)

    1991-01-01

    The surface of high temperature superconductors such as YBa2Cu3O(7-x) are passivated by reacting the native Y, Ba and Cu metal ions with an anion such as sulfate or oxalate to form a surface film that is impervious to water and has a solubility in water of no more than 10(exp -3) M. The passivating treatment is preferably conducted by immersing the surface in dilute aqueous acid solution since more soluble species dissolve into the solution. The treatment does not degrade the superconducting properties of the bulk material.