Science.gov

Sample records for ocean thermal energy

  1. Ocean Thermal Energy.

    ERIC Educational Resources Information Center

    Berkovsky, Boris

    1987-01-01

    Describes Ocean Thermal Energy Conservation (OTEC) as a method for exploiting the temperature difference between warm surface waters of the sea and its cold depths. Argues for full-scale demonstrations of the technique for producing energy for coastal regions. (TW)

  2. Ocean Thermal Extractable Energy Visualization

    SciTech Connect

    Ascari, Matthew

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  3. Ocean Thermal Energy Conversion (OTEC)

    NASA Technical Reports Server (NTRS)

    Lavi, A.

    1977-01-01

    Energy Research and Development Administration research progress in Ocean Thermal Energy Conversion (OTEC) is outlined. The development program is being focused on cost effective heat exchangers; ammonia is generally used as the heat exchange fluid. Projected costs for energy production by OTEC vary between $1000 to $1700 per kW.

  4. Ocean Thermal Energy Conversion: An overview

    SciTech Connect

    Not Available

    1989-11-01

    Ocean thermal energy conversion, or OTEC is a technology that extracts power from the ocean's natural thermal gradient. This technology is being pursued by researchers from many nations; in the United States, OTEC research is funded by the US Department of Energy's Ocean Energy Technology program. The program's goal is to develop the technology so that industry can make a competent assessment of its potential -- either as an alternative or as a supplement to conventional energy sources. Federally funded research in components and systems will help OTEC to the threshold of commercialization. This publication provides an overview of the OTEC technology. 47 refs., 25 figs.

  5. French work on ocean thermal energy conversion

    NASA Astrophysics Data System (ADS)

    Marchand, P.

    The ocean is discussed as a world-wide potential source of renewable energy, with special attention given to the 'deposit' of ocean thermal energy, which is determined by the temperature difference existing between surface water and that at a depth of 1000 m. A brief history of work done in France is presented, and mention is made of the work of d'Arsonval (1881), Claude and Boucherot (1926), and of projects, such as those at Abidjan and Guadeloupe. Attention is given to the French ocean thermal energy sites, to the Empain-Schneider closed-cycle studies, and the open-cycle floating ocean thermal energy station, with a discussion of thermodynamic considerations and cold water pipes. Problems and prospects are reviewed.

  6. Alternative energy sources session ocean thermal energy conversion: Technology development

    NASA Astrophysics Data System (ADS)

    Richards, W. E.; Vadus, J. R.

    1980-03-01

    Four ocean-energy technologies with significant promise are explored: ocean thermal energy conversion; wave power; ocean currents; and salinity gradients. The major funding emphasis has been in OTEC. Technical developments, accomplishments and major findings, remaining problems, and proposed plans for the future are discussed.

  7. Open cycle ocean thermal energy conversion system

    SciTech Connect

    Wittig, J.M.

    1980-02-19

    An improved open cycle ocean thermal energy conversion system is described including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirtconduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a tranversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure.

  8. Ocean thermal energy conversion: a review

    SciTech Connect

    Yuen, P.C.

    1981-10-01

    The OTEC principle is discussed along with general system and cycle types, specific OTEC designs, OTEC applications, and the ocean thermal resource. The historic development of OTEC is briefly reviewed, and the status of French, Japanese, EUROCEAN, and US programs is assessed. US efforts are detailed and DOE's strategy outlined with OTEC-1 and Mini-OTEC information. Power system components of the more technically advanced closed-cycle OTEC concept are discussed. These include: heat exchangers, corrosion and biofouling countermeasures, working fluids, ammonia power systems, and on-platform seawater systems. Several open-cycle features are also discussed. A critical review is presented of the ocean engineering aspects of OTEC power systems. Major subsystems such as platform, cold water pipe, mooring system, dynamic positioning system, power transmission cable system are assessed for their relationships with the ocean environment and with each other. Nine available studies of OTEC costs are reviewed. Tentative comparisons are made between OTEC and traditional fuel costs, and OTEC products and markets are considered. Possible environmental and social effects of OTEC development are discussed. International, national, and local laws regulating OTEC plants and OTEC energy products are reviewed. Tax incentives, attitudes of the utilities, and additional legislative needs are considered. (LEW)

  9. OCEAN THERMAL ENERGY CONVERSION PROGRAMMATIC ENVIRONMENTAL ASSESSMENT

    SciTech Connect

    Sands, M. Dale

    1980-08-01

    Significant achievements in Ocean Thermal Energy Conversion (OTEC) technology have increased the probability of producing OTEC-derived power in this decade with subsequent large-scale commercialization to follow by the turn of the century. Under U.S. Department of Energy funding, Interstate Electronics has prepared an OTEC Programmatic Environmental Assessment (EA) that considers tne development, demonstration, and commercialization of OTEC power systems. The EA considers several tecnnological designs (open cycle and closed cycle), plant configurations (land-based, moored, and plantship), and power usages (baseload electricity and production of ammonia and aluminum). Potencial environmental impacts, health and safety issues, and a status update of international, federal, and state plans and policies, as they may influence OTEC deployments, are included.

  10. Ocean thermal energy conversion: Perspective and status

    NASA Astrophysics Data System (ADS)

    Thomas, Anthony; Hillis, David L.

    The use of the thermal gradient between the warm surface waters and the deep cold waters of tropical oceans was first proposed by J. A. d'Arsonval in 1881 and tried unsuccessfully by George Claude in 1930. Interest in Ocean Thermal Energy Conversion (OTEC) and other renewable energy sources revived in the 1970s as a result of oil embargoes. At that time, the emphasis was on large floating plants miles from shore producing 250 to 400 MW for maintained grids. When the problems of such plants became better understood and the price of oil reversed its upward trend, the emphasis shifted to smaller (10 MW) shore based plants on tropical islands. Such plants would be especially attractive if they produce fresh water as a by-product. During the past 15 years, major progress has been made in converting OTEC unknowns into knowns. Mini-OTEC proved the closed cycle concept. Cost effective heat exchanger concepts were identified. An effective biofouling control technique was discovered. Aluminum was determined to be promising for OTEC heat exchangers. Heat transfer augmentation techniques were identified, which promised a reduction on heat exchanger size and cost. Fresh water was produced by an OTEC open cycle flash evaporator, using the heat energy in the seawater itself. The current R and D emphasis is on the design and construction of a test facility to demonstrate the technical feasibility of the open cycle process. The 10 MW shore-based, closed cycle plant can be built with today's technology; with the incorporation of a flash evaporator, it will produce fresh water as well as electrical power; both valuable commodities on many tropical islands. The open cycle process has unknowns that require solution before the technical feasibility can be demonstrated. The economic viability of either cycle depends on reducing the capital costs of OTEC plants and on future trends in the costs of conventional energy sources.

  11. Open cycle ocean thermal energy conversion system

    DOEpatents

    Wittig, J. Michael

    1980-01-01

    An improved open cycle ocean thermal energy conversion system including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flowpath and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support therefor and impart a desired flow direction to the steam.

  12. Open cycle ocean thermal energy conversion system

    SciTech Connect

    Wittig, J.M.

    1980-02-19

    An improved open cycle ocean thermal energy conversion system includes a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flow path of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flow path and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support there for and impart a desired flow direction to the steam. 10 figs.

  13. Ocean Thermal Energy Conversion Act of 1980

    SciTech Connect

    Not Available

    1980-01-01

    A legislative proposal to develop ocean thermal energy conversion (OTEC) facilities for power generation was the subject of hearings held on April 10 and May 1, 1980. Following the test of S. 2492 are the statements of 20 witnesses and additional materials submitted for consideration. The need for a large-scale demonstration of OTEC and the need for a Federal regulatory, siting, and financial-assistance framework are the major commercialization issues. S. 2492 provides one-stop licensing by treating the facilities as vessels and making them eligible for loan guarantees. The bill complements S. 1430, which deals with the demonstration program. OTEC development in Hawaii has progressed to a second pilot project. (DCK)

  14. Ocean thermal energy conversion: A review

    NASA Astrophysics Data System (ADS)

    Yuen, P. C.

    1981-10-01

    The OTEC principle along with general system and cycle, types, specific OTEC designs, OTEC applications, and the ocean thermal resource are discussed. The historic development of OTEC is reviewed, and the status of French, Japanese, EUROCEAN, and US programs is assessed. Power system components of the more technically advanced closed cycle OTEC concept are examined. These include: heat exchangers, corrosion and biofouling countermeasures, working fluids, ammonia power systems, and on platform seawater systems. Several open cycle features are also discussed. The ocean engineering aspects of OTEC power systems are reviewed. Major subsystems such as platform, cold water pipe, mooring system, dynamic positioning system, power transmission cable system are assessed for their relationships with the ocean environment and with each other. Possible environmental and social effects of OTEC development are discussed.

  15. Solar Program Assessment: Environmental Factors - Ocean Thermal Energy Conversion.

    ERIC Educational Resources Information Center

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

    This report presents the environmental problems which may arise with the further development of Ocean Thermal Energy Conversion, one of the eight Federally-funded solar technologies. To provide a background for this environmental analysis, the history and basic concepts of the technology are reviewed, as are its economic and resource requirements.…

  16. Alcan's ocean thermal energy conversion (OTEC) program

    SciTech Connect

    Hron, V.; Fitzpatrick, N.P. ); Hay, E. ); Johnson, F.A. )

    1991-01-01

    Since 1985 Alcan has been operating equipment at a test site at the National Energy Laboratory of Hawaii at Keahole Point near Kona in Hawaii. Segments of aluminum heat exchangers are exposed to surface sea water at 27{degrees} C and to water from 2000 ft down coming in at 7{degrees} C. Progress was such that in 1988 Alcan contracted GEC to design a 250 kW pilot facility. The cold deep water, suitable for air conditioning, is rich in nutrients and the hierarchy of mariculture products one might select is outlined. This paper reports that closed-cycle OTEC may be economical, practical and capable of having a significant impact upon world energy needs. It can be implemented on a small scale using revenues derived from fresh water production and mariculture.

  17. Ocean Thermal Energy Conversion Program Management Plan

    SciTech Connect

    Combs, R E

    1980-01-01

    The Office of the Associate Laboratory Director for Energy and Environmental Technology has established the OTEC Program Management Office to be responsible for the ANL-assigned tasks of the OTEC Program under DOE's Chicago Operations and Regional Office (DOE/CORO). The ANL OTEC Program Management Plan is essentially a management-by-objective plan. The principal objective of the program is to provide lead technical support to CORO in its capacity as manager of the DOE power-system program. The Argonne OTEC Program is divided into three components: the first deals with development of heat exchangers and other components of OTEC power systems, the second with development of biofouling counter-measures and corrosion-resistant materials for these components in seawater service, and the third with environmental and climatic impacts of OTEC power-system operation. The essential points of the Management Plan are summarized, and the OTEC Program is described. The organization of the OTEC Program at ANL is described including the functions, responsibilities, and authorities of the organizational groupings. The system and policies necessary for the support and control functions within the organization are discussed. These functions cross organizational lines, in that they are common to all of the organization groups. Also included are requirements for internal and external reports.

  18. Conversion of ocean thermal energy with the salt cycle

    SciTech Connect

    Saikia, S.

    1997-07-01

    A temperature gradient exists between the top and the depths of oceans, the Salt Cycle is targeted at converting this thermal energy. The phases of certain solutions (liquid-liquid or solid-liquid) separate out at lower temperatures enabling the separation of the solute. By placing the solute behind a semipermeable membrane, at a higher temperature, an osmotic pressure can be developed. The pressure released into a turbine can generate power or may be put to other uses like desalination.

  19. Utilizing Ocean Thermal Energy in a Submarine Robot

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Chao, Yi

    2009-01-01

    A proposed system would exploit the ocean thermal gradient for recharging the batteries in a battery-powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and depths, measuring temperature and salinity. The proposed system is related to, but not the same as, previously reported ocean thermal energy conversion (OTEC) systems that exploit the ocean thermal gradient but consist of stationary apparatuses that span large depth ranges. The system would include a turbine driven by working fluid subjected to a thermodynamic cycle. CO2 has been provisionally chosen as the working fluid because it has the requisite physical properties for use in the range of temperatures expected to be encountered in operation, is not flammable, and is much less toxic than are many other commercially available refrigerant fluids. The system would be housed in a pressurized central compartment in a UUV equipped with a double hull (see figure). The thermodynamic cycle would begin when the UUV was at maximum depth, where some of the CO2 would condense and be stored, at relatively low temperature and pressure, in the annular volume between the inner and outer hulls. The cycle would resume once the UUV had ascended to near the surface, where the ocean temperature is typically greater than or equals 20 C. At this temperature, the CO2 previously stored at depth in the annular volume between the inner and outer hulls would be pressurized to approx. equals 57 bar (5.7 MPa). The pressurized gaseous CO2 would flow through a check valve into a bladder inside the pressurized compartment, thereby storing energy of the relatively warm, pressurized CO2 for subsequent use after the next descent to maximum depth.

  20. Environmental programs for ocean thermal energy conversion (OTEC)

    SciTech Connect

    Wilde, P.

    1981-07-01

    The environmental research effort in support of the US Department of Energy's Ocean Thermal Energy Conversion (OTEC) program has the goal of providing documented information on the effect of proposed operations on the ocean and the effect of oceanic conditions on the plant. The associated environment program consists of archival studies in potential areas serial oceanographic cruises to sites or regions of interest, studies from various fixed platforms at sites, and compilation of such information for appropriate legal compliance and permit requirements and for use in progressive design of OTEC plants. Site/regions investigated are south of Mobile and west of Tampa, Gulf of Mexico; Punta Tuna, Puerto Rico; St. Croix, Virgin Islands; Kahe Point, Oahu and Keahole Point, Hawaii, Hawaiian Islands; and off the Brazilian south Equatorial Coast. Four classes of environmental concerns identified are: redistribution of oceanic properties (ocean water mixing, impingement/entrainment etc.); chemical pollution (biocides, working fluid leaks, etc.); structural effects (artificial reef, aggregation, nesting/migration, etc.); socio-legal-economic (worker safety, enviromaritime law, etc.).

  1. OCEAN THERMAL ENERGY CONVERSION: AN OVERALL ENVIRONMENTAL ASSESSMENT

    SciTech Connect

    Sands, M. Dale

    1980-08-01

    Significant acccrmplishments in Ocean Thermal Energy Conversion (OTEC) technology have increased the probability of producing OTEC-derived power within this decade with subsequent large scale commercialization following by the turn of the century. Under U.S. Department of Energy funding, the Oceanic Engineering Operations of Interstate Electronics Corporation has prepared several OTEC Environmental Assessments over the past years, in particular, the OTEC Programmatic Environmental Assessment. The Programmatic EA considers several technological designs (open- and closed-cycle), plant configuratlons (land-based, moored, and plant-ship), and power usages (baseload electricity, ammonia and aluminum production). Potential environmental impacts, health and safetv issues and a status update of the institutional issues as they influence OTEC deployments, are included.

  2. Heat transfer research for ocean thermal energy conversion

    NASA Astrophysics Data System (ADS)

    Kreith, F.; Bharathan, D.

    1987-03-01

    In this lecture an overview of the heat- and mass-transfer phenomena of importance in ocean thermal energy conversion (OTEC) is presented with particular emphasis on open-cycle OTEC systems. Also included is a short historical review of OTEC developments in the past century and a comparison of open- and closed-cycle thermodynamics. Finally, results of system analyses, showing the effect of plant size on cost and the near-term potential of using OTEC for combined power production and desalination systems are briefly discussed.

  3. Carbon dioxide release from ocean thermal energy conversion (OTEC) cycles

    SciTech Connect

    Green, H.J. ); Guenther, P.R. )

    1990-09-01

    This paper presents the results of recent measurements of CO{sub 2} release from an open-cycle ocean thermal energy conversion (OTEC) experiment. Based on these data, the rate of short-term CO{sub 2} release from future open-cycle OTEC plants is projected to be 15 to 25 times smaller than that from fossil-fueled electric power plants. OTEC system that incorporate subsurface mixed discharge are expected to result in no long-term release. OTEC plants can significantly reduce CO{sub 2} emissions when substituted for fossil-fueled power generation. 12 refs., 4 figs., 3 tabs.

  4. Waterborne noise due to ocean thermal energy conversion plants

    NASA Astrophysics Data System (ADS)

    Janota, C. P.; Thompson, D. E.

    1982-06-01

    Public law reflects a United States national commitment to the rapid development of Ocean Thermal Energy Conversion (OTEC) as an alternate energy source. OTEC plants extract the stored solar energy from the world's tropical seas and in so doing pose a potential for altering the character of the ambient noise there. The sources of noise from an OTEC plant are analyzed in the context of four configurations, two of which were built and tested, and two which are concepts for future full-scale moored facilities. The analysis indicates that the noise resulting from the interaction of turbulence with the sea-water pumps is expected to dominate in the frequency range 10 Hz to 1 kHZ. Measured radiated noise data from the OTEC-I research plant, located near the island of Hawaii, are compared with the analysis. The measured data diverge from the predicted levels at frequencies above about 60 Hz because of dominant non-OTEC noise sources on this platform. However, at low frequency, the measured broadband noise is comparable to that predicted.

  5. Waterborne noise due to ocean thermal energy conversion plants

    SciTech Connect

    Janota, C.P.; Thompson, D.E.

    1983-07-01

    Public law reflects a United States national commitment to the rapid development of Ocean Thermal Energy Conversion (OTEC) as an alternate energy source. OTEC plants extract the stored solar energy from the world's tropical seas and in so doing pose a potential for altering the character of the ambient noise there. The sources of noise from an OTEC plant are analyzed in the context of four configurations, two of which were built and tested, and two which are concepts for future full-scale moored facilities. The analysis indicates that the noise resulting from the interaction of turbulence with the seawater pumps is expected to dominate in the frequency range 10 Hz to 1 kHz. Measured radiated noise data from the OTEC-I research plant, located near the island of Hawaii, are compared with the analysis. The measured data diverge from the predicted levels at frequencies above about 60 Hz because of dominant non-OTEC noise sources on this platform. However, at low frequency, the measured broadband noise is comparable to that predicted.

  6. Ocean thermal energy conversion: Historical highlights, status, and forecast

    SciTech Connect

    Dugger, G.L.; Avery, W.H.; Francis, E.J.; Richards, D.

    1983-07-01

    In 1881, d'Arsonval conceived the closed-Rankine-cycle ocean thermal energy conversion (OTEC) system in which a working fluid is vaporized by heat exchange with cold water drawn from a 700-1200 m depth. In 1930, Claude demonstrated an open-cycle process in Cuba. Surface water was flash-vaporized at 3 kPa to drive a turbine directly (no secondary working fluid) and then was condensed by direct contact with water drawn from a 700-m depth through a 1.6m-diam, 1.75-km-long cold-water pipe (CWP). From a delta T of 14/sup 0/C his undersized turbine generated 22 kW. In 1956 a French team designed a 3.5-MW (net) open-cycle plant for installation off Abidjan on the Ivory Coast of Africa and demonstrated the necessary CWP deployment. The at-sea demonstrations by Mini-OTEC and OTEC-1 and other recent advances in OTEC technology summarized herein represent great progress. All of the types of plants proposed for the DOE's PON program may be worthy of development; certainly work on a grazing plant is needed. Our estimates indicate that the U.S. goals established by Public Law 96-310 leading to 10 GW of OTEC power and energy product equivalents by 1999 are achievable, provided that adequate federal financial incentives are retained to assure the building of the first few plants.

  7. Modeling Thermal and Environmental Effects of Prototype Scale Ocean Thermal Energy Conversion

    NASA Astrophysics Data System (ADS)

    Hamrick, J. M.

    2010-12-01

    Ocean thermal energy conversion (OTEC) utilizes the temperature difference between the mix lay and deep water electricity generation. The small temperature difference compared to other thermal-electric generation devises, typically between 20 and 25 C, requires the substantial volumetric flows on the order of hundreds of cubic meters per second to generate net energy and recover capital investments. This presentation described the use of a high resolution three-dimensional EFDC model with an embedded jet-plume model to simulate the thermal and environmental impacts of a number of prototype OTEC configurations on the southwest coast of Oahu, Hawaii. The EFDC model is one-way nested into a larger scale ROMS model to allow for realistic incorporation of region processes including external and internal tides and sub-tidal circulation. Impacts on local thermal structure and the potential for nutrient enrichment of the mixed layer are addressed with model and presented.

  8. Draft environmental assessment: Ocean Thermal Energy Conversion (OTEC) Pilot Plants

    SciTech Connect

    Sullivan, S.M.; Sands, M.D.; Donat, J.R.; Jepsen, P.; Smookler, M.; Villa, J.F.

    1981-02-01

    This Environmental Assessment (EA) has been prepared, in accordance with the National Environmental Policy Act of 1969, for the deployment and operation of a commercial 40-Megawatt (MW) Ocean Thermal Energy Conversion (OTEC) Pilot Plant (hereafter called the Pilot Plant). A description of the proposed action is presented, and a generic environment typical of the candidate Pilot Plant siting regions is described. An assessment of the potential environmental impacts associated with the proposed action is given, and the risk of credible accidents and mitigating measures to reduce these risks are considered. The Federal and State plans and policies the proposed action will encompass are described. Alternatives to the proposed action are presented. Appendix A presents the navigation and environmental information contained in the US Coast Pilot for each of the candidate sites; Appendix B provides a brief description of the methods and calculations used in the EA. It is concluded that environmental disturbances associated with Pilot Plant activities could potentially cause significant environmental impacts; however, the magnitude of these potential impacts cannot presently be assessed, due to insufficient engineering and environmental information. A site- and design-specific OTEC Pilot Plant Environmental Impact Statement (EIS) is required to resolve the potentially significant environmental effects associated with Pilot Plant deployment and operation. (WHK)

  9. Calibration of sonic flowmeters for Ocean Thermal Energy Conversion (OTEC)

    NASA Astrophysics Data System (ADS)

    Lott, D. F.; Salsman, G. G.; Hodges, C. E.

    1980-12-01

    Scientists at the Naval Coastal Systems Center (NCSC) at Panama City, Florida, have used a commercially available acoustic flowmeter to monitor critical flow conditions during an OTEC (Ocean Thermal Energy Conversion) funded study of the effects of biofouling on the efficiency of a prototype heat transfer system. Flowmeters of this type are particularly useful in applications requiring unimpeded flow; i.e., no sensor projecting into the moving fluid. Unfortunately, sonic flowmeters are somewhat difficult to calibrate and may be subject to drift. A method of calibration devised by NCSC may thus be of some interest to other users. It is the purpose of this report to document the special procedures used by test personnel to calibrate the flowmeters. Briefly, the calibration consisted of pumping sea water through the flowmeter into a tank suspended beneath a special load cell which provided an output voltage proportional to the weight of water in the tank. A programmable desktop calculator system was used to monitor changes in voltage as a function of time and convert these changes into flow rates for direct comparison with values read from the sonic flowmeter's digital display. Calibration checks were made at metered flows of 8, 10, 12, 14, 16, and 18 gallons per minute (gpm). It was found that computed flows were essentially linear but differed from metered values by as much as 9.0 percent.

  10. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    SciTech Connect

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  11. Potential environmental consequences of ocean thermal energy conversion (OTEC) plants. A workshop

    SciTech Connect

    Walsh, J.J.

    1981-05-01

    The concept of generating electrical power from the temperature difference between surface and deep ocean waters was advanced over a century ago. A pilot plant was constructed in the Caribbean during the 1920's but commercialization did not follow. The US Department of Energy (DOE) earlier planned to construct a single operational 10MWe Ocean Thermal Energy Conversion (OTEC) plant by 1986. However, Public Law P.L.-96-310, the Ocean Thermal Energy Conversion Research, Development and Demonstration Act, and P.L.-96-320, the Ocean Thermal Energy Conversion Act of 1980, now call for acceleration of the development of OTEC plants, with capacities of 100 MWe in 1986, 500 MWe in 1989, and 10,000 MWe by 1999 and provide for licensing and permitting and loan guarantees after the technology has been demonstrated.

  12. Open cycle ocean thermal energy conversion system structure

    DOEpatents

    Wittig, J. Michael

    1980-01-01

    A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

  13. Open-cycle Ocean Thermal Energy Conversion (OTEC): Status and potential

    NASA Astrophysics Data System (ADS)

    Bharathan, D.

    1984-08-01

    Tropical oceans with a 20 C or more temperature difference between surface and deep water represent a vast resource of renewable thermal energy. One of the methods of harnessing this resource is an open-cycle Ocean Thermal Energy Conversion (OTEC) system utilizing steam evaporated from the surface water for powering the turbine. In this paper, the state of the art of research and component development, as related to heat and mass transfer processes, power production, noncondensable gas handling, and seawater flow hydraulics, are described through an illustrated preliminary design study of a 1-MW facility.

  14. Coupling Ocean Thermal Energy Conversion technology /OTEC/ with nuclear power plants

    NASA Astrophysics Data System (ADS)

    Goldstein, M. K.; Rezachek, D.; Chen, C. S.

    The use of an Ocean Thermal Energy Conversion Related Bottoming Cycle (ORBC) to recover the waste heat generated by a large nuclear or fossil power plant is considered. To take advantage of an ORBC, a plant must be located close to cold, deep ocean water, either open-ocean or shore-based. The ORBC can also be retrofitted to existing shore-based nuclear plants or it can be a part of the design of future plants. The increased efficiency of a nuclear floating system due to the ammonia bottoming cycle and ORBC systems is shown for the example of the proposed facility in Murata, Japan. It is noted that the size of the heat exchangers and the diameter of the cold water pipe would be relatively smaller for an ORBC than for a conventional ocean thermal energy conversion system.

  15. Ocean thermal energy at the Johns Hopkins University Applied Physics Laboratory

    NASA Astrophysics Data System (ADS)

    1982-07-01

    Ocean Thermal Energy Conversion (OTEC) systems that provide synthetic fuels (e.g., methanol), energy intensive products such as ammonia (for fertilizers and chemicals), and aluminum were developed. The work also includes assessment and design concepts for hybrid plants, such as geothermal OTEC (GEOTEC) plants. Management of the conceptual design activity of the two industry teams that are designing offshore OTEC pilot plants that could deliver power to Oahu, Hawaii is discussed. In addition, a program in which tests of a different kind of ocean energy device, a turbine that is air driven as a result of wave action in a chamber is being planned.

  16. Geotechnical and geologic design considerations for a shelf mounted OTEC (Ocean Thermal Energy Conversion) facility

    NASA Astrophysics Data System (ADS)

    Miller, J. S.; Smith, R. E.

    1984-04-01

    Topics relating to the siting of an ocean thermal energy conversion facility off the coast of Oahu, Hawaii are discussed. Anticipated site conditions which would affect information requirements; potential foundation schemes used to identify key geotechnical parameters; techniques available for exploration and site characterization; and geologic and geotechnical factors and uncertainties that may be associated with site exploration and design information are discussed.

  17. Ocean thermal energy. Quarterly report, April-June 1982

    SciTech Connect

    Not Available

    1982-06-30

    This quarterly report includes summaries of the following tasks: (1) OTEC pilot plant conceptual design review; (2) OTEC methanol; (3) management decision requirements for OTEC construction; (4) hybrid geothermal - OTEC (GEOTEC) power plant performance estimates; and (5) supervision of testing of pneumatic wave energy conversion system.

  18. Ocean thermal energy. Quarterly report, January-March 1982

    SciTech Connect

    Not Available

    1982-03-30

    This quarterly report summarizes work of the following tasks as of March 31, 1982: OTEC pilot plant conceptual design review; OTEC methanol; review of electrolyzer development programs and requirements; financial and legal considerations in OTEC implementation; potential Navy sites for GEOTEC systems; hybrid geothermal-OTEC power plants: single-cycle performance estimates; and supervision of testing of pneumatic wave energy conversion system.

  19. Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power. [Ocean Thermal Energy Conversion (OTEC)

    SciTech Connect

    Rabas, T.; Panchal, C.; Genens, L.

    1990-01-01

    There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. This paper describes different OTEC plants that can supply various mixes of desalinated water and vapor -- the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs were appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed -- 40-inch high-density polyethylene pipe at Keahole Point in Hawaii. 30 refs., 6 figs., 8 tabs.

  20. Review of electrochemical energy conversion and storage for ocean thermal and wind energy systems

    NASA Astrophysics Data System (ADS)

    Landgrebe, A. R.; Donley, S. W.

    A literature review on electrochemical storage techniques related to ocean thermal (OTEC) and wind energy conversion systems (WECS) is presented. Battery use for WECS is foreseen because of siting size, variable capacity, quiet operation, and high efficiency; high cost and the necessity for further input voltage regulation is noted, as are prospects for technology transfer from existing programs for photovoltaic panel battery development. Fuel cells, which can run on hydrogen, ammonia, methanol, naphtha, etc., are encouraging because capacity increases are possible by simple addition of more fuel, and high thermal efficiency. Electrolytic use is seen as a cheap replacement source of electricity for metals refining and brine electrolysis. Systems of energy 'bridges' for OTEC plants, to transmit power to users, are reviewed as redox-flow, lithium-water-air, and aluminum batteries, fuel cells, electrolytic hydrogen, methane, and ammonia production, and the use of OTECs as power sources for floating factories. Directions of future research are indicated, noting that WECS will be in commercial production by 1985, while OTEC is far term, around 2025.

  1. Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012

    SciTech Connect

    Martel, Laura; Smith, Paul; Rizea, Steven; Van Ryzin, Joe; Morgan, Charles; Noland, Gary; Pavlosky, Rick; Thomas, Michael; Halkyard, John

    2012-05-30

    The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawaii and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the

  2. Countermeasures to Microbiofouling in Simulated Ocean Thermal Energy Conversion Heat Exchangers with Surface and Deep Ocean Waters in Hawaii

    PubMed Central

    Berger, Leslie Ralph; Berger, Joyce A.

    1986-01-01

    Countermeasures to biofouling in simulated ocean thermal energy conversion heat exchangers have been studied in single-pass flow systems, using cold deep and warm surface ocean waters off the island of Hawaii. Manual brushing of the loops after free fouling periods removed most of the biofouling material. However, over a 2-year period a tenacious film formed. Daily free passage of sponge rubber balls through the tubing only removed the loose surface biofouling layer and was inadequate as a countermeasure in both titanium and aluminum alloy tubes. Chlorination at 0.05, 0.07, and 0.10 mg liter-1 for 1 h day-1 lowered biofouling rates. Only at 0.10 mg liter-1 was chlorine adequate over a 1-year period to keep film formation and heat transfer resistance from rising above the maximum tolerated values. Lower chlorination regimens led to the buildup of uneven or patchy films which produced increased flow turbulence. The result was lower heat transfer resistance values which did not correlate with the amount of biofouling. Surfaces which were let foul and then treated with intermittent or continuous chlorination at 0.10 mg of chlorine or less per liter were only partially or unevenly cleaned, although heat transfer measurements did not indicate that fact. It took continuous chlorination at 0.25 mg liter-1 to bring the heat transfer resistance to zero and eliminate the fouling layer. Biofouling in deep cold seawater was much slower than in the warm surface waters. Tubing in one stainless-steel loop had a barely detectable fouling layer after 1 year in flow. With aluminum alloys sufficient corrosion and biofouling material accumulated to require that some fouling coutermeasure be used in long-term operation of an ocean thermal energy conversion plant. Images PMID:16347076

  3. Test results of heat exchanger cleaning in support of ocean thermal energy conversion

    NASA Astrophysics Data System (ADS)

    Lott, D. F.

    1980-12-01

    This report documents tests conducted at the Naval Coastal Systems Center (NCSC) in support of the Department of Energy's Ocean Thermal Energy Conversion (OTEC) Program. These tests covered the period September 1978 to May 1980 and evaluated flow-driven brushes, recirculating sponge rubber balls, chlorination, and mechanical system/chlorination combinations for in-situ cleaning of two potential heat exchanger materials: titanium and aluminum alloy 5052. Tests were successful when fouling resistance was 0.0003 sq. ft. hr-F/Btu. Results indicated systems and cleaning techniques using brushes, soft sponge balls, and various concentrations of chlorine had some potential for maintaining heat transfer efficiency.

  4. Ocean thermal plant

    NASA Technical Reports Server (NTRS)

    Owens, L. J. (Inventor)

    1978-01-01

    A floating energy converter is described which uses large volumes of sea water to produce electrical power. In this plant, a fluid working medium is pumped to an evaporator where is is heated by a flow of warm surface sea water. The fluid in liquid form boils to a pressurized gas vapor which is routed to drive a turbine that, in turn, drives a generator for producing electricity. The gas vapor then enters a condenser immersed in cold sea water pumped from lower depths, condenses to its original liquid form, and then pumped to the evaporator to repeat the cycle. Modular components can be readily interchanged on the ocean thermal unit and inlet pipes for the sea water are provided with means for maintaining the pipes in alignment with the oncoming current. The modular construction allows for the testing of various components to provide a more rapid optimization of a standardized plant.

  5. In-situ biofouling of ocean thermal energy conversion (OTEC) evaporator tubes

    SciTech Connect

    Sasscer, D.S.; Morgan, T.

    1981-05-01

    The Puerto Rico Center for Energy and Environmental Research equipped a LCU facility in 1100 m of water near Punta Tuna, Puerto Rico to measure in situ biofouling of simulated Ocean Thermal Energy Conversion evaporator tubes. The system consisted of two 5052 aluminum alloy and two titanium tubes, through which a continuous flow of ocean water was maintained. The tubes were cleaned three times and the fouling resistance was measured, showing only slight differences between the tubes with respect to heat transfer loss resulting from biofouling. In all units, the average fouling rate after cleaning was greater than before cleaning, and only after the first cleaning did the aluminum units show greater fouling rates than did the titanium. The titanium units showed a progressive increase in the fouling rates with each cleaning. The subsequent average fouling rates for all units after eight months were between 4 and 4.6 x 0.000010 sq m-k/W-day.

  6. Gas exchange in seawater with special emphasis on open-cycle ocean thermal energy conversion

    SciTech Connect

    Zapka, M.J.

    1988-01-01

    This study examined gas-transfer characteristics of seawater. Special emphasis is on gas-transfer processes in connection with Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) applications. Experiments probed the mechanism regulating gas transfer in bubbles and in a packed column. In order to compare gas transfer in seawater with extensively documented transfer characteristics of fresh water, all tests were conducted using both seawater and fresh water in the same experimental setting. Ten main findings are listed and briefly discussed. With appropriate system conditions, an approximately 85% removal of dissolved gas from the OC-OTEC feed stream appears to be feasible.

  7. GEOTEC (Geothermal-Enhanced Ocean Thermal Energy Conversion) engineering concept study

    SciTech Connect

    Not Available

    1984-03-01

    The project was to provide a conceptual design for a modular state-of-the-art geothermal-enhanced ocean thermal energy conversion (GEOTEC) plant for implementation at a Navy site on Adak Island, Alaska. This report includes the following appendices: (1) statement of work; (2) geothermal resource assessment; (3) assessment of environmental issues; (4) design optimization program formulations for GEOTEC; (5) calculation of geofluid temperature drop in brine collection system; (6) pressure losses and pumping requirements for seawater pipeline system; (7) geocost comparison of single and dual binary cycle systems; (8) description of seawater pipeline system; and (9) plant system installed cost estimates. (ACR)

  8. Ocean energy program summary

    SciTech Connect

    Not Available

    1990-01-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71% of the earth's surface, they collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the US Department of Energy's (DOE) Ocean Energy Technology (OET) Program is to develop techniques that harness this ocean energy cost-effectively and in a way that does not harm the environment. The program seeks to develop ocean energy technology to a point where industry can accurately assess whether the technology is a viable energy conversion alternative, or supplement, to current power-generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the OET Program is concentrating on research that advances the OTEC technology. The program also continues to monitor and study developments in wave energy, ocean current, and salinity gradient concepts; but it is not actively developing these technologies now. 13 figs.

  9. Ocean energy program summary

    NASA Astrophysics Data System (ADS)

    1990-01-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71 percent of the earth's surface, they collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the U.S. Department of Energy's (DOE) Ocean Energy Technology (OET) Program is to develop techniques that harness this ocean energy cost effectively and in a way that does not harm the environment. The program seeks to develop ocean energy technology to a point where industry can accurately assess whether the technology is a viable energy conversion alternative, or supplement, to current power generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the OET Program is concentrating on research that advances the OTEC technology. The program also continues to monitor and study developments in wave energy, ocean current, and salinity gradient concepts; but it is not actively developing these technologies now.

  10. Seawater test results of Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) components

    NASA Astrophysics Data System (ADS)

    Zangrando, F.; Bharathan, D.; Link, H.; Panchal, C. B.

    Key components of open-cycle ocean thermal energy conversion systems- the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and two direct-contact condenser stages- have been tested using seawater. These components operate at lower steam pressures and higher inlet noncondensable gas concentrations than do conventional power plant heat exchangers. The rate of heat exchanged between the evaporator and the condenser is on the order of 1.25MW-thermal, requiring a warm seawater flow of about 0.1 cu m/s; the cold seawater flow is on the order of half the warm water flow. In addition to characterizing the performance of the various components, the system has produced potable water from condensation of the steam produced in the evaporator. The information obtained in these tests is being used to design a larger scale experiment in which net power production is expected to be demonstrate for the first time using OC-OTEC technology.

  11. An assessment of ocean thermal energy conversion as an advanced electric generation methodology

    NASA Astrophysics Data System (ADS)

    Heydt, Gerald T.

    1993-03-01

    Ocean thermal energy conversion (OTEC) is a process that employs the temperature difference between surface and deep ocean water to alternately evaporate and condense a working fluid. In the open-cycle OTEC configuration, the working fluid is seawater. In the closed-cycle configuration, a working fluid such as propane is used. In this paper, OTEC is assessed for its practical merits for electric power generation, and the history of the process is reviewed. Because the OTEC principle operates under a small net temperature difference regime, rather large amounts of seawater and working fluid are required. The energy requirements for pumping these fluids may be greater than the energy recovered from the OTEC engine itself. The concept of net power production is discussed. The components of a typical OTEC plant are discussed with emphasis on the evaporator heat exchanger. Operation of an OTEC electric generating station is discussed, including transient operation. Perhaps the most encouraging aspect of OTEC is the recent experiments and efforts at the Natural Energy Laboratory in Hawaii, which are discussed in the paper. Remarks are made on bottlenecks and the future of OTEC as an advanced electric generation methodology.

  12. An assessment of ocean thermal energy conversion as an advanced electric generation methodology

    SciTech Connect

    Heydt, G.T. . School of Electrical Engineering)

    1993-03-01

    Ocean thermal energy conversion (OTEC) is a process that employs the temperature difference between surface and deep ocean water to alternately evaporate and condense a working fluid. In the open-cycle OTEC configuration, the working fluid is seawater. In the closed-cycle configuration, a working fluid such as propane is used. In this paper, OTEC is assessed for its practical merits for electric power generation. The process is not new--and its history is reviewed. Because the OTEC principle operates under a small net temperature difference regime, rather large amounts of seawater and working fluid are required. The energy requirements for pumping these fluids may be greater than the energy recovered from the OTEC engine itself. The concept of net power production is discussed. The components of a typical OTEC plant are discussed with emphasis on the evaporator heat exchanger. Operation of an OTEC electric generating station is discussed, including transient operation. Perhaps the most encouraging aspect of OTEC is the recent experiments and efforts at the Natural Energy Laboratory--Hawaii (NELH). The NELH work is summarized in the paper. Remarks are made on bottlenecks and the future of OTEC as an advanced electric generation methodology.

  13. Ocean Thermal Energy Conversion Project: OTEC support services. Monthly technical status report, October 1-31, 1980

    SciTech Connect

    1980-11-14

    The objective of this project is to provide technical engineering and management support services for the Ocean Thermal Energy Conversion (OTEC) program of the Division of Ocean Energy Systems, DOE. The principal contributions made are outlined for the following tasks: (1) Survey, analysis and recommendation concerning program performance; (2) Program technical monitoring; (3) Technical assessments; (4) OTEC system integration; (5) Environment and siting considerations; and (6) Transmission subsystem considerations.

  14. Ocean energy systems

    NASA Astrophysics Data System (ADS)

    1984-04-01

    The Johns Hopkins University Applied Physics Laboratory is engaged in developing ocean thermal energy conversion (OTEC) systems that are to provide synthetic fuels or an energy intensive product such as ammonia or aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC plants. The laboratory also has a technical advisory role with respect to DOE/DOET's management of the preliminary design activity of an industry team headed by Ocean Thermal Corporation that is designing an OTEC pilot plant that could be built in shallow water off the shore of Oahu, Hawaii. In addition, the Laboratory is now taking part in a program to evaluate and test the pneumatic wave energy conversion system, an ocean energy device consisting of a turbine that is air driven as a result of wave action in a chamber.

  15. Approach to the realization of a closed cycle Ocean Thermal Energy Conversion /OTEC/ system

    NASA Astrophysics Data System (ADS)

    Kajikawa, T.

    1981-08-01

    The design and operational features and goals of a Japanese 1 MWe Ocean Thermal Energy Conversion (OTEC) demonstration plant are described. Japan research and development efforts in OTEC systems are reviewed, along with results which have encouraged the decision to construct the demonstration plant. The plant is being designed for implementation in the seas around Japan, is required to function for 6 mos/yr, and will provide engineering data on the performance of both tube and shell type heat exchangers. The initial test will be run using Freon 22 as the working fluid, followed by NH3 in subsequent trials. The system will be barge-mounted and have a cooling water pipe fixed by single-point mooring. Mainly a proof of principle in large-scale OTEC, the plant will provide a test bed for environmental monitoring and power transmission through the sea, and will serve as a model for a 10 MWe plant.

  16. Ocean Thermal Extractable Energy Visualization- Final Technical Report on Award DE-EE0002664. October 28, 2012

    SciTech Connect

    Ascari, Matthew B.; Hanson, Howard P.; Rauchenstein, Lynn; Van Zwieten, James; Bharathan, Desikan; Heimiller, Donna; Langle, Nicholas; Scott, George N.; Potemra, James; Nagurny, N. John; Jansen, Eugene

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world's ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today's state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources. The OTEEV project leverages existing NREL renewable energy GIS technologies and integrates extractable energy estimated from quality-controlled data and projected optimal achievable energy conversion rates. Input data are synthesized from a broad range of existing in-situ measurements and ground-truthed numerical models with temporal and spatial resolutions sufficient to reflect the local resource. Energy production rates are calculated for regions based on conversion rates estimated for current technology, local energy density of the resource, and sustainable resource extraction. Plant spacing and maximum production rates are then estimated based on a default plant size and transmission mechanisms. The resulting data are organized, displayed, and accessed using a multi-layered GIS mapping tool, http://maps.nrel.gov/mhk_atlas with a user-friendly graphical user interface.

  17. Assessment of Microbial Fouling in an Ocean Thermal Energy Conversion Experiment

    PubMed Central

    Aftring, R. Paul; Taylor, Barrie F.

    1979-01-01

    A project to investigate biofouling, under conditions relevant to ocean thermal energy conversion heat exchangers, was conducted during July through September 1977 at a site about 13 km north of St. Croix (U.S. Virgin Islands). Seawater was drawn from a depth of 20 m, within the surface mixed layer, through aluminum pipes (2.6 m long, 2.5-cm internal diameter) at flow velocities of about 0.9 and 1.8 m/s. The temperature of the seawater entering the mock heat exchanger units was between 27.8 and 28.6°C. After about 10 weeks of exposure to seawater, when their thermal conductivity was reported to be significantly impaired, the pipes were assayed for the accumulation of biological material on their inner surfaces. The extent of biofouling was very low and independent of flow velocity. Bacterial populations, determined from plate counts, were about 107 cells per cm2. The ranges of mean areal densities for other biological components were: organic carbon, 18 to 27 μg/cm2; organic nitrogen, 1.5 to 3.0 μg/cm2; adenosine 5′-triphosphate, 4 to 28 ng/cm2; carbohydrate (as glucose in the phenol assay), 3.8 to 7.0 μg/cm2; chlorophyll a, 0.2 to 0.8 ng/cm2. It was estimated from the adenosine 5′-triphosphate and nitrogen contents that the layer of live bacteria present after 10 weeks was only of the order of 1μm thick. The C/N ratio of the biological material suggested the presence of extracellular polysaccharidic material. Such compounds, because of their water-retaining capacities, could account for the related increase in thermal resistance associated with the pipes. This possibility merits further investigation, but the current results emphasize the minor degree of biofouling which is likely to be permissible in ocean thermal energy conversion heat exchangers. Images PMID:16345450

  18. Gas desorption from seawater in open-cycle ocean thermal energy conversion barometric upcomers

    SciTech Connect

    Ghiaasiaan, S.M.; Wassel, A.T. ); Pesaran, A.A. )

    1990-08-01

    Gas desorption from warm and cold seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions is addressed in this paper. The desorption process of dissolved O{sub 2}, N{sub 2}, and CO{sub 2} in the barometric upcomers of an OTEC plant is simulated mathematically. The model considers the growth of bubbles originating in the ocean and bubbles formed in the upcomers. Bubble growth is induced by gas mass transfer and water evaporation at the bubble-liquid interface, as well as by the decreasing hydrostatic pressure. Heterogeneous nucleation at pipe wall crevices and on suspended particles in the water stream is also modeled. Bubble coalescence due to turbulent shear and differential buoyancy is simulated. The results generated show the deaeration efficiency as a function of flow and geometric parameters. The calculations show that gas desorption in the barometric upcomers can be appreciable. Such desorption is enhanced by increasing the concentration of the incoming and/or the heterogeneously formed bubbles. Results of existing experiments are discussed and predictions are shown for the selected test conditions.

  19. Seawater test results of open-cycle ocean thermal energy conversion (OC-OTEC) components

    SciTech Connect

    Zangrando, F.; Bharathan, D.; Link, H. ); Panchal, C.B. )

    1994-01-01

    Key components of open-cycle ocean thermal energy conversion systems--the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and two direct-contact condenser stages--have been tested using seawater. These components operate at lower steam pressures and higher inlet noncondensable gas concentrations than do conventional power plant heat exchangers. The rate of heat exchanged between the evaporator and the condenser is on the order of 1.25MW-thermal, requiring a warm seawater flow of about 0.1 m[sup 3]/s; the cold seawater flow is on the order of half the warm water flow. In addition to characterizing the performance of the various components, the system has produced potable water from condensation of the steam produced in the evaporator. The information obtained in these tests is being used to design a larger scale experiment in which net power production is expected to be demonstrate for the first time using OC-OTEC technology.

  20. Thermodynamic systems analysis of open-cycle Ocean Thermal Energy Conversion (OTEC)

    NASA Astrophysics Data System (ADS)

    Parsons, B. K.; Bharathan, D.; Althof, J. A.

    1985-09-01

    This report describes an updated thermal-hydraulic systems analysis program called OTECSYS that studies the integrated performance of an open-cycle ocean thermal energy conversion (OTEC) plant, specifically, the effects of component performance, design parameters, and site specific resource data on the total system performance and plant size. OTECSYS can size the various open-cycle power cycle and hydraulic components. Models for the evaporator, mist eliminator, turbine-generator diffuser, direct-contact condenser, exhaust compressors, seawater pumps, and seawater piping are included, as are evaluations of the pressure drops associated with the intercomponent connections. It can also determine the required steam, cold seawater, and warm seawater flow rates. OTECSYS uses an approach similar to earlier work and integrates the most up-to-date developments in component performance and configuration. The program format allows the user to examine subsystem concepts not currently included by creating new component models. It will be useful to the OTEC plant designer who wants to quantify the design point sizing, performance, and power production using site-specific resource data. Detailed design trade-offs are easily evaluated, and several examples of these types of investigations are presented using plant size and power as criteria.

  1. Waterborne noise due to ocean thermal energy conversion plants. Technical memo

    SciTech Connect

    Janota, C.P.; Thompson, D.E.

    1982-06-17

    Public law reflects a United States national commitment to the rapid development of Ocean Thermal Energy Conversion (OTEC) as an alternate energy source. OTEC plants extract the stored solar energy from the world's tropical seas and in so doing pose a potential for altering the character of the ambient noise there. The sources of noise from an OTEC plant are analyzed in the context of four configurations, two of which were built and tested, and two which are concepts for future full-scale moored facilities. The analysis indicates that the noise resulting from the interaction of turbulence with the sea-water pumps is expected to dominate in the frequency range 10 Hz to 1 kHZ. Measured radiated noise data from the OTEC-I research plant, located near the island of Hawaii, are compared with the analysis. The measured data diverge from the predicted levels at frequencies above about 60 Hz because of dominant non-OTEC noise sources on this platform. However, at low frequency, the measured broadband noise is comparable to that predicted.

  2. Ocean energy systems

    SciTech Connect

    Cavanagh, J.E.; Clarke, J.H.; Price, R.

    1993-12-31

    Energy is stored by nature in the tides, waves, and thermal and salinity gradients of the world`s oceans. Although the total energy flux of each of these renewable resources is large, only a small fraction of their potential is likely to be exploited in the foreseeable future. There are two reasons for this. First, ocean energy is spread diffusely over a wide area, requiring large and expensive plants for its collection; and second, the energy is often available in areas remote from centers of consumption. Tidal energy, which entails the use of estuarine barrages at sites having high tidal ranges, offers the best prospects in the short to medium term. Not only are its components commercially available, but many of the best sites for implementation have been identified. Indeed, on the basis of current field experience, tidal power may be regarded as a technically proven, dependable and long-lived source of electric power. The exploitation of wave energy, by comparison, is still in its infancy. Small shoreline and nearshore devices are likely to be developed first, but their applicability and potential is limited. More powerful, large-wave offshore energy plants are unlikely to be deployed for a few decades, although the bulk of ocean-energy potential is located offshore. Ocean thermal energy conversion (OTEC), which is currently in the prototype stage, is costly and largely restricted to tropical locations. Its applications are likely to be limited. Salt-gradient energy, once a focus of interest, is not expected to be exploited in the foreseeable future. Overall, the pace and extent of commercial exploitation of ocean energy is likely to be affected by the rising environmental costs of fossil fuels and by the availability of construction capital at modes real interest rates. If the largest projects are to succeed, however, government support at the national level may be necessary. 42 refs., 13 figs., 4 tabs.

  3. Ocean Thermal Energy Conversion moored pipe/mobile platform design study

    SciTech Connect

    Bullock, H.O.; McNatt, T.R.; Ross, J.M.; Stambaugh, K.A.; Watts, J.L.

    1982-07-30

    The Ocean Thermal Energy Conversion (OTEC) Moored Pipe/Mobile Platform (MP-Squared) Design Study was carried out to investigate an innovative approach to the moored floating OTEC plant. In the past, a number of concepts have been examined by NOAA for floating OTEC plants. These concepts have considered various configurations for platforms, cold water pipes and mooring systems. In most cases the cold water pipe (CWP) was permanently attached to the platform and the platform was permanently moored on station. Even though CWP concepts incorporating articulated joints or flexible pipes were used, the CWP stresses induced by platform motion were frequently excessive and beyond the design limits of the CWP. This was especially true in the survival (100-year storm) case. It may be feasible that the concept of a permanently moored CWP attached through a flexible transition CWP to the platform could reduce the degree of technical risk by de-coupling the CWP from the motions of the platform. In addition, if the platform is capable of disconnecting from the CWP during survival conditions, even less technical risk may be inherent in the OTEC system. The MP-Squared Design Study was an engineering evaluation of the concepts described above. The effort has been carried through to the conceptual design level, and culminated in model tests in an experimental wave basin.

  4. Vacuum deaeration for ocean thermal-energy-conversion open-cycle applications

    SciTech Connect

    Golshani, A.; Chen, F.C.

    1981-01-01

    Seawater deaeration is a process affecting almost all proposed Ocean Thermal Energy Conversion (OTEC) open-cycle power systems. If the noncondensable dissolved air is not removed from a power system, it will accumulate in the condenser, reduce the effectiveness of condensation, and result in deterioration of system performance. A gas desorption study was initiated at Oak Ridge National Laboratory (ORNL) with the goal of mitigating these effects; this study is designed to investigate the vacuum deaeration process for low-temperature OTEC conditions where conventional steam stripping deaeration may not be applicable. Studies were carried out on two areas: (1) vacuum deaeration in a packed column; and (2) deaeration in the barometric leg of the intake system. The design of a gas desorption test loop and a barometric intake system are described, the results of vacuum deaeration in a packed column and a barometric intake system are presented, and the saving that can be achieved when the packed column is combined with the barometric system is discussed. Vacuum deaeration laboratory experiments of three different kinds of packing in a packed column test section and a series of barometric intake deaeration experiments have been performed. A conceptual OTEC deaeration subsystem design based on these results and its implications upon an OTEC open cycle power system are presented.

  5. A review and critique of the socioeconomic impact assessment for the Kahe Point Ocean Thermal Energy Conversion (OTEC) facility

    SciTech Connect

    Bowen, R; Gopalakrishnan, C; Samples, K

    1988-01-01

    This report addresses the adequacy of Ocean Thermal Corporation's socioeconomic impact assessment of its 40-MWe closed-cycle ocean thermal energy conversion (OTEC) pilot plant proposed for Kahe Point, Oahu, Hawaii. The socioeconomic impacts identified as relevant to the plant were assessed in detail, including potential economic-demographic, public-service and fiscal, ocean-use, aesthetic, cultural, and energy impacts. The economic-demographic impact assessment does not estimate the full extent of population and income changes or second-order effects associated with the plant. There is no subjective assessment of perceptions on the part of local communities concerning probable changes in land values, housing, and population. Anticipated public-service and fiscal impacts are found to be relatively unimportant; however, the measurement of the impact of the plant on tax revenues needs improvement. The assessment does not sufficiently consider the objective and subjective assessment of ocean-use, aesthetic, and cultural impacts, which are of major significance to the local communities. The quantification of physical impacts, perceptions of impacts, and potential mitigation measures is inadequate. The energy impacts need to be updated to reflect the recent declines in oil prices and price projections. An assessment of low-probability, high-risk occurrences may be necessary. 12 refs., 3 tabs.

  6. Ocean energy systems

    NASA Astrophysics Data System (ADS)

    Progress is reported on the development of Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol), energy-intensive products such as ammonia (for fertilizers and chemicals), and aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. Another effort that began in the spring of 1982 is a technical advisory role to DOE with respect to their management of the conceptual and preliminary design activity of industry teams that are designing a shelf-mounted offshore OTEC pilot plant that could deliver power to Oahu, Hawaii. In addition, a program is underway to evaluate and test the Pneumatic Wave-Energy Conversion System (PWECS), an ocean-energy device consisting of a turbine that is air-driven as a result of wave action in a chamber. The work on the various tasks as of 31 March 1983 is reported.

  7. OTEC (Ocean Thermal Energy Conversion) Cold Water Pipe At-Sea Test Program. Phase 2: Suspended pipe test

    NASA Astrophysics Data System (ADS)

    McHale, F. A.

    1984-08-01

    An important step in the development of technology for Ocean Thermal Energy Conversion (OTEC) cold water pipes (CWP) is the at-sea testing and subsequent evaluation of a large diameter fiberglass reinforced plastic (FRP) pipe. Focus was on the CWP since it is the most critical element in any OTEC design. The results of the second phase of the CWP At-Sea Test Program are given. During this phase an 8 foot diameter, 400 foot long sandwich wall FRP syntactic foam configuration CWP test article was developed, constructed, deployed and used for data acquisition in the open ocean near Honolulu, Hawaii. This instrumented CWP as suspended from a moored platform for a three week experiment in April-May, 1983. The CWP represented a scaled version of a 40 megawatt size structure, nominally 30 feet in diameter and 3000 feet long.

  8. Ocean thermal gradient hydraulic power plant.

    PubMed

    Beck, E J

    1975-07-25

    Solar energy stored in the oceans may be used to generate power by exploiting ploiting thermal gradients. A proposed open-cycle system uses low-pressure steam to elevate vate water, which is then run through a hydraulic turbine to generate power. The device is analogous to an air lift pump. PMID:17813707

  9. The impact of coastal phytoplankton blooms on ocean-atmosphere thermal energy exchange: Evidence from a two-way coupled numerical modeling system

    NASA Astrophysics Data System (ADS)

    Jolliff, Jason K.; Smith, Travis A.; Barron, Charlie N.; deRada, Sergio; Anderson, Stephanie C.; Gould, Richard W.; Arnone, Robert A.

    2012-12-01

    A set of sensitivity experiments are performed with a two-way coupled and nested ocean-atmosphere forecasting system in order to deconvolve how dense phytoplankton stocks in a coastal embayment may impact thermal energy exchange processes. Monterey Bay simulations parameterizing solar shortwave transparency in the surface ocean as an invariant oligotrophic oceanic water type estimate consistently colder sea surface temperature (SST) than simulations utilizing more realistic, spatially varying shortwave attenuation terms based on satellite estimates of surface algal pigment concentration. These SST differences lead to an ∼88% increase in the cumulative turbulent thermal energy transfer from the ocean to the atmosphere over the three month simulation period. The result is a warmer simulated atmospheric boundary layer with respective local air temperature differences approaching ∼2°C. This study suggests that the retention of shortwave solar flux by ocean flora may directly impact even short-term forecasts of coastal meteorological variables.

  10. Ocean Thermal Energy Conversion: the potential impact on microphytoplankton of bottom water discharge at subsurface in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Giraud, Mélanie; Boye, Marie; Garçon, Véronique; L'Helguen, Stéphane; Donval, Anne; De la Broise, Denis

    2015-04-01

    Part of the solar energy can be harvested and used in different processes. Taking advantage of the natural temperature gradient between the surface and deep ocean, the Ocean Thermal Energy Conversion (OTEC) process fulfills this goal. The IMPALA project (Impacts of artificial upwelling on microplankton) aims to study the potential environmental impacts of releasing, below the surface, deep seawater flowing out of a scheduled OTEC pilot plant offshore the Martinique Island in the Caribbean Sea. Biogeochemical processes involved in the artificial upwelling generated by the use of an Ocean Thermal Energy Conversion (OTEC) plant were studied in this poor nutrient environment. The biogeochemical and physical ecosystem structure and functioning on the OTEC site were described and deep seawater discharge using in situ microcosm experiments was carried out off Martinique. Surface seawater was collected in ultra-clean conditions at two depths (corresponding to the maximum of chlorophyll a concentration and bottom of nutricline) and mixed in different proportions with deep seawater (2% and 10%). Pigments determination, picophytoplankton abundance, macro-nutrients (silicates, nitrates, and phosphates), particular organic carbon and nitrogen concentrations and primary production were documented to assess the variability between the natural environment and within the microcosms. The latter were immersed for 6 days on a 250 meters mooring. Variations observed in microcosms experiments and in the surrounding waters were compared in order to evaluate the natural variability of the phytoplankton assemblage and the potential shifts induced by deep water supply. Results obtained during two fields campaigns conducted off Martinique at the onset of the dry (November-December 2013) and wet seasons (June 2014), respectively, will be presented and discussed. Incubating mixtures of subsurface and deep waters at two ratios and at two depths, allows evaluating the potential impact of a deep

  11. Conceptual design of an open-cycle ocean thermal energy conversion net power-producing experiment (OC-OTEC NPPE)

    SciTech Connect

    Bharathan, D.; Green, H.J.; Link, H.F.; Parsons, B.K.; Parsons, J.M.; Zangrando, F.

    1990-07-01

    This report describes the conceptual design of an experiment to investigate heat and mass transfer and to assess the viability of open-cycle ocean thermal energy conversion (OC-OTEC). The experiment will be developed in two stages, the Heat- and Mass-Transfer Experimental Apparatus (HMTEA) and the Net Power-Producing Experiment (NPPE). The goal for the HMTEA is to test heat exchangers. The goal for the NPPE is to experimentally verify OC-OTEC's feasibility by installing a turbine and testing the power-generating system. The design effort met the goals of both the HMTEA and the NPPE, and duplication of hardware was minimal. The choices made for the design resource water flow rates are consistent with the availability of cold and warm seawater as a result of the seawater systems upgrade carried out by the US Department of Energy (DOE), the state of Hawaii, and the Pacific International Center for High Technology Research. The choices regarding configuration of the system were made based on projected performance, degree of technical risk, schedule, and cost. The cost for the future phase of the design and the development of the HMTEA/NPPE is consistent with the projected future program funding levels. The HMTEA and NPPE were designed cooperatively by PICHTR, Argonne National Laboratory, and Solar Energy Research Institute under the guidance of DOE. The experiment will be located at the DOE's Seacoast Test Facility at the Natural Energy Laboratory of Hawaii, Kailua-Kona, Hawaii. 71 refs., 41 figs., 34 tabs.

  12. Conceptual design of an Open-Cycle Ocean Thermal Energy Conversion Net Power-Producing Experiment (OC-OTEC NPPE)

    NASA Astrophysics Data System (ADS)

    Bharathan, D.; Green, H. J.; Link, H. F.; Parsons, B. K.; Parsons, J. M.; Zangrando, F.

    1990-07-01

    This report describes the conceptual design of an experiment to investigate heat and mass transfer and to assess the viability of open-cycle ocean thermal energy conversion (OC-OTEC). The experiment will be developed in two stages, the Heat- and Mass-Transfer Experimental Apparatus (HMTEA) and the Net Power-Producing Experiment (NPPE). The goal for the HMTEA is to test heat exchangers. The goal for the NPPE is to experimentally verify OC-OTEC's feasibility by installing a turbine and testing the power-generating system. The design effort met the goals of both the HMTEA and the NPPE, and duplication of hardware was minimal. The choices made for the design resource water flow rates are consistent with the availability of cold and warm seawater as a result of the seawater systems upgrade carried out by the U.S. Department of Energy (DOE), the state of Hawaii, and the Pacific International Center for High Technology Research. The choices regarding configuration of the system were made based on projected performance, degree of technical risk, schedule, and cost. The cost for the future phase of the design and the development of the HMTEA/NPPE is consistent with the projected future program funding levels. The HMTEA and NPPE were designed cooperatively by PICHTR, Argonne National Laboratory, and Solar Energy Research Institute under the guidance of DOE. The experiment will be located at the DOE's Seacoast Test Facility at the Natural Energy Laboratory of Hawaii, Kailua-Kona, Hawaii.

  13. Ocean energy conversion systems report

    NASA Astrophysics Data System (ADS)

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. The lift of seawater entrained in a vertical steam flow provides potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential cost must be completed to support concept evaluation. Exploratory development is completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are evaluated by analysis and model testing with emphasis on pneumatic turbines and wave focussing. Several conversion approaches to ocean current energy are being evaluated.

  14. Ocean thermal energy conversion power system development. Final design report: PSD-I, Phase II

    SciTech Connect

    1980-06-30

    The PSD-I program provides a heat exchanger sytem consisting of an evaporator, condenser and various ancillaries with ammonia used as a working fluid in a closed simulated Rankine cycle. It is to be installed on the Chepachet Research Vessel for test and evaluation of a number of OTEC concepts in a true ocean environment. It is one of several test articles to be tested. Primary design concerns include control of biofouling, corrosion and erosion of aluminum tubes, selection of materials, and the development of a basis for scale-up to large heat exchangers so as to ultimately demonstrate economic feasibility on a commercial scale. The PSD-I test article is devised to verify thermodynamic, environmental, and mechanical performance of basic design concepts. The detailed design, development, fabrication, checklist, delivery, installation support, and operation support for the Test Article Heat Exchangers are described. (WHK)

  15. Study of domestic social and economic impacts of ocean thermal energy conversion (OTEC) commercial development. Volume II. Industry profiles

    SciTech Connect

    1981-12-22

    Econoimc profiles of the industries most affected by the construction, deployment, and operation of Ocean Thermal Energy Conversion (OTEC) powerplants are presented. Six industries which will contribute materials and/or components to the construction of OTEC plants have been identified and are profiled here. These industries are: steel industry, concrete industry, titanium metal industry, fabricated structural metals industry, fiber glass-reinforced plastics industry, and electrical transmission cable industry. The economic profiles for these industries detail the industry's history, its financial and economic characteristics, its technological and production traits, resource constraints that might impede its operation, and its relation to OTEC. Some of the historical data collected and described in the profile include output, value of shipments, number of firms, prices, employment, imports and exports, and supply-demand forecasts. For most of the profiled industries, data from 1958 through 1980 were examined. In addition, profiles are included on the sectors of the economy which will actualy construct, deploy, and supply the OTEC platforms.

  16. Results of scoping tests for open-cycle OTEC (Ocean Thermal Energy Conversion) components operating with seawater

    NASA Astrophysics Data System (ADS)

    Zangrando, F.; Bharathan, D.; Green, H. J.; Link, H. F.; Parsons, B. K.; Parsons, J. M.; Pesaran, A. A.; Panchal, C. B.

    1990-09-01

    This report presents comprehensive documentation of the experimental research conducted on open-cycle ocean thermal energy conversion (OC-OTEC) components operating with seawater as a working fluid. The results of this research are presented in the context of previous analysis and fresh-water testing; they provide a basis for understanding and predicting with confidence the performance of all components of an OC-OTEC system except the turbine. Seawater tests have confirmed the results that were obtained in fresh-water tests and predicted by the analytical models of the components. A sound technical basis has been established for the design of larger systems in which net power will be produced for the first time from OC-OTEC technology. Design and operation of a complete OC-OTEC system that produces power will provide sufficient confidence to warrant complete transfer of OC-OTEC technology to the private sector. Each components performance is described in a separate chapter written by the principal investigator responsible for technical aspects of the specific tests. Chapters have been indexed separately for inclusion on the data base.

  17. Experiments on oxygen desorption from surface warm seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions

    SciTech Connect

    Pesaran, A A

    1989-12-01

    This paper reports the results of scoping deaeration experiments conducted with warm surface seawater under open-cycle ocean thermal energy conversion (OC-OTEC). Concentrations of dissolved oxygen in seawater at three locations (in the supply water, water leaving a predeaerator, and discharge water from an evaporator) were measured and used to estimate oxygen desorption levels. The results suggest that 7% to 60% of dissolved oxygen in the supply water was desorbed from seawater in the predeaerator for pressures ranging from 9 to 35 kPa. Bubble injection in the upcomer increased the oxygen desorption rate by 20% to 60%. The dependence of oxygen desorption with flow rate could not be determined. The data also indicated that at typical OC-OTEC evaporator pressures when flashing occurred, 75% to 95% of dissolved oxygen was desorbed overall from the warm seawater. The uncertainty in results is larger than one would desire. These uncertainties are attributed to the uncertainties and difficulties in the dissolved oxygen measurements. Methods to improve the measurements for future gas desorption studies for warm surface and cold deep seawater under OC-OTEC conditions are recommended. 14 refs., 5 figs., 2 tabs.

  18. Technology Development Plan: Geotechnical survey systems for OTEC (Ocean Thermal Energy Conversion) cold water pipes: Final subcontract report

    SciTech Connect

    Valent, P.J.; Riggins, M.

    1989-04-01

    This report provides an overview of current and developing technologies and techniques for performing geotechnical investigations for siting and designing Cold Water Pipes (CWP) for shelf-resting Ocean Thermal Energy Conversion (OTEC) power plants. The geotechnical in situ tools used to measure the required parameters and the equipment/systems used to deploy these tools are identified. The capabilities of these geotechnical tools and deployment systems are compared to the data requirements for the CWP foundation/anchor design, and shortfalls are identified. For the last phase of geotechnical data gathering for design, a drillship will be required to perform soil boring work, to obtain required high-quality sediment samples for laboratory dynamic testing, and to perform deep-penetration in situ tests. To remedy shortfalls and to reduce the future OTEC CWP geotechnical survey costs, it is recommended that a seafloor-resting machine be developed to advance the friction cone penetrometer, and also probably a pressuremeter, to provide geotechnical parameters to shallow subseafloor penetrations on slopes of 35/degree/ and in water depths to 1300 m. 74 refs., 19 figs., 6 tabs.

  19. Results of scoping tests for open-cycle OTEC (ocean thermal energy conversion) components operating with seawater

    SciTech Connect

    Zangrando, F; Bharathan, D; Green, H J; Link, H F; Parsons, B K; Parsons, J M; Pesaran, A A; Panchal, C B

    1990-09-01

    This report presents comprehensive documentation of the experimental research conducted on open-cycle ocean thermal energy conversion (OC-OTEC) components operating with seawater as a working fluid. The results of this research are presented in the context of previous analysis and fresh-water testing; they provide a basis for understanding and predicting with confidence the performance of all components of an OC-OTEC system except the turbine. Seawater tests have confirmed the results that were obtained in fresh-water tests and predicted by the analytical models of the components. A sound technical basis has been established for the design of larger systems in which net power will be produced for the first time from OC-OTEC technology. Design and operation of a complete OC-OTEC system that produces power will provide sufficient confidence to warrant complete transfer of OC-OTEC technology to the private sector. Each components performance is described in a separate chapter written by the principal investigator responsible for technical aspects of the specific tests. Chapters have been indexed separately for inclusion on the data base.

  20. First production of potable water by OTEC (ocean thermal energy conversion) and its potential applications

    SciTech Connect

    Thomas, A.; Hillis, D.L.

    1988-01-01

    An experiment--the Heat and Mass Transfer Scoping Test Apparatus--was built to obtain design data for a larger test that will assess the technical feasibility of the open-cycle OTEC process. (The closed-cycle concept was successfully demonstrated in 1979.) The DOE-funded project is a joint effort between Argonne National Laboratory (ANL) and the Solar Energy Research Institute (SERI). The apparatus was erected at the Natural Energy Laboratory of Hawaii and became operational in the summer of 1987. It is used by both ANL and SERI to conduct open-cycle OTEC experiments. After initial debugging, it produced 350 gallons per hour of potable water having a salinity of 86 ppM, one-fifth that of local tap water available at the test site. 6 refs., 6 figs.

  1. First production of potable water by OTEC (Ocean Thermal Energy Conversion) and its potential applications

    NASA Astrophysics Data System (ADS)

    Thomas, Anthony; Hillis, David L.

    An experiment--the Heat and Mass Transfer Scoping Test Apparatus--was built to obtain design data for a larger test that will assess the technical feasibility of the open-cycle OTEC process. (The closed-cycle concept was successfully demonstrated in 1979.) The DOE-funded project is a joint effort between Argonne National Laboratory (ANL) and the Solar Energy Research Institute (SERI). The apparatus was erected at the Natural Energy Laboratory of Hawaii and became operational in the summer of 1987. It is used by both ANL and SERI to conduct open-cycle OTEC experiments. After initial debugging, it produced 350 gallons per hour of potable water having a salinity of 86 ppM, one-fifth that of local tap water available at the test site.

  2. Impact of ocean acidification on energy metabolism of oyster, Crassostrea gigas--changes in metabolic pathways and thermal response.

    PubMed

    Lannig, Gisela; Eilers, Silke; Pörtner, Hans O; Sokolova, Inna M; Bock, Christian

    2010-01-01

    Climate change with increasing temperature and ocean acidification (OA) poses risks for marine ecosystems. According to Pörtner and Farrell, synergistic effects of elevated temperature and CO₂-induced OA on energy metabolism will narrow the thermal tolerance window of marine ectothermal animals. To test this hypothesis, we investigated the effect of an acute temperature rise on energy metabolism of the oyster, Crassostrea gigas chronically exposed to elevated CO₂ levels (partial pressure of CO₂ in the seawater ~0.15 kPa, seawater pH ~ 7.7). Within one month of incubation at elevated PCo₂ and 15 °C hemolymph pH fell (pH(e) = 7.1 ± 0.2 (CO₂-group) vs. 7.6 ± 0.1 (control)) and P(e)CO₂ values in hemolymph increased (0.5 ± 0.2 kPa (CO₂-group) vs. 0.2 ± 0.04 kPa (control)). Slightly but significantly elevated bicarbonate concentrations in the hemolymph of CO₂-incubated oysters ([HCO₃⁻](e) = 1.8 ± 0.3 mM (CO₂-group) vs. 1.3 ± 0.1 mM (control)) indicate only minimal regulation of extracellular acid-base status. At the acclimation temperature of 15 °C the OA-induced decrease in pH(e) did not lead to metabolic depression in oysters as standard metabolism rates (SMR) of CO₂-exposed oysters were similar to controls. Upon acute warming SMR rose in both groups, but displayed a stronger increase in the CO₂-incubated group. Investigation in isolated gill cells revealed a similar temperature dependence of respiration between groups. Furthermore, the fraction of cellular energy demand for ion regulation via Na+/K+-ATPase was not affected by chronic hypercapnia or temperature. Metabolic profiling using ¹H-NMR spectroscopy revealed substantial changes in some tissues following OA exposure at 15 °C. In mantle tissue alanine and ATP levels decreased significantly whereas an increase in succinate levels was observed in gill tissue. These findings suggest shifts in metabolic pathways following OA-exposure. Our study confirms that OA affects energy

  3. Impact of Ocean Acidification on Energy Metabolism of Oyster, Crassostrea gigas—Changes in Metabolic Pathways and Thermal Response

    PubMed Central

    Lannig, Gisela; Eilers, Silke; Pörtner, Hans O.; Sokolova, Inna M.; Bock, Christian

    2010-01-01

    Climate change with increasing temperature and ocean acidification (OA) poses risks for marine ecosystems. According to Pörtner and Farrell [1], synergistic effects of elevated temperature and CO2-induced OA on energy metabolism will narrow the thermal tolerance window of marine ectothermal animals. To test this hypothesis, we investigated the effect of an acute temperature rise on energy metabolism of the oyster, Crassostrea gigas chronically exposed to elevated CO2 levels (partial pressure of CO2 in the seawater ~0.15 kPa, seawater pH ~ 7.7). Within one month of incubation at elevated Pco2 and 15 °C hemolymph pH fell (pHe = 7.1 ± 0.2 (CO2-group) vs. 7.6 ± 0.1 (control)) and Peco2 values in hemolymph increased (0.5 ± 0.2 kPa (CO2-group) vs. 0.2 ± 0.04 kPa (control)). Slightly but significantly elevated bicarbonate concentrations in the hemolymph of CO2-incubated oysters ([HCO− 3]e = 1.8 ± 0.3 mM (CO2-group) vs. 1.3 ± 0.1 mM (control)) indicate only minimal regulation of extracellular acid-base status. At the acclimation temperature of 15 °C the OA-induced decrease in pHe did not lead to metabolic depression in oysters as standard metabolism rates (SMR) of CO2-exposed oysters were similar to controls. Upon acute warming SMR rose in both groups, but displayed a stronger increase in the CO2-incubated group. Investigation in isolated gill cells revealed a similar temperaturedependence of respiration between groups. Furthermore, the fraction of cellular energy demand for ion regulation via Na+/K+-ATPase was not affected by chronic hypercapnia or temperature. Metabolic profiling using 1H-NMR spectroscopy revealed substantial changes in some tissues following OA exposure at 15 °C. In mantle tissue alanine and ATP levels decreased significantly whereas an increase in succinate levels was observed in gill tissue. These findings suggest shifts in metabolic pathways following OA-exposure. Our study confirms that OA affects energy metabolism in oysters and

  4. Federal Ocean Energy Technology

    NASA Astrophysics Data System (ADS)

    1987-10-01

    The Department of Energy's (DOE) Ocean Energy Technology (OET) Program is looking for cost-effective ways to harness ocean energy to help power tomorrow's world. Federally sponsored researchers are studying methods to transform the solar heat stored in the ocean's surface waters into electricity as well as new ways to convert wave energy into mechanical energy or electricity. This report provides a summary of research completed during FY86. Four major research areas are addressed in the work covered by this report: Thermodynamic Research and Analysis addresses the process and system analyses which provide the underlying understanding of physical effects which constitute the energy conversion processes, Experimental Verification and Testing provides confirmation of the analytical projections and empirical relationships, Materials and Structural Research addresses special materials compatibility issues related to operation in the sea. Much of its focus is on concepts for the system CWP which is a major technology cost driver, and Oceanographic, Environmental, and Geotechnical Research addresss those unique design requirements imposed by construction in steep slope coastal areas.

  5. Ocean energy - Forms and prospects

    NASA Astrophysics Data System (ADS)

    Isaacs, J. D.; Schmitt, W. R.

    1980-01-01

    The primary nonpetroleum power sources of the sea can be classified as mechanical (waves, tides and currents), chemical (salinity gradients and biomass), and thermal (temperature gradients, including ice). Power potential of each of these sources, their particular characteristics, geographic distribution, energy density and feasibility of practical utilization are analyzed. Waves, tides and currents are already employed to produce power. Examples of some existing practical devices which utilize tidal and wave power are: wave pumps, Salter's Duck power plants, and tidal power plants. Different approaches to utilizing other marine power sources are discussed. The complexity of practical devices for the extraction of power seems to vary with energy density, the salinity gradient requiring the most complex approaches and the currents the simplest. Even more important than direct utilization of ocean energy may be the use of seawater as a coolant and of the sediments below the seabed for the disposal of nuclear wastes.

  6. Measurements of gas sorption from seawater and the influence of gas release on open-cycle ocean thermal energy conversion (OC-OTEC) system performance

    SciTech Connect

    Penney, T R; Althof, J A

    1985-06-01

    The technical community has questioned the validity and cost-effectiveness of open-cycle ocean thermal energy conversion (OC-OTEC) systems because of the unknown effect of noncondensable gas on heat exchanger performance and the power needed to run vacuum equipment to remove this gas. To date, studies of seawater gas desorption have not been prototypical for system level analysis. This study gives preliminary gas desorption data on a vertical spout, direct contact evaporator and multiple condenser geometries. Results indicate that dissolved gas can be substantially removed before the seawater enters the heat exchange process, reducing the uncertainty and effect of inert gas on heat exchanger performance.

  7. OTEC (Ocean Thermal Energy Conversion) cold-water pipe at-sea test program. Phase 2. Suspended pipe test. Final report

    SciTech Connect

    McHale, F.A.

    1984-08-01

    An important step in the development of technology for Ocean Thermal Energy Conversion (OTEC) cold water pipes (CWP) is the at-sea testing and subsequent evaluation of a large-diameter fiberglass-reinforced plastic (FRP) pipe. Focus has been on the CWP since it is the most critical element in any OTEC design. This report presents the results of the second phase of the CWP At-Sea Test Program. During this phase an 8-foot diameter, 400-foot long sandwich wall FRP syntactic foam configuration CWP test article was developed, constructed, deployed and used for data acquisition in the open ocean near Honolulu, Hawaii. This instrumented CWP was suspended from a moored platform for a three-week experiment in April - May, 1983. The CWP represented a scaled version of a 40-megawatt size structure, nominally 30 feet in diameter and 3000 feet long.

  8. Seasonal thermal energy storage

    SciTech Connect

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  9. Ocean Energy Program Overview, Fiscal years 1990--1991

    SciTech Connect

    Not Available

    1992-05-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71% of the earth's surface, the oceans collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the US Department of Energy's (DOE) Ocean Energy Program is to develop techniques that harness ocean energy cost effectively and in ways that do not harm the environment. The program seeks to develop ocean energy technology to a point at which industry can accurately assess whether the applications of the technology are viable energy conversion alternatives, or supplements to current power-generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the Ocean Energy Program has concentrated research that advances OTEC technology. The program also monitored developments in wave energy, ocean current, and salinity gradient concepts. It is not actively developing these technologies now. The mission of the Ocean Energy Program is to develop techniques to harness the vast solar energy stored in the oceans' waves, currents, and thermal and salinity gradients.

  10. Ocean Energy Program overview, fiscal years 1990-1991

    NASA Astrophysics Data System (ADS)

    1992-05-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71 percent of the earth's surface, the oceans collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the US Department of Energy's (DOE) Ocean Energy Program is to develop techniques that harness ocean energy cost effectively and in ways that do not harm the environment. The program seeks to develop ocean energy technology to a point at which industry can accurately assess whether the applications of the technology are viable energy conversion alternatives, or supplements to current power-generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the Ocean Energy Program has concentrated research that advances OTEC technology. The program also monitored developments in wave energy, ocean current, and salinity gradient concepts. It is not actively developing these technologies now. The mission of the Ocean Energy Program is to develop techniques to harness the vast solar energy stored in the oceans' waves, currents, and thermal and salinity gradients.

  11. Ocean energy contract list, fiscal year 1990

    SciTech Connect

    Not Available

    1991-08-01

    The purpose of the federal Ocean Energy Technology (OET) Program is to develop techniques that harness ocean energy (waves, currents, and thermal and salinity gradients) in a cost-effective and environmentally acceptable manner. The OET Program seeks to develop ocean energy technology to a point at which the commercial sector can assess whether applications of the technology are viable energy conversion alternatives or supplements to systems. The federal OET Program is conducted by DOE and is assigned to the Assistant Secretary for Conservation and Renewable Energy. Past studies conducted by the US Department of Energy (DOE) have identified ocean thermal energy conversion (OTEC) as the largest potential contributor to US energy supplies from the ocean resource. As a result, of the OET Program concentrates on research to advance OTEC technology. The FY 1990 contract overview comprises a list of all subcontracts begun, ongoing, or completed during FY 1990 (October 1, 1989, through September 30, 1990). Under each managing laboratory, projects are listed alphabetically by project area and then by subcontractor name.

  12. Ocean energy contract list, fiscal year 1990

    NASA Astrophysics Data System (ADS)

    1991-08-01

    The purpose of the Federal Ocean Energy Technology (OET) Program is to develop techniques that harness ocean energy (waves, currents, and thermal and salinity gradients) in a cost-effective and environmentally acceptable manner. The OET Program seeks to develop ocean energy technology to a point at which the commercial sector can assess whether applications of the technology are viable energy conversion alternatives or supplements to systems. The Federal OET Program is conducted by DOE and is assigned to the Assistant Secretary for Conservation and Renewable Energy. Past studies conducted by the U.S. Department of Energy (DOE) have identified ocean thermal energy conversion (OTEC) as the largest potential contributor to U.S. energy supplies from the ocean resource. As a result, the OET Program concentrates on research to advance OTEC technology. The FY 1990 contract overview comprises a list of all subcontracts begun, ongoing, or completed during FY 1990 (October 1, 1989, through September 30, 1990). Under each managing laboratory, projects are listed alphabetically by project area and then by subcontractor name.

  13. NOAA OTEC CWP (National Oceanic and Atmospheric Administration Ocean Thermal Energy Conversion Cold Water Pipe) at-sea test. Volume 3: Additional tabulation of the power spectra, part 2

    NASA Astrophysics Data System (ADS)

    1983-12-01

    Data collected during the Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe At Sea Test are analyzed. Also included are the following ittems: (1) sensor factors and offsets, and the data processing algorithms used to convert the recorded sensor measurements from electrical to engineering units; (2) plots of the power spectra estimates obtained from a fast fourier transform (FFT) analysis of selected channels; (3) plots of selected sensor measurements as a function of time; and (4) plots of bending strain along the pipe using statistics and values presented.

  14. NOAA OTEC CWP (National Oceanic and Atmospheric Administration Ocean Thermal Energy Conversion Cold Water Pipe) at-sea test. Volume 3, part 1: Tabulation of the power spectra for selected channels

    NASA Astrophysics Data System (ADS)

    1983-11-01

    Data collected during the Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe At-Sea Test was analyzed. Data presented included: (1)sensor factors and off sets and the data processing algorithms used to convert the recorded sensor measurements from electrical units to engineering units; (2) plots of the power spectra estimates obtained from a fast Fourier transform (FFT) analysis of selected channels; (3) plots of selected sensor measurements as a function of time; and (4) plots of bending strain along the pipe. The mean, root-mean-square (RMS) maximum, and minimum values at each depth are shown in each plot.

  15. Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power

    NASA Astrophysics Data System (ADS)

    Rabas, T.; Panchal, C. B.; Genens, L.

    There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. Different OTEC plants are described that can supply various mixes of desalinated water and vapor; the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs where appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed; 40 inch high density polyethylene pipe at Keahole Point in Hawaii.

  16. Ocean, Wave and Tidal Energy Systems; (USA)

    SciTech Connect

    Raridon, M.H.; Hicks, S.C.

    1991-01-01

    Ocean, Wave, and Tidal Energy Systems (OES) announces on a biomonthly basis the current worldwide information available on all aspects of ocean thermal energy conversion systems based on exploitation of the temperature difference between the surface water and ocean depth. All aspects of salinity gradient power systems based on extracting energy from mixing fresh water with seawater are included, along with information on wave and tidal power. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past two months. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements.

  17. Convective Available Potential Energy of World Ocean

    NASA Astrophysics Data System (ADS)

    Su, Z.; Ingersoll, A. P.; Thompson, A. F.

    2012-12-01

    Here, for the first time, we propose the concept of Ocean Convective Available Potential Energy (OCAPE), which is the maximum kinetic energy (KE) per unit seawater mass achievable by ocean convection. OCAPE occurs through a different mechanism from atmospheric CAPE, and involves the interplay of temperature and salinity on the equation of state of seawater. The thermobaric effect, which arises because the thermal coefficient of expansion increases with depth, is an important ingredient of OCAPE. We develop an accurate algorithm to calculate the OCAPE for a given temperature and salinity profile. We then validate our calculation of OCAPE by comparing it with the conversion of OCAPE to KE in a 2-D numerical model. We propose that OCAPE is an important energy source of ocean deep convection and contributes to deep water formation. OCAPE, like Atmospheric CAPE, can help predict deep convection and may also provide a useful constraint for modelling deep convection in ocean GCMs. We plot the global distribution of OCAPE using data from the World Ocean Atlas 2009 (WOA09) and see many important features. These include large values of OCAPE in the Labrador, Greenland, Weddell and Mediterranean Seas, which are consistent with our present observations and understanding, but also identify some new features like the OCAPE pattern in the Antarctic Circumpolar Current (ACC). We propose that the diagnosis of OCAPE can improve our understanding of global patterns of ocean convection and deep water formation as well as ocean stratification, the meridional overturning circulation and mixed layer processes. The background of this work is briefly introduced as below. Open-ocean deep convection can significantly modify water properties both at the ocean surface and throughout the water column (Gordon 1982). Open-ocean convection is also an important mechanism for Ocean Deep Water formation and the transport of heat, freshwater and nutrient (Marshall and Schott 1999). Open-ocean

  18. 40-MW(e) OTEC (Ocean Thermal Energy Conversion) plant at Kahe Point, Oahu, Hawaii: a case study of potential biological impacts. Technical memo

    SciTech Connect

    Harrison, J.T.

    1987-02-01

    Construction and operation of an Ocean Thermal Energy Conversion (OTEC) facility will affect marine, terrestrial, and atmospheric environments. The nature and degree of OTEC environmental impacts have been subjects of numerous studies and reports. The proposed 40-MWe OTEC plant at Kahe Point, Oahu, Hawaii has been the focus of much of the work. The first section provides a summary of pertinent design features of the proposed plant, including standard operating parameters. Next, salient elements of the biological oceanography in the region of the proposed development are summarized. The following sections discuss expected impacts of construction and operation of the plant, and finally, significant aspects of modeling studies conducted in support of the Kahe OTEC plant development are presented.

  19. Modeling the Physical and Biochemical Influence of Ocean Thermal Energy Conversion Plant Discharges into their Adjacent Waters

    SciTech Connect

    PAT GRANDELLI, P.E.; GREG ROCHELEAU; JOHN HAMRICK, Ph.D.; MATT CHURCH, Ph.D.; BRIAN POWELL, Ph.D.

    2012-09-29

    This paper describes the modeling work by Makai Ocean Engineering, Inc. to simulate the biochemical effects of of the nutrient-enhanced seawater plumes that are discharged by one or several 100 megawatt OTEC plants. The modeling is needed to properly design OTEC plants that can operate sustainably with acceptably low biological impact. In order to quantify the effect of discharge configuration and phytoplankton response, Makai Ocean Engineering implemented a biological and physical model for the waters surrounding O`ahu, Hawai`i, using the EPA-approved Environmental Fluid Dynamics Code (EFDC). Each EFDC grid cell was approximately 1 square kilometer by 20 meters deep, and used a time step of three hours. The biological model was set up to simulate the biochemical response for three classes of organisms: Picoplankton (< 2 um) such as prochlorococccus, nanoplankton (2-20 um), and microplankton (> 20 um) e.g., diatoms. The dynamic biological phytoplankton model was calibrated using chemical and biological data collected for the Hawaii Ocean Time Series (HOTS) project. Peer review of the biological modeling was performed. The physical oceanography model uses boundary conditions from a surrounding Hawai'i Regional Ocean Model, (ROM) operated by the University of Hawai`i and the National Atmospheric and Oceanic Administration. The ROM provided tides, basin scale circulation, mesoscale variability, and atmospheric forcing into the edges of the EFDC computational domain. This model is the most accurate and sophisticated Hawai'ian Regional Ocean Model presently available, assimilating real-time oceanographic observations, as well as model calibration based upon temperature, current and salinity data collected during 2010 near the simulated OTEC site. The ROM program manager peer-reviewed Makai's implementation of the ROM output into our EFDC model. The supporting oceanographic data was collected for a Naval Facilities Engineering Command / Makai project. Results: The model

  20. Ocean energy conversion systems annual research report

    SciTech Connect

    Not Available

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost-effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. Research projects have been funded and reported in each of these areas. The lift of seawater entrained in a vertical steam flow can provide potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential costs must be completed to support concept evaluation. Exploratory development is being completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are being evaluated by analysis and model testing with present emphasis on pneumatic turbines and wave focussing. Likewise, several conversion approaches to ocean current energy are being evaluated. The use of salinity resources requires further research in membranes or the development of membraneless processes. Using the thermal resource in a Claude cycle process as a power converter is promising, and a program of R and D and subsystem development has been initiated to provide confirmation of the preliminary conclusion.

  1. Seasonal thermal energy storage

    NASA Astrophysics Data System (ADS)

    Allen, R. D.; Kannberg, L. D.; Raymond, J. R.

    1984-05-01

    Seasonal thermal energy storage (STES) using heat or cold available from surplus, waste, climatic, or cogeneration sources show great promise to reduce peak demand, reduce electric utility load problems, and contribute to establishing favorable economics for district heating and cooling systems. Heated and chilled water can be injected, stored, and recovered from aquifers. Geologic materials are good thermal insulators, and potentially suitable aquifers are distributed throughout the United States. Potential energy sources for use in an aquifer thermal energy storage system include solar heat, power plant cogeneration, winter chill, and industrial waste heat source. Topics covered include: (1) the U.S. Department of Energy seasonal thermal energy storage program; (2) aquifer thermal energy storage technology; (3) alternative STES technology; (4) foreign studies in seasonal thermal energy storage; and (5) economic assessment.

  2. Ocean tide energy converter

    SciTech Connect

    Rainey, D.E.

    1980-06-24

    A tide motor energy source includes a tidal piston with a valved chamber. The piston drives a hydraulic ram to generate electrical power through a pressure accumulator and hydraulic motor. The ram can be locked hydraulically to enable the tidal piston to be held fixed at a desired elevation and the valves in the chamber permit it to be filled with water or air. The piston with its chamber filled with air at its low tide position and then released for controlled ascent while submerged acts as a submerged float for driving the ram upwardly while the tide runs in during one phase of its operation. The piston with its chamber filled with water while locked at its highest position as the tide begins to run out, and then released to fall under control, acts as a weight suspended in air after the water level drops below the piston for driving the ram downwardly during the second phase of its operation. The rising and falling motion of the tidal piston is used as the energy source.

  3. Thermal energy storage

    SciTech Connect

    Tomlinson, J.J. ); Kannberg, L.D. )

    1990-09-01

    This paper discusses how thermal energy storage (TES) can aid in the efficient use and provision of thermal energy, wherever there is a mismatch between energy generation and use. Three fundamental types of thermal energy storage processes (sensible, latent, and thermochemical) can be used, and many different media are available within each type. Various subsets of these processes are being researched and developed to accelerate TES implementation, focusing on applications in building heating and cooling, industrial energy efficiency, and utility and space power systems. TES can contribute significantly to meeting society's needs for more efficient, environmentally benign energy use in these and other sectors.

  4. HEATS: Thermal Energy Storage

    SciTech Connect

    2012-01-01

    HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

  5. Thermal energy transformer

    NASA Technical Reports Server (NTRS)

    Berdahl, C. M.; Thiele, C. L. (Inventor)

    1979-01-01

    For use in combination with a heat engine, a thermal energy transformer is presented. It is comprised of a flux receiver having a first wall defining therein a radiation absorption cavity for converting solar flux to thermal energy, and a second wall defining an energy transfer wall for the heat engine. There is a heat pipe chamber interposed between the first and second walls having a working fluid disposed within the chamber and a wick lining the chamber for conducting the working fluid from the second wall to the first wall. Thermal energy is transferred from the radiation absorption cavity to the heat engine.

  6. Thermal energy storage

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Picklesimer, E. A.

    1978-01-01

    The general scope of study on thermal energy storage development includes: (1) survey and review possible concepts for storing thermal energy; (2) evaluate the potentials of the surveyed concepts for practical applications in the low and high temperature ranges for thermal control and storage, with particular emphasis on the low temperature range, and designate the most promising concepts; and (3) determine the nature of further studies required to expeditiously convert the most promising concept(s) to practical applications. Cryogenic temperature control by means of energy storage materials was also included.

  7. Ocean wave energy converting vessel

    SciTech Connect

    Boyce, P.F.

    1986-08-26

    An ocean wave energy conversion system is described comprised of a four beam quadrapod supported by bouyant members from which is suspended a pendulum. The pendulum contains a vertical generator shaft and a generator, the generator shaft being splined and fitted with two racheted pulleys, the pulleys being looped, one clockwise and one counterclockwise with separate cables. The cables are attached at their ends to the bow and stern of the quadrapod, whereby the generator shaft will pin when the quadrapod rocks over waves and the pendulum tends toward the center of earth.

  8. Thermal energy storage

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

  9. Ocean energy systems: Multiyear program plan

    NASA Astrophysics Data System (ADS)

    1980-05-01

    Specific planned activities to be conducted by the Department of Energy in connection with the Ocean Energy System Program for FY 1979 through FY 1984 are described. Program funding is presently 95 percent OTEC, with 5 percent directed toward alternate energy sources such as salinity gradients waves and currents, technical status, ocean energy systems resource requirements, issues, and a management plan are discussed.

  10. Ocean Energy Program Overview, Fiscal years 1990--1991. Programs in utility technologies

    SciTech Connect

    Not Available

    1992-05-01

    The oceans are the world`s largest solar energy collector and storage system. Covering 71% of the earth`s surface, the oceans collect and store this energy as waves, currents, and thermal and salinity gradients. The purpose of the US Department of Energy`s (DOE) Ocean Energy Program is to develop techniques that harness ocean energy cost effectively and in ways that do not harm the environment. The program seeks to develop ocean energy technology to a point at which industry can accurately assess whether the applications of the technology are viable energy conversion alternatives, or supplements to current power-generating systems. In past studies, DOE identified ocean thermal energy conversion (OTEC), which uses the temperature difference between warm surface water and cold deep water, as the most promising of the ocean energy technologies. As a result, the Ocean Energy Program has concentrated research that advances OTEC technology. The program also monitored developments in wave energy, ocean current, and salinity gradient concepts. It is not actively developing these technologies now. The mission of the Ocean Energy Program is to develop techniques to harness the vast solar energy stored in the oceans` waves, currents, and thermal and salinity gradients.

  11. Thermal energy and the origin of life.

    PubMed

    Muller, Anthonie W J; Schulze-Makuch, Dirk

    2006-04-01

    Life has evolved on Earth with electromagnetic radiation (light), fermentable organic molecules, and oxidizable chemicals as sources of energy. Biological use of thermal energy has not been observed although heat, and the thermal gradients required to convert it into free energy, are ubiquitous and were even more abundant at the time of the origin of life on Earth. Nevertheless, Earth-organisms sense thermal energy, and in suitable environments may have gained the capability to use it as energy source. It has been proposed that the first organisms obtained their energy by a first protein named pF(1) that worked on a thermal variation of the binding change mechanism of today's ATP sythase enzyme. Organisms using thermosynthesis may still live where light or chemical energy sources are not available. Possible suitable examples are subsurface environments on Earth and in the outer Solar System, in particular the subsurface oceans of the icy satellites of Jupiter and Saturn. PMID:16642267

  12. Comprehensive plate models for the thermal evolution of oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Grose, Christopher J.; Afonso, Juan Carlos

    2013-09-01

    Seafloor spreading and the cooling of oceanic lithosphere is a fundamental feature of plate tectonics in the Earth, the details of which are unveiled by modeling with constraints from mineral physics and geophysical observations. To work toward a more complete model of the thermal evolution of oceanic lithosphere, we investigate the contributions of axial hydrothermal circulation, oceanic crust, and temperature-pressure-dependent thermal properties. We find that models with only temperature-dependent properties disagree with geophysical observations unless properties are artificially modified. On the other hand, more comprehensive models are in better agreement with geophysical observations. Our preferred model requires a thermal expansivity reduction of 15% from a mineral physics estimate, and predicts a plate thickness of about 110-130 km. A principal result of our analysis is that the oceanic crust is a major contributor to the cooling of oceanic lithosphere. The oceanic crust acts as an insulating lid on the mantle, causing the rate of lithospheric cooling to increase from "crustal" values near the ridge to higher mantle values at old-age. Major consequences of this insulation effect are: (a) low seafloor subsidence rate in proximity to ridge axes (<5 Ma), (b) the thermal structure of oceanic lithosphere is significantly warmer than previous models, (c) seafloor heat flow is significantly lower over young (<35 Ma) seafloor compared to simple models, (d) a low net seafloor heat flux (˜27 TW), and (e) temperature at the base of the seismogenic zone extends to 700-800°C mantle.

  13. Oceanic lithosphere and asthenosphere: The thermal and mechanical structure

    NASA Technical Reports Server (NTRS)

    Schubert, G.; Froidevaux, C.; Yuen, D. A.

    1976-01-01

    A coupled thermal and mechanical solid state model of the oceanic lithosphere and asthenosphere is presented. The model includes vertical conduction of heat with a temperature dependent thermal conductivity, horizontal and vertical advection of heat, viscous dissipation or shear heating, and linear or nonlinear deformation mechanisms with temperature and pressure dependent constitutive relations between shear stress and strain rate. A constant horizontal velocity u sub 0 and temperature t sub 0 at the surface and zero horizontal velocity and constant temperature t sub infinity at great depth are required. In addition to numerical values of the thermal and mechanical properties of the medium, only the values of u sub 0, t sub 0 and t sub infinity are specified. The model determines the depth and age dependent temperature horizontal and vertical velocity, and viscosity structures of the lithosphere and asthenosphere. In particular, ocean floor topography, oceanic heat flow, and lithosphere thickness are deduced as functions of the age of the ocean floor.

  14. Ocean, Wave, and Tidal Energy Systems: Current abstracts

    NASA Astrophysics Data System (ADS)

    Smith, L.; Lane, D. W.

    1988-01-01

    Ocean, Wave, and Tidal Energy Systems (OES) announces on a bimonthly basis the current worldwide information available on all aspects of ocean thermal energy conversion systems based on exploitation of the temperature difference between the surface water and ocean depth. All aspects of salinity gradient power systems based on extracting energy from mixing fresh water with seawater are included, along with information on wave and tidal power. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Data Base (EDB) during the past two months. Also included are U.S. information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements.

  15. Thermal energy storage material

    DOEpatents

    Leifer, Leslie

    1976-01-01

    A thermal energy storage material which is stable at atmospheric temperature and pressure and has a melting point higher than 32.degree.F. is prepared by dissolving a specific class of clathrate forming compounds, such as tetra n-propyl or tetra n-butyl ammonium fluoride, in water to form a substantially solid clathrate. The resultant thermal energy storage material is capable of absorbing heat from or releasing heat to a given region as it transforms between solid and liquid states in response to temperature changes in the region above and below its melting point.

  16. Ocean energy program summary. Volume 2: Research summaries

    NASA Astrophysics Data System (ADS)

    1990-01-01

    The oceans are the world's largest solar energy collector and storage system. Covering 71 percent of the earth's surface, this stored energy is realized as waves, currents, and thermal salinity gradients. The purpose of the Federal Ocean Energy Technology (OET) Program is to develop techniques that harness this ocean energy in a cost effective and environmentally acceptable manner. The OET Program seeks to develop ocean energy technology to a point where the commercial sector can assess whether applications of the technology are viable energy conversion alternatives or supplements to systems. Past studies conducted by the U.S. Department of Energy (DOE) have identified ocean thermal energy conversion (OTEC) as the largest potential contributor to United States energy supplies from the ocean resource. As a result, the OET Program concentrates on research to advance OTEC technology. Current program emphasis has shifted to open-cycle OTEC power system research because the closed-cycle OTEC system is at a more advanced stage of development and has already attracted industrial interest. During FY 1989, the OET Program focused primarily on the technical uncertainties associated with near-shore open-cycle OTEC systems ranging in size from 2 to 15 MW(sub e). Activities were performed under three major program elements: thermodynamic research and analysis, experimental verification and testing, and materials and structures research. These efforts addressed a variety of technical problems whose resolution is crucial to demonstrating the viability of open-cycle OTEC technology. This publications is one of a series of documents on the Renewable Energy programs sponsored by the U.S. Department of Energy. An overview of all the programs is available, entitled Programs in Renewable Energy.

  17. Solar thermal energy receiver

    NASA Technical Reports Server (NTRS)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  18. Ocean floor mounting of wave energy converters

    SciTech Connect

    Siegel, Stefan G

    2015-01-20

    A system for mounting a set of wave energy converters in the ocean includes a pole attached to a floor of an ocean and a slider mounted on the pole in a manner that permits the slider to move vertically along the pole and rotate about the pole. The wave energy converters can then be mounted on the slider to allow adjustment of the depth and orientation of the wave energy converters.

  19. Article for thermal energy storage

    DOEpatents

    Salyer, Ival O.

    2000-06-27

    A thermal energy storage composition is provided which is in the form of a gel. The composition includes a phase change material and silica particles, where the phase change material may comprise a linear alkyl hydrocarbon, water/urea, or water. The thermal energy storage composition has a high thermal conductivity, high thermal energy storage, and may be used in a variety of applications such as in thermal shipping containers and gel packs.

  20. Aquifer thermal energy storage program

    NASA Technical Reports Server (NTRS)

    Fox, K.

    1980-01-01

    The purpose of the Aquifer Thermal Energy Storage Demonstration Program is to stimulate the interest of industry by demonstrating the feasibility of using a geological formation for seasonal thermal energy storage, thereby, reducing crude oil consumption, minimizing thermal pollution, and significantly reducing utility capital investments required to account for peak power requirements. This purpose will be served if several diverse projects can be operated which will demonstrate the technical, economic, environmental, and institutional feasibility of aquifer thermal energy storage systems.

  1. Thermal Energy Conversion Branch

    NASA Technical Reports Server (NTRS)

    Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

    2004-01-01

    The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

  2. Thermal Coupling Between the Ocean and Mantle of Europa: Implications for Ocean Convection

    NASA Astrophysics Data System (ADS)

    Soderlund, Krista M.; Schmidt, Britney E.; Wicht, Johannes; Blankenship, Donald D.

    2015-11-01

    Magnetic induction signatures at Europa indicate the presence of a subsurface ocean beneath the cold icy crust. The underlying mantle is heated by radioactive decay and tidal dissipation, leading to a thermal contrast sufficient to drive convection and active dynamics within the ocean. Radiogenic heat sources may be distributed uniformly in the interior, while tidal heating varies spatially with a pattern that depends on whether eccentricity or obliquity tides are dominant. The distribution of mantle heat flow along the seafloor may therefore be heterogeneous and impact the regional vigor of ocean convection. Here, we use numerical simulations of thermal convection in a global, Europa-like ocean to test the sensitivity of ocean dynamics to variations in mantle heat flow patterns. Towards this end, three end-member cases are considered: an isothermal seafloor associated with dominant radiogenic heating, enhanced seafloor temperatures at high latitudes associated with eccentricity tides, and enhanced equatorial seafloor temperatures associated with obliquity tides. Our analyses will focus on convective heat transfer since the heat flux pattern along the ice-ocean interface can directly impact the ice shell and the potential for geologic activity within it.

  3. The thermal infrared radiance properties of dust aerosol over ocean

    NASA Astrophysics Data System (ADS)

    Hao, Zengzhou; Pan, Delu; Tu, Qianguang; Gong, Fang; Chen, Jianyu

    2015-10-01

    Asian dust storms, which can long-range transport to ocean, often occur on spring. The present of Asian dust aerosols over ocean makes some difficult for other studies, such as cloud detection, and also take some advantage for ocean, such as take nutrition into the ocean by dry or wet deposition. Therefore, it is important to study the dust aerosol and retrieve the properties of dust from satellite observations that is mainly from the thermal infrared radiance. In this paper, the thermal infrared radiance properties of dust aerosol over ocean are analyzed from MODIS and MTSAT2 observations and Streamer model simulations. By analyzing some line samples and a series of dust aerosol region, it shows that the dust aerosol brightness temperature at 12μm (BT12) is always greater than BT11 and BT8.5, and BT8.5 is general greater than BT11. The brightness temperature different between 11μm and 12μm (BTD11-12) increases with the dust intensity. And the BTD11-12 will become positive when the atmospheric relative humidity is greater than 70%. The BTD11-12 increases gradually with the surface temperature while the effect on BTD11-12 of dust layer temperature is not evident. Those are caused by the transmission of the dust aerosol is different at the two thermal infrared channels. During daytime, dust infrared brightness temperature at mid-infrared bands should reduce the visual radiance, which takes about 25K or less. In general, BT3.7 is greater than BT11 for dust aerosol. Those results are helpful to monitor or retrieve dust aerosol physical properties over ocean from satellite.

  4. Thermal evolution and chemical differentiation of the terrestrial magma ocean

    NASA Technical Reports Server (NTRS)

    Abe, Y.

    1992-01-01

    The release of gravitational energy resulted in global melting and formation of a magma ocean during accretion of the Earth. Although it is believed that the formation of the magma ocean resulted in gravitational differentiation of melt and solid, the differentiation might be disturbed by the following processes: (1) convective mixing; (2) cooling and solidification; and (3) growth of the earth, which results in secular increase of pressure, and stirring by planetesimal impacts. The purpose of this study is to investigate the differentiation processes of the terrestrial magma ocean by taking into account various disturbing processes.

  5. HARNESSING OCEAN WAVE ENERGY TO GENERATE ELECTRICITY

    EPA Science Inventory

    A technical challenge to sustainability is finding an energy source that is abundant enough to meet global demands without producing greenhouse gases or radioactive waste. Energy from ocean surface waves can provide the people of this planet a clean, endless power source to me...

  6. Ocean energy systems. Quarterly report, January-March 1983

    SciTech Connect

    Not Available

    1983-03-30

    Progress is reported on the development of Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol), energy-intensive products such as ammonia (for fertilizers and chemicals), and aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. Another effort that began in the spring of 1982 is a technical advisory role to DOE with respect to their management of the conceptual and preliminary design activity of industry teams that are designing a shelf-mounted offshore OTEC pilot plant that could deliver power to Oahu, Hawaii. In addition, a program is underway to evaluate and test the Pneumatic Wave-Energy Conversion System (PWECS), an ocean-energy device consisting of a turbine that is air-driven as a result of wave action in a chamber. This Quarterly Report summarizes the work on the various tasks as of 31 March 1983.

  7. Thermal energy test apparatus

    NASA Astrophysics Data System (ADS)

    Audet, N. F.

    1991-10-01

    The Navy Clothing and Textile Research Facility (NCTRF) designed and fabricated a thermal energy test apparatus to permit evaluation of the heat protection provided by crash crew firefighter's proximity clothing materials against radiant and convective heat loads, similar to those found outside the flame zone of aircraft fuel fires. The apparatus employs electrically operated quartz lamp radiant heaters and a hot air convective heater assembly to produce the heat load conditions the materials to be subjected to, and is equipped with heat flux sensors of different sensitivities to measure the incident heat flux on the sample material as well as the heat flux transmitted by the sample. Tests of the apparatus have shown that it can produce radiant heat flux levels equivalent to those estimated to be possible in close proximity to large aircraft fuel fires, and can produce convective heat fluxes equivalent to those measured in close proximity to aircraft fuel fires at upwind and sidewind locations. Work was performed in 1974.

  8. The global land and ocean mean energy balance

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris

    2016-04-01

    The energy balance over land and oceans governs a diversity of terrestrial and maritime processes and is the key determinant of climatic conditions in these areas. Despite its crucial role, climate models show significant differences in the individual components of the energy balance over both land and oceans, particularly at the surface. Here we combine a comprehensive set of radiation observations from GEBA and BSRN with 43 state-of-the-art climate models to infer best estimates for present day annual mean downward solar and thermal radiation averaged over land and ocean surfaces, together with their uncertainty ranges. Over land (including the polar ice sheets), where most direct observations are available to constrain the surface fluxes, we obtain 184 and 306 Wm-2 for solar and thermal downward radiation, respectively. Over oceans, with weaker observational constraints, corresponding estimates are around 185 and 356 Wm-2. These values closely agree, mostly within 3 Wm-2, with the respective quantities independently derived by a state-of-the-art reanalysis (ERA-Interim) and satellite-derived product (surface CERES EBAF). This remarkable consistency enhances confidence in the determined flux magnitudes, which so far stated large uncertainty sources in the energy budgets. The estimated downward solar radiation averaged over land and ocean surfaces is almost identical despite differences in the incoming solar flux at the Top-of-Atmosphere (TOA) around 20 Wm-2, indicative of an overall less transparent atmosphere over oceans than land. Considering additionally surface albedo and emissivity, we infer a surface absorbed solar and net thermal radiation of 136 and -66 Wm-2 over land, and 170 and -53 Wm-2 over oceans, respectively. The surface net radiation is thus estimated at 70 Wm-2 over land and 117 Wm-2 over oceans, which may impose additional constraints on the poorly known sensible and latent heat flux magnitudes. These are estimated here near 32 and 38 Wm-2 over

  9. Oceanic lithosphere and asthenosphere - Thermal and mechanical structure

    NASA Technical Reports Server (NTRS)

    Schubert, G.; Yuen, D. A.; Froidevaux, C.

    1976-01-01

    A coupled thermomechanical subsolidus model of the oceanic lithosphere and asthenosphere is developed which includes vertical heat conduction, a temperature-dependent thermal conductivity, heat advection by a horizontal and vertical mass flow that depends on depth and age, contributions of viscous dissipation or shear heating, a linear or nonlinear deformation law relating shear stress and strain rate, as well as a temperature- and pressure-dependent viscosity. The model requires a constant horizontal velocity and temperature at the surface, but zero horizontal velocity and constant temperature at great depths. The depth- and age-dependent temperature, horizontal and vertical velocities, and viscosity structure of the lithosphere and asthenosphere are determined along with the age-dependent shear stress in those two zones. The ocean-floor topography, oceanic heat flow, and lithosphere thickness are deduced as functions of ocean-floor age; seismic velocity profiles which exhibit a marked low-velocity zone are constructed from the age-dependent geotherms and assumed values of the elastic parameters. It is found that simple boundary-layer cooling determines the thermal structure at young ages, while effects of viscous dissipation become more important at older ages.

  10. Thermal stresses due to cooling of a viscoelastic oceanic lithosphere

    SciTech Connect

    Denlinger, R.P. ); Savage, W.Z. )

    1989-01-10

    Theories based upon thermal contraction of cooling oceanic lithosphere provide a successful basis for correlating seafloor bathymetry and heat flow. The horizontal components of the contraction of the lithosphere as it cools potentially give rise to large thermal stresses. Current methods to calculate these stresses assume that on the time scales of cooling, the lithosphere initially behaves as an inviscid fluid and instantly freezes into an elastic solid at some critical temperature. These instant-freezing methods inaccurately predict transient thermal stresses in rapidly cooling silicate glass plates because of the temperature dependent rheology of the material. The temperature dependent rheology of the lithosphere may affect the transient thermal stress distribution in a similar way, and for this reason the authors use a thermoviscoelastic model to estimate thermal stresses in young oceanic lithosphere. This theory is formulated here for linear creep processes that have an Arrhenius rate dependence on temperature. Results show that the stress differences between instant freezing and linear thermoviscoelastic theory are most pronounced at early times (0-20 m.y.) when the instant freezing stresses may be twice as large. The solutions for the two methods asymptotically approach the same solution with time. A comparison with intraplate seismicity shows that both methods underestimate the depth of compressional stresses inferred from the seismicity in a systematic way.

  11. Thermal stresses due to cooling of a viscoelastic oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Denlinger, Roger P.; Savage, William Z.

    1989-01-01

    Theories based upon thermal contraction of cooling oceanic lithosphere provide a successful basis for correlating seafloor bathymetry and heat flow. The horizontal components of the contraction of the lithosphere as it cools potentially give rise to large thermal stresses. Current methods to calculate these stresses assume that on the time scales of cooling, the lithosphere initially behaves as an inviscid fluid and instantly freezes into an elastic solid at some critical temperature. These instant-freezing methods inaccurately predict transient thermal stresses in rapidly cooling silicate glass plates because of the temperature dependent rheology of the material. The temperature dependent rheology of the lithosphere may affect the transient thermal stress distribution in a similar way, and for this reason we use a thermoviscoelastic model to estimate thermal stresses in young oceanic lithosphere. This theory is formulated here for linear creep processes that have an Arrhenius rate dependence on temperature. Our results show that the stress differences between instant freezing and linear thermoviscoelastic theory are most pronounced at early times (0-20 m.y.) when the instant freezing stresses may be twice as large. The solutions for the two methods asymptotically approach the same solution with time. A comparison with intraplate seismicity shows that both methods underestimate the depth of compressional stresses inferred from the seismicity in a systematic way.

  12. Ocean thermal plantships for production of ammonia as the hydrogen carrier.

    SciTech Connect

    Panchal, C.B.; Pandolfini, P. P.; Kumm, W. H.; Energy Systems; Johns Hopkins Univ.; Arctic Energies, Ltd.

    2009-12-02

    Conventional petroleum, natural gas, and coal are the primary sources of energy that have underpinned modern civilization. Their continued availability in the projected quantities required and the impacts of emission of greenhouse gases (GHGs) on the environment are issues at the forefront of world concerns. New primary sources of energy are being sought that would significantly reduce the emissions of GHGs. One such primary source that can help supply energy, water, and fertilizer without GHG emissions is available in the heretofore unexploited thermal gradients of the tropical oceans. The world's oceans are the largest natural collector and reservoir of solar energy. The potential of ocean energy is limitless for producing base-load electric power or ammonia as the hydrogen carrier and fresh water from seawater. However, until now, ocean energy has been virtually untapped. The general perception is that ocean thermal energy is limited to tropical countries. Therefore, the full potential of at-sea production of (1) ammonia as a hydrogen carrier and (2) desalinated water has not been adequately evaluated. Using ocean thermal plantships for the at-sea co-production of ammonia as a hydrogen carrier and desalinated water offer potential energy, environmental, and economic benefits that support the development of the technology. The introduction of a new widespread solution to our projected energy supply requires lead times of a decade or more. Although continuation of the ocean thermal program from the 1970s would likely have put us in a mitigating position in the early 2000s, we still have a window of opportunity to dedicate some of our conventional energy sources to the development of this renewable energy by the time new sources would be critically needed. The primary objective of this project is to evaluate the technical and economic viability of ocean thermal plantships for the production of ammonia as the hydrogen carrier. This objective is achieved by

  13. Ocean energy systems. Quarterly report, October-December 1982

    SciTech Connect

    Not Available

    1982-12-01

    Research progress is reported on developing Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol), energy-intensive products such as ammonia (for fertilizers and chemicals), and aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. Another effort that began in the spring of 1982 is a technical advisory role to DOE with respect to their management of the conceptual design activity of the two industry teams that are designing offshore OTEC pilot plants that could deliver power to Oahu, Hawaii. In addition, a program is underway in which tests of a different kind of ocean-energy device, a turbine that is air-driven as a result of wave action in a chamber, are being planned. This Quarterly Report summarizes the work on the various tasks as of 31 December 1982.

  14. Thermal energy storage test facility

    NASA Technical Reports Server (NTRS)

    Ternes, M. P.

    1980-01-01

    The thermal behavior of prototype thermal energy storage units (TES) in both heating and cooling modes is determined. Improved and advanced storage systems are developed and performance standards are proposed. The design and construction of a thermal cycling facility for determining the thermal behavior of full scale TES units is described. The facility has the capability for testing with both liquid and air heat transport, at variable heat input/extraction rates, over a temperature range of 0 to 280 F.

  15. Thermal energy storage apparatus

    SciTech Connect

    Thoma, P.E.

    1980-04-22

    A thermal energy storage apparatus and method employs a container formed of soda lime glass and having a smooth, defectfree inner wall. The container is filled substantially with a material that can be supercooled to a temperature greater than 5* F., such as ethylene carbonate, benzophenone, phenyl sulfoxide, di-2-pyridyl ketone, phenyl ether, diphenylmethane, ethylene trithiocarbonate, diphenyl carbonate, diphenylamine, 2benzoylpyridine, 3-benzoylpyridine, 4-benzoylpyridine, 4methylbenzophenone, 4-bromobenzophenone, phenyl salicylate, diphenylcyclopropenone, benzyl sulfoxide, 4-methoxy-4prmethylbenzophenone, n-benzoylpiperidine, 3,3pr,4,4pr,5 pentamethoxybenzophenone, 4,4'-bis-(Dimethylamino)-benzophenone, diphenylboron bromide, benzalphthalide, benzophenone oxime, azobenzene. A nucleating means such as a seed crystal, a cold finger or pointed member is movable into the supercoolable material. A heating element heats the supercoolable material above the melting temperature to store heat. The material is then allowed to cool to a supercooled temperature below the melting temperature, but above the natural, spontaneous nucleating temperature. The liquid in each container is selectively initiated into nucleation to release the heat of fusion. The heat may be transferred directly or through a heat exchange unit within the material.

  16. Thermal-Mechanical Behavior of Oceanic Transform Faults- Implications for Hydration of the Upper Oceanic Mantle

    NASA Astrophysics Data System (ADS)

    Roland, E. C.; Behn, M. D.; Hirth, G.

    2007-12-01

    The presence of water at oceanic transform faults influences the thermal structure, rheology, and petrology of the upper mantle. Serpentinization at ridges and transforms plays an important role for the large-scale water budget of the mantle and eventual flux melting that is responsible for arc volcanism at convergent margins. The extent to which hydrous minerals (e.g., serpentine and talc) are incorporated into the upper mantle at oceanic transform faults is highly dependent on the thermal structure and stress state. Previous numerical modeling studies have suggested that the mantle beneath oceanic transform faults is anomalously cold, with depressed isotherms relative to a half-space cooling model [1,2,3]. However, recent models, that incorporate brittle rheology, show that transform faults may represent a region of enhanced mantle upwelling and elevated temperatures [4]. To investigate the thermal-mechanical behavior of oceanic transform faults, we utilize a 3D finite element model, assuming mantle convection, conduction, and steady-state incompressible mantle flow. Our model incorporates a non-linear viscous rheology with a visco-plastic approximation to simulate lithospheric brittle failure. The introduction of water into the lithosphere causes rheological changes with additional feedbacks on the thermal and rheologic structure such as enhanced conductive cooling and changes in frictional behavior. We incorporate the effects of these feedbacks, and our derived thermal structures are integrated with the estimated zone of permeable fluid flow to approximate the stability fields of hydrous phases in the upper mantle. Through examining a rage of parameters, including spreading rate, fault length, and the efficiency of hydrothermal circulation, we constrain the potential for transform faults to act as a source for mantle hydration, and estimate the amount of water that could be bound in hydrous phases as a result of brittle cracking at oceanic faults. 1. Furlong et

  17. Thermal-Mechanical Behavior of Oceanic Transform Faults- Implications for Hydration of the Upper Oceanic Mantle

    NASA Astrophysics Data System (ADS)

    Roland, E. C.; Behn, M. D.; Hirth, G.

    2004-12-01

    The presence of water at oceanic transform faults influences the thermal structure, rheology, and petrology of the upper mantle. Serpentinization at ridges and transforms plays an important role for the large-scale water budget of the mantle and eventual flux melting that is responsible for arc volcanism at convergent margins. The extent to which hydrous minerals (e.g., serpentine and talc) are incorporated into the upper mantle at oceanic transform faults is highly dependent on the thermal structure and stress state. Previous numerical modeling studies have suggested that the mantle beneath oceanic transform faults is anomalously cold, with depressed isotherms relative to a half-space cooling model [1,2,3]. However, recent models, that incorporate brittle rheology, show that transform faults may represent a region of enhanced mantle upwelling and elevated temperatures [4]. To investigate the thermal-mechanical behavior of oceanic transform faults, we utilize a 3D finite element model, assuming mantle convection, conduction, and steady-state incompressible mantle flow. Our model incorporates a non-linear viscous rheology with a visco-plastic approximation to simulate lithospheric brittle failure. The introduction of water into the lithosphere causes rheological changes with additional feedbacks on the thermal and rheologic structure such as enhanced conductive cooling and changes in frictional behavior. We incorporate the effects of these feedbacks, and our derived thermal structures are integrated with the estimated zone of permeable fluid flow to approximate the stability fields of hydrous phases in the upper mantle. Through examining a rage of parameters, including spreading rate, fault length, and the efficiency of hydrothermal circulation, we constrain the potential for transform faults to act as a source for mantle hydration, and estimate the amount of water that could be bound in hydrous phases as a result of brittle cracking at oceanic faults. 1. Furlong et

  18. Observed ocean thermal response to Hurricanes Gustav and Ike

    NASA Astrophysics Data System (ADS)

    Meyers, Patrick C.; Shay, Lynn K.; Brewster, Jodi K.; Jaimes, Benjamin

    2016-01-01

    The 2008 Atlantic hurricane season featured two hurricanes, Gustav and Ike, crossing the Gulf of Mexico (GOM) within a 2 week period. Over 400 airborne expendable bathythermographs (AXBTs) were deployed in a GOM field campaign before, during, and after the passage of Gustav and Ike to measure the evolving upper ocean thermal structure. AXBT and drifter deployments specifically targeted the Loop Current (LC) complex, which was undergoing an eddy-shedding event during the field campaign. Hurricane Gustav forced a 50 m deepening of the ocean mixed layer (OML), dramatically altering the prestorm ocean conditions for Hurricane Ike. Wind-forced entrainment of colder thermocline water into the OML caused sea surface temperatures to cool by over 5°C in GOM common water, but only 1-2°C in the LC complex. Ekman pumping and a near-inertial wake were identified by fluctuations in the 20°C isotherm field observed by AXBTs and drifters following Hurricane Ike. Satellite estimates of the 20° and 26°C isotherm depths and ocean heat content were derived using a two-layer model driven by sea surface height anomalies. Generally, the satellite estimates correctly characterized prestorm conditions, but the two-layer model inherently could not resolve wind-forced mixing of the OML. This study highlights the importance of a coordinated satellite and in situ measurement strategy to accurately characterize the ocean state before, during, and after hurricane passage, particularly in the case of two consecutive storms traveling through the same domain.

  19. 78 FR 8575 - Ocean Energy Safety Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Ocean Energy Safety Advisory Committee AGENCY: Bureau of Safety and Environmental Enforcement (BSEE), Interior. ACTION: Notice of Renewal of the Ocean Energy Safety Advisory Committee. SUMMARY: Following... . Certification I hereby certify that the renewal of the Ocean Energy Safety Advisory Committee is in the...

  20. Lih thermal energy storage device

    DOEpatents

    Olszewski, Mitchell; Morris, David G.

    1994-01-01

    A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures.

  1. Ocean thermal gradient as a generator of electricity. OTEC power plant

    NASA Astrophysics Data System (ADS)

    Enrique, Luna-Gomez Victor; Angel, Alatorre-Mendieta Miguel

    2016-04-01

    The OTEC (Ocean Thermal Energy Conversion) is a power plant that uses the thermal gradient of the sea water between the surface and a depth of about 700 meters. It works by supplying the heat to a steam machine, for evaporation, with sea water from the surface and cold, to condense the steam, with deep sea water. The energy generated by the power plant OTEC can be transferred to the electric power grid, another use is to desalinate seawater. During the twentieth century in some countries experimental power plants to produce electricity or obtaining drinking water they were installed. On the Mexico's coast itself this thermal gradient, as it is located in tropical seas it occurs, so it has possibilities of installing OTEC power plant type. In this paper one type OTEC power plant operation is represented in most of its components.

  2. Oceanic Platform of the Canary Islands: an ocean testbed for ocean energy converters

    NASA Astrophysics Data System (ADS)

    González, Javier; Hernández-Brito, Joaquín.; Llinás, Octavio

    2010-05-01

    The Oceanic Platform of the Canary Islands (PLOCAN) is a Governmental Consortium aimed to build and operate an off-shore infrastructure to facilitate the deep sea research and speed up the technology associated. This Consortium is overseen by the Spanish Ministry of Science and Innovation and the Canarian Agency for Research and Innovation. The infrastructure consists of an oceanic platform located in an area with depths between 50-100 meters, close to the continental slope and four kilometers off the coast of Gran Canaria, in the archipelago of the Canary Islands. The process of construction will start during the first months of 2010 and is expected to be finished in mid-year 2011. PLOCAN serves five strategic lines: an integral observatory able to explore from the deep ocean to the atmosphere, an ocean technology testbed, a base for underwater vehicles, an innovation platform and a highly specialized training centre. Ocean energy is a suitable source to contribute the limited mix-energy conformed in the archipelago of the Canary Islands with a total population around 2 million people unequally distributed in seven islands. Islands of Gran Canaria and Tenerife support the 80% of the total population with 800.000 people each. PLOCAN will contribute to develop the ocean energy sector establishing a marine testbed allowing prototypes testing at sea under a meticulous monitoring network provided by the integral observatory, generating valuable information to developers. Reducing costs throughout an integral project management is an essential objective to be reach, providing services such as transportation, customs and administrative permits. Ocean surface for testing activities is around 8 km2 with a depth going from 50 to 100 meters, 4km off the coast. Selected areas for testing have off-shore wind power conditions around 500-600 W/m2 and wave power conditions around 6 kW/m in the East coast and 10 kW/m in the North coast. Marine currents in the Canary Islands are

  3. Seafloor morphology and the thermal evolution of oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Stein, Carol

    2010-05-01

    Standard reference models for the cooling of oceanic lithosphere, on average, predict the observed temperature-dependent properties, such as depth and heat flow with age. However, for all generally accepted models a significant discrepancy exists between measured and expected heat flow for ages less than about 65 million years. Traditionally lower measured heat flow average values are explained by significant hydrothermal circulation through the uppermost oceanic crust. In this approach, it is assumed that some of the heat transferred by conduction from lithospheric depths is removed by the water flow and transferred between the oceans and crust at locations where the seafloor is bare or poorly sedimented. This component of heat transfer would not be detected by the measurements, which record only conductive transfer. However, recently Hofmeister and Criss [2005] have suggested that hydrothermal circulation is not a significant factor, so the measured marine heat flow results should be used instead of the thermal models in calculating total heat loss for the earth. This approach lowers the loss by about 25%. This hypothesis is tested by examining whether the discrepancy between the predicted and measured heat flows varies between sites such that the highest heat flow is observed where hydrothermal flux should be least due to the regional topography of the igneous basement and sediment thickness. This appears to be the case. Sites with ages less than 65 million years in areas with smooth basement and thick sediment cover have average heat flow equal to that expected from thermal cooling models, except at the very youngest ages. In contrast, sites in areas with thinly sedimented basement outcrops have significantly lower heat flow. These sites make up a progressively lower fraction of the total at older ages as sedinent cover increases. Moreover, for all site types, the measured heat flow approaches the cooling model's predictions at older ages. As a result, by 65

  4. Seasonal Thermal Energy Storage Program

    NASA Technical Reports Server (NTRS)

    Minor, J. E.

    1980-01-01

    The Seasonal Thermal Energy Storage (STES) Program designed to demonstrate the storage and retrieval of energy on a seasonal basis using heat or cold available from waste or other sources during a surplus period is described. Factors considered include reduction of peak period demand and electric utility load problems and establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The initial thrust of the STES Program toward utilization of ground water systems (aquifers) for thermal energy storage is emphasized.

  5. Thermal Energy Storage: Fourth Annual Review Meeting

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The development of low cost thermal energy storage technologies is discussed in terms of near term oil savings, solar energy applications, and dispersed energy systems for energy conservation policies. Program definition and assessment and research and technology development are considered along with industrial storage, solar thermal power storage, building heating and cooling, and seasonal thermal storage. A bibliography on seasonal thermal energy storage emphasizing aquifer thermal energy is included.

  6. Thermal structure, radial anisotropy, and dynamics of oceanic boundary layers

    NASA Astrophysics Data System (ADS)

    Auer, Ludwig; Becker, Thorsten W.; Boschi, Lapo; Schmerr, Nicholas

    2015-11-01

    Defining the oceanic lithosphere as a thermal boundary layer allows to explain, to first order, age-dependent bathymetry and isotropic wave speeds. In contrast, SS precursors and receiver functions suggest a subhorizontal interface within this layer, on top of a radially anisotropic zone. Comparing a suite of geodynamic scenarios against surface wave dispersion data and seismic discontinuities, we find that only weak age dependency of the radially anisotropic zone is compatible with observations. We show that this zone is confined from below by a second weaker seismic interface. While observed azimuthal anisotropy is consistent with lattice-preferred orientation of olivine due to asthenospheric flow underneath the lithosphere, radial anisotropy requires additional contributions, perhaps from petrological fabrics or melt ponding. This implies that seismic reflectors previously associated with the base of the lithosphere are instead associated with preserved structures embedded in it. They carry information about plate formation but have little control on plate deformation.

  7. Ocean energy researchers information user study

    SciTech Connect

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

    1981-03-01

    This report describes the results of a series of telephone interviews with groups of users of information on ocean energy systems. 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 report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. Only high-priority groups were examined. Results from 2 groups of researchers are analyzed in this report: DOE-Funded Researchers and Non-DOE-Funded Researchers. 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.

  8. Thermal energy storage and transport

    NASA Technical Reports Server (NTRS)

    Hausz, W.

    1980-01-01

    The extraction of thermal energy from large LWR and coal fired plants for long distance transport to industrial and residential/commercial users is analyzed. Transport of thermal energy as high temperature water is shown to be considerably cheaper than transport as steam, hot oil, or molten salt over a wide temperature range. The delivered heat is competitive with user-generated heat from oil, coal, or electrode boilers at distances well over 50 km when the pipeline operates at high capacity factor. Results indicate that thermal energy storage makes meeting of even very low capacity factor heat demands economic and feasible and gives the utility flexibility to meet coincident electricity and heat demands effectively.

  9. Thermal and mechanical structure of the upper mantle: A comparison between continental and oceanic models

    NASA Technical Reports Server (NTRS)

    Froidevaux, C.; Schubert, G.; Yuen, D. A.

    1976-01-01

    Temperature, velocity, and viscosity profiles for coupled thermal and mechanical models of the upper mantle beneath continental shields and old ocean basins show that under the continents, both tectonic plates and the asthenosphere, are thicker than they are beneath the oceans. The minimum value of viscosity in the continental asthenosphere is about an order of magnitude larger than in the shear zone beneath oceans. The shear stress or drag underneath continental plates is also approximately an order of magnitude larger than the drag on oceanic plates. Effects of shear heating may account for flattening of ocean floor topography and heat flux in old ocean basins.

  10. Energy conversion method in the ocean using the density difference of water

    SciTech Connect

    Mochizuki, H.; Mitsuhashi, W.

    1981-01-01

    A new method which produces energy from the ocean by utilizing the density difference of water, by means of a ''chimney effect'', is proposed. Density difference of water in the ocean occurs in two ways, namely differences of consistency and water temperature. For instance, fresh river water and melting flows and icebergs are pointed out as some origins of the former, while thermal effects of volcanoes and hot springs may account for the latter. 5 refs.

  11. Ocean energy systems at the Johns Hopkins University Applied Physics Laboratory

    NASA Astrophysics Data System (ADS)

    1983-12-01

    The Johns Hopkins University Applied Physics Laboratory, is engaged in developing Ocean Thermal Energy Conversion systems that will provide synthetic fuels (e.g., methanol) or an energy-intensive product such as ammonia (for fertilizers and chemicals) or aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC plants. The Laboratory also has a technical advisory role with respect to DOE/DOET's management of the preliminary design activity of an industry team headed by Ocean Thermal Corporation that is designing an OTEC pilot plant that could be built in shallow water off the shore of Oahu, Hawaii. In addition, the Laboratory is now taking part in a program to evaluate and test the Pneumatic Wave-Energy conversion System, an ocean-energy device consisting of a turbine that is air-driven as a result of wave action in a chamber. Work on the various tasks as of 31 December 1983 is summarized.

  12. Thermal energy storage program description

    SciTech Connect

    Reimers, E.

    1989-03-01

    The U.S. Department of Energy (DOE) has sponsored applied research, development, and demonstration of technologies aimed at reducing energy consumption and encouraging replacement of premium fuels (notably oil) with renewable or abundant indigenous fuels. One of the technologies identified as being able to contribute to these goals is thermal energy storage (TES). Based on the potential for TES to contribute to the historic mission of the DOE and to address emerging energy issues related to the environment, a program to develop specific TES technologies for diurnal, industrial, and seasonal applications is underway. Currently, the program is directed toward three major application targets: (1) TES development for efficient off-peak building heating and cooling, (2) development of advanced TES building materials, and (3) TES development to reduce industrial energy consumption.

  13. Microwavable thermal energy storage material

    DOEpatents

    Salyer, Ival O.

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

  14. Microwavable thermal energy storage material

    DOEpatents

    Salyer, I.O.

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

  15. More Efficient Solar Thermal-Energy Receiver

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  16. The Warming Hiatus, Natural Variability and Thermal Ocean Structure

    NASA Astrophysics Data System (ADS)

    Groth, A.; Moron, V.; Robertson, A. W.; Kondrashov, D. A.; Ghil, M.

    2015-12-01

    Long before the recent concern with the warming hiatus, Ghil and Vautard (1991, Nature) stated at the end of their abstract that "The oscillatory components [in global temperature time series] have combined (peak-to-peak) amplitudes of 0.2°C, and therefore limit our ability to predict whether the inferred secular warming of 0.005°C/yr will continue." Present capabilities of the advanced spectral methods introduced into the global warming problem by that paper permit us now to consider oscillatory aspects of natural variability in much greater detail. In a multivariate analysis of the upper-ocean thermal structure, we examine properties of the recent long-term changes and of the naturally occurring global-climate fluctuations on interannual-to-interdecadal time scales. M. Ghil and associates (Ghil and Vautard 1991; Plaut et al. 1995, Science; Ghil et al. 2002, Rev. Geophys.), among others, have argued that this natural variability has some regularity embedded into it. Although the existence of such regularity on the interannual time scale is fairly well established by now, evidence for similar regularity on decadal and interdecadal time scales is more difficult to establish, due to the shortness of instrumental temperature data. To identify spatio-temporal patterns, we rely on the method of multichannel singular spectrum analysis [M-SSA; see Ghil et al. (2002) for a review] and on its recent improvements that help separate distinct patterns (Groth and Ghil 2011, Phys. Rev. E; Groth and Ghil 2015, J. Climate). Results on the temperature field from the Simple Ocean Data Assimilation (SODA) reanalysis (Carton and Giese 2008, Mon. Wea. Rev.; Giese and Ray 2011, J. Geophys. Res.) will be shown and contrasted with results on the HadCRUT surface temperature dataset (Morice et al. 2012, J. Geophys. Res.). We will focus, in particular, on the robustness of the geographical distribution of long-term changes in both data sets and discuss the significance of superimposed

  17. Thermal energy storage flight experiments

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1989-01-01

    Consideration is given to the development of an experimental program to study heat transfer, energy storage, fluid movement, and void location under microgravity. Plans for experimental flight packages containing Thermal Energy Storage (TES) material applicable for advanced solar heat receivers are discussed. Candidate materials for TES include fluoride salts, salt eutectics, silicides, and metals. The development of a three-dimensional computer program to describe TES material behavior undergoing melting and freezing under microgravity is also discussed. The TES experiment concept and plans for ground and flight tests are outlined.

  18. 77 FR 32994 - Bureau of Ocean Energy Management

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ... Register on March 30, 2012 (see 77 FR 19321) opening a 60-day comment period originally scheduled to close... Bureau of Ocean Energy Management Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf; Draft Programmatic Environmental Impact Statement AGENCY: Bureau of Ocean Energy...

  19. Bioenergetic response by steelhead to variation in diet, thermal habitat, and climate in the north Pacific Ocean

    USGS Publications Warehouse

    Atcheson, Margaret E.; Myers, Katherine W.; Beauchamp, David A.; Mantua, Nathan J.

    2012-01-01

    Energetic responses of steelhead Oncorhynchus mykiss to climate-driven changes in marine conditions are expected to affect the species’ ocean distribution, feeding, growth, and survival. With a unique 18-year data series (1991–2008) for steelhead sampled in the open ocean, we simulated interannual variation in prey consumption and growth efficiency of steelhead using a bioenergetics model to evaluate the temperature-dependent growth response of steelhead to past climate events and to estimate growth potential of steelhead under future climate scenarios. Our results showed that annual ocean growth of steelhead is highly variable depending on prey quality, consumption rates, total consumption, and thermal experience. At optimal growing temperatures, steelhead can compensate for a low-energy diet by increasing consumption rates and consuming more prey, if available. Our findings suggest that steelhead have a narrow temperature window in which to achieve optimal growth, which is strongly influenced by climate-driven changes in ocean temperature.

  20. Thermal to Electric Energy Conversion

    NASA Astrophysics Data System (ADS)

    Hagelstein, Peter L.

    2005-12-01

    As research in the area of excess power production moves forward, issues associated with thermal to electric conversion become increasingly important. This paper provides a brief tutorial on basic issues, including the Carnot limit, entropy, and thermoelectric conversion. Practical thermal to electric conversion is possible well below the Carnot limit, and this leads to a high threshold for self-sustaining operation in Pons-Fleischmann type experiments. Excess power production at elevated temperatures will become increasingly important as we move toward self-sustaining devices and energy production for applications. Excess power production in heat-producing systems that do not require electrical input have an enormous advantage over electrochemical systems. Such systems should be considered seriously within our community in the coming years.

  1. Mesoscale atmosphere ocean coupling enhances the transfer of wind energy into the ocean

    PubMed Central

    Byrne, D.; Münnich, M.; Frenger, I.; Gruber, N.

    2016-01-01

    Although it is well established that the large-scale wind drives much of the world's ocean circulation, the contribution of the wind energy input at mesoscales (10–200 km) remains poorly known. Here we use regional simulations with a coupled high-resolution atmosphere–ocean model of the South Atlantic, to show that mesoscale ocean features and, in particular, eddies can be energized by their thermodynamic interactions with the atmosphere. Owing to their sea-surface temperature anomalies affecting the wind field above them, the oceanic eddies in the presence of a large-scale wind gradient provide a mesoscale conduit for the transfer of energy into the ocean. Our simulations show that this pathway is responsible for up to 10% of the kinetic energy of the oceanic mesoscale eddy field in the South Atlantic. The conditions for this pathway to inject energy directly into the mesoscale prevail over much of the Southern Ocean north of the Polar Front. PMID:27292447

  2. Mesoscale atmosphere ocean coupling enhances the transfer of wind energy into the ocean.

    PubMed

    Byrne, D; Münnich, M; Frenger, I; Gruber, N

    2016-01-01

    Although it is well established that the large-scale wind drives much of the world's ocean circulation, the contribution of the wind energy input at mesoscales (10-200 km) remains poorly known. Here we use regional simulations with a coupled high-resolution atmosphere-ocean model of the South Atlantic, to show that mesoscale ocean features and, in particular, eddies can be energized by their thermodynamic interactions with the atmosphere. Owing to their sea-surface temperature anomalies affecting the wind field above them, the oceanic eddies in the presence of a large-scale wind gradient provide a mesoscale conduit for the transfer of energy into the ocean. Our simulations show that this pathway is responsible for up to 10% of the kinetic energy of the oceanic mesoscale eddy field in the South Atlantic. The conditions for this pathway to inject energy directly into the mesoscale prevail over much of the Southern Ocean north of the Polar Front. PMID:27292447

  3. Possible Factors affecting the Thermal Contrast between Middle-Latitude Asian Continent and Adjacent Ocean

    NASA Astrophysics Data System (ADS)

    Cheng, Huaqiong; Wu, Tongwen; Dong, Wenjie

    2015-04-01

    A middle-latitude Land-Sea thermal contrast Index was used in this study which has close connection to the East Asian summer precipitation. The index has two parts which are land thermal index defined as JJA 500-hPa geopotential height anomalies at a land area (75°-90° E, 40° -55°N ) and ocean thermal index defined as that at an oceanic area (140° -150°E, 35° -42.5°N). The impact of the surface heat flux and atmospheric diabatic heating over the land and the ocean on the index was studied. The results show that the surface heat flux over Eurasian inner land has little influence to the land thermal index, while the variation of the surface latent heat flux and long-wave radiation over the Pacific adjacent to Japan has highly correlation with the ocean thermal index. The changes with height of the atmospheric diabatic heating rates over the Eurasian inner land and the Pacific adjacent to Japan have different features. The variations of the middle troposphere atmospheric long-wave and short-wave radiation heating have significantly influences on land thermal index, and that of the low troposphere atmospheric long-wave radiation, short-wave radiation and deep convective heating also have impact on the yearly variation of the land thermal index. For the ocean thermal index, the variations of the surface layer atmospheric vertical diffuse heating, large-scale latent heating and long-wave radiation heating are more important, low and middle troposphere atmospheric large-scale latent heating and shallow convective heating also have impact on the yearly variation of the ocean thermal index. And then the ocean thermal index has closely connection with the low troposphere atmospheric temperature, while the land thermal index has closely connection with the middle troposphere atmospheric temperature. The Effect of the preceding global SST anomalies on the index also was analyzed. The relations of land thermal index and ocean thermal index and the global SST anomalies

  4. Constraints on lithospheric thermal structure for the Indian Ocean from depth and heat flow data

    NASA Technical Reports Server (NTRS)

    Shoberg, Tom; Stein, Carol A.; Stein, Seth

    1993-01-01

    Models for the thermal evolution of oceanic lithosphere are primarily constrained by variations in seafloor depth and heat flow with age. These models have been largely based on data from the Pacific and Atlantic Ocean basins. We construct seafloor age relations for the Indian Ocean which we combine with bathymetric, sediment isopach and heat flow data to derive curves for depth and heat flow versus age. Comparison of these curves with predictions from three thermal models shows that they are better fit by the shallower depths and higher heat flow for the GDH1 model, which is characterized by a thinner and hotter lithosphere than previous models.

  5. Solar energy thermally powered electrical generating system

    NASA Technical Reports Server (NTRS)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  6. 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.

  7. 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.

  8. Thermal modeling and optimization of a thermally matched energy harvester

    NASA Astrophysics Data System (ADS)

    Boughaleb, J.; Arnaud, A.; Cottinet, P. J.; Monfray, S.; Gelenne, P.; Kermel, P.; Quenard, S.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

    2015-08-01

    The interest in energy harvesting devices has grown with the development of wireless sensors requiring small amounts of energy to function. The present article addresses the thermal investigation of a coupled piezoelectric and bimetal-based heat engine. The thermal energy harvester in question converts low-grade heat flows into electrical charges by achieving a two-step conversion mechanism for which the key point is the ability to maintain a significant thermal gradient without any heat sink. Many studies have previously focused on the electrical properties of this innovative device for energy harvesting but until now, no thermal modeling has been able to describe the device specificities or improve its thermal performances. The research reported in this paper focuses on the modeling of the harvester using an equivalent electrical circuit approach. It is shown that the knowledge of the thermal properties inside the device and a good comprehension of its heat exchange with the surrounding play a key role in the optimization procedure. To validate the thermal modeling, finite element analyses as well as experimental measurements on a hot plate were carried out and the techniques were compared. The proposed model provided a practical guideline for improving the generator design to obtain a thermally matched energy harvester that can function over a wide range of hot source temperatures for the same bimetal. A direct application of this study has been implemented on scaled structures to maintain an important temperature difference between the cold surface and the hot reservoir. Using the equations of the thermal model, predictions of the thermal properties were evaluated depending on the scaling factor and solutions for future thermal improvements are presented.

  9. Thermal energy management process experiment

    NASA Technical Reports Server (NTRS)

    Ollendorf, S.

    1984-01-01

    The thermal energy management processes experiment (TEMP) will demonstrate that through the use of two-phase flow technology, thermal systems can be significantly enhanced by increasing heat transport capabilities at reduced power consumption while operating within narrow temperature limits. It has been noted that such phenomena as excess fluid puddling, priming, stratification, and surface tension effects all tend to mask the performance of two-phase flow systems in a 1-g field. The flight experiment approach would be to attack the experiment to an appropriate mounting surface with a 15 to 20 meter effective length and provide a heat input and output station in the form of heaters and a radiator. Using environmental data, the size, location, and orientation of the experiment can be optimized. The approach would be to provide a self-contained panel and mount it to the STEP through a frame. A small electronics package would be developed to interface with the STEP avionics for command and data handling. During the flight, heaters on the evaporator will be exercised to determine performance. Flight data will be evaluated against the ground tests to determine any anomalous behavior.

  10. Thermal Energy Harvesting from Wildlife

    NASA Astrophysics Data System (ADS)

    Woias, P.; Schule, F.; Bäumke, E.; Mehne, P.; Kroener, M.

    2014-11-01

    In this paper we present the measurement of temperature differences between the ambient air and the body temperature of a sheep (Heidschnucke) and its applicability for thermoelectric energy harvesting from livestock, demonstrated via the test of a specially tailored TEG system in a real-life experiment. In three measurement campaigns average temperature differences were found between 2.5 K and 3.5 K. Analytical models and FEM simulations were carried out to determine the actual thermal resistance of the sheep's fur from comparisons with the temperature measurements. With these data a thermoelectric (TEG) generator was built in a thermally optimized housing with adapted heats sink. The whole TEG system was mounted to a collar, including a data logger for recording temperature and TEG voltage. First measurements at the neck of a sheep were accomplished, with a calculated maximal average power output of 173 μW at the TEG. Taking the necessity of a low-voltage step-up converter into account, an electric output power of 54 μW is available which comes close to the power consumption of a low-power VHF tracking system.

  11. Thermal response of mid-ocean ridge hydrothermal systems to perturbations

    NASA Astrophysics Data System (ADS)

    Singh, Shreya; Lowell, Robert P.

    2015-11-01

    Mid-ocean ridges are subject to episodic disturbances in the form of magmatic intrusions and earthquakes. Following these events, the temperature of associated hydrothermal vent fluids is observed to increase within a few days. In this paper, we aim to understand the rapid thermal response of hydrothermal systems to such disturbances. We construct a classic single-pass numerical model and use the examples of the 1995 and 1999 non-eruptive events at East Pacific Rise (EPR) 9°50‧N and Main Endeavour Field (MEF), respectively. We model both the thermal effects of dikes and permeability changes that might be attributed to diking and/or earthquake swarms. We find that the rapid response of vent temperatures results from steep thermal gradients close to the surface. When the perturbations are accompanied by an increase in permeability, the response on the surface is further enhanced. For EPR9°50‧N, the observed ~7 °C rise can be obtained for a ~50% increase in permeability in the diking zone. The mass flow rate increases as a result of change in permeability deeper in the system, and, therefore, the amount of hot fluid in the diffused flow also increases. Using a thermal energy balance, we show that the ~10 °C increase in diffuse flow temperatures recorded for MEF after the 1999 event may result from a 3-4 times increase in permeability. The rapid thermal response of the system resulting from a change in permeability also occurs for cases in which there is no additional heat input, indicating that hydrothermal systems may respond similarly to purely seismic and non-eruptive magmatic events.

  12. The Thermal Response of Mid-Ocean Ridge Hydrothermal Systems to Perturbations

    NASA Astrophysics Data System (ADS)

    Singh, S.; Lowell, R. P.

    2014-12-01

    Mid-ocean ridges are subject to episodic disturbances in the form of magmatic intrusions and earthquakes. Following these events, the temperature of associated hydrothermal vent fluids is observed to increase within a few days. In this paper, we aim to understand the rapid thermal response of hydrothermal systems to such disturbances. We construct a classic single-pass numerical model and use the examples of the 1995 and 1999 non-eruptive events at East Pacific Rise 9⁰50' N and Main Endeavour Field, respectively. We model both the thermal effects of dikes and permeability changes that might be attributed to diking and/or earthquake swarms. We find that the rapid response of vent temperatures results from steep thermal gradients close to the surface. When the perturbations are accompanied by an increase in permeability, the response on the surface is enhanced further. For East Pacific Rise 9⁰50' N, the observed ~7°C rise can be obtained for a ~ 50% increase in permeability in the diking zone. The mass flow rate increases as a result of change in permeability deeper in the system, and, therefore, the amount of hot fluid in the diffused flow also increases. Using a thermal energy balance, we show that the ~ 10 ⁰C increase in diffuse flow temperatures recorded for MEF after the 1999 event may result from a 3-4 times increase in permeability. The rapid thermal response of the system resulting from a change in permeability also occurs for cases in which there is no additional heat input, indicating that hydrothermal systems may respond similarly to purely seismic and non-eruptive magmatic events.

  13. Phase change thermal energy storage material

    SciTech Connect

    Benson, D.K.; Burrows, R.W.

    1987-10-27

    A thermal energy storage tank is described comprising a containment vessel arranged for exposure to thermal energy, and a thermal energy storage composition disposed within the vessel and comprising a non-chloride hydrate having a phase change transition temperature in the range of 70/sup 0/-95/sup 0/F and a latent heat of transformation of greater than about 35 calories/gram. The non-chloride hydrate comprises trimethyol ethane hydrate.

  14. The Ocean Food and Energy Farm Project

    ERIC Educational Resources Information Center

    Wilcox, Howard A.

    1976-01-01

    This three-phase, 15-year project is designed to explore and develop the ability to raise the grant California kelp and other marine organisms for food, fuels, fertilizers and plastics in the temperate and tropical oceans. The needed technology is established, but the economic feasibility is yet to be determined. (BT)

  15. Thermal energy storage for cogeneration applications

    NASA Astrophysics Data System (ADS)

    Drost, M. K.; Antoniak, Z. I.

    1992-04-01

    Cogeneration is playing an increasingly important role in providing energy efficient power generation and thermal energy for space heating and industrial process heat applications. However, the range of applications for cogeneration could be further increased if the generation of electricity could be decoupled from the generation of process heat. Thermal energy storage (TES) can decouple power generation from the production of process heat, allowing the production of dispatchable power while fully utilizing the thermal energy available from the prime mover. The Pacific Northwest Laboratory (PNL) leads the US Department of Energy's Thermal Energy Storage Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility applications (utility thermal energy storage (UTES)). Several of these technologies can be used in a cogeneration facility. This paper discusses TES concepts relevant to cogeneration and describes the current status of these TES systems.

  16. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    DOEpatents

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  17. Navigating a sea of values: Understanding public attitudes toward the ocean and ocean energy resources

    NASA Astrophysics Data System (ADS)

    Lilley, Jonathan Charles

    In examining ocean values and beliefs, this study investigates the moral and ethical aspects of the relationships that exist between humans and the marine environment. In short, this dissertation explores what the American public thinks of the ocean. The study places a specific focus upon attitudes to ocean energy development. Using both qualitative and quantitative methods, this research: elicits mental models that exist in society regarding the ocean; unearths what philosophies underpin people's attitudes toward the ocean and offshore energy development; assesses whether these views have any bearing on pro-environmental behavior; and gauges support for offshore drilling and offshore wind development. Despite the fact that the ocean is frequently ranked as a second-tier environmental issue, Americans are concerned about the state of the marine environment. Additionally, the data show that lack of knowledge, rather than apathy, prevents people from undertaking pro-environmental action. With regard to philosophical beliefs, Americans hold slightly more nonanthropocentric than anthropocentric views toward the environment. Neither anthropocentrism nor nonanthropocentrism has any real impact on pro-environmental behavior, although nonanthropocentric attitudes reduce support for offshore wind. This research also uncovers two gaps between scientific and public perceptions of offshore wind power with respect to: 1) overall environmental effects; and 2) the size of the resource. Providing better information to the public in the first area may lead to a shift toward offshore wind support among opponents with nonanthropocentric attitudes, and in both areas, is likely to increase offshore wind support.

  18. Physiological response of the cold-water coral Desmophyllum dianthus to thermal stress and ocean acidification.

    PubMed

    Gori, Andrea; Ferrier-Pagès, Christine; Hennige, Sebastian J; Murray, Fiona; Rottier, Cécile; Wicks, Laura C; Roberts, J Murray

    2016-01-01

    Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coral Desmophyllum dianthus maintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2 conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2 levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2 significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology of D. dianthus is more sensitive to thermal than pCO2 stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species. PMID:26855864

  19. Physiological response of the cold-water coral Desmophyllum dianthus to thermal stress and ocean acidification

    PubMed Central

    Ferrier-Pagès, Christine; Hennige, Sebastian J.; Murray, Fiona; Rottier, Cécile; Wicks, Laura C.; Roberts, J. Murray

    2016-01-01

    Rising temperatures and ocean acidification driven by anthropogenic carbon emissions threaten both tropical and temperate corals. However, the synergistic effect of these stressors on coral physiology is still poorly understood, in particular for cold-water corals. This study assessed changes in key physiological parameters (calcification, respiration and ammonium excretion) of the widespread cold-water coral Desmophyllum dianthus maintained for ∼8 months at two temperatures (ambient 12 °C and elevated 15 °C) and two pCO2 conditions (ambient 390 ppm and elevated 750 ppm). At ambient temperatures no change in instantaneous calcification, respiration or ammonium excretion rates was observed at either pCO2 levels. Conversely, elevated temperature (15 °C) significantly reduced calcification rates, and combined elevated temperature and pCO2 significantly reduced respiration rates. Changes in the ratio of respired oxygen to excreted nitrogen (O:N), which provides information on the main sources of energy being metabolized, indicated a shift from mixed use of protein and carbohydrate/lipid as metabolic substrates under control conditions, to less efficient protein-dominated catabolism under both stressors. Overall, this study shows that the physiology of D. dianthus is more sensitive to thermal than pCO2 stress, and that the predicted combination of rising temperatures and ocean acidification in the coming decades may severely impact this cold-water coral species. PMID:26855864

  20. Thermal history of the interior ocean during the past 21,000 years

    NASA Astrophysics Data System (ADS)

    Rosenthal, Y.; Linsley, B. K.; Oppo, D.

    2011-12-01

    The deep ocean, due to its high density and heat capacity, constitutes the largest yet temporally responsive heat store in the Earth system. Here we present new sediment records of intermediate water temperature and δ18Osw (an indicator of salinity) from the equatorial Indo-Pacific region (water depth of 500-700m) reconstructed using paired δ18O and Mg/Ca measurements in benthic foraminifera (Hyalinea balthica). Our results indicate ~3°C LGM to early Holocene warming of the regional intermediate water. Following maximum warming at the "Holocene thermal maximum" (HTM), the intermediate water masses, consisting of modified North Pacific and Antarctic Intermediate Water (NPIW and AAIW, respectively), cooled by ~2°C toward the present. In contrast the overlying equatorial western Pacific surface water were less than 1°C warmer during the HTM relative to the present. We suggest that the early Holocene warmth and late Holocene cooling observed in our intermediate depth records are related to changes in the end-member properties of the water masses ventilating the Indonesian Seas and therefore reflect climate variability at the northern and southern high-latitude source regions. These observations are supported by records from other ocean regions (albeit few), and therefore might indicate global warming at the HTM, apparently in contrast with expected changes due to incoming solar radiation from the mid to late Holocene and also with sea surface temperature (SST) records, which do not exhibit a globally synchronous and coherent trends, but rather suggest that SST changes were only regionally coherent. Superimposed on the long-term Holocene trend we observe a ~1°C cooling of the intermediate water during the Little Ice Age consistent with the reconstruction of SST in this region. Combined, these observations indicate apparently high sensitivity of the ocean heat storage thus providing a new perspective on the Earth's energy budget.

  1. Thermal convection in high-pressure ice layers beneath a buried ocean within Titan and Ganymede

    NASA Astrophysics Data System (ADS)

    Choblet, G.; Tobie, G.; Dumont, M.

    2015-10-01

    Deep interiors of large icy satellites such as Titan and Ganymede probably harbor a buried ocean above highpressure (HP) ice layers. The nature and location of the lower interface of the ocean involves equilibration of heat and melt transfer in the HP ices. It is ultimately controlled by the amount of heat transferred through the surface ice Ih layer. We describe 3D spherical simulations of thermal convection in these HP ices layers that address for the first time this complex interplay.

  2. Meridional overturning in the thermally-driven ocean

    NASA Astrophysics Data System (ADS)

    LaCasce, Joe; Gjermundsen, Ada

    2015-04-01

    As opposed to the wind-driven ocean circulation, there is no commonly accepted dynamical framework for rationalizing the buoyancy-driven circulation. However, an analytical model of the overturning exists, based on the quasigeostrophic model of Pedlosky (1969) and studied subsequently by Salmon (1986), LaCasce (2004) and Pedloksy and Spall (2005). A key aspect is that the overturning in the model is determined almost exclusively by upwelling and sinking occurring in the interior; the boundary layers have little net contribution to the vertical transport. Thus the overturning in the model can be understood by the baroclinic flow in the interior, which is conceptually simple. The only exception is when a form of "convection" is allowed, in which case the northern boundary can contribute significantly as well. We review key aspects of the model circulation and demonstrate how the boundary current dynamics are consistent between models with different frictional parameterizations. We also compare to numerical simulations using a full GCM in an idealized basin. References: Pedlosky, J. (1969). Linear theory of the circulation of a stratified ocean. Journal of Fluid Mechanics, 35, 185-205. Salmon. R. (1986). A simplified linear ocean circulation theory. Journal of Marine Research, 44, 695-711. LaCasce, J. H. (2004). Diffusivity and viscosity dependence in the linear thermocline. Journal of Marine Research, 62, 743-769. Pedlosky, J. and M. A. Spall (2005). Boundary intensification of vertical velocity in a β-plane basin. Journal of Physical Oceanography, 35(12), 2487-2500.

  3. 76 FR 18232 - Ocean Energy Safety Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Ocean Energy Safety Advisory Committee; Notice of Meeting AGENCY: Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE), Interior. ACTION: Notice of meeting. SUMMARY: The Ocean Energy Safety Advisory Committee will meet at the...

  4. The Effect of Thermal Cycling on Crystal-Liquid Separation During Lunar Magma Ocean Differentiation

    NASA Technical Reports Server (NTRS)

    Mills, Ryan D.

    2013-01-01

    Differentiation of magma oceans likely involves a mixture of fractional and equilibrium crystallization [1]. The existence of: 1) large volumes of anorthosite in the lunar highlands and 2) the incompatible- rich (KREEP) reservoir suggests that fractional crystallization may have dominated during differentiation of the Moon. For this to have occurred, crystal fractionation must have been remarkably efficient. Several authors [e.g. 2, 3] have hypothesized that equilibrium crystallization would have dominated early in differentiation of magma oceans because of crystal entrainment during turbulent convection. However, recent numerical modeling [4] suggests that crystal settling could have occurred throughout the entire solidification history of the lunar magma ocean if crystals were large and crystal fraction was low. These results indicate that the crystal size distribution could have played an important role in differentiation of the lunar magma ocean. Here, I suggest that thermal cycling from tidal heating during lunar magma ocean crystallization caused crystals to coarsen, leading to efficient crystal-liquid separation.

  5. Global representation of tropical cyclone-induced short-term ocean thermal changes using Argo data

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Zhu, J.; Sriver, R. L.

    2015-09-01

    Argo floats are used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. We present a footprint method that analyzes cross-track thermal responses along all storm tracks during the period 2004-2012. We combine the results into composite representations of the vertical structure of the average thermal response for two different categories: tropical storms/tropical depressions (TS/TD) and hurricanes. The two footprint composites are functions of three variables: cross-track distance, water depth and time relative to TC passage. We find that this footprint strategy captures the major features of the upper-ocean thermal response to TCs on timescales up to 20 days when compared against previous case study results using in situ measurements. On the global scale, TCs are responsible for 1.87 PW (11.05 W m-2) of heat transfer annually from the global ocean to the atmosphere during storm passage (0-3 days). Of this total, 1.05 ± 0.20 PW (4.80 ± 0.85 W m-2) is caused by TS/TD and 0.82 ± 0.21 PW (6.25 ± 1.5 W m-2) is caused by hurricanes. Our findings indicate that ocean heat loss by TCs may be a substantial missing piece of the global ocean heat budget. Changes in ocean heat content (OHC) after storm passage are estimated by analyzing the temperature anomalies during wake recovery following storm events (4-20 days after storm passage) relative to pre-storm conditions. Results indicate the global ocean experiences a 0.75 ± 0.25 PW (5.98 ± 2.1 W m-2) heat gain annually for hurricanes. In contrast, under TS/TD conditions, the ocean experiences 0.41 ± 0.21 PW (1.90 ± 0.96 W m-2) ocean heat loss, suggesting the overall oceanic thermal response is particularly sensitive to the intensity of the event. The ocean heat uptake caused by all storms during the restorative stage is 0.34 PW.

  6. Evolution of the Upper-Ocean Thermal Structure beneath Hurricanes Iselle and Julio (2014)

    NASA Astrophysics Data System (ADS)

    Sanabia, E.; Jayne, S. R.

    2014-12-01

    The impact of Hurricanes Iselle and Julio (2014) on the upper-ocean thermal structure east of the Hawaiian Islands is investigated in this analysis of data collected from AXBT and Alamo profiling floats deployed from USAF WC-130Js as part of the Training and Research in Oceanic and atmospheric Processes In tropical Cyclones (TROPIC) 2014 field program. Originating in the eastern Pacific, Hurricanes Iselle and Julio followed very similar paths west northwestward. The passage of Julio over the wake of Iselle presented a unique opportunity to explore the impact of consecutive tropical cyclones on the upper ocean.

  7. Proceedings of the ocean energy information dissemination workshop, December 1979

    SciTech Connect

    Petty, D.

    1980-04-01

    The workshop was held to discuss the status of marketing ocean energy information and to develop an understanding of information needs and how to satisfy them. Presentations were made by the Solar Energy Research Institute (SERI) staff and media consultants about the effective use of audio-visual and print products, the mass media, and audience needs. Industry and government representatives reported on current efforts in each of their communication programs and outlined future plans. Four target audiences (DOE contractors, researchers, influencers, and general public) were discussed with respect to developing priorities for projects to enhance the commercialization of ocean energy technology.

  8. Diagnosing ocean energy transports from earth radiation budget measurements

    NASA Technical Reports Server (NTRS)

    Sohn, Byung-Ju; Smith, Eric A.

    1992-01-01

    The maximum energy production (MEP) principle suggested by Paltridge (1975) is applied to separate the satellite-inferred required total transports into the atmospheric and the oceanic components within a two-dimensional (2D) framework. For this purpose, the required 2D energy transports (Sohn and Smith, 1991) are imposed on Paltridge's energy balance model which is then solved as a variational problem. The results provide separated atmospheric and oceanic transports on a 2D basis such that the total divergence is equal to the net radiation measured from a satellite.

  9. Proceedings of the Ocean Energy Information Dissemination Workshop

    NASA Astrophysics Data System (ADS)

    Petty, D.

    1980-04-01

    The workshop was held to discuss the status of marketing ocean energy information and to develop an understanding of information needs and how to satisfy them. Presentations were made by the Solar Energy Research Institute (SERI) staff and media consultants about the effective use of audio visual and print products, the mass media, and audience needs. Industry and government representatives reported on current efforts in each of their communication programs and outlined future plans. Four target audiences (DOE contractors, researchers, influencers, and general public) were discussed with respect to developing priorities for projects to enhance the commercialization of ocean energy technology.

  10. Thermal stresses, differential subsidence, and flexure at oceanic fracture zones

    NASA Technical Reports Server (NTRS)

    Wessel, Pal; Haxby, William F.

    1990-01-01

    Geosat geoid undulations over four Pacific fracture zones have been analyzed. After correcting for the isostatic thermal edge effect, the amplitudes of the residuals are shown to be proportional to the age offset. The shape of the residuals seems to broaden with increasing age. Both geoid anomalies and available ship bathymetry data suggest that slip must sometimes occur on the main fracture zone or secondary faults. Existing models for flexure at fracture zones cannot explain the observed anomalies. A combination model accounting for slip and including flexure from thermal stresses and differential subsidence is presented. This model accounts for lateral variations in flexural rigidity from brittle and ductile yielding due to both thermal and flexural stresses and explains both the amplitudes and the shape of the anomalies along each fracture zone. The best fitting models have mechanical plate thicknesses that are described by the depth to the 600-700 C isotherms.

  11. Nonlinear Scale Interactions and Energy Pathways in the Ocean

    NASA Astrophysics Data System (ADS)

    Aluie, Hussein; Hecht, Matthew; Vallis, Geoffrey; Bryan, Kirk; Maltrud, Mathew; Ecke, Robert; Wingate, Beth

    2013-03-01

    Large-scale currents and eddies pervade the ocean and play a prime role in the general circulation and climate. The coupling between scales ranging from O (104) km down to O (1) mm presents a major difficulty in understanding, modeling, and predicting oceanic circulation and mixing, where the energy budget is uncertain within a factor possibly as large as ten. Identifying the energy sources and sinks at various scales can reduce such uncertainty and yield insight into new parameterizations. To this end, we refine a novel coarse-graining framework to directly analyze the coupling between scales. The approach is very general, allows for probing the dynamics simultaneously in scale and in space, and is not restricted by usual assumptions of homogeneity or isotropy. We apply these tools to study the energy pathways from high-resolution ocean simulations using LANL's Parallel Ocean Program. We examine the extent to which the traditional paradigm for such pathways is valid at various locations such as in western boundary currents, near the equator, and in the deep ocean. We investigate the contribution of various nonlinear mechanisms to the transfer of energy across scales such as baroclinic and barotropic instabilities, barotropization, and Rossby wave generation.

  12. Energy Pathways and Scale Interactions in the Ocean

    NASA Astrophysics Data System (ADS)

    Aluie, H.; Hecht, M. W.; Vallis, G. K.; Bryan, K.; Ecke, R. E.; Maltrud, M. E.; Wingate, B. A.

    2012-12-01

    Large-scale currents and eddies pervade the ocean and play a prime role in the general circulation and climate. The coupling between scales ranging from O(104) km down to O(1) mm presents a major difficulty in understanding, modeling, and predicting oceanic circulation and mixing, where the energy budget is uncertain within a factor possibly as large as ten. Identifying the energy sources and sinks at various scales can reduce such uncertainty and yield insight into new parameterizations. To this end, we refine a novel coarse-graining framework to directly analyze the coupling between scales. The approach is very general, allows for probing the dynamics simultaneously in scale and in space, and is not restricted by usual assumptions of homogeneity or isotropy. We apply these tools to study the energy pathways from high-resolution ocean simulations using LANL's Parallel Ocean Program. We examine the extent to which the traditional paradigm for such pathways is valid at various locations such as in western boundary currents, near the equator, and in the deep ocean. We investigate the contribution of various nonlinear mechanisms to the transfer of energy across scales such as baroclinic and barotropic instabilities, barotropization, and Rossby wave generation.

  13. Nonlinear Scale Interactions and Energy Pathways in the Ocean

    NASA Astrophysics Data System (ADS)

    Aluie, Hussein; Hecht, Matthew; Vallis, Geoffrey

    2013-11-01

    Large-scale currents and eddies pervade the ocean and play a prime role in the general circulation and climate. The coupling between scales ranging from O (104) km down to O (1) mm presents a major difficulty in understanding, modeling, and predicting oceanic circulation and mixing, where the energy budget is uncertain within a factor possibly as large as ten. Identifying the energy sources and sinks at various scales can reduce such uncertainty and yield insight into new parameterizations. To this end, we refine a novel coarse-graining framework to directly analyze the coupling between scales. The approach is very general, allows for probing the dynamics simultaneously in scale and in space, and is not restricted by usual assumptions of homogeneity or isotropy. We apply these tools to study the energy pathways from high-resolution ocean simulations using LANL's Parallel Ocean Program. We examine the extent to which the traditional paradigm for such pathways is valid at various locations such as in western boundary currents, near the equator, and in the deep ocean. We investigate the contribution of various nonlinear mechanisms to the transfer of energy across scales such as baroclinic and barotropic instabilities.

  14. Thermal energy scavenger (flow control)

    SciTech Connect

    Hochstein, P.A.; Milton, H.W.; Pringle, W.L.

    1981-12-22

    A thermal energy scavenger assembly is described including a plurality of temperature-sensitive wires made of material which exhibits shape memory due to a thermoelastic, martensitic phase transformation. The wires are placed in tension between fixed and movable plates which are, in turn, supported by a pair of wheels which are rotatably supported by a housing for rotation about a central axis. A pair of upper and lower cams are fixed to the housing and cam followers react with the respective cams. Each cam transmits forces through a pair of hydraulic pistons. One of the pistons is connected to a movable plate to which one end of the wires are connected whereby a stress is applied to the wires to strain the wires during a first phase and whereby the cam responds to the unstraining of the wires during a second phase. A housing defines fluid compartments through which hot and cold fluid passes and flows radially through the wires whereby the wires become unstrained and shorten in length when subjected to the hot fluid for causing a reaction between the cam followers and the cams to effect rotation of the wheels about the central axis of the assembly, which rotation of the wheels is extracted through beveled gearing. The wires are grouped into a plurality of independent modules with each module having a movable plate, a fixed plate and the associated hydraulic pistons and cam follower. The hydraulic pistons and cam follower of a module are disposed at ends of the wires opposite from the ends of the wires at which the same components of the next adjacent modules are disposed so that the cam followers of alternate modules react with one of the cams and the remaining cam followers of the remaining modules react with the other cam. There is also including stress limiting means in the form of coil springs associated with alternate ends of the wires for limiting the stress or strain in the wires.

  15. Arctic Crustal Thickness and Ocean-Continent Transition from Gravity Inversion Incorporating a Lithosphere Thermal Correction

    NASA Astrophysics Data System (ADS)

    Greenhalgh, E.; Kusznir, N. J.; Lebedeva-Ivanova, N.; Alvey, A.; Gaina, C.; Torsvik, T. H.

    2007-12-01

    Crustal thickness and continental lithosphere thinning factors have been determined for the High Arctic using a gravity inversion method which incorporates a lithosphere thermal gravity anomaly correction. Continental lithosphere thinning factor maps, determined by the inversion of the NGA (U) Arctic Gravity Project data have been used to predict the distribution of oceanic lithosphere and ocean-continent transition (OCT) location for the Amerasia Basin. Thin crust and high lithosphere thinning factors are predicted in the Makarov, Podvodnikov and Canada Basins consistent with these basins being oceanic. Larger crustal thicknesses, in the range 20 - 30 km, are predicted for the Lomonosov, Alpha and Mendeleev Ridges. Moho depths predicted by gravity inversion have been compared with seismic estimates for the TransArctica and Arctica profiles with seismically observed sediment thickness included in the gravity inversion. Agreement between gravity and seismic Moho depths is generally good. The largest differences between gravity and seismic Moho depths occur where lower crustal seismic velocities, Vp, are in excess of ~ 7.3km/s. Gravity inversion to determine Moho depth and crustal thickness variation is carried out in the 3D spectral domain. A correction for the large negative residual thermal gravity anomaly within oceanic and stretched continental margin lithosphere is made and requires a lithosphere thermal model to predict the present day lithosphere thermal anomaly. For continental margin lithosphere, the lithosphere thermal perturbation is calculated from the lithosphere thinning factor (1-1/beta) obtained from crustal thinning determined by gravity inversion and breakup age for thermal re-equilibration time. A correction is made for crustal volcanic addition due to decompression melting during breakup and sea-floor spreading. For the Amerasia Basin, where ocean isochrons are uncertain, all lithosphere is assumed to be initially continental, and a lithosphere

  16. Hybrid energy harvesting using active thermal backplane

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  17. Meridional thermal field of a coupled ocean-atmosphere system: a conceptual model

    NASA Astrophysics Data System (ADS)

    Ou, Hsien-Wang

    2006-05-01

    This paper constitutes the author's continuing effort in the construction of a minimal theory of the earth's climate. In an earlier paper published in the Journal of Climate in 2001, this author has derived the global-mean fields of an aquatic planet forced by the solar insolation, which provide the necessary constraints for the present derivation of the meridional thermal field. The model closure invokes maximized entropy production (MEP), a thermodynamic principle widely used in turbulence and climate studies. Based on differing convective regimes of the ocean and atmosphere, both fluids are first reduced two thermal masses with aligned fronts, consistent with a minimal description of the observed field. Subjected to natural bounds, a robust solution is then found, characterized by an ice-free ocean, near-freezing cold fluid masses, mid-latitude fronts, and comparable ocean and atmosphere heat transports. The presence of polar continents, however, sharply reduces the ocean heat transport outside the tropics, but leaves the thermal field largely unchanged. Given the limitation of an extremely crude model, the deduced thermal field nonetheless seems sensible, suggesting that the model has captured the physics for a minimal account of the observed field. Together with the above-mentioned paper, the model reinforces the pre-eminent role of the triple point of water in stabilizing the surface temperature - against changing external condition. Such internal control is made possible by the turbulent nature of the climate fluids, which necessitates a selection rule based on extremization.

  18. Interpreting the implied meridional oceanic energy transport in AMIP

    SciTech Connect

    Randall, D.A.; Gleckler, P.J.

    1993-09-01

    The Atmospheric Model Intercomparison Project (AMIP) was outlined in Paper No. CLIM VAR 2.3 (entitled {open_quote}The validation of ocean surface heat fluxes in AMIP`) of these proceedings. Preliminary results of AMIP subproject No. 5 were also summarized. In particular, zonally averaged ocean surface heat fluxes resulting from various AMIP simulations were intercompared, and to the extent possible they were validated with uncertainties in observationally-based estimates of surface heat fluxes. The intercomparison is continued in this paper by examining the Oceanic Meridional Energy Transport (OMET) implied by the net surface heat fluxes of the AMIP simulations. As with the surface heat fluxes of the AMIP simulations. As with the surface heat fluxes, the perspective here will be very cursory. The annual mean implied ocean heat transport can be estimated by integrating the zonally averaged net ocean surface heat flux, N{sub sfc}, from one pole to the other. In AGCM simulations (and perhaps reality), the global mean N{sub sfc} is typically not in exact balance when averaged over one or more years. Because of this, an important assumption must be made about changes in the distribution of energy in the oceans. Otherwise, the integration will yield a non-zero transport at the endpoint of integration (pole) which is not physically realistic. Here the authors will only look at 10-year means of the AMIP runs, and for simplicity they assume that any long term imbalance in the global averaged N{sub sfc} will be sequestered (or released) over the global ocean. Tests have demonstrated that the treatment of how the global average energy imbalance is assumed to be distributed is important, especially when the long term imbalances are in excess of 10 W m{sup {minus}2}. However, this has not had a substantial impact on the qualitative features of the implied heat transport of the AMIP simulations examined thus far.

  19. Energy conservation, using remote thermal scanning

    NASA Technical Reports Server (NTRS)

    Bowman, R. L.; Jack, J. R.

    1978-01-01

    Airborne thermal infrared scans and thermal maps utilized in NASA's energy conservation program have proven to be efficient cost-effective method for identifying heat losses from building roofs and heating system distribution lines. Method employs commercially available equipment in highly developed way.

  20. Thermal Comfort and Strategies for Energy Conservation.

    ERIC Educational Resources Information Center

    Rohles, Frederick H., Jr.

    1981-01-01

    Discusses studies in thermal comfort which served as the basis for the comfort standard. Examines seven variables in the human response to the thermal environment in terms of the ways in which they can be modified to conserve energy. (Author/MK)

  1. Thermal energy storage effort at JPL

    NASA Technical Reports Server (NTRS)

    Young, D. L.

    1980-01-01

    The technical, operational, and economic readiness of parabolic dish systems for electric and thermal applications was investigated. A parabolic dish system was then developed to the point at which subsequent commercialization activities can lead to successful market penetration. The immediate possible applications of the dish system to thermal energy storage are discussed.

  2. TES (Thermal Energy Storage) Video News Release

    NASA Technical Reports Server (NTRS)

    1994-01-01

    TES is an in-space technology experiment that flew on STS-62. Its intent is to investigate the behavior of two different thermal energy storage materials as they undergo repeated melting and freezing in the microgravity environment.

  3. Enhancing radiative energy transfer through thermal extraction

    NASA Astrophysics Data System (ADS)

    Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

    2016-06-01

    Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

  4. Ocean energy systems at the Johns Hopkins University Applied Physics Laboratory, January - March 1983. Quarterly report

    SciTech Connect

    Not Available

    1983-01-01

    The Johns Hopkins University Applied Physics Laboratory, under a contract with the U.S. Department of Energy's Division of Ocean Energy Technology (DOE/DOET), is engaged in developing Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol), energy-intensive products such as ammonia (for fertilizers and chemicals), and aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. APL has been designated the Lead Laboratory in these areas by DOE/DOET. Another effort that began in the spring of 1982 is a technical advisory role to DOE with respect to their management of the conceptual and preliminary design activity of industry teams that are designing a shelf-mounted offshore OTEC pilot plant that could deliver power to Oahu, Hawaii. In addition, the Laboratory is now taking part in a program to evaluate and test the Pneumatic Wave-Energy Conversion System (PWECS), an ocean-energy device consisting of a turbine that is air-driven as a result of wave action in a chamber. This Quarterly Report summarizes the work on the various tasks as of 31 March 1983.

  5. Generation of Electric Energy and Desalinating Water from Solar Energy and the Oceans Hydropower

    NASA Astrophysics Data System (ADS)

    Elfikky, Niazi

    Brief.All warnings and fears about the environment in our Earth planet due to the serious effects of the industrial revolution were certainly predicted early. But the eager contest and the powerful desire for more profits beside the human interest for welfare and development closed all minds about the expected severe destuctive impacts on our earth planet. Also, we have to remember that the majority of the African, Asian and Latin American countries are still in the first stage of their development and if they will be left to generate all their demand of energy by the conventional machine e.g (Fossil Fuel, Biofuel and Nuclear Fuel), then our Earth planet will confront an endless and ceasless severe destructive impacts due to the encroach of the released hot Carbon Doxide and hot vapours of Acids which will never forgive any fruitful aspect in our Earth Planet from destruction. 1. Importance of the New Project. Building the Extra cheap, clean Power plants with safe and smooth Operation in addition to the long life time in service for generating enough and plentiful electric energy the sustainable renwable resources will invigorate the foresaking of all Nuclear, Fossil and Biofuel power plants to avoide the nuclear hazards and stop releasing the hot carbon doxide, hot acids for the recovery of our ill environment. Also, the main sustainable, renewable, and cheap resources for generating the bulky capacity of the electric energy in our project are the Sun and the Oceans in addition to all Seas Surrounding all Continents in our Earth planet. Therefore, our recourses are so much enormous plentiful, clean, and renewable. 2. .Generation of Electricity from Solar Energy by Photovoltiac Cells (PVCs) or Concentrated Solar Power (CSP). Characteristics of Photovoltiac Cells (PVCs). It is working only by Sun's Light (Light photons) and its efficiency will decrease as the Solar Thermal Radiation will increase, i.e. as the temerature of the Solar Voltiac will increase, its output

  6. Evaluation of New Thermally Conductive Geopolymer in Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    Černý, Matěj; Uhlík, Jan; Nosek, Jaroslav; Lachman, Vladimír; Hladký, Radim; Franěk, Jan; Brož, Milan

    This paper describes an evaluation of a newly developed thermally conductive geopolymer (TCG), consisting of a mixture of sodium silicate and carbon micro-particles. The TCG is intended to be used as a component of high temperature energy storage (HTTES) to improve its thermal diffusivity. Energy storage is crucial for both ecological and economical sustainability. HTTES plays a vital role in solar energy technologies and in waste heat recovery. The most advanced HTTES technologies are based on phase change materials or molten salts, but suffer with economic and technological limitations. Rock or concrete HTTES are cheaper, but they have low thermal conductivity without incorporation of TCG. It was observed that TCG is stable up to 400 °C. The thermal conductivity was measured in range of 20-23 W m-1 K-1. The effect of TCG was tested by heating a granite block with an artificial fissure. One half of the fissure was filled with TCG and the other with ballotini. 28 thermometers, 5 dilatometers and strain sensors were installed on the block. The heat transport experiment was evaluated with COMSOL Multiphysics software.

  7. Closing the energy cycle in an ocean model

    NASA Astrophysics Data System (ADS)

    Eden, Carsten

    2016-05-01

    An effort is discussed to construct a realistic ocean model in Boussinesq approximation which features a closed energy cycle up to numerical precision errors. In such a model, the energy related to the mean variables interacts with all parameterised forms of energy without any spurious energy sources or sinks. First, the concept of the energetics of the model in terms of resolved and unresolved energy variables is outlined using potential and dynamical enthalpy instead of internal and potential energy and without use of the concept of available potential energy. The role of energy transfer terms due to the non-linear, compressible equation of state is clarified. Second, a discretisation of the primitive equations is described in which energy transfers of viscous dissipation and mixing parameterisations are exactly calculated. Third, the model performance is documented using idealised and realistic global model configurations.

  8. Thermal Energy Storage Flight Experiment in Microgravity

    NASA Technical Reports Server (NTRS)

    Namkoong, David

    1992-01-01

    The Thermal Energy Storage Flight Experiment was designed to characterize void shape and location in LiF-based phase change materials in different energy storage configurations representative of advanced solar dynamic systems. Experiment goals and payload design are described in outline and graphic form.

  9. Thermal energy storage chiller management

    SciTech Connect

    Williams, C.D.

    1996-11-01

    This paper addresses chiller applications that are designed to get the maximum benefit form a chiller plant every day of the year. It treats all chillers as variable-capacity devices and applies them in thermal storage system configurations that efficiently take advantage of that capability. It also recognizes that a chiller operating temperature differential is always a variable to which a chiller must always adjust. All the applications addressed vary the flow and in some situations the operating temperature differential to maximize or optimize each chiller`s capacity. It is done in such a manner that the safety and reliability of the chiller are improved rather than jeopardized.

  10. Phase-Change Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    1989-11-01

    The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. Solar thermal technology concentrates the solar flux using tracking mirrors or lenses onto a receiver where the solar energy is absorbed as heat and converted into electricity or incorporated into products as process heat. The two primary solar thermal technologies, central receivers and distributed receivers, employ various point and line-focus optics to concentrate sunlight. Current central receiver systems use fields of heliostats (two-axes tracking mirrors) to focus the sun's radiant energy onto a single, tower-mounted receiver. Point focus concentrators up to 17 meters in diameter track the sun in two axes and use parabolic dish mirrors or Fresnel lenses to focus radiant energy onto a receiver. Troughs and bowls are line-focus tracking reflectors that concentrate sunlight onto receiver tubes along their focal lines. Concentrating collector modules can be used alone or in a multimodule system. The concentrated radiant energy absorbed by the solar thermal receiver is transported to the conversion process by a circulating working fluid. Receiver temperatures range from 100 C in low-temperature troughs to over 1500 C in dish and central receiver systems.

  11. Molten Salt Thermal Energy Storage Systems

    NASA Technical Reports Server (NTRS)

    Maru, H. C.; Dullea, J. F.; Kardas, A.; Paul, L.; Marianowski, L. G.; Ong, E.; Sampath, V.; Huang, V. M.; Wolak, J. C.

    1978-01-01

    The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored.

  12. Rapid and sustained surface ocean acidification during the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Penman, Donald E.; Hönisch, Bärbel; Zeebe, Richard E.; Thomas, Ellen; Zachos, James C.

    2014-05-01

    The Paleocene-Eocene Thermal Maximum (PETM) has been associated with the release of several thousands of petagrams of carbon (Pg C) as methane and/or carbon dioxide into the ocean-atmosphere system within ~10 kyr, on the basis of the co-occurrence of a carbon isotope excursion (CIE), widespread dissolution of deep sea carbonates, and global warming. In theory, this rapid carbon release should have severely acidified the surface ocean, though no geochemical evidence has yet been presented. Using boron-based proxies for surface ocean carbonate chemistry, we present the first observational evidence for a drop in the pH of surface and thermocline seawater during the PETM. Planktic foraminifers from a drill site in the North Pacific (Ocean Drilling Program Site 1209) show a ~0.8‰ decrease in boron isotopic composition (δ11B) at the onset of the event, along with a 30-40% reduction in shell B/Ca. Similar trends in δ11B are present in two lower-resolution records from the South Atlantic and Equatorial Pacific. These observations are consistent with significant, global acidification of the surface ocean lasting at least 70 kyr and requiring sustained carbon release. The anomalies in the B records are consistent with an initial surface pH drop of ~0.3 units, at the upper range of model-based estimates of acidification.

  13. Constraints on ocean circulation at the Paleocene-Eocene Thermal Maximum from neodymium isotopes

    NASA Astrophysics Data System (ADS)

    Abbott, April N.; Haley, Brian A.; Tripati, Aradhna K.; Frank, Martin

    2016-04-01

    Global warming during the Paleocene-Eocene Thermal Maximum (PETM) ˜ 55 million years ago (Ma) coincided with a massive release of carbon to the ocean-atmosphere system, as indicated by carbon isotopic data. Previous studies have argued for a role of changing ocean circulation, possibly as a trigger or response to climatic changes. We use neodymium (Nd) isotopic data to reconstruct short high-resolution records of deep-water circulation across the PETM. These records are derived by reductively leaching sediments from seven globally distributed sites to reconstruct past deep-ocean circulation across the PETM. The Nd data for the leachates are interpreted to be consistent with previous studies that have used fish teeth Nd isotopes and benthic foraminiferal δ13C to constrain regions of convection. There is some evidence from combining Nd isotope and δ13C records that the three major ocean basins may not have had substantial exchanges of deep waters. If the isotopic data are interpreted within this framework, then the observed pattern may be explained if the strength of overturning in each basin varied distinctly over the PETM, resulting in differences in deep-water aging gradients between basins. Results are consistent with published interpretations from proxy data and model simulations that suggest modulation of overturning circulation had an important role for initiation and recovery of the ocean-atmosphere system associated with the PETM.

  14. Constraints on ocean circulation at the Paleocene-Eocene Thermal Maximum from neodymium isotopes

    NASA Astrophysics Data System (ADS)

    Abbott, A. N.; Haley, B. A.; Tripati, A. K.; Frank, M.

    2015-06-01

    Global warming during the Paleocene Eocene Thermal Maximum (PETM) ~55 million years ago (Ma) coincided with a massive release of carbon to the ocean-atmosphere system, as indicated by carbon isotopic data. Previous studies have argued for a role for changing ocean circulation, possibly as a trigger or response to climatic changes. We use neodymium (Nd) isotopic data to reconstruct short high-resolution records of deep-water circulation across the PETM. These records are derived by reductively leaching sediments from seven globally distributed sites and comparing data with published data from fossil fish debris to reconstruct past deep ocean circulation across the PETM. The Nd data for the leachates are interpreted to be consistent with previous studies that have used fish teeth and benthic foraminiferal δ13C to constrain regions of convection. There is some evidence from combining Nd isotope and δ13C records that the three major ocean basins may not have had substantial exchanges of deep waters. If the isotopic data are interpreted within this framework, then the observed pattern may be explained if the strength of overturning in each basin varied distinctly over the PETM, resulting in differences in deep-water aging gradients between basins. Results are consistent with published interpretations from proxy data and model simulations that suggest modulation of overturning circulation had an important role for global recovery of the ocean-atmosphere system after the PETM.

  15. 77 FR 75444 - Ocean Energy Safety Advisory Committee (OESC); Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-20

    ... containment, spill response and safety management systems, the arctic and proposed ocean energy safety... Bureau of Safety and Environmental Enforcement Ocean Energy Safety Advisory Committee (OESC); Notice of... Director of BSEE on matters relating to ocean energy safety, including, but not limited to drilling...

  16. High temperature thermal energy storage, including a discussion of TES integrated into power plants

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1978-01-01

    Storage temperatures of 260 C and above are considered. Basic considerations concerning energy thermal storage are discussed, taking into account general aspects of thermal energy storage, thermal energy storage integrated into power plants, thermal storage techniques and technical considerations, and economic considerations. A description of system concepts is provided, giving attention to a survey of proposed concepts, storage in unpressurized fluids, water storage in pressurized containers, the use of an underground lined cavern for water storage, a submerged thin insulated steel shell under the ocean containing pressurized water, gas passage through solid blocks, a rock bed with liquid heat transport fluid, hollow steel ingots, heat storage in concrete or sand, sand in a fluidized bed, sand poured over pipes, a thermal energy storage heat exchanger, pipes or spheres filled with phase change materials (PCM), macroencapsulated PCM with heat pipe concept for transport fluid, solid PCM removed from heat transfer pipes by moving scrapers, and the direct contact between PCM and transport fluid.

  17. LiH thermal energy storage device

    DOEpatents

    Olszewski, M.; Morris, D.G.

    1994-06-28

    A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures. 5 figures.

  18. Thermal energy storage composition comprising peat moss

    SciTech Connect

    Rueffel, P.G.

    1980-11-04

    Peat moss is used in a thermal energy storage composition to provide a network in which to trap an incongruently melting salt hydrate capable of storing thermal energy as latent heat of phase change. The peat moss network is effective in preventing the segregation of a dehydrated form of the salt between heating and cooling cycles. In a preferred embodiment that salt hydrate is the decahydrate of sodium sulphate. A nucleating agent such as sodium tetraborate decahydrate is included to prevent supercooling in the composition, and promote crystallization of the decahydrate of sodium sulphate.

  19. Spacecraft thermal energy accommodation from atomic recombination

    NASA Technical Reports Server (NTRS)

    Carleton, Karen L.; Marinelli, William J.

    1991-01-01

    Measurements of atomic recombination probabilities important in determining energy release to reusable spacecraft thermal protection surfaces during reentry are presented. An experimental apparatus constructed to examine recombination of atomic oxygen from thermal protection and reference materials at reentry temperatures is described. The materials are examined under ultrahigh vacuum conditions to develop and maintain well characterized surface conditions that are free of contamination. When compared with stagnation point heat transfer measurements performed in arc jet facilities, these measurements indicate that a significant fraction of the excess energy available from atom recombination is removed from the surface as metastable O2.

  20. Aquifer thermal energy (heat and chill) storage

    SciTech Connect

    Jenne, E.A.

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

  1. Basin-Specific Variations in the Thermal Aging of Oceanic Asthenosphere

    NASA Astrophysics Data System (ADS)

    Paulson, E.; Jordan, T. H.

    2014-12-01

    To investigate the depth extent of mantle thermal aging beneath ocean basins, we project 3D Voigt averaged S-velocity variations from an ensemble of global tomographic models onto a 1º x 1º degree age-based regionalization and average each major ocean basin (Pacific, Atlantic, and Indian) in equal increments of the square-root of crustal age. By comparing the age averaged S-wave profiles, we estimate convergence depths, the minimum depths where age variations become statistically insignificant. Following Jordan & Paulson (JGR, doi:10.1002/jgrb.50263, 2013), we estimate aleatory variability in the S-wave profiles, correct for vertical smearing bias, and estimate epistemic uncertainties over the model ensemble. We can assert with 90% confidence that the age-correlated variations in Voigt-averaged S velocities persist to depths greater than 170 km. Given the strong evidence that the G discontinuity (~70 km) approximates the lithosphere-asthenosphere boundary (LAB) beneath ocean basins, we conclude that the upper part of the oceanic asthenosphere participates in the cooling that forms the kinematic plates. Age-averaged profiles show significant differences among the ocean basins. To quantify this, we fit age-dependent vertical travel times through the uppermost mantle of the models with an idealized Earth model having a strict square-root of age velocity structure in the ocean basins, suitably filtered to mimic tomographic smoothing. Good fits can be obtained for the Atlantic and Indian ocean basins out to 170 My, although the travel-time slopes for the former are steeper than the latter, implying more rapid cooling in the Atlantic. The Pacific basin shows significant deviations from simple conductive cooling for ages greater than about 50 My, in general agreement with previously published surface-wave models, indicating perturbations associated with small-scale convective processes. We conclude that large-scale flow advects small-scale heterogeneities due to

  2. The impact of wind energy turbine piles on ocean dynamics

    NASA Astrophysics Data System (ADS)

    Grashorn, Sebastian; Stanev, Emil V.

    2016-04-01

    The small- and meso-scale ocean response to wind parks has not been investigated in the southern North Sea until now with the help of high-resolution numerical modelling. Obstacles such as e.g. wind turbine piles may influence the ocean current system and produce turbulent kinetic energy which could affect sediment dynamics in the surrounding area. Two setups of the unstructured-grid model SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) have been developed for an idealized channel including a surface piercing cylindrical obstacle representing the pile and a more realistic test case including four exemplary piles. Experiments using a constant flow around the obstacles and a rotating M2 tidal wave are carried out. The resulting current and turbulence patterns are investigated to estimate the influence of the obstacles on the surrounding ocean dynamics. We demonstrate that using an unstructured ocean model provides the opportunity to embed a high-resolution representation of a wind park turbine pile system into a coarser North Sea setup, which is needed in order to perform a seamless investigation of the resulting geophysical processes.

  3. Ocean Wave Energy Regimes of the Circumpolar Coastal Zones

    NASA Astrophysics Data System (ADS)

    Atkinson, D. E.

    2004-12-01

    Ocean wave activity is a major enviromental forcing agent of the ice-rich sediments that comprise large sections of the arctic coastal margins. While it is instructive to possess information about the wind regimes in these regions, direct application to geomorphological and engineering needs requires knowledge of the resultant wave-energy regimes. Wave energy information has been calculated at the regional scale using adjusted reanalysis model windfield data. Calculations at this scale are not designed to account for local-scale coastline/bathymetric irregularities and variability. Results will be presented for the circumpolar zones specified by the Arctic Coastal Dynamics Project.

  4. Aquifer thermal energy storage. International symposium: Proceedings

    SciTech Connect

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  5. Applications and challenges for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Kannberg, L. D.; Tomlinson, J. T.

    1991-04-01

    New thermal energy storage (TES) technologies are being developed and applied as society strives to relieve increasing energy and environmental stresses. Applications for these new technologies range from residential and district heating and cooling using waste and solar energy, to high-temperature energy storage for power production and industrial processes. In the last two decades there has been great interest and development of heat storage systems, primarily for residential and commercial buildings. While development has continued, the rate of advancement has slowed with current technology considered adequate for electrically charged heat storage furnaces. Use of chill storage for building diurnal cooling has received substantial development.

  6. Ocean thermal conversion (OTEC) project bottom cable protection study. Analysis and selection of protection techniques

    SciTech Connect

    Not Available

    1981-10-01

    General guidelines and procedures for cable protection are given for the four proposed Ocean Thermal Energy Conversion (OTEC) plant sites and cable routes, together with seafloor scenarios and protection strategies for each site. Burial of the cable below the seafloor is the recommended and best method of protecting OTEC cables from the hazards existing at all sites, namely, chafe and corrosion, hydrodynamic forces, trawler/dredge, and ship anchor. For landslides and earthquakes the only feasible method of protection, although limited, is to provide slack, in the cable, i.e. lay extra length. Trenches for burying the cable are recommended to be constructed a) by blasting through hard bottom at Hawaii for the first nautical mile (n.m.) and at Puerto Rico for the first 0.9 n.m; b)by a plowing machine at Hawaii for the next 0.5 n.m.; c) by a trenching machine at Guam for the first 0.55 n.m.; d) by a trenching /laying machine at Florida for 110 n.m.; and e) by a conventional floating dredge for 15 n.m. For the outshore segments of the cable routes it is recommenced to lay the cable on th seafloor because bottom sediments are soft enough to permit the cable to bury itself. Except for the Florida route, a normal cable laying vessel is recommended for laying the cable from plant site to landfall and for performing the protection details which are temie concrete cover over the cable at Hawaii for 0.5 n.m. and split pipe and rock anchor at Puerto Rico for 0l2 n.m.

  7. The role of thermal energy storage in industrial energy conservation

    NASA Technical Reports Server (NTRS)

    Duscha, R. A.; Masica, W. J.

    1979-01-01

    Thermal Energy Storage for Industrial Applications is a major thrust of the Department of Energy's Thermal Energy Storage Program. Utilizing Thermal Energy Storage (TES) with process or reject heat recovery systems is shown to be extremely beneficial for several applications. Recent system studies resulting from contracts awarded by the Department of Energy (DOE) identified four especially significant industries where TES appears attractive - food processing, paper and pulp, iron and steel, and cement. Potential annual fuel savings with large scale implementation of near term TES systems for these industries is over 9,000,000 bbl of oil. This savings is due to recuperation and storage in the food processing industry, direct fuel substitution in the paper and pulp industry and reduction in electric utility peak fuel use through inplant production of electricity from utilization of reject heat in the steel and cement industries.

  8. Thermal Insulation Strips Conserve Energy

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Launching the space shuttle involves an interesting paradox: While the temperatures inside the shuttle s main engines climb higher than 6,000 F hot enough to boil iron for fuel, the engines use liquid hydrogen, the second coldest liquid on Earth after liquid helium. Maintained below 20 K (-423 F), the liquid hydrogen is contained in the shuttle s rust-colored external tank. The external tank also contains liquid oxygen (kept below a somewhat less chilly 90 K or -297 F) that combines with the hydrogen to create an explosive mixture that along with the shuttle s two, powdered aluminum-fueled solid rocket boosters allows the shuttle to escape Earth s gravity. The cryogenic temperatures of the main engines liquid fuel can cause ice, frost, or liquefied air to build up on the external tank and other parts of the numerous launch fueling systems, posing a possible debris risk when the ice breaks off during launch and causing difficulties in the transfer and control of these cryogenic liquid propellants. Keeping the fuel at the necessary ultra-cold temperatures while minimizing ice buildup and other safety hazards, as well as reducing the operational maintenance costs, has required NASA to explore innovative ways for providing superior thermal insulation systems. To address the challenge, the Agency turned to an insulating technology so effective that, even though it is mostly air, a thin sheet can prevent a blowtorch from igniting a match. Aerogels were invented in 1931 and demonstrate properties that make them the most extraordinary insulating materials known; a 1-inch-thick piece of aerogel provides the same insulation as layering 15 panes of glass with air pockets in between. Derived from silica, aluminum oxide, or carbon gels using a supercritical drying process - resulting in a composition of almost 99-percent air - aerogels are the world s lightest solid (among 15 other titles they hold in the Guinness World Records), can float indefinitely on water if treated to be

  9. Ecological analysis of spatial and temporal patterns of pelagic ecosystem components potentially interacting with an OTEC (Ocean Thermal Energy Conversion) plant near Punta Tuna, Puerto Rico: physical characteristics. Final report

    SciTech Connect

    Lopez, J.M.; Tilly, L.J.

    1983-01-01

    This hydrographic study characterizes the Punta Tuna area as a potential site for an OTEC power plant. Seven cruises were conducted at approximately two month intervals. Each cruise included at least 22 hydrocast stations, six done as serial stations in a small area to reveal temporal and small scale variability. The results of the analysis of these data so far indicate a bi-seasonality in the dynamics. Mesoscale eddies and meanders are a common feature of the circulation pattern on Puerto Rico's southern coast. The time series studies have shown their existence of a very energetic internal wave field with relatively large amplitude waves at the diurnal and semi-diurnal tidal frequencies. The results in terms of an OTEC power plant indicate the thermal resource to be at least a 20C thermal gradient in the upper 100 m year round.

  10. Phase change thermal energy storage material

    DOEpatents

    Benson, David K.; Burrows, Richard W.

    1987-01-01

    A thermal energy storge composition is disclosed. The composition comprises a non-chloride hydrate having a phase change transition temperature in the range of 70.degree.-95.degree. F. and a latent heat of transformation of at least about 35 calories/gram.

  11. Waste recycling primary source of energy in deep ocean

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-02-01

    In the dark reaches of the deep ocean, far from the photosynthesizing plants and plankton that fuel life in the surface waters, ecosystems survive on chemical energy. Decades of research on the life that clusters around deep-sea hydrothermal vents has hinted at the importance of light-free food webs, but a recent analysis by Middelburg suggests that another system—waste recycling—could be the dominant pillar of life on the abyssal plains. The realization was a result of the author's attempt to calculate the importance of chemoautotrophy to the carbon cycles of different ocean regions. levels increase rates of denitrification and methanogenesis, thus increasing gas production rates. The authors also found that methane bubbles surpass diffused nitrous oxide in terms of global warming potential, which they suggest could warrant a rethinking of the importance of streams and rivers to global warming. (Journal of Geophysical Research-Biogeosciences, doi:10.1029/2011JG001656, 2011)

  12. Making `Internal Thermal Energy' Visible

    NASA Astrophysics Data System (ADS)

    Zou, Xueli

    2004-09-01

    In a 1992 paper published in this journal, Uri Ganiel described a pair of model carts used to demonstrate elastic and inelastic collisions. The wooden carts had low-friction wheels and a steel-strip bumper on one end. On one of the carts, a number of brass washers were rigidly mounted in vertical stacks to a wooden framework. The other cart was similar except that the washers were tied to rubber bands that were stretched horizontally and diagonally across the framework. When the first cart was rolled into a wall it bounced off with only a small reduction in speed ("elastic" collision). The second cart, on the other hand, was found to come nearly to a complete stop upon colliding with the wall ("inelastic" collision). Following the instructions given in Ganiel's paper, I built a pair of carts and demonstrated them to introductory-level physics students at a large public university. It was interesting to find that many students were distracted by the different-looking structures of the two model carts.2 They thought the different distributions of washers between the carts resulted in the rubber-band cart bouncing back a significantly shorter distance than the rigid-rod one after they both collided with a wall at the same initial speed. Apparently, the students had difficulties in understanding the collisions and used surface features to reason about them. To avoid this superficial distraction and to help students visualize easily "where the kinetic energy goes in an inelastic collision," I modified the rigid-rod cart to have washers fixed on hollow aluminum rods mounted at four different levels horizontally and diagonally (see Fig. 1). The new pair of the model carts look very similar to each other: They have the same bumpers, same wheels, same distributions of washers, and same masses.

  13. Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

    SciTech Connect

    Haas, Kevin A.

    2013-10-03

    Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States.

  14. Mixing in thermally stratified energy stores

    SciTech Connect

    Berkle, J. van

    1996-10-01

    Two important aspects of short-term thermally stratified energy storage, thermocline mixing and thermocline thickness, are studied analytically, experimentally and numerically. The storage detrimental aspects are investigated for a simplified configuration, i.e., an adiabatic box containing a quasi-stationary thermocline. Numerical finite difference/volume simulations agree well with experiments. The dissipation-free 1D analytical model shows a large discrepancy. It appears that mixing inside thermally stratified stores is a two-state process. First fluid is withdrawn from the thermocline by viscous drag. Subsequent mixing takes place by stretching and folding of fluid particles, thereby enabling diffusion to become active. 17 refs., 10 figs., 2 tabs.

  15. Power inversion design for ocean wave energy harvesting

    NASA Astrophysics Data System (ADS)

    Talebani, Anwar N.

    The needs for energy sources are increasing day by day because of several factors, such as oil depletion, and global climate change due to the higher level of CO2, so the exploration of various renewable energy sources is very promising area of study. The available ocean waves can be utilized as free source of energy as the water covers 70% of the earth surface. This thesis presents the ocean wave energy as a source of renewable energy. By addressing the problem of designing efficient power electronics system to deliver 5 KW from the induction generator to the grid with less possible losses and harmonics as possible and to control current fed to the grid to successfully harvest ocean wave energy. We design an AC-DC full bridge rectifier converter, and a DC-DC boost converter to harvest wave energy from AC to regulated DC. In order to increase the design efficiency, we need to increase the power factor from (0.5-0.6) to 1. This is accomplished by designing the boost converter with power factor correction in continues mode with RC circuit as an input to the boost converter power factor correction. This design results in a phase shift between the input current and voltage of the full bridge rectifier to generate a small reactive power. The reactive power is injected to the induction generator to maintain its functionality by generating a magnetic field in its stator. Next, we design a single-phase pulse width modulator full bridge voltage source DC-AC grid-tied mode inverter to harvest regulated DC wave energy to AC. The designed inverter is modulated by inner current loop, to control current injected to the grid with minimal filter component to maintain power quality at the grid. The simulation results show that our design successfully control the current level fed to the grid. It is noteworthy that the simulated efficiency is higher than the calculated one since we used an ideal switch in the simulated circuit.

  16. Episodic and non-uniform shifts of thermal habitats in a warming ocean

    NASA Astrophysics Data System (ADS)

    Sen Gupta, A.; Brown, J. N.; Jourdain, N. C.; van Sebille, E.; Ganachaud, A.; Vergés, A.

    2015-03-01

    Ocean temperatures have warmed in most regions over the last century and are expected to warm at a faster rate in the future. Consistent with the view that marine species are thermally constrained, there is growing evidence that many marine species have already undergone poleward range shifts in line with warming trends. This study uses historical observations of ocean temperature and climate model projections to examine the movement of isotherms that mark the boundaries for species‧ thermal habitats. In particular, we compare the rates of isotherm movement between different ocean regions and at different time scales and examine to what extent the implied movement is uniform or sporadic. Widespread long-term warming implies poleward shifts of isotherms in almost all regions. However, as the speed of isotherm movement is inversely related to local meridional SST gradients and the pattern of ocean warming is heterogeneous, speeds vary considerably between regions, season and over time. At present on decadal and longer timescales, changes due to low frequency natural SST variability can dominate over human-induced changes. As such, there are multidecadal periods in certain regions when we would expect to see range shifts that are much faster or in the opposite direction to that implied by a monotonic warming. Based on central estimates from the latest suite of climate model projections, median isotherm speeds will be about seven times faster in the 21st century compared to the 20th century under business as usual emissions. Moreover, SST warming is projected to be greater in summer than in winter in most oceanic regions, contrary to what is projected to occur over land. As such net poleward isotherm speeds, particularly in the northern hemisphere summer, are projected to be considerably faster than in winter. Finally we show that isotherms can exhibit erratic migration rates over time, even under uniform warming. Isotherm movement tends to stall at thermal fronts

  17. Experimental ocean acidification alters the allocation of metabolic energy.

    PubMed

    Pan, T-C Francis; Applebaum, Scott L; Manahan, Donal T

    2015-04-14

    Energy is required to maintain physiological homeostasis in response to environmental change. Although responses to environmental stressors frequently are assumed to involve high metabolic costs, the biochemical bases of actual energy demands are rarely quantified. We studied the impact of a near-future scenario of ocean acidification [800 µatm partial pressure of CO2 (pCO2)] during the development and growth of an important model organism in developmental and environmental biology, the sea urchin Strongylocentrotus purpuratus. Size, metabolic rate, biochemical content, and gene expression were not different in larvae growing under control and seawater acidification treatments. Measurements limited to those levels of biological analysis did not reveal the biochemical mechanisms of response to ocean acidification that occurred at the cellular level. In vivo rates of protein synthesis and ion transport increased ∼50% under acidification. Importantly, the in vivo physiological increases in ion transport were not predicted from total enzyme activity or gene expression. Under acidification, the increased rates of protein synthesis and ion transport that were sustained in growing larvae collectively accounted for the majority of available ATP (84%). In contrast, embryos and prefeeding and unfed larvae in control treatments allocated on average only 40% of ATP to these same two processes. Understanding the biochemical strategies for accommodating increases in metabolic energy demand and their biological limitations can serve as a quantitative basis for assessing sublethal effects of global change. Variation in the ability to allocate ATP differentially among essential functions may be a key basis of resilience to ocean acidification and other compounding environmental stressors. PMID:25825763

  18. Experimental ocean acidification alters the allocation of metabolic energy

    PubMed Central

    Pan, T.-C. Francis; Applebaum, Scott L.; Manahan, Donal T.

    2015-01-01

    Energy is required to maintain physiological homeostasis in response to environmental change. Although responses to environmental stressors frequently are assumed to involve high metabolic costs, the biochemical bases of actual energy demands are rarely quantified. We studied the impact of a near-future scenario of ocean acidification [800 µatm partial pressure of CO2 (pCO2)] during the development and growth of an important model organism in developmental and environmental biology, the sea urchin Strongylocentrotus purpuratus. Size, metabolic rate, biochemical content, and gene expression were not different in larvae growing under control and seawater acidification treatments. Measurements limited to those levels of biological analysis did not reveal the biochemical mechanisms of response to ocean acidification that occurred at the cellular level. In vivo rates of protein synthesis and ion transport increased ∼50% under acidification. Importantly, the in vivo physiological increases in ion transport were not predicted from total enzyme activity or gene expression. Under acidification, the increased rates of protein synthesis and ion transport that were sustained in growing larvae collectively accounted for the majority of available ATP (84%). In contrast, embryos and prefeeding and unfed larvae in control treatments allocated on average only 40% of ATP to these same two processes. Understanding the biochemical strategies for accommodating increases in metabolic energy demand and their biological limitations can serve as a quantitative basis for assessing sublethal effects of global change. Variation in the ability to allocate ATP differentially among essential functions may be a key basis of resilience to ocean acidification and other compounding environmental stressors. PMID:25825763

  19. Thermal diffusion of the lunar magma ocean and the formation of the lunar crust

    NASA Astrophysics Data System (ADS)

    Zhu, D.; Wang, S.

    2010-12-01

    The magma ocean hypothesis is consistent with several lines of evidence including planet formation, core-mantle differentiation and geochemical observations, and it is proved as an inevitable stage in the early evolution of planets. The magma ocean is assumed to be homogeneous in previous models during solidification or crystallization[1]. Based on the recent advance and our new data in experimental igneous petrology[2], we question this assumption and propose that an gabbrotic melt, from which the anorthositic lunar crust crystallized, can be produced by thermal diffusion, rather than by magma fractionation. This novel model can provide explanations for the absence of the advection in lunar magma ocean[3] and the old age of the anorthositic lunar crust[4-5]. 1. Solomatov, V., Magma Oceans and Primordial Mantle Differentiation, in Treatise on Geophysics, S. Gerald, Editor. 2007, Elsevier: Amsterdam. p. 91-119. 2. Huang, F., et al., Chemical and isotopic fractionation of wet andesite in a temperature gradient: Experiments and models suggesting a new mechanism of magma differentiation. Geochimica Et Cosmochimica Acta, 2009. 73(3): p. 729-749. 3. Turcotte, D.L. and L.H. Kellogg, Implications of isotope data for the origin of the Moon, in Origin of the Moon, W.K. Hartmann, R.J. Phillips, and G.J. Taylor, Editors. 1986, Lunar and Planet. Inst.: Houston, TX. p. 311-329. 4. Alibert, C., M.D. Norman, and M.T. McCulloch, An ancient Sm-Nd age for a ferroan noritic anorthosite clast from lunar breccia 67016. Geochimica Et Cosmochimica Acta, 1994. 58(13): p. 2921-2926. 5. Touboul, M., et al., Tungsten isotopes in ferroan anorthosites: Implications for the age of the Moon and lifetime of its magma ocean. Icarus, 2009. 199(2): p. 245-249.

  20. A new local theory of available potential energy for quantifying energy pathways in the oceans

    NASA Astrophysics Data System (ADS)

    Tailleux, Remi

    2013-04-01

    Lorenz's theory of available potential energy (APE) has recently received much attention in the context of ocean energetics, for it is increasingly realized to be a key tool for clarifying the relative importance of the surface buoyancy fluxes in powering the ocean circulation, a controversial issue over the past 15 years or so. So far, however, most recent approaches have been restricted to global APE budgets, often for idealized equations of state, which is arguably of limited interest to understand the precise nature of the energy pathways in the oceans. Here, we will present a local extension of the theory of available potential energy, which is developed for the primitive equations that form the basis of most current general ocean circulation models, and which is valid for an arbitrary nonlinear equation of state. Another advantage of the new theory is that it does not require the reference state underlying Lorenz's APE theory to be necessarily the state of minimum potential energy obtained in an adiabatic re-arrangement of the fluid parcels, and hence does not suffer from traditional difficulties pertaining to how to do the sorting of the fluid parcels. The main result of this work is the ability in some instances to link local conversion of APE into kinetic energy directly to the local production of APE by surface fluxes. The framework is also shown to be useful to provide an energy-based characterization of oceanic water masses.

  1. Atmosphere-ocean energy and nitrous oxide exchange and mixed layer dynamics in the Caribbean Sea and neighboring Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Hernandez Figueroa, Jose Luis

    2000-12-01

    The air-sea fluxes of energy and nitrous oxide (N2O) in oceanic waters of the Caribbean Sea and neighboring Atlantic Ocean (10°N-24°N, 48°W-88°W) were studied. These fluxes were estimated using parameterization formulas and five gas exchange turbulent models applied to 1980-1995 COADS data. The region was divided in four subregions that exhibit different patterns of wind speed (W) and sea surface temperature ( Ts), the main parameters controlling regional heat fluxes. Monthly averages on latitude bands of 2° width and time spectral analysis were obtained for Ts, air surface temperature (Ta), W, relative humidity (RH), cloud cover ( C) and sea level pressure (P). The spatial and temporal behavior of these climate parameters reveals that oceanic regions mainly have annual variation, while coastal areas show biannual variation. The spatial distribution of Ts revealed that the Caribbean Sea is warmer than the Atlantic Ocean with a consistent difference of about 0.5°C-0.75°C throughout the year. Winds affect Ts at coastal areas inducing upwelling in the central (CC) and eastern Caribbean (EC) subregions. The southern part (11°N-13°N) of these subregions is cooler (~0.5°C) than the rest of the Caribbean from January to March. The temperature difference between those latitudes and higher latitudes (24°N) increases up to about 1°C in July when wind speed strengthens. This strengthening is associated to the meridional gradient of P. During July at CC, the highest gradient (0.58 mb/°lat) simultaneously occurs with the highest wind speeds. At low latitudes (11°N-15°N), C presents a maximum during June, simultaneously with a minimum in the solar heat flux. Thermal stability (dTs = Ts-Ta ) is of significant importance in the sea-atmosphere energy exchange. Over the region, a high correlation coefficient (-0.92) was found between net heat flux and dTs. This parameter also controls the mixed layer depth, except in February and July when wind effects become

  2. Thermal Profiling of Residential Energy Use

    SciTech Connect

    Albert, A; Rajagopal, R

    2015-03-01

    This work describes a methodology for informing targeted demand-response (DR) and marketing programs that focus on the temperature-sensitive part of residential electricity demand. Our methodology uses data that is becoming readily available at utility companies-hourly energy consumption readings collected from "smart" electricity meters, as well as hourly temperature readings. To decompose individual consumption into a thermal-sensitive part and a base load (non-thermally-sensitive), we propose a model of temperature response that is based on thermal regimes, i.e., unobserved decisions of consumers to use their heating or cooling appliances. We use this model to extract useful benchmarks that compose thermal profiles of individual users, i.e., terse characterizations of the statistics of these users' temperature-sensitive consumption. We present example profiles generated using our model on real consumers, and show its performance on a large sample of residential users. This knowledge may, in turn, inform the DR program by allowing scarce operational and marketing budgets to be spent on the right users-those whose influencing will yield highest energy reductions-at the right time. We show that such segmentation and targeting of users may offer savings exceeding 100% of a random strategy.

  3. Solar Thermal Energy Storage Device: Hybrid Nanostructures for High-Energy-Density Solar Thermal Fuels

    SciTech Connect

    2012-01-09

    HEATS Project: MIT is developing a thermal energy storage device that captures energy from the sun; this energy can be stored and released at a later time when it is needed most. Within the device, the absorption of sunlight causes the solar thermal fuel’s photoactive molecules to change shape, which allows energy to be stored within their chemical bonds. A trigger is applied to release the stored energy as heat, where it can be converted into electricity or used directly as heat. The molecules would then revert to their original shape, and can be recharged using sunlight to begin the process anew. MIT’s technology would be 100% renewable, rechargeable like a battery, and emissions-free. Devices using these solar thermal fuels—called Hybrisol—can also be used without a grid infrastructure for applications such as de-icing, heating, cooking, and water purification.

  4. Operational Experience from Solar Thermal Energy Projects

    NASA Technical Reports Server (NTRS)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  5. Analysis of lunar regolith thermal energy storage

    SciTech Connect

    Colozza, A.J.

    1991-11-01

    The concept of using lunar regolith as a thermal energy storage medium was evaluated. The concept was examined by mathematically modeling the absorption and transfer of heat by the lunar regolith. Regolith thermal and physical properties were established through various sources as functions of temperature. Two cases were considered: a semi-infinite, constant temperature, cylindrical heat source embedded in a continuum of lunar regolith and a spherically shaped molten zone of lunar regolith set with an initial temperature profile. The cylindrical analysis was performed in order to examine the amount of energy which can be stored in the regolith during the day. At night, the cylinder acted as a perfect insulator. This cycling was performed until a steady state situation was reached in the surrounding regolith. It was determined that a cycling steady state occurs after approximately 15 day/night cycles. Results were obtained for cylinders of various diameters. The spherical molten zone analysis was performed to establish the amount of thermal energy, within the regolith, necessary to maintain some molten material throughout a nighttime period. This surrounding temperature profile was modeled after the cycling steady state temperature profile established by the cylindrical analysis. It was determined that a molten sphere diameter of 4.76 m is needed to maintain a core temperature near the low end of the melting temperature range throughout one nighttime period.

  6. Analysis of lunar regolith thermal energy storage

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.

    1991-01-01

    The concept of using lunar regolith as a thermal energy storage medium was evaluated. The concept was examined by mathematically modeling the absorption and transfer of heat by the lunar regolith. Regolith thermal and physical properties were established through various sources as functions of temperature. Two cases were considered: a semi-infinite, constant temperature, cylindrical heat source embedded in a continuum of lunar regolith and a spherically shaped molten zone of lunar regolith set with an initial temperature profile. The cylindrical analysis was performed in order to examine the amount of energy which can be stored in the regolith during the day. At night, the cylinder acted as a perfect insulator. This cycling was performed until a steady state situation was reached in the surrounding regolith. It was determined that a cycling steady state occurs after approximately 15 day/night cycles. Results were obtained for cylinders of various diameters. The spherical molten zone analysis was performed to establish the amount of thermal energy, within the regolith, necessary to maintain some molten material throughout a nighttime period. This surrounding temperature profile was modeled after the cycling steady state temperature profile established by the cylindrical analysis. It was determined that a molten sphere diameter of 4.76 m is needed to maintain a core temperature near the low end of the melting temperature range throughout one nighttime period.

  7. Mass and thermal energy balance of potato processing operations

    SciTech Connect

    Chadbourne, D.L.; Heldman, D.R.

    1981-01-01

    A mass and thermal energy analysis was conducted for a potato peeling operation. Results provide insight into opportunities for process modifications leading to increased recovery of product components and thermal energy.

  8. Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum

    USGS Publications Warehouse

    Sluijs, A.; Schouten, S.; Pagani, M.; Woltering, M.; Brinkhuis, H.; Damste, J.S.S.; Dickens, G.R.; Huber, M.; Reichart, G.-J.; Stein, R.; Matthiessen, J.; Lourens, L.J.; Pedentchouk, N.; Backman, J.; Moran, K.; Clemens, S.; Cronin, T.; Eynaud, F.; Gattacceca, J.; Jakobsson, M.; Jordan, R.; Kaminski, M.; King, J.; Koc, N.; Martinez, N.C.; McInroy, D.; Moore, T.C., Jr.; O'Regan, M.; Onodera, J.; Palike, H.; Rea, B.; Rio, D.; Sakamoto, T.; Smith, D.C.; St John, K.E.K.; Suto, I.; Suzuki, N.; Takahashi, K.; Watanabe, M. E.; Yamamoto, M.

    2006-01-01

    The Palaeocene/Eocene thermal maximum, ???55 million years ago, was a brief period of widespread, extreme climatic warming, that was associated with massive atmospheric greenhouse gas input. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition. We show that sea surface temperatures near the North Pole increased from ???18??C to over 23??C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10??C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms-perhaps polar stratospheric clouds or hurricane-induced ocean mixing-to amplify early Palaeogene polar temperatures. ?? 2006 Nature Publishing Group.

  9. Simulation of the ocean's spectral radiant thermal source and boundary conditions

    NASA Astrophysics Data System (ADS)

    Merzlikin, Vladimir; Krass, Maxim; Cheranev, Svyatoslav; Aloric, Aleksandra

    2013-05-01

    This article considers the analysis of radiant heat transfer for semitransparent natural and polluted seawaters and its physical interpretations. Technogenic or natural pollutions are considered as ensembles of selective scattering, absorbing and emitting particles with complex refractive indices in difference spectral ranges of external radiation. Simulation of spectral radiant thermal sources within short wavelength of solar penetrating radiation for upper oceanic depth was carried out for deep seawater on regions from ˜ 300 to ˜ 600 nm and for subsurface layers (not more ˜ 1 m) - on one ˜ 600 - 1200 nm. Model boundary conditions on exposed oceanic surface are defined by (1) emittance of atmosphere and seawater within long wavelength radiation ˜ 9000 nm, (2) convection, and (3) thermal losses due to evaporation. Spatial and temporal variability of inherent optical properties, temperature distributions of the upper overheated layer of seawater, the appearance of a subsurface temperature maximum and a cool surface skin layer in response to penetrating solar radiation are explained first of all by the effects of volumetric scattering (absorption) and surface cooling of polluted seawater. The suggested analysis can become an important and useful subject of research for oceanographers and climatologists.

  10. Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab Hyas araneus

    NASA Astrophysics Data System (ADS)

    Walther, K.; Sartoris, F. J.; Bock, C.; Pörtner, H. O.

    2009-10-01

    Future scenarios for the oceans project combined developments of CO2 accumulation and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of elevated CO2 concentrations on thermal tolerance of the cold-eurythermal spider crab Hyas araneus from the population around Helgoland. Here ambient temperatures characterize the southernmost distribution limit of this species. Animals were exposed to present day normocapnia (380 ppm CO2), CO2 levels expected towards 2100 (710 ppm) and beyond (3000 ppm). Heart rate and haemolymph PO2 (PeO2) were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling, the highest values being reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc) was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

  11. Ocean energy system at the Johns Hopkins University Applied Physics Laboratory

    NASA Astrophysics Data System (ADS)

    Richards, D.; Avery, W. H.; Richards, D.; Francis, E. J.

    1982-10-01

    The Johns Hopkins University Applied Physics laboratory, is engaged in developing Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol), energy intensive products such as ammonia (for fertilizers and chemicals), and aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. APL has been designated the Lead Laboratory in these areas by DOE/DOET. Another effort that began in the spring of 1982 is a technical advisory role to DOE with respect to their management of the conceptual design activity of the two industry teams that are designing offshore OTEC pilot plants that could deliver power to Oahu, Hawaii.

  12. Maximizing Thermal Efficiency and Optimizing Energy Management (Fact Sheet)

    SciTech Connect

    Not Available

    2012-03-01

    Researchers at the Thermal Test Facility (TTF) on the campus of the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) in Golden, Colorado, are addressing maximizing thermal efficiency and optimizing energy management through analysis of efficient heating, ventilating, and air conditioning (HVAC) strategies, automated home energy management (AHEM), and energy storage systems.

  13. Attenuation of Scattered Thermal Energy Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Seroka, Katelyn T.; McPhate, Jason B.; Miller, Sharon K.

    2011-01-01

    The attenuation of scattered thermal energy atomic oxygen is relevant to the potential damage that can occur within a spacecraft which sweeps through atomic oxygen in low Earth orbit (LEO). Although there can be significant oxidation and resulting degradation of polymers and some metals on the external surfaces of spacecraft, there are often openings on a spacecraft such as telescope apertures, vents, and microwave cavities that can allow atomic oxygen to enter and scatter internally to the spacecraft. Atomic oxygen that enters a spacecraft can thermally accommodate and scatter to ultimately react or recombine on surfaces. The atomic oxygen that does enter a spacecraft can be scavenged by use of high erosion yield polymers to reduce its reaction on critical surfaces and materials. Polyoxymethylene and polyethylene can be used as effective atomic oxygen scavenging polymers.

  14. Thermal energy in dry snow avalanches

    NASA Astrophysics Data System (ADS)

    Steinkogler, W.; Sovilla, B.; Lehning, M.

    2015-09-01

    Avalanches can exhibit many different flow regimes from powder clouds to slush flows. Flow regimes are largely controlled by the properties of the snow released and entrained along the path. Recent investigations showed the temperature of the moving snow to be one of the most important factors controlling the mobility of the flow. The temperature of an avalanche is determined by the temperature of the released and entrained snow but also increases by frictional processes with time. For three artificially released avalanches, we conducted snow profiles along the avalanche track and in the deposition area, which allowed quantifying the temperature of the eroded snow layers. This data set allowed to calculate the thermal balance, from release to deposition, and to discuss the magnitudes of different sources of thermal energy of the avalanches. For the investigated dry avalanches, the thermal energy increase due to friction was mainly depending on the effective elevation drop of the mass of the avalanche with a warming of approximately 0.3 °C per 100 vertical metres. Contrarily, the temperature change due to entrainment varied for the individual avalanches, from -0.08 to 0.3 °C, and depended on the temperature of the snow along the path and the erosion depth. Infrared radiation thermography (IRT) was used to assess the surface temperature before, during and just after the avalanche with high spatial resolution. This data set allowed to identify the warmest temperatures to be located in the deposits of the dense core. Future research directions, especially for the application of IRT, in the field of thermal investigations in avalanche dynamics are discussed.

  15. TARA OCEANS: A Global Analysis of Oceanic Plankton Ecosystems (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Karsenti, Eric

    2013-03-01

    Eric Karsenti of EMBL delivers the closing keynote on "TARA OCEANS: A Global Analysis of Oceanic Plankton Ecosystems" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, Calif.

  16. Nanowires for thermal energy conversion and management

    NASA Astrophysics Data System (ADS)

    Chen, Renkun

    This dissertation presents the application of nanowires in two aspects of thermal energy conversion and management: (i) silicon (Si) nanowires as efficient and scalable thermoelectric materials due to the reduced thermal conductivity (k), and (ii) Si and copper (Cu) nanowire arrays for enhanced phase change heat transfer including boiling and evaporation and their applications in thermal management of microelectronics. In the first half of the thesis (chapter 2 and 3), we describe thermal and thermoelectric measurements of individual Si nanowires for studying phonon transport properties and their potential application in thermoelectrics. A theoretical model based on coherent phonon scattering was developed to explain the experiemental data, which suggests that phonon-boundary scattering is highly frequency dependent. For low frequency (long wavelength) phonons, the transport is nearly ballistic, whereas high frequency or short wavelength phonons scatter diffusively at nanowire boundary. The competition between the two phonon transmission regimes results in the unusual linear behavior of the thermal conductance of thin VLS Si nanowires at low temperature. Next, the thermal conductivity of EE Si nanowires, which have much rougher surface compared to VLS nanowires, was measured and found to be five-eight times lower than that of VLS counterparts with similar diameters. The substantial reduction in k is presumably due to the higher surface roughness, since both types of nanowires have single crystalline cores. In particular, for ˜ 50 nm EE Si nanowires etched from 0.1 O-cm B-doped p-Si <111> (˜2 x 1017 cm-3 dopant concentration), the k is around 1.6 Wm-1K-1 and the kL is ˜1.2 Wm-1 K-1 at room temperature, approaching that of amorphous Si. The single nanowire measurements show the great promise of using Si nanowire arrays as high-performance, scalable thermoelectric materials. As the second focus of the thesis (chapter 4 and 5), nanowire arrays were used for enhanced

  17. Composite Transport Coefficient for Electron Thermal Energy

    NASA Astrophysics Data System (ADS)

    Coppi, B.; Daughton, W.

    1996-11-01

    A series of experiments by the Alcator C-Mod machine over a range of heating conditions (ohmic to strongly r.f. heated) has led to the construction of a composite transport coefficient for the electron thermal energy. This is represented by the difference of two terms: one corresponding to an outflow of thermal energy and the other one corresponding to an inflow. There are theoretical arguments(B. Coppi and F. Pegoraro, Phys. Fluids B) 3 p. 2582 (1991) in support of a composite transport coefficient involving the elements of a transport matrix with an inflow term related for instance to the features of the current density profile relative to those of the electron temperature. In deriving the transport coefficient D_e^th that has been used to simulate the Alcator C-Mod plasmas, we have assumed that the driving factor of the underlying modes is the plasma pressure gradient. Thus D_e^th ∝ D_e^o [β_p* - C] where β_p* = (8π p* / B_p^2), p* ≡ -r(dp/dr) is evaluated at the point of maximum pressure gradient, C ≈ 3/16 is a positive numerical coefficient and D_e^o ∝ I_p/(nT)^5/6 is basically the Coppi-Mazzucato-Gruber diffusion coefficient introduced earlier to reproduce the results of experiments with ohmic heating. Supported in part by the U.S. Department of Energy

  18. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans.

    PubMed

    Jiménez-Muñoz, Juan C; Mattar, Cristian; Sobrino, José A; Malhi, Yadvinder

    2015-01-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download. PMID:26029379

  19. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans

    PubMed Central

    Jiménez-Muñoz, Juan C.; Mattar, Cristian; Sobrino, José A.; Malhi, Yadvinder

    2015-01-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download. PMID:26029379

  20. High temperature underground thermal energy storage system for solar energy

    NASA Technical Reports Server (NTRS)

    Collins, R. E.

    1980-01-01

    The activities feasibility of high temperature underground thermal storage of energy was investigated. Results indicate that salt cavern storage of hot oil is both technically and economically feasible as a method of storing huge quantities of heat at relatively low cost. One particular system identified utilizes a gravel filled cavern leached within a salt dome. Thermal losses are shown to be less than one percent of cyclically transferred heat. A system like this having a 40 MW sub t transfer rate capability and over eight hours of storage capacity is shown to cost about $13.50 per KWh sub t.

  1. Boron Proxy Evidence for Ocean Acidification during the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Hoenisch, B.; Penman, D. E.; Zeebe, R. E.; Zachos, J. C.; Thomas, E.

    2013-12-01

    Quantifying the magnitude and rate of carbon cycle perturbations is key to identifying and interpreting past intervals of ocean acidification. However, paleocean acidification has commonly been inferred from biotic changes, which could have been caused by other environmental changes, including temperature, nutrient supply and oxygenation. Independent geochemical proxy evidence for paleo- seawater pH and carbonate saturation is therefore critical to confirm that ocean acidification did indeed take place, and how severe it was. We focus on the Paleocene/Eocene Thermal Maximum (56 Ma), an extreme climate perturbation that closely resembles worst-case scenarios for the future, in terms of massive carbon release (~4,500 Pg C) as expressed in a global negative carbon isotope excursion (CIE), and associated global warming (5-9°C). We used samples from the central equatorial Pacific to perform high resolution boron isotope and B/Ca analyses in shells of the surface dwelling, symbiont-bearing planktic foraminifer Morozovella velascoensis, to quantify the extent of ocean acidification during this event. We found a significant decrease in values of both proxies, paralleling the CIE, and followed by recovery to pre-event conditions. Onset and duration of the observed geochemical anomalies are similar to carbon cycle model simulations, but the magnitude of both the boron isotope and B/Ca excursions is larger than suggested by the model. Quantification of the pH change is difficult because of a number of uncertainties, including the largely unknown boron isotopic composition of seawater, the baseline-pH prior to the event, temperature and salinity, and the effects of partial dissolution, recrystallization, and potential loss of symbionts. Complementary analyses of M. velascoensis from two sites in the Pacific and Atlantic Oceans yield similar results, confirming that diagenesis likely did not bias the records. Using the best possible constraints, we estimate that the ocean

  2. Energy from the Sea. Ocean Related Curriculum Activities.

    ERIC Educational Resources Information Center

    Jones, Claire

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  3. Thermal Constraints on the Rheology of Segmented Oceanic Transform Fault Systems

    NASA Astrophysics Data System (ADS)

    Wolfson-Schwehr, M. L.; Boettcher, M. S.; Behn, M. D.

    2012-12-01

    Mid-ocean ridge transform fault (RTF) systems may be comprised of two or more fault segments that are physically offset by an extensional basin or intra-transform spreading center. These intra-transform offsets affect the thermal structure underlying the transform fault and may act as barriers to rupture propagation. The seismogenic zone of RTFs is thermally controlled and limited by the 600°C isotherm, as evidenced by earthquake hypocentral depths and laboratory friction experiments. Observations from a recent ocean bottom seismic study found that RTF earthquakes rarely occur above ~2 km depth. These findings suggest that the seismogenic zone on RTFs likely extends from ~2 km to the 600°C isotherm. Here we utilize finite element analysis to model the thermal structure of a RTF system comprised of two transform fault segments separated by an extensional offset. The mantle is assumed to have a visco-plastic rheology to simulate brittle failure at temperatures <600°C. We vary offset length, spreading rate, and degree of hydrothermal circulation to examine how these parameters control the underlying thermal structure of segmented RTFs. Longer offsets and faster spreading rates result in warmer thermal structures. Enhanced hydrothermal circulation efficiently cools shallow regions, resulting in an increased area of brittle deformation, and may have a complex effect on the seismogenic zone due to the possible creation of weak, velocity-strengthening alteration phases such as serpentine and talc, and/or changes in fault zone porosity. Incorporating these processes into our model, we are able to assess the potential for an intra-transform offset to act as a barrier to rupture propagation. As a case study, we focus on the Discovery transform fault, located at 4°S on the East Pacific Rise. Discovery consists of two sub-parallel fault segments with lengths of 36 km and 27 km, separated by a 6 km intra-transform spreading center. On a number of intermediate- and fast

  4. Boosting CSP Production with Thermal Energy Storage

    SciTech Connect

    Denholm, P.; Mehos, M.

    2012-06-01

    Combining concentrating solar power (CSP) with thermal energy storage shows promise for increasing grid flexibility by providing firm system capacity with a high ramp rate and acceptable part-load operation. When backed by energy storage capability, CSP can supplement photovoltaics by adding generation from solar resources during periods of low solar insolation. The falling cost of solar photovoltaic (PV) - generated electricity has led to a rapid increase in the deployment of PV and projections that PV could play a significant role in the future U.S. electric sector. The solar resource itself is virtually unlimited; however, the actual contribution of PV electricity is limited by several factors related to the current grid. The first is the limited coincidence between the solar resource and normal electricity demand patterns. The second is the limited flexibility of conventional generators to accommodate this highly variable generation resource. At high penetration of solar generation, increased grid flexibility will be needed to fully utilize the variable and uncertain output from PV generation and to shift energy production to periods of high demand or reduced solar output. Energy storage is one way to increase grid flexibility, and many storage options are available or under development. In this article, however, we consider a technology already beginning to be used at scale - thermal energy storage (TES) deployed with concentrating solar power (CSP). PV and CSP are both deployable in areas of high direct normal irradiance such as the U.S. Southwest. The role of these two technologies is dependent on their costs and relative value, including how their value to the grid changes as a function of what percentage of total generation they contribute to the grid, and how they may actually work together to increase overall usefulness of the solar resource. Both PV and CSP use solar energy to generate electricity. A key difference is the ability of CSP to utilize high

  5. Crustal Thickness Mapping of the Rifted Margin Ocean-Continent Transition using Satellite Gravity Inversion Incorporating a Lithosphere Thermal Correction

    NASA Astrophysics Data System (ADS)

    Hurst, N. W.; Kusznir, N. J.

    2005-05-01

    A new method of inverting satellite gravity at rifted continental margins to give crustal thickness, incorporating a lithosphere thermal correction, has been developed which does not use a priori information about the location of the ocean-continent transition (OCT) and provides an independent prediction of OCT location. Satellite derived gravity anomaly data (Sandwell and Smith 1997) and bathymetry data (Gebco 2003) are used to derive the mantle residual gravity anomaly which is inverted in 3D in the spectral domain to give Moho depth. Oceanic lithosphere and stretched continental margin lithosphere produce a large negative residual thermal gravity anomaly (up to -380 mgal), which must be corrected for in order to determine Moho depth. This thermal gravity correction may be determined for oceanic lithosphere using oceanic isochron data, and for the thinned continental margin lithosphere using margin rift age and beta stretching estimates iteratively derived from crustal basement thickness determined from the gravity inversion. The gravity inversion using the thermal gravity correction predicts oceanic crustal thicknesses consistent with seismic observations, while that without the thermal correction predicts much too great oceanic crustal thicknesses. Predicted Moho depth and crustal thinning across the Hatton and Faroes rifted margins, using the gravity inversion with embedded thermal correction, compare well with those produced by wide-angle seismology. A new gravity inversion method has been developed in which no isochrons are used to define the thermal gravity correction. The new method assumes all lithosphere to be initially continental and a uniform lithosphere stretching age is used corresponding to the time of continental breakup. The thinning factor produced by the gravity inversion is used to predict the thickness of oceanic crust. This new modified form of gravity inversion with embedded thermal correction provides an improved estimate of rifted

  6. Ocean Renewable Energy Research at U. New Hampshire

    NASA Astrophysics Data System (ADS)

    Wosnik, M.; Baldwin, K.; White, C.; Carter, M.; Gress, D.; Swift, R.; Tsukrov, I.; Kraft, G.; Celikkol, B.

    2008-11-01

    The University of New Hampshire (UNH) is strategically positioned to develop and evaluate wave and tidal energy extraction technologies, with much of the required test site infrastructure in place already. Laboratory facilities (wave/tow tanks, flumes, water tunnels) are used to test concept validation models (scale 1:25--100) and design models (scale 1:10--30). The UNH Open Ocean Aquaculture (OOA) site located 1.6 km south of the Isles of Shoals (10 km off shore) and the General Sullivan Bridge testing facility in the Great Bay Estuary are used to test process models (scale 1:3--15) and prototype/demonstration models (scale 1:1-- 4) of wave energy and tidal energy extraction devices, respectively. Both test sites are easily accessible and in close proximity of UNH, with off-the-shelf availability. The Great Bay Estuary system is one of the most energetic tidally driven estuaries on the East Coast of the U.S. The current at the General Sullivan bridge test facility reliably exceeds four knots over part of the tidal cycle. The OOA site is a ten year old, well established offshore test facility, and is continually serviced by a dedicated research vessel and operations/diving crew. In addition to an overview of the physical resources, results of recent field testing of half- and full-scale hydrokinetic turbines, and an analysis of recent acoustic Doppler surveys of the tidal estuary will be presented.

  7. Multiyear sea ice thermal regimes and oceanic heat flux derived from an ice mass balance buoy in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Lei, Ruibo; Li, Na; Heil, Petra; Cheng, Bin; Zhang, Zhanhai; Sun, Bo

    2014-01-01

    The conductive and oceanic heat fluxes and the mass balance of sea ice were investigated utilizing an ice mass balance buoy (IMB) deployed in the Arctic Ocean. After IMB deployment, the ice thinned from 1.95 m in late August to 1.46 m by mid-October 2008. From then on, ice growth until mid-June 2009 increased the ice thickness to 3.12 m. The ice temperature and consequently the conductive heat flux at the ice surface exhibited persistent high-frequency variations due to diurnal and synoptic-scale atmospheric forcing. These signals propagated downward with damped magnitude and temporal lag. The competition of oceanic and conductive heat flux dominated the low-frequency variations of ice growth. However, high-frequency variations in ice growth were controlled largely by the oceanic heat flux. From mid-November 2008 to mid-June 2009, the average oceanic heat flux along a track from 86.2°N, 115.2°W to 84.6°N, 33.9°W was 7.1 W/m2. This was in agreement with that derived from an IMB deployed in 2005, about 1.5° to the north of our buoy. We attributed the relatively high oceanic heat flux (10-15 W/m2) observed during autumn and early winter to summer warming of the surface ocean. Upward mixing of warm deep water, as observed when our buoy drifted over the shallow region of the Lomonosov Ridge (85.4°-85.9°N, 52.2°-66.4°W), demonstrated the impact of bathymetry on the oceanic heat flux under ice cover, and consequently on the basal ice mass balance.

  8. Dynamics of Carbon Burial in the Coastal Oceans through the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Schneider-Mor, A.; Bowen, G. J.

    2008-12-01

    Climatic recovery from the Paleocene-Eocene boundary thermal maximum (PETM) involved the rapid burial of thousands of petagrams of carbon, a significant fraction of which may have been sequestered in marginal marine sediments. This burial flux may have been modulated by changes in climate, biology, sea level, and sediment flux, but the primary pathways and controls on excess carbon burial have remained speculative to this point. Using the global PETM carbon isotope excursion and C/N ratios as tracer of organic carbon source, we investigated preservation of organic carbon through the PETM as particulate organic carbon (POC) and mineral-bound carbon (MBC) at three coastal ocean sites (Tawanui, New Zealand; IODP leg 302, Arctic Ocean; and Wilson Lake, NJ, USA). We show that an increase in total organic carbon burial during the PETM is dominated by burial of young (<10,000 year old), land-derived POC, but that elevated POC burial was limited to sites with high sedimentation rates through the event (ca. 5 cm/kyr). In contrast, MBC sources were more variable, both among sites and through the PETM, and although there was no conclusive evidence for reburial of kerogen-derived MBC at the study sites the carbon isotope data suggest that a fraction of the MBC at each site may have had a long (>10,000 years) residence time prior to burial. MBC dominated the organic burial flux only at the low sedimentation-rate site (Tawanui), but also contributed significantly to changes in total burial at the Arctic site where bottom water anoxia or suboxia has been inferred during the PETM. Our results demonstrate that changes in total carbon burial rates in marginal marine sediments were determined by decoupled responses of the POC and MBC burial pathways that varied substantially among locations, and that the strongest feedbacks on PETM climate involved changes in the transfer of sediment and particulate organic carbon from the continents to the coastal oceans.

  9. Cloud-radiative effects on implied oceanic energy transports as simulated by atmospheric general circulation models

    SciTech Connect

    Gleckler, P.J.; Randall, D.A.; Boer, G.

    1994-03-01

    This paper reports on energy fluxes across the surface of the ocean as simulated by fifteen atmospheric general circulation models in which ocean surface temperatures and sea-ice boundaries are prescribed. The oceanic meridional energy transport that would be required to balance these surface fluxes is computed, and is shown to be critically sensitive to the radiative effects of clouds, to the extent that even the sign of the Southern Hemisphere ocean energy transport can be affected by the errors in simulated cloud-radiation interactions.

  10. OCEAN THERMAL ENERGY CONVERSION (OTEC) PROGRAMMATIC ENVIRONMENTAL ANALYSIS

    SciTech Connect

    Sands, M. D.

    1980-01-01

    This programmatic environmental analysis is an initial assessment of OTEC technology considering development, demonstration and commercialization; it is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties.

  11. Ocean thermal energy. Quarterly report, October-December 1981

    SciTech Connect

    Not Available

    1981-12-30

    This quarterly report summarizes work on the following tasks: OTEC methanol; approaches for financing OTEC proof-of-concept experimental vessels; investigation of OTEC-ammonia as an alternative fuel; review of electrolyzer development programs and requirements; hybrid geothermal-OTEC power plants: single-cycle performance; estimates; and hybrid geothermal-OTEC power plants: dual-cycle performance estimates.

  12. Ocean thermal energy conversion - Historical highlights, status, and forecast

    NASA Astrophysics Data System (ADS)

    Dugger, G. L.; Richards, D.; Francis, E. J.; Avery, W. H.

    1983-08-01

    Design concepts, materials, and performance data from the first OTEC demonstration plants are reviewed. The first plant, using a closed cycle fluid loop (NH3), generated 10-15 kWe in 1979 at Keahole Point, HI. Subsequently, a follow-up project provided data on 1 MWe heat exchangers and biofouling in 1981. The federal government passed legislation in 1980 mandating the generation of 500 MW from OTEC plants in 1989 and 10 GW in 1999. A resource assessment has indicated favorable temperature gradients in retrievable depths of near 24 deg C in the Atlantic and the Pacific. Sensitivity analyses have shown that the cost of electricity from OTEC plants varies with the length of cable needed to deliver the power, the resource, standardization of OTEC components, and the choice of moored or cruising ships (which could follow seasonal temperature changes). Overall efficiencies for the OTEC plants of about 2.5 pct are projected. Baseline designs have been developed for 40 MWe plants, although choices are not yet finalized for the cold water intake or final product, whether electricity, NH3, or methanol for fuel cells.

  13. Coccolithophore skeletal sensitivity to ocean acidification at the Paleocene Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    O'Dea, S. A.; Gibbs, S.; Bown, P. R.; Young, J. R.; Newsam, C.; Poulton, A.; Wilson, P. A.

    2012-12-01

    Acidification and reduced carbonate saturation of the ocean are measurable responses to anthropogenic emissions of carbon dioxide (CO2). As the dominant pelagic producers of calcium carbonate, the effect of this ongoing environmental change on coccolithophores is of particular concern. Here, we investigate the impact of past global warming and ocean acidification on coccolithophore biomineralisation across a geological analogue for modern climate change, the Paleocene Eocene Thermal Maximum (PETM; ~56 million years ago). We use a new method to quantify the skeletal thickness of pristine fossil coccoliths and consider potential adaptive responses in the two dominant Paleogene taxa (Coccolithus and Toweius). Our records reveal species-specific variations in size-normalised coccolith thickness, which are consistent with growth strategy. Changes in surface water chemistry across the PETM are accompanied by modest biomineralisation sensitivity and high adaptability in Paleogene taxa, with no evidence for reduced population growth. We explore the implications of coccolithophore skeletal thickness for biogenic carbonate production and suggest that modern species may have the adaptive potential to maintain cellular calcification and growth under future climate scenarios.

  14. Changes in benthic ecosystems and ocean circulation in the Southeast Atlantic across Eocene Thermal Maximum 2

    NASA Astrophysics Data System (ADS)

    Jennions, S. M.; Thomas, E.; Schmidt, D. N.; Lunt, D.; Ridgwell, A.

    2015-08-01

    Eocene Thermal Maximum 2 (ETM2) occurred ~1.8 Myr after the Paleocene-Eocene Thermal Maximum (PETM) and, like the PETM, was characterized by a negative carbon isotope excursion and warming. We combined benthic foraminiferal and sedimentological records for Southeast Atlantic Sites 1263 (1500 m paleodepth) and 1262 (3600 m paleodepth) to show that benthic foraminiferal diversity and accumulation rates declined more precipitously and severely at the shallower site during peak ETM2. As the sites are in close proximity, differences in surface productivity cannot have caused this differential effect. Instead, we infer that changes in ocean circulation across ETM2 may have produced more pronounced warming at intermediate depths (Site 1263). The effects of warming include increased metabolic rates, a decrease in effective food supply and increased deoxygenation, thus potentially explaining the more severe benthic impacts at Site 1263. In response, bioturbation may have decreased more at Site 1263 than at Site 1262, differentially affecting bulk carbonate records. We use a sediment-enabled Earth system model to test whether a reduction in bioturbation and/or the likely reduced carbonate saturation of more poorly ventilated waters can explain the more extreme excursion in bulk δ13C and sharper transition in wt % CaCO3 at Site 1263. We find that both enhanced acidification and reduced bioturbation during the ETM2 peak are needed to account for the observed features. Our combined ecological and modeling analysis illustrates the potential role of ocean circulation changes in amplifying local environmental changes and driving temporary, but drastic, loss of benthic biodiversity and abundance.

  15. 76 FR 64431 - Reorganization of Title 30: Bureaus of Safety and Environmental Enforcement and Ocean Energy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ...This rule contains regulations that will be under the authority of two newly formed Bureaus, the Bureau of Safety and Environmental Enforcement (BSEE) and the Bureau of Ocean Energy Management (BOEM), both within the Department of the Interior. On May 19, 2010, the Secretary of the Interior announced the separation of the responsibilities performed by the Bureau of Ocean Energy Management,......

  16. Commercialization of aquifer thermal energy storage technology

    SciTech Connect

    Hattrup, M.P.; Weijo, R.O.

    1989-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. The purpose of the study was to develop and screen a list of potential entry market applications for aquifer thermal energy storage (ATES). Several initial screening criteria were used to identify promising ATES applications. These include the existence of an energy availability/usage mismatch, the existence of many similar applications or commercial sites, the ability to utilize proven technology, the type of location, market characteristics, the size of and access to capital investment, and the number of decision makers involved. The in-depth analysis identified several additional screening criteria to consider in the selection of an entry market application. This analysis revealed that the best initial applications for ATES are those where reliability is acceptable, and relatively high temperatures are allowable. Although chill storage was the primary focus of this study, applications that are good candidates for heat ATES were also of special interest. 11 refs., 3 tabs.

  17. Development of thermal energy storage units for spacecraft cryogenic coolers

    NASA Technical Reports Server (NTRS)

    Richter, R.; Mahefkey, E. T.

    1980-01-01

    Thermal Energy Storage Units were developed for storing thermal energy required for operating Vuilleumier cryogenic space coolers. In the course of the development work the thermal characteristics of thermal energy storage material was investigated. By three distinctly different methods it was established that ternary salts did not release fusion energy as determined by ideality at the melting point of the eutectic salt. Phase change energy was released over a relatively wide range of temperature with a large change in volume. This strongly affects the amount of thermal energy that is available to the Vuilleumier cryogenic cooler at its operating temperature range and the amount of thermal energy that can be stored and released during a single storage cycle.

  18. Heat pipe solar receiver with thermal energy storage

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.

    1981-01-01

    An HPSR Stirling engine generator system featuring latent heat thermal energy storge, excellent thermal stability and self regulating, effective thermal transport at low system delta T is described. The system was supported by component technology testing of heat pipes and of thermal storage and energy transport models which define the expected performance of the system. Preliminary and detailed design efforts were completed and manufacturing of HPSR components has begun.

  19. Advanced Thermal Energy Storage: Novel Tuning of Critical Fluctuations for Advanced Thermal Energy Storage

    SciTech Connect

    2011-12-01

    HEATS Project: NAVITASMAX is developing a novel thermal energy storage solution. This innovative technology is based on simple and complex supercritical fluids— substances where distinct liquid and gas phases do not exist, and tuning the properties of these fluid systems to increase their ability to store more heat. In solar thermal storage systems, heat can be stored in NAVITASMAX’s system during the day and released at night—when the sun is not shining—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in NAVITASMAX’s system at night and released to produce electricity during daytime peak-demand hours.

  20. Development of MEMS based pyroelectric thermal energy harvesters

    NASA Astrophysics Data System (ADS)

    Hunter, Scott R.; Lavrik, Nickolay V.; Bannuru, Thirumalesh; Mostafa, Salwa; Rajic, Slo; Datskos, Panos G.

    2011-06-01

    The efficient conversion of waste thermal energy into electrical energy is of considerable interest due to the huge sources of low-grade thermal energy available in technologically advanced societies. Our group at the Oak Ridge National Laboratory (ORNL) is developing a new type of high efficiency thermal waste heat energy converter that can be used to actively cool electronic devices, concentrated photovoltaic solar cells, computers and large waste heat producing systems, while generating electricity that can be used to power remote monitoring sensor systems, or recycled to provide electrical power. The energy harvester is a temperature cycled pyroelectric thermal-to-electrical energy harvester that can be used to generate electrical energy from thermal waste streams with temperature gradients of only a few degrees. The approach uses a resonantly driven pyroelectric capacitive bimorph cantilever structure that potentially has energy conversion efficiencies several times those of any previously demonstrated pyroelectric or thermoelectric thermal energy harvesters. The goals of this effort are to demonstrate the feasibility of fabricating high conversion efficiency MEMS based pyroelectric energy converters that can be fabricated into scalable arrays using well known microscale fabrication techniques and materials. These fabrication efforts are supported by detailed modeling studies of the pyroelectric energy converter structures to demonstrate the energy conversion efficiencies and electrical energy generation capabilities of these energy converters. This paper reports on the modeling, fabrication and testing of test structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal-to-electrical energy harvesters.

  1. New Planetary Energy Balance, Ocean-Atmosphere Interaction and their Effects on Extreme Events in North Atlantic

    NASA Astrophysics Data System (ADS)

    Karrouk, Mohammed-Said

    2016-04-01

    Global warming has now reached the energetic phase of H2O's return to the ground after the saturation of the atmosphere in evaporation since the 80s and 90s of the last century, which were characterized by severe droughts, mainly in Africa. This phase is the result of the accumulation of thermal energy exchanges in the Earth-Ocean-Atmosphere system that resulted in the thrust reversal of the energy balance toward the poles. This situation is characterized by a new thermal distribution: above the ocean, the situation is more in surplus compared to the mainland, or even opposite when the balance is negative on the land, and in the atmosphere, warm thermal advection easily reach the North Pole (planetary crests), as well as cold advection push deep into North Africa and the Gulf of Mexico (planetary valleys). This "New Ground Energy Balance" establishes a "New Meridian Atmospheric Circulation (MAC)" with an undulating character throughout the year, including the winter characterized by intense latitudinal very active energy exchanges between the surplus areas (tropical) and the deficit (polar) on the one hand, and the atmosphere, the ocean and the continent on the other. The excess radiation balance increases the potential evaporation of the atmosphere and provides a new geographical distribution of H2O worldwide: the excess water vapor is easily converted by cold advection (polar vortex) to heavy rains that cause floods or snow storms that paralyze the normal functioning of human activities, which creates many difficulties for users and leaves damage and casualties, but ensures water availability missing since a long time in many parts of the world, in Africa, Europe and America. The new thermal distribution reorganizes the geography of atmospheric pressure: the ocean energy concentration is transmitted directly to the atmosphere, and the excess torque is pushed northward. The Azores anticyclone is strengthened and is a global lock by the Atlantic ridge at Greenland

  2. MEMS based pyroelectric thermal energy harvester

    SciTech Connect

    Hunter, Scott R; Datskos, Panagiotis G

    2013-08-27

    A pyroelectric thermal energy harvesting apparatus for generating an electric current includes a cantilevered layered pyroelectric capacitor extending between a first surface and a second surface, where the first surface includes a temperature difference from the second surface. The layered pyroelectric capacitor includes a conductive, bimetal top electrode layer, an intermediate pyroelectric dielectric layer and a conductive bottom electrode layer. In addition, a pair of proof masses is affixed at a distal end of the layered pyroelectric capacitor to face the first surface and the second surface, wherein the proof masses oscillate between the first surface and the second surface such that a pyroelectric current is generated in the pyroelectric capacitor due to temperature cycling when the proof masses alternately contact the first surface and the second surface.

  3. Aquifer Thermal Energy Storage in the US

    NASA Astrophysics Data System (ADS)

    Kannberg, L. D.

    1985-06-01

    DOE has funded investigation of Aquifer Thermal Energy Storage (ATES) since 1975. The scope of the ATES investigation has encompassed numerical modeling, field testing, economic analyses, and evaluation of institutional issues. ATES has received the bulk of the attention because of its widespread potential in the US. US efforts are now concentrated on a high temperature (up to 150C) ATES field test on the St. Paul campus of the University of Minnesota. Four short-term test cycles and the first of two long-term test cycles have been completed at this site. Utilization of chill ATES to meet summer air conditioning demands has been monitored at two operating sites in Tuscaloosa, Alabama. The systems utilize a cooling tower to directly chill groundwater pumped from a water table aquifer for storage in the same aquifer. The first of the two systems has exhibited relatively poor performance. More comprehensive monitoring has recently been undertaken at another site.

  4. Vertical kinetic energy and turbulent dissipation in the ocean

    NASA Astrophysics Data System (ADS)

    Thurnherr, A. M.; Kunze, E.; Toole, J. M.; St. Laurent, L.; Richards, K. J.; Ruiz-Angulo, A.

    2015-09-01

    Oceanic internal waves are closely linked to turbulence. Here a relationship between vertical wave number (kz) spectra of fine-scale vertical kinetic energy (VKE) and turbulent dissipation ɛ is presented using more than 250 joint profiles from five diverse dynamic regimes, spanning latitudes between the equator and 60°. In the majority of the spectra VKE varies as kz-2. Scaling VKE with √ɛ collapses the off-equatorial spectra to within √2 but underestimates the equatorial spectrum. The simple empirical relationship between VKE and ɛ fits the data better than a common shear-and-strain fine-scale parameterization, which significantly underestimates ɛ in the two data sets that are least consistent with the Garrett-Munk (GM) model. The new relationship between fine-scale VKE and dissipation rate can be interpreted as an alternative, single-parameter scaling for turbulent dissipation in terms of fine-scale internal wave vertical velocity that requires no reference to the GM model spectrum.

  5. Solar-thermal conversion and thermal energy storage of graphene foam-based composites

    NASA Astrophysics Data System (ADS)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-07-01

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a

  6. District Energy Corporation SW 40th Street Thermal Energy Plant

    SciTech Connect

    Davlin, Thomas

    2014-06-06

    The overall deliverable from the project is the design, construction and commissioning of a detention facility heating and cooling system that minimizes ownership costs and maximizes efficiency (and therefore minimizes environmental impact). The primary deliverables were the proof of concept for the application of geothermal systems for an institutional facility and the ongoing, quarterly system operating data downloads to the Department of Energy . The primary advantage of geothermal based heat pump systems is the higher efficiency of the system compared to a conventional chiller, boiler, cooling tower based system. The higher efficiency results in a smaller environmental foot print and lower energy costs for the detention facility owner, Lancaster County. The higher efficiency for building cooling is primarily due to a more constant compressor condensing temperature with the geothermal well field acting as a thermal “sink” (in place of the conventional system’s cooling tower). In the heating mode, Ground Couple Heat Pump (GCHP) systems benefits from the advantage of a heat pump Coefficient of Performance (COP) of approximately 3.6, significantly better than a conventional gas boiler. The geothermal well field acting as a thermal “source” allows the heat pumps to operate efficiently in the heating mode regardless of ambient temperatures. The well field is partially located in a wetland with a high water table so, over time, the project will be able to identify the thermal loading characteristics of a well field located in a high water table location. The project demonstrated how a large geothermal well field can be installed in a wetland area in an economical and environmentally sound manner. Finally, the SW 40th Street Thermal Energy Plant project demonstrates the benefits of providing domestic hot water energy, as well as space heating, to help balance well filed thermal loading in a cooling dominated application. During the period of August 2012 thru

  7. Scaling Relations for the Thermal Structure of Segmented Oceanic Transform Faults

    NASA Astrophysics Data System (ADS)

    Wolfson-Schwehr, M.; Boettcher, M. S.; Behn, M. D.

    2015-12-01

    Mid-ocean ridge-transform faults (RTFs) are a natural laboratory for studying strike-slip earthquake behavior due to their relatively simple geometry, well-constrained slip rates, and quasi-periodic seismic cycles. However, deficiencies in our understanding of the limited size of the largest RTF earthquakes are due, in part, to not considering the effect of short intra-transform spreading centers (ITSCs) on fault thermal structure. We use COMSOL Multiphysics to run a series of 3D finite element simulations of segmented RTFs with visco-plastic rheology. The models test a range of RTF segment lengths (L = 10-150 km), ITSC offset lengths (O = 1-30 km), and spreading rates (V = 2-14 cm/yr). The lithosphere and upper mantle are approximated as steady-state, incompressible flow. Coulomb failure incorporates brittle processes in the lithosphere, and a temperature-dependent flow law for dislocation creep of olivine activates ductile deformation in the mantle. ITSC offsets as small as 2 km affect the thermal structure underlying many segmented RTFs, reducing the area above the 600˚C isotherm, A600, and thus the size of the largest expected earthquakes, Mc. We develop a scaling relation for the critical ITSC offset length, OC, which significantly reduces the thermal affect of adjacent fault segments of length L1 and L2. OC is defined as the ITSC offset that results in an area loss ratio of R = (Aunbroken - Acombined)/Aunbroken - Adecoupled) = 63%, where Aunbroken = C600(L1+L2)1.5V-0.6 is A600 for an RTF of length L1 + L2; Adecoupled = C600(L11.5+L21.5)V-0.6 is the combined A600 of RTFs of lengths L1 and L2, respectively; and Acombined = Aunbroken exp(-O/ OC) + Adecoupled (1-exp(-O/ OC)). C600 is a constant. We use OC and kinematic fault parameters (L1, L2, O, and V) to develop a scaling relation for the approximate seismogenic area, Aseg, for each segment of a RTF system composed of two fault segments. Finally, we estimate the size of Mc on a fault segment based on Aseg. We

  8. Thermal models of dyke intrusion during development of continent-ocean transition

    NASA Astrophysics Data System (ADS)

    Daniels, K. A.; Bastow, I. D.; Keir, D.; Sparks, R. S. J.; Menand, T.

    2014-01-01

    thickness and Moho depth in the Danakil region of northernmost Afar are markedly reduced and seismicity is shallower than in the MER. Thermally driven variations in crustal rheology over time in response to dyke intrusion thus play an important role in the development of continent-ocean transition.

  9. Potential energy savings from aquifer thermal energy storage

    SciTech Connect

    Anderson, M.R.; Weijo, R.O.

    1988-07-01

    Pacific Northwest Laboratory researchers developed an aggregate-level model to estimate the short- and long-term potential energy savings from using aquifer thermal storage (ATES) in the United States. The objectives of this effort were to (1) develop a basis from which to recommend whether heat or chill ATES should receive future research focus and (2) determine which market sector (residential, commercial, or industrial) offers the largest potential energy savings from ATES. Information was collected on the proportion of US land area suitable for ATES applications. The economic feasibility of ATES applications was then evaluated. The potential energy savings from ATES applications was calculated. Characteristic energy use in the residential, commercial, and industrial sectors was examined, as was the relationship between waste heat production and consumption by industrial end-users. These analyses provided the basis for two main conclusions: heat ATES applications offer higher potential for energy savings than do chill ATES applications; and the industrial sector can achieve the highest potential energy savings for the large consumption markets. Based on these findings, it is recommended that future ATES research and development efforts be directed toward heat ATES applications in the industrial sector. 11 refs., 6 figs., 9 tabs.

  10. Mathematical modeling of moving boundary problems in thermal energy storage

    NASA Technical Reports Server (NTRS)

    Solomon, A. D.

    1980-01-01

    The capability for predicting the performance of thermal energy storage (RES) subsystems and components using PCM's based on mathematical and physical models is developed. Mathematical models of the dynamic thermal behavior of (TES) subsystems using PCM's based on solutions of the moving boundary thermal conduction problem and on heat and mass transfer engineering correlations are also discussed.

  11. 30 CFR 250.1451 - What may the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) do if I...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What may the Bureau of Ocean Energy Management... a Federal oil and gas lease? 250.1451 Section 250.1451 Mineral Resources BUREAU OF OCEAN ENERGY... Correct § 250.1451 What may the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE)...

  12. Composite materials for thermal energy storage: enhancing performance through microstructures.

    PubMed

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-05-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

  13. Optimizing Ice Thermal Storage to Reduce Energy Cost

    NASA Astrophysics Data System (ADS)

    Hall, Christopher L.

    Energy cost for buildings is an issue of concern for owners across the U.S. The bigger the building, the greater the concern. A part of this is due to the energy required to cool the building and the way in which charges are set when paying for energy consumed during different times of the day. This study will prove that designing ice thermal storage properly will minimize energy cost in buildings. The effectiveness of ice thermal storage as a means to reduce energy costs lies within transferring the time of most energy consumption from on-peak to off-peak periods. Multiple variables go into the equation of finding the optimal use of ice thermal storage and they are all judged with the final objective of minimizing monthly energy costs. This research discusses the optimal design of ice thermal storage and its impact on energy consumption, energy demand, and the total energy cost. A tool for optimal design of ice thermal storage is developed, considering variables such as chiller and ice storage sizes and charging and discharge times. The simulations take place in a four-story building and investigate the potential of Ice Thermal Storage as a resource in reducing and minimizing energy cost for cooling. The simulations test the effectiveness of Ice Thermal Storage implemented into the four-story building in ten locations across the United States.

  14. Comparison of plate and asthenospheric flow models for the thermal evolution of oceanic lithosphere

    NASA Technical Reports Server (NTRS)

    Stein, Carol A.; Stein, Seth

    1994-01-01

    Although seafloor depth and heat flow for young oceanic lithosphere can be descibed by modeling the lithosphere as the boundary layer of a cooling halfspace, a long standing question has been why data at older ages deviate from those expected for a halfspace. Two classes of models have been proposed for these deviations. In one, heat added from below 'flattens' depth and heat flow. In the other, asthenospheric flow beneath the lithosphere perturbs the depths. We compare recent versions of the model classes: the GDH1 thin-lithosphere plate model (Stein and Stein, 1992) and an asthenospehric flow model (Phipps Morgan and Smith, 1992). The plate model fits heat flow data better than the flow model for all cases considered, and topographic data in all but one case. The flow model significantly overpredicts depths for the North Atlantic, because the assumed asthenospheric flow in the plate motion direction would yield deepening for old ages rather than the observed flattening. Overall, the GDH1 global average model does better than this flow model, whose parameters were fit to specific plates. Moreover, the plate models fit to specific plates do better than the flow model. Plate models thus appear more useful than this flow model, suggesting that deviations from a cooling halfspace are largely thermal in origin.

  15. The Paleocene-Eocene Thermal Maximum at DSDP Site 277, Campbell Plateau, southern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Hollis, C. J.; Hines, B. R.; Littler, K.; Villasante-Marcos, V.; Kulhanek, D. K.; Strong, C. P.; Zachos, J. C.; Eggins, S. M.; Northcote, L.; Phillips, A.

    2015-07-01

    Re-examination of sediment cores from Deep Sea Drilling Project (DSDP) Site 277 on the western margin of the Campbell Plateau (paleolatitude of ~65° S) has identified an intact Paleocene-Eocene (P-E) boundary overlain by a 34 cm thick record of the Paleocene-Eocene Thermal Maximum (PETM) within nannofossil chalk. The upper part of the PETM is truncated, either due to drilling disturbance or a sedimentary hiatus. An intact record of the onset of the PETM is indicated by a gradual decrease in δ13C values over 20 cm, followed by a 14 cm interval in which δ13C is 2 ‰ lighter than uppermost Paleocene values. After accounting for effects of diagenetic alteration, we use δ18O and Mg/Ca values from foraminiferal tests to determine that intermediate and surface waters warmed by ~5-6° at the onset of the PETM prior to the full development of the negative δ13C excursion. After this initial warming, sea temperatures were relatively stable through the PETM but declined abruptly across the horizon that truncates the event at this site. Mg/Ca analysis of foraminiferal tests indicates peak intermediate and surface water temperatures of ~19 and ~32 °C, respectively. These temperatures may be influenced by residual diagenetic factors and changes in ocean circulation, and surface water values may also be biased towards warm-season temperatures.

  16. Anisotropy Enhancement of Thermal Energy Transport in Supported Black Phosphorene.

    PubMed

    Chen, Jige; Chen, Shunda; Gao, Yi

    2016-07-01

    Thermal anisotropy along the basal plane of materials possesses both theoretical importance and application value in thermal transport and thermoelectricity. Though common two-dimensional materials may exhibit in-plane thermal anisotropy when suspended, thermal anisotropy would often disappear when supported on a substrate. In this Letter, we find a strong anisotropy enhancement of thermal energy transport in supported black phosphorene. The chiral preference of energy transport in the zigzag rather than the armchair direction is greatly enhanced by coupling to the substrate, up to a factor of approximately 2-fold compared to the suspended one. The enhancement originates from its puckered lattice structure, where the nonplanar armchair energy transport relies on the out-of-plane corrugation and thus would be hindered by the flexural suppression due to the substrate, while the planar zigzag energy transport is not. As a result, thermal conductivity of supported black phosphorene shows a consistent anisotropy enhancement under different temperatures and substrate coupling strengths. PMID:27320775

  17. Ocean Energy Systems at the Johns Hopkins University Applied Physics Laboratory, July-September 1983, October-December 1983. Quarterly report

    SciTech Connect

    Not Available

    1983-12-01

    The Johns Hopkins University Applied Physics Laboratory, under a contract with the U.S. Department of Energy's Division of Ocean Energy Technology (DOE/DOET), is engaged in developing Ocean Thermal Energy Conversion (OTEC) systems that will provide synthetic fuels (e.g., methanol) or an energy-intensive product such as ammonia (for fertilizers and chemicals) or aluminum. The work also includes assessment and design concepts for hybrid plants, such as geothermal-OTEC (GEOTEC) plants. The Laboratory also has a technical advisory role with respect to DOE/DOET's management of the preliminary design activity of an industry team headed by Ocean Thermal Corporation that is designing an OTEC pilot plant that could be built in shallow water off the shore of Oahu, Hawaii. In addition, the Laboratory is now taking part in a program to evaluate and test the Pneumatic Wave-Energy conversion System (PWECS), an ocean-energy device consisting of a turbine that is air-driven as a result of wave action in a chamber. This report summarizes the work on the various tasks as of 31 December 1983.

  18. Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

    PubMed

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy. PMID:27430282

  19. Flight experiment of thermal energy storage

    NASA Technical Reports Server (NTRS)

    Namkoong, David

    1989-01-01

    Thermal energy storage (TES) enables a solar dynamic system to deliver constant electric power through periods of sun and shade. Brayton and Stirling power systems under current considerations for missions in the near future require working fluid temperatures in the 1100 to 1300+ K range. TES materials that meet these requirements fall into the fluoride family of salts. These salts store energy as a heat of fusion, thereby transferring heat to the fluid at constant temperature during shade. The principal feature of fluorides that must be taken into account is the change in volume that occurs with melting and freezing. Salts shrink as they solidify, a change reaching 30 percent for some salts. The location of voids that form as result of the shrinkage is critical when the solar dynamic system reemerges into the sun. Hot spots can develop in the TES container or the container can become distorted if the melting salt cannot expand elsewhere. Analysis of the transient, two-phase phenomenon is being incorporated into a three-dimensional computer code. The code is capable of analysis under microgravity as well as 1 g. The objective of the flight program is to verify the predictions of the code, particularly of the void location and its effect on containment temperature. The four experimental packages comprising the program will be the first tests of melting and freezing conducted under microgravity. Each test package will be installed in a Getaway Special container to be carried by the shuttle. The package will be self-contained and independent of shuttle operations other than the initial opening of the container lid and the final closing of the lid. Upon the return of the test package from flight, the TES container will be radiographed and finally partitioned to examine the exact location and shape of the void. Visual inspection of the void and the temperature data during flight will constitute the bases for code verification.

  20. Feasibility studies of aquifer thermal energy storage

    SciTech Connect

    Hall, S. H.

    1993-01-01

    Determining the feasibility of using aquifer thermal energy storage (ATES) for a particular heating or cooling application is an interdisciplinary effort, requiring (at a minimum) expertise in engineering and hydrology. The feasibility study should proceed in two distinct stages. The first stage, which is limited in scope and detail, is intended to show if an ATES system is technically and economically suited to the application. Focus of this preliminary investigation is on revealing the existence of factors that might weigh heavily against the use of ATES methods, and, in the absence of such factors, on choosing a suitable scale for the ATES plant and well field. The results of the preliminary investigation are used to determine if more detailed investigation--including field studies--are justified, and to facilitate comparing the advantages of ATES to those of other means of providing heating or cooling. The second stage of the feasibility study focuses on detailed aquifer characterization, refinement of engineering design and cost estimates, and economic and environmental risk analysis. The results of this investigation, if favorable, will be used to justify the expense of constructing the ATES system.

  1. Composite materials for thermal energy storage

    DOEpatents

    Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

    1985-01-04

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  2. Composite materials for thermal energy storage

    DOEpatents

    Benson, David K.; Burrows, Richard W.; Shinton, Yvonne D.

    1986-01-01

    The present invention discloses composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These phase change materials do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions, such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  3. Composite materials for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Benson, D. K.; Burrows, R. W.; Shinton, Y. D.

    1985-01-01

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations are discussed. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  4. Lateral Temperature Variations in Upwelling Limbs of the Asthenosphere and its Implications for Thermal Models of the Oceanic Lithosphere

    NASA Astrophysics Data System (ADS)

    Hamza, V. M.; Cardoso, R. R.

    2008-05-01

    Thermal models of the lithosphere proposed to date (the Half-Space Cooling and Plate models) have failed to provide satisfactory accounts of some of the important features in large-scale variations of oceanic heat flow. The systematic difference between model values and observational data have given rise to the so-called "oceanic heat flow paradox", for which no satisfactory solution has been found for over the last forty years. In the present work, we point out that this paradox is a consequence of the model assumption that lateral temperature variations are absent in the sublithospheric mantle. We propose a new thermal model of the oceanic lithosphere that can overcome such inconsistencies. Designated CMI, the new model assumes existence of lateral temperature variations in up-welling limbs of the asthenosphere, similar in character to those commonly observed in tectonothermal processes in the upper crust and in laboratory experiments of thermal plumes. CMI model simulations indicate that the thickness of the young lithosphere increases with distance from the ridge axis, at rates faster than those predicted by Half-Space Cooling and Plate models. As a result, the width of magma injection zone at mid-ocean ridges is relatively narrower in CMI model. Another noteworthy feature of the new model is its ability to provide vastly improved fits for observational heat flow data, in both young (ages less than 55 ma) and old (ages greater than 55 ma) oceanic lithosphere. More importantly, the improved fits to heat flow have been achieved without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation in stable ocean crust. Also, use of CMI model does not lead to artificial discontinuities in the temperature field of the lithosphere, as is the case with GDH reference models. The results of the CMI model provide a better understanding of the global heat flow variations and estimates of global heat loss. In particular, the model is capable of

  5. Method and apparatus for thermal energy storage. [Patent application

    DOEpatents

    Gruen, D.M.

    1975-08-19

    A method and apparatus for storing energy by converting thermal energy to potential chemically bound energy in which a first metal hydride is heated to dissociation temperature, liberating hydrogen gas which is compressed and reacted with a second metal to form a second metal hydride while releasing thermal energy. Cooling the first metal while warming the second metal hydride to dissociation temperature will reverse the flow of hydrogen gas back to the first metal, releasing additional thermal energy. The method and apparatus are particularly useful for the storage and conversion of thermal energy from solar heat sources and for the utilization of this energy for space heating purposes, such as for homes or offices.

  6. Tidal Energy Available for Deep Ocean Mixing: Bounds from Altimetry Data

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, Gary D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented an interesting problem. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  7. Tidal Energy Available for Deep Ocean Mixing: Bounds From Altimetry Data

    NASA Technical Reports Server (NTRS)

    Egbert, Gary D.; Ray, Richard D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented a problem to oceanographers. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  8. Energy transports by ocean and atmosphere based on an entropy extremum principle. I - Zonal averaged transports

    NASA Technical Reports Server (NTRS)

    Sohn, Byung-Ju; Smith, Eric A.

    1993-01-01

    The maximum entropy production principle suggested by Paltridge (1975) is applied to separating the satellite-determined required total transports into atmospheric and oceanic components. Instead of using the excessively restrictive equal energy dissipation hypothesis as a deterministic tool for separating transports between the atmosphere and ocean fluids, the satellite-inferred required 2D energy transports are imposed on Paltridge's energy balance model, which is then solved as a variational problem using the equal energy dissipation hypothesis only to provide an initial guess field. It is suggested that Southern Ocean transports are weaker than previously reported. It is argued that a maximum entropy production principle can serve as a governing rule on macroscale global climate, and, in conjunction with conventional satellite measurements of the net radiation balance, provides a means to decompose atmosphere and ocean transports from the total transport field.

  9. Global representation of tropical cyclone-induced ocean thermal changes using Argo data - Part 1: Methods and results

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Zhu, J.; Sriver, R. L.

    2014-12-01

    Argo floats are used to examine tropical cyclone (TC)-induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. We present a footprint method that analyzes cross-track thermal responses along all storm tracks during the period 2004-2012. We combine the results into composite representations of the vertical structure of the average thermal response for two different categories: tropical storms/depressions (TS/TD) and hurricanes. The two footprint composites are functions of three variables: cross-track distance, water depth and time relative to TC passage. We find that this footprint strategy captures the major features of the upper-ocean thermal response to TCs on time scales up to 20 days when compared against previous case study results using in situ measurements. Further, TC effects are distinguishable from background sampling variability, but the significance of this result depends on differences in regional oceanic conditions and the intensity of the TC events. On the global scale, results indicate that hurricanes induce strong upwelling near the storm center, along with downwelling away from the storm, during the first 3 days after storm passage. We also find significant subsurface warming between 30 and 200 m depth for both hurricanes and TS/TDs. On average, the subsurface ocean response persists along storm tracks for up to 20 days down to 200 (400) m depth for TS/TD (Hurricanes), exhibiting peak warming of 0.4 °C at 60 m for hurricanes and 0.2 °C at 35 m for TS/TD. The footprint method shows a weak cooling response between 200 and 400 m, which is significant for Hurricanes but not for TS/TD.

  10. Can tidal energy farms create temperature fronts in the coastal ocean?

    NASA Astrophysics Data System (ADS)

    Shapiro, G. I.

    2012-04-01

    Although an industrial scale tidal farm comprising a large set of submerged turbines has not been built yet, tidal power is considered to be one of potential sources of renewable energy in the future. For example, India plans to install a 50MW tidal farm in the Gulf of Kutch which could be further expanded to deliver more than 200MW. As tidal stream generators extract kinetic energy from the ocean currents, they change the circulation pattern and hence affect the marine environment. Recent research has shown ( Shapiro, 2011, Neill et al., 2009) that a tidal farm can modify currents and sediment transport outside the farm as far as up to a hundred kilometres. This paper studies the potential effect of a tidal farm on the temperature structure in a shallow sea using a 3D ocean model POLCOMS which was modified to include effects of kinetic energy extraction as detailed in (Shapiro, 2011). The model is set up in the Celtic Sea known for its high levels of tidal energy. The model is driven by 15 tidal constituents and the meteo forcing. Effects of tidal farms of varying sizes and power capacities (from 50 MW to 1500MW) have been studied during summer months. The simulated farms are placed in various locations north of the Cornish coast. It has been shown that even smaller farms can modify temperature distribution as far as a few tens of kilometres from the farm, and sometimes generate localised temperature fronts. This effect is particularly strong during the month of June when the fronts penetrate from surface to the seabed. The fronts are more pronounced during the spring tides, however they are still seen during the neaps. As the seasonal thermocline strengthens towards the end of summer, the fronts are mostly seen in the upper ocean layer, with warmer waters in the area of the farm and cooler waters outside the farm. The physical mechanism of front generation is linked to abrupt changes in the current patterns due to energy extraction from the ocean. The currents

  11. Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data

    PubMed

    Egbert; Ray

    2000-06-15

    How and where the ocean tides dissipate their energy are long-standing questions that have consequences ranging from the history of the Moon to the mixing of the oceans. Historically, the principal sink of tidal energy has been thought to be bottom friction in shallow seas. There has long been suggestive evidence, however, that tidal dissipation also occurs in the open ocean through the scattering by ocean-bottom topography of surface tides into internal waves, but estimates of the magnitude of this possible sink have varied widely. Here we use satellite altimeter data from Topex/Poseidon to map empirically the tidal energy dissipation. We show that approximately 10(12) watts--that is, 1 TW, representing 25-30% of the total dissipation--occurs in the deep ocean, generally near areas of rough topography. Of the estimated 2 TW of mixing energy required to maintain the large-scale thermohaline circulation of the ocean, one-half could therefore be provided by the tides, with the other half coming from action on the surface of the ocean. PMID:10866194

  12. Significant Dissipation of Tidal Energy in the Deep Ocean Inferred from Satellite Altimeter Data

    NASA Technical Reports Server (NTRS)

    Egbert, G. D.; Ray, R. D.

    2000-01-01

    How and where the ocean tides dissipate their energy are longstanding questions that have consequences ranging from the history of the Moon to the mixing of the oceans. Historically, the principal sink of tidal energy has been thought to be bottom friction in shallow seas. There has long been suggestive however, that tidal dissipation also occurs in the open ocean through the scattering by ocean-bottom topography of surface tides into internal waves, but estimates of the magnitude of this possible sink have varied widely. Here we use satellite altimeter data from Topex/Poseidon to map empirically the tidal energy dissipation. We show that approximately 10(exp 12) watts-that is, 1 TW, representing 25-30% of the total dissipation-occurs in the deep ocean, generally near areas of rough topography. Of the estimated 2 TW of mixing energy required to maintain the large-scale thermohaline circulation of the ocean, one-half could therefore be provided by the tides, with the other half coming from action on the surface of the ocean.

  13. The Ocean's Gravitational Potential Energy Budget in a Coupled Climate Model

    NASA Astrophysics Data System (ADS)

    Butler, Edward; Oliver, Kevin; Gregory, Jonathan; Tailleux, Remi

    2014-05-01

    It has been suggested that the ocean's budget of mechanical energy can provide insights into the nature of global ocean circulation and its driving processes. However, the energetics of the physical ocean and realistic ocean and coupled climate models are not well understood, even at steady-state. This study examines, in a unified fashion, the budgets of ocean gravitational potential energy (GPE) and available gravitational potential energy (AGPE) in the control simulation of the coupled atmosphere-ocean general circulation model HadCM3. Only AGPE can be converted into kinetic energy by adiabatic processes. However, not all oceanic processes affect GPE and AGPE in the same way. Diapycnal mixing supplies GPE, but not AGPE, whereas the reverse is true of the combined effect of surface buoyancy forcing and convection. Mixing and buoyancy forcing, thus, play complementary roles in sustaining the large scale circulation. Indeed, surface buoyancy fluxes are the largest globally integrated source of AGPE (+0.72 TW). However, the largest globally integrated source of GPE is resolved advection (+0.57 TW) and the largest sink is through parameterized eddy transports (-0.82 TW). The effect of these adiabatic processes on AGPE is identical to their effect on GPE, except for small perturbations due to numerical leakage exacerbated by nonlinearities in the equation of state.

  14. Application of Satellite Altimeter Data to Studies of Ocean Surface Heat Flux and Upper Ocean Thermal Processes

    NASA Technical Reports Server (NTRS)

    Yan, Xiao-Hal

    2003-01-01

    This is a one-year cost extension of previous grant but carrying a new award number for the administrative purpose. Supported by this one-year extension, the following research has continued and obtained significant results. 20 papers have been published (9) or submitted (11) to scientific journals in this one-year period. A brief summary of scientific results on: 1. A new method for estimation of the sensible heat flux using satellite vector winds, 2. Pacific warm pool excitation, earth rotation and El Nino Southern Oscillations, 3. A new study of the Mediterranean outflow and Meddies at 400-meter isopycnal surface using multi-sensor data, 4. Response of the coastal ocean to extremely high wind, and 5. Role of wind on the estimation of heat flux using satellite data, are provided below as examples of our many research results conducted in the last year,

  15. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage

    SciTech Connect

    Durgun, E; Grossman, JC

    2013-03-21

    Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

  16. Shelf and open-ocean calcareous phytoplankton assemblages across the Paleocene-Eocene thermal maximum: Implications for global productivity gradients

    USGS Publications Warehouse

    Gibbs, S.J.; Bralower, T.J.; Bown, P.R.; Zachos, J.C.; Bybell, L.M.

    2006-01-01

    Abrupt global warming and profound perturbation of the carbon cycle during the Paleocene-Eocene Thermal Maximum (PETM, ca. 55 Ma) have been linked to a massive release of carbon into the ocean-atmosphere system. Increased phytoplankton productivity has been invoked to cause subsequent CO2 drawdown, cooling, and environmental recovery. However, interpretations of geochemical and biotic data differ on when and where this increased productivity occurred. Here we present high-resolution nannofossil assemblage data from a shelf section (the U.S. Geological Survey [USGS] drill hole at Wilson Lake, New Jersey) and an open-ocean location (Ocean Drilling Program [ODP] Site 1209, paleoequatorial Pacific). These data combined with published biotic records indicate a transient steepening of shelf-offshelf trophic gradients across the PETM onset and peak, with a decrease in open-ocean productivity coeval with increased nutrient availability in shelf areas. Productivity levels recovered in the open ocean during the later stages of the event, which, coupled with intensified continental weathering rates, may have played an important role in carbon sequestration and CO2 drawdown. ?? 2006 Geological Society of America.

  17. Thermal energy and charge currents in multi-terminal nanorings

    NASA Astrophysics Data System (ADS)

    Kramer, Tobias; Kreisbeck, Christoph; Riha, Christian; Chiatti, Olivio; Buchholz, Sven S.; Wieck, Andreas D.; Reuter, Dirk; Fischer, Saskia F.

    2016-06-01

    We study in experiment and theory thermal energy and charge transfer close to the quantum limit in a ballistic nanodevice, consisting of multiply connected one-dimensional electron waveguides. The fabricated device is based on an AlGaAs/GaAs heterostructure and is covered by a global top-gate to steer the thermal energy and charge transfer in the presence of a temperature gradient, which is established by a heating current. The estimate of the heat transfer by means of thermal noise measurements shows the device acting as a switch for charge and thermal energy transfer. The wave-packet simulations are based on the multi-terminal Landauer-Büttiker approach and confirm the experimental finding of a mode-dependent redistribution of the thermal energy current, if a scatterer breaks the device symmetry.

  18. Building heating and cooling applications thermal energy storage program overview

    NASA Technical Reports Server (NTRS)

    Eissenberg, D. M.

    1980-01-01

    Thermal energy storage technology and development of building heating and cooling applications in the residential and commercial sectors is outlined. Three elements are identified to undergo an applications assessment, technology development, and demonstration. Emphasis is given to utility load management thermal energy system application where the stress is on the 'customer side of the meter'. Thermal storage subsystems for space conditioning and conservation means of increased thermal mass within the building envelope and by means of low-grade waste heat recovery are covered.

  19. Unlocking Electric Power in the Oceans.

    ERIC Educational Resources Information Center

    Hurwood, David L.

    1985-01-01

    Cruising or stationary ocean thermal plants could convert the vast heat energy of the ocean into electricity for islands and underdeveloped countries. This approach to energy conservation is described with suggestions for design and outputs of plants. A model project operating in Hawaii is noted. (DH)

  20. Thermal energy scavenger (rotating wire modules)

    SciTech Connect

    Hochstein, P.A.; Milton, H.W.; Pringle, W.L.

    1980-11-04

    A thermal energy scavenger assembly is is described including a plurality of temperature-sensitive wires made of material which exhibits shape memory due to a thermoelastic, martensitic phase transformation. The wires are placed in tension between fixed and movable plates which are, in turn, supported by a pair of wheels which are rotatably supported by a housing for rotation about a central axis. A pair of upper and lower cams are fixed to the housing and cam followers react with the respective cams. Each cam transmits forces through a pair of hydraulic pistons. One of the pistons is connected to a movable plate to which one end of the wires are connected whereby a stress is applied to the wires to strain the wires during a first phase and whereby the cam responds to the unstraining of the wires during a second phase. A housing defines fluid compartments through which hot and cold fluid passes and flows radially through the wires whereby the wires become unstrained and shorten in length when subjected to the hot fluid for causing a reaction between the cam followers and the cams to effect rotation of the wheels about the central axis of the assembly, which rotation of the wheels is extracted through beveled gearing. The wires are grouped into a plurality of independent modules with each module having a movable plate, a fixed plate and the associated hydraulic pistons and cam follower. The hydraulic pistons and cam follower of a module are disposed at ends of the wires opposite from the ends of the wires at which the same components of the next adjacent modules are disposed so that the cam followers of alternate modules react with one of the cams and the remaining cam followers of the remaining modules react with the other cam. There is also included stress limiting means in the form of coil springs associated with alternate ends of the wires for limiting the stress or strain in the wires.

  1. Energy extraction from ocean currents and waves: Mapping the most promising locations

    NASA Astrophysics Data System (ADS)

    Ordonez, A.; Hamlington, P.; Fox-Kemper, B.

    2012-12-01

    Concerns about fossil fuel supplies and an ever-increasing demand for energy have prompted the search for alternative power sources. One option is the ocean, a power-dense and renewable source of energy, but its capacity to meet human energy demands is poorly understood. Although raw wave energy resources have been investigated at many scales, there is still substantial uncertainty regarding how much useful power can be extracted. Even less is known about the energy available in ocean currents, especially on a global scale. Moreover, no studies have attempted to examine wave and current energy simultaneously while at the same time taking into account geographical, environmental, and technical factors that can substantially limit the amount of extractable energy. In this study, we use high fidelity oceanographic model data to assess the availability, recoverability, and value of energy in ocean wind waves and currents. Global wave energy transport, coastal wave energy flux, and current energy are calculated and mapped using the model data. These maps are then incorporated into a geographic information system (GIS) in order to assess the U.S. recoverable ocean energy resource. In the GIS, the amount of recoverable energy is estimated by combining the power output from realistic wave and current energy farms with physical and ecological data such as bathymetry and environmentally protected areas. This holistic approach is then used to examine the distribution and value of extractable wave and current energy along the U.S. coast. The results support previous studies that show that the U.S. West Coast has large potential for wave energy extraction and that the Florida Strait has high potential for current energy extraction. We also show that, at any particular location, the amount of available ocean energy is only one factor of many that determines the ultimate feasibility and value of the energy. We outline ways in which the GIS framework used in this assessment can be

  2. Deep-ocean contribution to sea level and energy budget not detectable over the past decade

    NASA Astrophysics Data System (ADS)

    Llovel, W.; Willis, J. K.; Landerer, F. W.; Fukumori, I.

    2014-11-01

    As the dominant reservoir of heat uptake in the climate system, the world's oceans provide a critical measure of global climate change. Here, we infer deep-ocean warming in the context of global sea-level rise and Earth's energy budget between January 2005 and December 2013. Direct measurements of ocean warming above 2,000 m depth explain about 32% of the observed annual rate of global mean sea-level rise. Over the entire water column, independent estimates of ocean warming yield a contribution of 0.77 +/- 0.28 mm yr-1 in sea-level rise and agree with the upper-ocean estimate to within the estimated uncertainties. Accounting for additional possible systematic uncertainties, the deep ocean (below 2,000 m) contributes -0.13 +/- 0.72 mm yr-1 to global sea-level rise and -0.08 +/- 0.43 W m-2 to Earth's energy balance. The net warming of the ocean implies an energy imbalance for the Earth of 0.64 +/- 0.44 W m-2 from 2005 to 2013.

  3. Deep Ocean Contribution to Sea Level and Energy Budget Not Detectable over the Past Decade

    NASA Astrophysics Data System (ADS)

    Llovel, W.; Willis, J. K.; Landerer, F. W.; Fukumori, I.

    2014-12-01

    As the dominant reservoir of heat uptake in the climate system, the world's oceans provide a critical measure of global climate change. Here, we infer deep ocean warming in the context of global sea level rise and Earth's energy budget between January 2005 and December 2013 based on satellite altimetry, GRACE and Argo floats. Direct measurements of ocean warming above 2000m depth explain 0.9 +/- 0.15 mm/yr of the observed 2.78 +/- 0.32 mm/yr rate of global mean sea level rise. Over the entire water column, independent estimates of ocean warming yield a contribution of 0.77+/-0.28 mm/yr in sea level rise and agree with the upper ocean estimate to within the estimated uncertainties. Accounting for additional possible systematic uncertainties, the deep ocean (below 2000m) contributes -0.13 +/- 0.72 mm/yr to global sea level rise and -0.08 +/- 0.43 W/m2 to Earth's energy balance. The net warming of the ocean implies an energy imbalance for the Earth of 0.64 ± 0.44 W/m2 from 2005 to 2013.

  4. Alternative biomass sources for thermal energy generation

    NASA Astrophysics Data System (ADS)

    Steensen, Torge; Müller, Sönke; Dresen, Boris; Büscher, Olaf

    2015-04-01

    of Bottrop-Kirchhellen in the state of North Rhine-Westphalia. This region consists of nature reserves, forests, farmland and a few villages. To present a qualitative comparison between simulated and true biomass volume, we conducted field work by mapping the spatial extent of the desired biomass occurrences in the area. First results indicate a qualitative match of about 75%. Our research highlights the small-scale biomass features that have not been incorporated in previous biomass estimates. With the regular trimming and the accompanied raw material that becomes available, a new sector of thermal energy generation can be outlined. An automated quantification using satellite and GIS data will allow a regular monitoring of the vegetation growth and an assessment of the transport routes and costs as well as the location of the prospective power plants. In the endeavour of creating a sustainable energy supply, these biomass units should not be neglected, especially since the usage of the traditional units is limited due to competing interests in food production and nature conservation.

  5. Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

    SciTech Connect

    Regnier, Cindy

    2012-08-31

    Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

  6. Nutritional and environmental studies on an ocean-going oil tanker. 1. Thermal environment

    PubMed Central

    Collins, K. J.; Eddy, T. P.; Lee, D. E.; Swann, P. G.

    1971-01-01

    Collins, K. J., Eddy, T. P., Lee, D. E., and Swann, P. G. (1971).Brit. J. industr. Med.,28, 237-245. Nutritional and environmental studies on an ocean-going oil tanker. I. Thermal environment. Investigations were made on board a modern, air-conditioned oil tanker (S.S. Esso Newcastle) en route to the Persian Gulf in July to August 1967 in order to study thermal conditions in the working environment, and the nutritional status of the crew, and to examine the interrelationship between climate and nutritional balance. In this introductory paper an account is given of the aims and design of the experiments together with details of the environmental survey. The voyage round Africa lasted one month, with high ambient temperatures of 37·7°C dry bulb, 30·8°C wet bulb (100/87°F) occurring only on the last few days into and out of the Persian Gulf. Mean accommodation temperature was maintained in the zone of comfort throughout, and at 23·9°C (75°F) Corrected Effective Temperature (CET) in the Gulf. On a previous voyage in a tanker without air-conditioning CETs up to 31·6°C (89°F) had been recorded in the accommodation in the same ambient conditions. With exposure to high solar radiation in the Gulf, the deck officer's cabins and bridge house in the upper superstructure became uncomfortably warm (CET exceeding 26·6°C (80°F)) and in these temperatures skilled performance is likely to deteriorate. The main thermal problems in the working environment were associated with the engine and boiler rooms which were consistently 11 to 17°C (20 to 30°F) higher than ambient temperature. For personnel on watch, the levels of heat stress were high but not intolerable if advantage was taken of the air blowers. Conditions under which emergency or repair tasks were carried out in very hot engine-room spaces were examined and often found to allow only a small margin of safety. Predicted average tolerance times were deduced from the Wet Bulb Globe Temperature (WBGT) scale of

  7. Energy and environmental issues of aquifer thermal energy storage

    SciTech Connect

    Kannberg, L.D.

    1988-08-01

    Aquifer thermal energy storage (ATES) has the potential to provide storage for large-scale industrial and building heating and cooling at many sites in the US. However, implementation requires careful attention to site geohydraulic and geochemical characteristics. Field tests in the US have shown that over 60% of the heat injected at temperatures over 100/degree/C can be recovered on a seasonal cycle. Similarly, aquifer storage of chilled groundwater can provide building cooling with a reduction of over 50% in annual cooling electrical energy consumption and a factor of 20 reduction in summer cooling peak electrical demand. Heat ATES will require water treatment at most sites to prevent precipitation of calcium and magnesium carbonates and silica (depending upon the temperature regime). Environmental concerns create a need for detailed geochemical and water treatment analysis using models and laboratory studies. At some sites microbiological issues must also be resolved. In some instances bacteria can cause extensive corrosion or clogging of the well screen and surrounding porous media. At other sites effects on indigenous beneficial microbiota and the potential for augmenting growth and release of pathogenic organisms are of concern. Laboratory research as well as field testing is being conducted to extend and augment experience in related technologies. Results from field testing and environmental monitoring have not revealed dramatic environmental impacts. Rather, they have revealed the strong potential for geochemical and geohydraulic factors to influence successful ATES operations. 12 refs., 3 figs., 2 tabs.

  8. Buffer thermal energy storage for an air Brayton solar engine

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.

  9. Real-time Ocean Wave Prediction for Optimal Performance of a Wave Energy Converter

    NASA Astrophysics Data System (ADS)

    Cavaglieri, Daniele; Bewley, Thomas

    2013-11-01

    In recent years, there has been a growing interest in renewable energy. Among all the available possibilities, wave energy conversion, due to the huge availability of energy that the ocean could provide, represents nowadays one of the most promising solutions. However, the efficiency of a wave energy converter for ocean wave energy harvesting is still far from making it competitive with more mature fields of renewable energy, such as solar and wind energy. One of the main problems is related to the inability to accurately predict the profile of oncoming waves approaching the wave energy converter. For this reason, we developed a new hybrid method for state estimation of nonlinear systems, which is based on a variational formulation of an ensemble smoother, combined with the formulation of the ensemble Kalman smoother. This method has been employed for the optimal forecasting of ocean waves via sensors placed on an array of wave energy converters. The coupled simulation of ocean waves and energy devices has been carried out leveraging a nonlinear High Order Spectral code.

  10. Thermal energy storage for industrial waste heat recovery

    NASA Technical Reports Server (NTRS)

    Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

    1978-01-01

    Thermal energy storage systems designed for energy conservation through the recovery, storage, and reuse of industrial process waste heat are reviewed. Consideration is given to systems developed for primary aluminum, cement, the food processing industry, paper and pulp, and primary iron and steel. Projected waste-heat recovery and energy savings are listed for each category.

  11. Thermal-energy conversion: Under pressure

    NASA Astrophysics Data System (ADS)

    Phillip, William A.

    2016-07-01

    The conversion of low-grade waste heat into electrical energy is an attractive opportunity to harvest a sustainable energy resource. A thermo-osmotic energy conversion process that uses Earth-abundant materials has now been shown to convert waste heat into electrical energy from sources at temperatures as low as 40 °C.

  12. Solar photovoltaic/thermal (hybrid) energy project

    NASA Astrophysics Data System (ADS)

    Sheldon, D. B.

    1981-09-01

    Development of photovoltaic/thermal (PV/T) collectors and residential heat pump systems is reported. Candidate collector and residential heat pump systems were evaluated using the TRNSYS computer program. It is found that combined heat pump and PV array is a promising method for achieving economical solar cooling. Where the cooling load is dominant, exclusively PV collectors rather than PV/T collectors are preferred. Where the heating load is dominant, the thermal component of PV/T collectors makes a significant contribution to heating a residence. PV/T collectors were developed whose combined efficiency approaches the efficiency of a double glazed, exclusively thermal collector. The design and operational problems of air source heat pumps are reviewed. Possible effects of compressor startup transients on PV power system operation are discussed.

  13. An optimal control method for maximizing the efficiency of direct drive ocean wave energy extraction system.

    PubMed

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913

  14. An Optimal Control Method for Maximizing the Efficiency of Direct Drive Ocean Wave Energy Extraction System

    PubMed Central

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913

  15. Solar thermal energy utilization: A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Bibliographic series, which is periodically updated, cites documents published since 1957 relating to practical thermal utilization of solar energy. Bibliography is indexed by author, corporate source, title, and keywords.

  16. Energy consumption in buildings and female thermal demand

    NASA Astrophysics Data System (ADS)

    Kingma, Boris; van Marken Lichtenbelt, Wouter

    2015-12-01

    Energy consumption of residential buildings and offices adds up to about 30% of total carbon dioxide emissions; and occupant behaviour contributes to 80% of the variation in energy consumption. Indoor climate regulations are based on an empirical thermal comfort model that was developed in the 1960s (ref. ). Standard values for one of its primary variables--metabolic rate--are based on an average male, and may overestimate female metabolic rate by up to 35% (ref. ). This may cause buildings to be intrinsically non-energy-efficient in providing comfort to females. Therefore, we make a case to use actual metabolic rates. Moreover, with a biophysical analysis we illustrate the effect of miscalculating metabolic rate on female thermal demand. The approach is fundamentally different from current empirical thermal comfort models and builds up predictions from the physical and physiological constraints, rather than statistical association to thermal comfort. It provides a substantiation of the thermal comfort standard on the population level and adds flexibility to predict thermal demand of subpopulations and individuals. Ultimately, an accurate representation of thermal demand of all occupants leads to actual energy consumption predictions and real energy savings of buildings that are designed and operated by the buildings services community.

  17. Cloud-radiative effects on implied oceanic energy transport as simulated by atmospheric general circulation models

    NASA Technical Reports Server (NTRS)

    Gleckler, P. J.; Randall, D. A.; Boer, G.; Colman, R.; Dix, M.; Galin, V.; Helfand, M.; Kiehl, J.; Kitoh, A.; Lau, W.

    1995-01-01

    This paper summarizes the ocean surface net energy flux simulated by fifteen atmospheric general circulation models constrained by realistically-varying sea surface temperatures and sea ice as part of the Atmospheric Model Intercomparison Project. In general, the simulated energy fluxes are within the very large observational uncertainties. However, the annual mean oceanic meridional heat transport that would be required to balance the simulated surface fluxes is shown to be critically sensitive to the radiative effects of clouds, to the extent that even the sign of the Southern Hemisphere ocean heat transport can be affected by the errors in simulated cloud-radiation interactions. It is suggested that improved treatment of cloud radiative effects should help in the development of coupled atmosphere-ocean general circulation models.

  18. Applications of thermal energy storage in the cement industry

    NASA Technical Reports Server (NTRS)

    Jaeger, F. A.; Beshore, D. G.; Miller, F. M.; Gartner, E. M.

    1978-01-01

    In the manufacture of cement, literally trillions of Btu's are rejected to the environment each year. The purpose of this feasibility study program was to determine whether thermal energy storage could be used to conserve or allow alternative uses of this rejected energy. This study identifies and quantifies the sources of rejected energy in the cement manufacturing process, established use of this energy, investigates various storage system concepts, and selects energy conservation systems for further study. Thermal performance and economic analyses are performed on candidate storage systems for four typical cement plants representing various methods of manufacturing cement. Through the use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 10 to the 13th power Btu/year, or an equivalent on investment of the proposed systems are an incentive for further development.

  19. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    PubMed

    Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. PMID:27253462

  20. Laser-assisted manufacturing of thermal energy devices

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Tewolde, Mahder; Kim, Ki-Hoon; Seo, Dong-Min; Longtin, Jon P.; Hwang, David J.

    2016-03-01

    In this study, we will present recent progress in the laser-assisted manufacturing of thermal energy devices that require suppressed thermal transport characteristics yet maintaining other functionalities such as electronic transport or mechanical strength. Examples of such devices to be demonstrated include thermoelectric generator or insulating materials. To this end, it will be shown that an additive manufacturing approaches can be facilitated and improved by unique processing capabilities of lasers in composite level. In order to tailor thermal characteristics in thermal devices, we will mainly investigate the potential of laser heating, curing, selective removal and sintering processes of material systems in the composite level.

  1. Smart Building: Decision Making Architecture for Thermal Energy Management

    PubMed Central

    Hernández Uribe, Oscar; San Martin, Juan Pablo; Garcia-Alegre, María C.; Santos, Matilde; Guinea, Domingo

    2015-01-01

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction. PMID:26528978

  2. Smart Building: Decision Making Architecture for Thermal Energy Management.

    PubMed

    Uribe, Oscar Hernández; Martin, Juan Pablo San; Garcia-Alegre, María C; Santos, Matilde; Guinea, Domingo

    2015-01-01

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction. PMID:26528978

  3. Projected Impact of Climate Change on the Energy Budget of the Arctic Ocean by a Global Climate Model

    NASA Technical Reports Server (NTRS)

    Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)

    2001-01-01

    The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is

  4. Pulse thermal energy transport/storage system

    DOEpatents

    Weislogel, Mark M.

    1992-07-07

    A pulse-thermal pump having a novel fluid flow wherein heat admitted to a closed system raises the pressure in a closed evaporator chamber while another interconnected evaporator chamber remains open. This creates a large pressure differential, and at a predetermined pressure the closed evaporator is opened and the opened evaporator is closed. This difference in pressure initiates fluid flow in the system.

  5. Aquifer thermal energy storage reference manual: seasonal thermal energy storage program

    SciTech Connect

    Prater, L.S.

    1980-01-01

    This is the reference manual of the Seasonal Thermal Energy Storage (STES) Program, and is the primary document for the transfer of technical information of the STES Program. It has been issued in preliminary form and will be updated periodically to include more technical data and results of research. As the program progresses and new technical data become available, sections of the manual will be revised to incorporate these data. This primary document contains summaries of: the TRW, incorporated demonstration project at Behtel, Alaska, Dames and Moore demonstration project at Stony Brook, New York, and the University of Minnesota demonstration project at Minneapolis-St. Paul, Minnesota; the technical support programs including legal/institutional assessment; economic assessment; environmental assessment; field test facilities; a compendia of existing information; numerical simulation; and non-aquifer STES concepts. (LCL)

  6. Legal and regulatory issues affecting aquifer thermal energy storage

    SciTech Connect

    Hendrickson, P.L.

    1981-10-01

    This document updates and expands the report with a similar title issued in October 1980. This document examines a number of legal and regulatory issues that potentially can affect implementation of the aquifer thermal energy storage (ATES) concept. This concept involves the storage of thermal energy in an underground aquifer until a later date when it can be effectively utilized. Either heat energy or chill can be stored. Potential end uses of the energy include district space heating and cooling, industrial process applications, and use in agriculture or aquaculture. Issues are examined in four categories: regulatory requirements, property rights, potential liability, and issues related to heat or chill delivery.

  7. Thermally driven electrokinetic energy conversion with liquid water microjets

    NASA Astrophysics Data System (ADS)

    Lam, Royce K.; Gamlieli, Zach; Harris, Stephen J.; Saykally, Richard J.

    2015-11-01

    A goal of current energy research is to design systems and devices that can efficiently exploit waste heat and utilize solar or geothermal heat energy for electrical power generation. We demonstrate a novel technique exploiting water's large coefficient of thermal expansion, wherein modest thermal gradients produce the requisite high pressure for driving fast-flowing liquid water microjets, which can effect the direct conversion of the kinetic energy into electricity and gaseous hydrogen. Waste heat in thermoelectric generating plants and combustion engines, as well as solar and geothermal energy could be used to drive these systems.

  8. High Density Thermal Energy Storage with Supercritical Fluids

    NASA Technical Reports Server (NTRS)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  9. Thermal energy storage apparatus enabling use of aqueous or corrosive thermal storage media

    SciTech Connect

    James, T.W.

    1993-08-31

    A holdover plate is described for thermal energy storage in refrigeration and air conditioning systems, the holdover plate comprising: a heat exchanger with an adjacent space in close proximity thereto; a plurality of expandable capsules containing a thermal energy storage medium, the capsules substantially filling the adjacent space and the capsules including means to provide for expansion of the thermal energy storage medium without altering outer envelope dimensions of the capsules; a containment means forming an exterior of the holdover plate and surrounding the heat exchanger and the adjacent space filled with the capsules, the containment means further containing a convective coupling fluid which thermally couples and is non-corrosive to the heat exchanger, the capsules, and the containment means; and wherein the convective coupling fluid transfers heat primarily through natural convection and conduction and does not freeze at operational temperatures of the heat exchanger.

  10. An assessment of research and development leadership in ocean energy technologies

    SciTech Connect

    Bruch, V.L.

    1994-04-01

    Japan is clearly the leader in ocean energy technologies. The United Kingdom also has had many ocean energy research projects, but unlike Japan, most of the British projects have not progressed from the feasibility study stage to the demonstration stage. Federally funded ocean energy research in the US was stopped because it was perceived the technologies could not compete with conventional sources of fuel. Despite the probable small market for ocean energy technologies, the short sighted viewpoint of the US government regarding funding of these technologies may be harmful to US economic competitiveness. The technologies may have important uses in other applications, such as offshore construction and oil and gas drilling. Discontinuing the research and development of these technologies may cause the US to lose knowledge and miss market opportunities. If the US wishes to maintain its knowledge base and a market presence for ocean energy technologies, it may wish to consider entering into a cooperative agreement with Japan and/or the United Kingdom. Cooperative agreements are beneficial not only for technology transfer but also for cost-sharing.

  11. New estimates of oceanic tidal energy dissipation from satellite altimetry

    NASA Technical Reports Server (NTRS)

    Cartwright, David E.; Ray, Richard D.

    1989-01-01

    As a novel approach to computing the flux of tidal power into shelf areas, tidal maps of an oceanic area near the Patagonian Shelf are derived from 11 months of altimetry records from the GEOSAT satellite. Power fluxes are computed from the maps through Laplace's tidal equations. Flux vectors for M2 clearly show a convergence on to the southern portion of the shelf sea and their total is nearly twice the loss computed by Miller for that area. A decrease of 'quality factor' with frequency from M2 to S2 is in keeping with Webb's hypothesis of shelf resonances at frequencies a little higher than the tidal band.

  12. Thermal energy transport in a surface phonon-polariton crystal

    NASA Astrophysics Data System (ADS)

    Ordonez-Miranda, Jose; Tranchant, Laurent; Joulain, Karl; Ezzahri, Younes; Drevillon, Jérémie; Volz, Sebastian

    2016-01-01

    We demonstrate that the energy transport of surface phonon polaritons can efficiently be observed in a crystal made up of a three-dimensional assembly of spheroidal nanoparticles of silicon carbide. The ultralow phonon thermal conductivity of this nanostructure, along with its high surface area-to-volume ratio, allows the predominance of the polariton energy over that generated by phonons. The polariton dispersion relation, propagation length, and thermal conductance are numerically determined as functions of the size, shape, and temperature of the nanoparticles. It is shown that the thermal conductance of a crystal with prolate nanoparticles at 500 K and a minor (major) axis of 50 nm (5 μ m ) is 0.5 nW K-1 , which is comparable to the quantum of thermal conductance of polar nanowires. We also show that a nanoparticle size dispersion of up to 200 nm does not change significantly the polariton energy, which supports the technological feasibility of the proposed crystal.

  13. Rapid Charging of Thermal Energy Storage Materials through Plasmonic Heating

    PubMed Central

    Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

    2014-01-01

    Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites. PMID:25175717

  14. Tidal Energy Available for Deep Ocean Mixing: Bounds from Altimetry Data

    NASA Technical Reports Server (NTRS)

    Egbert, Gary D.; Ray, Richard D.

    1999-01-01

    Maintenance of the large-scale thermohaline circulation has long presented a problem to oceanographers. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon (T/P) satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

  15. Modeling of Store Gletscher's calving dynamics, West Greenland, in response to ocean thermal forcing

    NASA Astrophysics Data System (ADS)

    Morlighem, M.; Bondzio, J.; Seroussi, H.; Rignot, E.; Larour, E.; Humbert, A.; Rebuffi, S.

    2016-03-01

    Glacier-front dynamics is an important control on Greenland's ice mass balance. Warmer ocean waters trigger ice-front retreats of marine-terminating glaciers, and the corresponding loss in resistive stress leads to glacier acceleration and thinning. Here we present an approach to quantify the sensitivity and vulnerability of marine-terminating glaciers to ocean-induced melt. We develop a plan view model of Store Gletscher that includes a level set-based moving boundary capability, a parameterized ocean-induced melt, and a calving law with complete and precise land and fjord topographies to model the response of the glacier to increased melt. We find that the glacier is stabilized by a sill at its terminus. The glacier is dislodged from the sill when ocean-induced melt quadruples, at which point the glacier retreats irreversibly for 27 km into a reverse bed. The model suggests that ice-ocean interactions are the triggering mechanism of glacier retreat, but the bed controls its magnitude.

  16. Reduction of Near-Inertial Energy by Ocean-Surface-Velocity-Dependent Wind Stress

    NASA Astrophysics Data System (ADS)

    Rath, Willi; Greatbatch, Richard; Zhai, Xiaoming

    2013-04-01

    This study aims at understanding the effect of including or neglecting the surface velocity of the ocean into the wind stress parameterization for the strength and distribution of near-inertial oscillations. Wind-generated near-inertial oscillations are an important source of energy for surface mixed layer deepening as well as for internal wave breaking and the associated diapycnal mixing at depth which, in turn, is thought to be important for driving the meridional overturning circulation. By using a realistic primitive equation model of the Southern Ocean at eddying resolution, we find that including ocean surface velocities into the wind stress leads to a large reduction of both wind power input into near-inertial oscillations (WPI) and near-inertial energy (NIE) in the surface mixed layer. The relative reduction of WPI can be as large as 30 percent and the relative reduction of NIE can be as large as 50 percent. Using both, the primitive equation model and a simple linear local slab-ocean model for illustration, we find that a large part of this reduction can be explained by the leading order modification to the wind stress if ocean surface velocities are included. We also find that the strength of the reduction is modulated by the inverse of the ocean surface mixed layer depth.

  17. Thermal conductor for high-energy electrochemical cells

    DOEpatents

    Hoffman, Joseph A.; Domroese, Michael K.; Lindeman, David D.; Radewald, Vern E.; Rouillard, Roger; Trice, Jennifer L.

    2000-01-01

    A thermal conductor for use with an electrochemical energy storage device is disclosed. The thermal conductor is attached to one or both of the anode and cathode contacts of an electrochemical cell. A resilient portion of the conductor varies in height or position to maintain contact between the conductor and an adjacent wall structure of a containment vessel in response to relative movement between the conductor and the wall structure. The thermal conductor conducts current into and out of the electrochemical cell and conducts thermal energy between the electrochemical cell and thermally conductive and electrically resistive material disposed between the conductor and the wall structure. The thermal conductor may be fabricated to include a resilient portion having one of a substantially C-shaped, double C-shaped, Z-shaped, V-shaped, O-shaped, S-shaped, or finger-shaped cross-section. An elastomeric spring element may be configured so as to be captured by the resilient conductor for purposes of enhancing the functionality of the thermal conductor. The spring element may include a protrusion that provides electrical insulation between the spring conductor and a spring conductor of an adjacently disposed electrochemical cell in the presence of relative movement between the cells and the wall structure. The thermal conductor may also be fabricated from a sheet of electrically conductive material and affixed to the contacts of a number of electrochemical cells.

  18. Magneto-Thermo-Triboelectric Generator (MTTG) for thermal energy harvesting

    NASA Astrophysics Data System (ADS)

    Jang, Kwang Yeop; Lee, James; Lee, Dong-Gun

    2016-04-01

    We present a novel thermal energy harvesting system using triboelectric effect. Recently, there has been intensive research efforts on energy harvesting using triboelectric effect, which can produce surprising amount of electric power (when compared to piezoelectric materials) by rubbing or touching (i.e, electric charge by contact and separation) two different materials together. Numerous studies have shown the possibility as an attractive alternative with good transparency, flexibility and low cost abilities for its use in wearable device and smart phone applications markets. However, its application has been limited to only vibration source, which can produce sustained oscillation with maintaining contact and separation states repeatedly for triboelectric effect. Thus, there has been no attempt toward thermal energy source. The proposed approach can convert thermal energy into electricity by pairing triboelectric effect and active ferromagnetic materials The objective of the research is to develop a new manufacturing process of design, fabrication, and testing of a Magneto-Thermo-Triboelectric Generator (MTTG). The results obtained from the approach show that MTTG devices have a feasible power energy conversion capability from thermal energy sources. The tunable design of the device is such that it has efficient thermal capture over a wide range of operation temperature in waste heat.

  19. IECEC '83; Proceedings of the Eighteenth Intersociety Energy Conversion Engineering Conference, Orlando, FL, August 21-26, 1983. Volume 1 - Thermal energy systems

    NASA Astrophysics Data System (ADS)

    Among the topics discussed are the nuclear fuel cycle, advanced nuclear reactor designs, developments in central status power reactors, space nuclear reactors, magnetohydrodynamic devices, thermionic devices, thermoelectric devices, geothermal systems, solar thermal energy conversion systems, ocean thermal energy conversion (OTEC) developments, and advanced energy conversion concepts. Among the specific questions covered under these topic headings are a design concept for an advanced light water breeder reactor, energy conversion in MW-sized space power systems, directionally solidified cermet electrodes for thermionic energy converters, boron-based high temperature thermoelectric materials, geothermal energy commercialization, solar Stirling cycle power conversion, and OTEC production of methanol. For individual items see A84-30027 to A84-30055

  20. Engineering evaluation of a sodium hydroxide thermal energy storage module

    NASA Technical Reports Server (NTRS)

    Perdue, D. G.; Gordon, L. H.

    1980-01-01

    An engineering evaluation of thermal energy storage prototypes was performed in order to assess the development status of latent heat storage media. The testing and the evaluation of a prototype sodium hydroxide module is described. This module stored off-peak electrical energy as heat for later conversion to domestic hot water needs.

  1. SURVEY OF EPA FACILITIES FOR SOLAR THERMAL ENERGY APPLICATIONS

    EPA Science Inventory

    A study was done to assess the feasibility of applying solar thermal energy systems to EPA facilities. A survey was conducted to determine those EPA facilities where solar energy could best be used. These systems were optimized for each specific application and the system/facilit...

  2. Survey on utility technology of a tidal and ocean current energy

    NASA Astrophysics Data System (ADS)

    Hirose, Manabu; Kadoyu, Masataka; Tanaka, Hiroyoshi

    1987-06-01

    A study is made to show the current technological levels in Japan and other nations regarding the conversion of tidal current or ocean current energy to electric power and to determine the latent energy quantities and energy-related characteristics of tidal and ocean currents. In Japan, relatively large-scale experiments made so far mostly used one of the following three types of devices: Savonius-wheel type, Darrieus-wheel type, and cross-flow-wheel type. Field experiments of tidal energy conversion have been performed at the Naruto and Kurushima Straits. The energy in the Kuroshio current is estimated at about 170 billion kWh per year. Ocean current energy does not undergo large seasonal variations. The total energy in major straits and channels in the Inland Sea and other sea areas to the west is estimated at about 124 billion kWh per year. Tidal current energy shows large seasonal variations, but it is possible to predict the changes. A survey is made to determine energy-related characteristics of a tidal current at Chichino-seto, Kagoshima Prefecture. At Chichino-seto, the flow velocity ranges from 0 to 2.2m/s, with a latent tidal current energy of about 70 kW, of which about 20 kW can actually be utilized.

  3. Thermal evolution of the oceanic lithosphere revisited with the help of an upper-mantle velocity model

    NASA Astrophysics Data System (ADS)

    Goutorbe, Bruno

    2010-05-01

    There are presently several candidate models for the thermal structure and evolution of the oceanic lithosphere, which essentially differ by the imposed basal condition. The latter condition represents the additional heat brought at the base of lithosphere (should it exist), and it can take the form of a fixed basal temperature or a fixed basal heat flow. I investigate this problem with the help of a shear velocity model of the upper mantle. Velocities of the lithospheric mantle are converted to temperatures using up-to-date constraints related to the velocity-temperature relationship (namely, constraints on thermoelastic parameters, mantle composition and attenuation factor), and an averaging by age interval is then applied. A particular care is dedicated to the estimation of final uncertainties on temperature, to allow for a quantitative interpretation. This work reconfirms that heat is brought by some mean at the base of the lithosphere, as a half-space cooling thermal evolution falls well below the seismically derived temperatures and their uncertainties. However, I do not observe within the age range (0-160 My) an asymptotic thickness for the lithosphere, which is at odds with the widely used plate model, whereby the additional heat supply is represented by a fixed temperature at some depth. Adding bathymetry and surface heat flow as joint constraints, I find that a model which prescribes a constant heat flow at some isotherm (the so-called Chablis model) provides a better fit to the data than the plate model. Only a strongly reduced thermal expansivity (reduction by at least 30 per cent with respect to the experimental value) allows the latter model achieving a joint-fitting comparable to the former model, and then with a fit to temperature that remains poor. The good fit of the plate model thus relies on a thermal expansivity reduced down to the lowest limit and on ocean depth, whose behaviour at old ages is considerably obscured by anomalous crust. The

  4. Novel two-stage piezoelectric-based ocean wave energy harvesters for moored or unmoored buoys

    NASA Astrophysics Data System (ADS)

    Murray, R.; Rastegar, J.

    2009-03-01

    Harvesting mechanical energy from ocean wave oscillations for conversion to electrical energy has long been pursued as an alternative or self-contained power source. The attraction to harvesting energy from ocean waves stems from the sheer power of the wave motion, which can easily exceed 50 kW per meter of wave front. The principal barrier to harvesting this power is the very low and varying frequency of ocean waves, which generally vary from 0.1Hz to 0.5Hz. In this paper the application of a novel class of two-stage electrical energy generators to buoyant structures is presented. The generators use the buoy's interaction with the ocean waves as a low-speed input to a primary system, which, in turn, successively excites an array of vibratory elements (secondary system) into resonance - like a musician strumming a guitar. The key advantage of the present system is that by having two decoupled systems, the low frequency and highly varying buoy motion is converted into constant and much higher frequency mechanical vibrations. Electrical energy may then be harvested from the vibrating elements of the secondary system with high efficiency using piezoelectric elements. The operating principles of the novel two-stage technique are presented, including analytical formulations describing the transfer of energy between the two systems. Also, prototypical design examples are offered, as well as an in-depth computer simulation of a prototypical heaving-based wave energy harvester which generates electrical energy from the up-and-down motion of a buoy riding on the ocean's surface.

  5. Micro rectennas: Brownian ratchets for thermal-energy harvesting

    SciTech Connect

    Pan, Y.; Powell, C. V.; Balocco, C.; Song, A. M.

    2014-12-22

    We experimentally demonstrated the operation of a rectenna for harvesting thermal (blackbody) radiation and converting it into dc electric power. The device integrates an ultrafast rectifier, the self-switching nanodiode, with a wideband log-periodic spiral microantenna. The radiation from the thermal source drives the rectenna out of thermal equilibrium, permitting the rectification of the excess thermal fluctuations from the antenna. The power conversion efficiency increases with the source temperatures up to 0.02% at 973 K. The low efficiency is attributed mainly to the impedance mismatch between antenna and rectifier, and partially to the large field of view of the antenna. Our device not only opens a potential solution for harvesting thermal energy but also provides a platform for experimenting with Brownian ratchets.

  6. Metal hydrides for concentrating solar thermal power energy storage

    NASA Astrophysics Data System (ADS)

    Sheppard, D. A.; Paskevicius, M.; Humphries, T. D.; Felderhoff, M.; Capurso, G.; Bellosta von Colbe, J.; Dornheim, M.; Klassen, T.; Ward, P. A.; Teprovich, J. A.; Corgnale, C.; Zidan, R.; Grant, D. M.; Buckley, C. E.

    2016-04-01

    The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room temperature and as high as 1100 °C. The potential of metal hydrides for thermal storage is explored, while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature TES are also addressed.

  7. Using the shield for thermal energy storage in PULSAR

    NASA Astrophysics Data System (ADS)

    Sager, G. T.; Wong, C. P. C.; Sze, D.-K.; Bathe, C. G.; Blanchard, J. P.; Brimer, C.; Cheng, E. T.; El-Guebaly, L. A.; Hasan, M. Z.; Najmabadi, F.

    1994-04-01

    The PULSAR pulsed tokamak power plant design utilizes the outboard shield for thermal energy storage to maintain full 1000 MW(e) output during the dwell period of 200 s. Thermal energy resulting from direct nuclear heating is accumulated in the shield during the 7200 s fusion power production phase. The maximum shield temperature may be much higher than that for the blanket because radiation damage is significantly reduced. During the dwell period, thermal power discharged from the shield and coolant temperature are simultaneously regulated by controlling the coolant mass flow rate at the shield inlet. This is facilitated by throttled coolant bypass. Design concepts using helium and lithium coolant have been developed. Two-dimensional, time-dependent thermal hydraulic calculations were performed to confirm performance capabilities required of the design concepts. The results indicate that the system design and performance can accommodate uncertainties in material limits or the length of the dwell period.

  8. Conversion of broadband to narrowband thermal emission through energy recycling

    NASA Astrophysics Data System (ADS)

    de Zoysa, Menaka; Asano, Takashi; Mochizuki, Keita; Oskooi, Ardavan; Inoue, Takuya; Noda, Susumu

    2012-08-01

    Converting from a broadband to a narrowband thermal emission spectrum with minimal loss of energy is important in the creation of efficient environmental sensors and biosensors as well as thermo-photovoltaic power generation systems. Here, we demonstrate such thermal emission control by manipulating photonic modes with photonic crystals as well as material absorption with quantum-well intersubband transitions. We show that the emission peak intensity for our device can be more than four times greater than that of a blackbody sample under the same input power and thermal management conditions due to an increase in the temperature compared to the blackbody reference, and the emission bandwidth and angular spread are narrowed by a factor of 30 and 8, respectively. These results indicate that the energy saved by thermal emission control can be recycled and concentrated to enhance the narrow peak emission intensity.

  9. Study of thermal energy storage using fluidized bed heat exchangers

    NASA Technical Reports Server (NTRS)

    Weast, T. E.; Shannon, L. J.; Ananth, K. P.

    1980-01-01

    The technical and economic feasibility of fluid bed heat exchangers (FBHX) for thermal energy storage (TES) in waste heat recovery applications is assessed by analysis of two selected conceptual systems, the rotary cement kiln and the electric arc furnace. It is shown that the inclusion of TES in the energy recovery system requires that the difference in off-peak and on-peak energy rates be large enough so that the value of the recovered energy exceeds the value of the stored energy by a wide enough margin to offset parasitic power and thermal losses. Escalation of on-peak energy rates due to fuel shortages could make the FBHX/TES applications economically attractive in the future.

  10. Geothermal energy enhancement by thermal fracture. [REX (Rock Energy Extraction)

    SciTech Connect

    Demuth, R.B.; Harlow, F.H.

    1980-12-01

    A large, vertical, circular fracture created deep within hot rock is connected to the surface through two holes. The inlet provides a source of cold water and the outlet extracts heated water. Cooling of the rock produces thermal stresses that fracture the rock adjacent to the primary crack, thereby enhancing the heat extraction rate by means of convective transport. The properties of the thermal fracture network vary with position and time. The REX code for high-speed computer was written and used to study the coupled processes of primary-crack flow and lateral thermal fracture heat transport. Calculations for elapsed times of 100 y show that thermal fracture enhancement can double the heat extraction rate over the results from conduction alone. Long-term enhancement predictions depend on data from rock-mechanics studies, which the REX code is prepared to accept as they become available.

  11. Buffer thermal energy storage for a solar Brayton engine

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    A study has been completed on the application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine. To aid in the study, a computer program was written for complete transient/stead-state Brayton cycle performance. The results indicated that thermal storage can afford a significant decrease in the number of engine shutdowns as compared to operating without thermal storage. However, the number of shutdowns does not continuously decrease as the storage material weight increases. In fact, there appears to be an optimum weight for minimizing the number of shutdowns.

  12. Tropical Ocean Surface Energy Balance Variability: Linking Weather to Climate Scales

    NASA Technical Reports Server (NTRS)

    Roberts, J. Brent; Clayson, Carol Anne

    2013-01-01

    Radiative and turbulent surface exchanges of heat and moisture across the atmosphere-ocean interface are fundamental components of the Earth s energy and water balance. Characterizing the spatiotemporal variability of these exchanges of heat and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. These fluxes are integral components to tropical ocean-atmosphere variability; they can drive ocean mixed layer variations and modify the atmospheric boundary layer properties including moist static stability, thereby influencing larger-scale tropical dynamics. Non-parametric cluster-based classification of atmospheric and ocean surface properties has shown an ability to identify coherent weather regimes, each typically associated with similar properties and processes. Using satellite-based observational radiative and turbulent energy flux products, this study investigates the relationship between these weather states and surface energy processes within the context of tropical climate variability. Investigations of surface energy variations accompanying intraseasonal and interannual tropical variability often use composite-based analyses of the mean quantities of interest. Here, a similar compositing technique is employed, but the focus is on the distribution of the heat and moisture fluxes within their weather regimes. Are the observed changes in surface energy components dominated by changes in the frequency of the weather regimes or through changes in the associated fluxes within those regimes? It is this question that the presented work intends to address. The distribution of the surface heat and moisture fluxes is evaluated for both normal and non-normal states. By examining both phases of the climatic oscillations, the symmetry of energy and water cycle responses are considered.

  13. Effects of ocean acidification on the marine calcium isotope record at the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Griffith, Elizabeth M.; Fantle, Matthew S.; Eisenhauer, Anton; Paytan, Adina; Bullen, Thomas D.

    2015-06-01

    Carbonates are used extensively to reconstruct paleoclimate and paleoceanographic conditions over geologic time scales. However, these archives are susceptible to diagenetic alteration via dissolution, recrystallization and secondary precipitation, particularly during ocean acidification events when intense dissolution can occur. Despite the possible effects of diagenesis on proxy fidelity, the impacts of diagenesis on the calcium isotopic composition (δ44Ca) of carbonates are unclear. To shed light on this issue, bulk carbonate δ44Ca was measured at high resolution in two Pacific deep sea sediment cores (ODP Sites 1212 and 1221) with considerably different dissolution histories over the Paleocene-Eocene Thermal Maximum (PETM, ∼ 55 Ma). The δ44Ca of marine barite was also measured at the deeper Site 1221, which experienced severe carbonate dissolution during the PETM. Large variations (∼ 0.8 ‰) in bulk carbonate δ44Ca occur in the deeper of the two sites at depths corresponding to the peak carbon isotope excursion, which correlate with a large drop in carbonate weight percent. Such an effect is not observed in either the 1221 barite record or the bulk carbonate record at the shallower Site 1212, which is also less affected by dissolution. We contend that ocean chemical changes associated with abrupt and massive carbon release into the ocean-atmosphere system and subsequent ocean acidification at the PETM affected the bulk carbonate δ44Ca record via diagenesis in the sedimentary column. Such effects are considerable, and need to be taken into account when interpreting Ca isotope data and, potentially, other geochemical proxies over extreme climatic events that drive sediment dissolution.

  14. Solar thermal parabolic dish energy applications

    NASA Technical Reports Server (NTRS)

    Pijawka, W.

    1981-01-01

    Vu-graphs are presented that show that applications are a viable distributed renewable power generation option. Quality energy can be produced in the form of electricity and high temperature heat. Modular systems are described that can be distributed to new or existing plants and that are mass producible with the associated economies of production.

  15. Electromagnetic thermal corrections to Casimir energy

    NASA Astrophysics Data System (ADS)

    Nazari, Borzoo

    2016-07-01

    In [B. Nazari, Mod. Phys. Lett. A 31, 1650007 (2016)], we calculated finite temperature corrections to the energy of the Casimir effect of two conducting parallel plates in a general weak gravitational field. The calculations was done for the case a scalar field was present between the plates. Here we find the same results in the presence of an electromagnetic field.

  16. Chemical energy storage system for SEGS solar thermal power plant

    NASA Astrophysics Data System (ADS)

    Brown, D. R.; Lamarche, J. L.; Spanner, G. E.

    1991-09-01

    In October 1988, a symposium was held in Helendale, California, to discuss thermal energy storage (TES) concepts applicable to medium temperature (200 to 400 C) solar thermal electric power plants, in general, and the solar electric generating system (SEGS) plants developed by Luz International, in particular. Chemical reaction energy storage based on the reversible reaction between metal oxides and metal hydroxides was identified as a leading candidate for meeting Luz International's cost and performance requirements. The principal objectives of this study were to identify the design conditions, requirements, and potential feasibility for a chemical energy storage system applied to a SEGS solar thermal power plant. The remaining sections of this report begin by providing an overview of the chemical reaction energy storage concept and a SEGS solar thermal power plant. Subsequent sections describe the initial screening of alternative evaporation energy sources and the more detailed evaluation of design alternatives considered for the preferred evaporation energy source. The final sections summarize the results, conclusions, and recommendations.

  17. Pyroelectric energy harvesting using liquid-based switchable thermal interfaces

    SciTech Connect

    Cha, G; Ju, YS

    2013-01-15

    The pyroelectric effect offers an intriguing solid-state approach for harvesting ambient thermal energy to power distributed networks of sensors and actuators that are remotely located or otherwise difficult to access. There have been, however, few device-level demonstrations due to challenges in converting spatial temperature gradients into temporal temperature oscillations necessary for pyroelectric energy harvesting. We demonstrate the feasibility of a device concept that uses liquid-based thermal interfaces for rapid switching of the thermal conductance between a pyroelectric material and a heat source/sink and can thereby deliver high output power density. Using a thin film of a pyroelectric co-polymer together with a macroscale mechanical actuator, we operate pyroelectric thermal energy harvesting cycles at frequencies close to 1 Hz. Film-level power densities as high as 110 mW/cm(3) were achieved, limited by slow heat diffusion across a glass substrate. When combined with a laterally interdigitated electrode array and a MEMS actuator, the present design offers an attractive option for compact high-power density thermal energy harvesters. (C) 2012 Elsevier B.V. All rights reserved.

  18. Descriptive analysis of aquifer thermal energy storage systems

    SciTech Connect

    Reilly, R.W.

    1980-06-01

    The technical and economic feasibility of large-scale aquifer thermal energy storage (ATES) was examined. A key to ATESs attractiveness is its simplicity of design and construction. The storage device consists of two ordinary water wells drilled into an aquifer, connected at the surface by piping and a heat exchanger. During the storage cycle water is pumped out of the aquifer, through the heat exchanger to absorb thermal energy, and then back down into the aquifer through the second well. The thermal storage remains in the aquifer storage bubble until required for use, when it is recovered by reversing the storage operation. For many applications the installation can probably be designed and constructed using existing site-specific information and modern well-drilling techniques. The potential for cost-effective implementation of ATES was investigated in the Twin Cities District Heating-Cogeneration Study in Minnesota. In the study, ATES demonstrated a net energy saving of 32% over the nonstorage scenario, with an annual energy cost saving of $31 million. Discounting these savings over the life of the project, the authors found that the break-even capital cost for ATES construction was $76/kW thermal, far above the estimated ATES development cost of $23 to 50/kW thermal. It appears tht ATES can be highly cost effective as well as achieve substantial fuel savings. ATES would be environmentally beneficial and could be used in many parts of the USA. The existing body of information on ATES indicates that it is a cost-effective, fuel-conserving technique for providing thermal energy for residential, commercial, and industrial users. The negative aspects are minor and highly site-specific, and do not seem to pose a threat to widespread commercialization. With a suitable institutional framework, ATES promises to supply a substantial portion of the nation's future energy needs. (LCL)

  19. A simple metabolic model of glacial-interglacial energy supply to the upper ocean

    NASA Astrophysics Data System (ADS)

    Pelegrí, J. L.; Olivella, R.; García-Olivares, A.

    2011-03-01

    We use a simple two-state two-box ocean to simulate the CO2 signal during the last four glacial-interglacial transitions in the earth system. The model is inspired by the similarity in spatial organization and temporal transition patterns between the earth and other complex systems, such as mammals. The comparison identifies the earth's metabolic rate with net autotrophic primary production in the upper ocean, sustained through new inorganic carbon and nutrients advected from the deep ocean and organic matter remineralized within the upper ocean. We view the glacial-interglacial transition as a switch of the upper ocean from a basal to an enhanced metabolic state, with energy supply initially relying on the remineralization of the local organic sources and the eventual steady state resulting from the increased advective supply of inorganic deep sources. During the interglacial-glacial transition the opposite occurs, with an initial excess of advective supply and primary production that allows the replenishment of the upper-ocean organic storages. We set the relative change in energy supply from the CO2 signal and use genetic algorithms to explore the sensitivity of the model output to both the basal recirculation rate and the intensity-timing of the maximum recirculation rate. The model is capable of reproducing quite well the long-term oscillations, as shown by correlations with observations typically about 0.8. The dominant time scale for each cycle ranges between about 40 and 45 kyr, close to the 41 kyr average obliquity astronomical period, and the deep-ocean recirculation rate increases between one and two orders of magnitude from glacial to interglacial periods.

  20. Thermal energy storage technical progress report, April 1992--March 1993

    SciTech Connect

    Olszewski, M.

    1993-05-01

    The Department of Energy (DOE) is supporting development of thermal energy storage (TES) as a means of efficiently coupling energy supplies to variable heating or cooling demands. Uses of TES include electrical demand-side management in buildings and industry, extending the utilization of renewable energy resources such as solar, and recovery of waste heat from periodic industrial processes. Technical progress to develop TES for specific diurnal and industrial applications under the Oak Ridge National Laboratory`s TES program from April 1992 to March 1993 is reported and covers research in the areas of low temperature sorption, thermal energy storage water heater, latent heat storage wallboard and latent/sensible heat regenerator technology development.

  1. 75 FR 44276 - Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE); Cancellation of Oil and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... Horizon Oil Spill and Offshore Drilling, (the National Commission was established by Executive Order 13543, dated May 21, 2010, as published in the Federal Register on May 26, 2010, (75 FR 29397)), environmental... Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE); Cancellation of Oil and...

  2. 75 FR 44276 - Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE); Cancellation of Oil and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    .... The findings of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling... the Federal Register on May 26, 2010 (75 FR 29397)), environmental reviews, science-based analysis... Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE); Cancellation of Oil and...

  3. Thermobaric control of gravitational potential energy generation by diapycnal mixing in the deep ocean

    NASA Astrophysics Data System (ADS)

    Oliver, K. I. C.; Tailleux, R.

    2013-01-01

    Sources and sinks of gravitational potential energy (GPE) play a rate-limiting role in the large-scale ocean circulation. A key source is turbulent diapycnal mixing, whereby irreversible mixing across isoneutral surfaces is enhanced by turbulent straining of these surfaces. This has motivated international observational efforts to map diapycnal mixing in the global ocean. However, in order to accurately relate the GPE supplied to the large-scale circulation by diapycnal mixing to the mixing energy source, it is first necessary to determine the ratio, ξ, of the GPE generation rate to the available potential energy dissipation rate associated with turbulent mixing. Here the link between GPE and hydrostatic pressure is used to derive the GPE budget for a compressible ocean with a nonlinear equation of state. The role of diapycnal mixing is isolated and from this a global climatological distribution of ξ is calculated. It is shown that, for a given source of mixing energy, typically three times as much GPE is generated if the mixing takes place in bottom waters rather than in the pycnocline. This is due to GPE destruction by cabbelling in the pycnocline, as opposed to thermobaric enhancement of GPE generation by diapycnal mixing in the deep ocean.

  4. Nanoengineered Surfaces for Thermal Energy Conversion

    NASA Astrophysics Data System (ADS)

    Bhatia, Bikram; Preston, Daniel J.; Bierman, David M.; Miljkovic, Nenad; Lenert, Andrej; Enright, Ryan; Nam, Youngsuk; Lopez, Ken; Dou, Nicholas; Sack, Jean; Chan, Walker R.; Celanović, Ivan; Soljačić, Marin; Wang, Evelyn N.

    2015-12-01

    We provide an overview of the impact of using nanostructured surfaces to improve the performance of solar thermophotovoltaic (STPV) energy conversion and condensation systems. We demonstrated STPV system efficiencies of up to 3.2%, compared to ≤1% reported in the literature, made possible by nanophotonic engineering of the absorber and emitter. For condensation systems, we showed enhanced performance by using scalable superhydrophobic nanostructures via jumping-droplet condensation. Furthermore, we observed that these jumping droplets carry a residual charge which causes the droplets to repel each other mid-flight. Based on this finding of droplet residual charge, we demonstrated electric-field-enhanced condensation and jumping-droplet electrostatic energy harvesting.

  5. Alkali metal/halide thermal energy storage systems performance evaluation

    NASA Technical Reports Server (NTRS)

    Phillips, W. M.; Stearns, J. W.

    1986-01-01

    A pseudoheat-pipe heat transfer mechanism has been demonstrated effective in terms of both total heat removal efficiency and rate, on the one hand, and system isothermal characteristics, on the other, for solar thermal energy storage systems of the kind being contemplated for spacecraft. The selection of appropriate salt and alkali metal substances for the system renders it applicable to a wide temperature range. The rapid heat transfer rate obtainable makes possible the placing of the thermal energy storage system around the solar receiver canister, and the immersing of heat transfer fluid tubes in the phase change salt to obtain an isothermal heat source.

  6. Phase change thermal storage for a solar total energy system

    NASA Technical Reports Server (NTRS)

    Rice, R. E.; Cohen, B. M.

    1978-01-01

    An analytical and experimental program is being conducted on a one-tenth scale model of a high-temperature (584 K) phase-change thermal energy storage system for installation in a solar total energy test facility at Albuquerque, New Mexico, U.S.A. The thermal storage medium is anhydrous sodium hydroxide with 8% sodium nitrate. The program will produce data on the dynamic response of the system to repeated cycles of charging and discharging simulating those of the test facility. Data will be correlated with a mathematical model which will then be used in the design of the full-scale system.

  7. Energy conservation in dissipative processes: Teacher expectations and strategies associated with imperceptible thermal energy

    NASA Astrophysics Data System (ADS)

    Daane, Abigail R.; McKagan, Sarah B.; Vokos, Stamatis; Scherr, Rachel E.

    2015-06-01

    Research has demonstrated that many students and some teachers do not consistently apply the conservation of energy principle when analyzing mechanical scenarios. In observing elementary and secondary teachers engaged in learning activities that require tracking and conserving energy, we find that challenges to energy conservation often arise in dissipative scenarios in which kinetic energy transforms into thermal energy (e.g., a ball rolls to a stop). We find that teachers expect that when they can see the motion associated with kinetic energy, they should be able to perceive the warmth associated with thermal energy. Their expectations are violated when the warmth produced is imperceptible. In these cases, teachers reject the idea that the kinetic energy transforms to thermal energy. Our observations suggest that apparent difficulties with energy conservation may have their roots in a strong and appropriate association between forms of energy and their perceptible indicators. We see teachers resolve these challenges by relating the original scenario to an exaggerated version in which the dissipated thermal energy is associated with perceptible warmth. Using these exaggerations, teachers infer that thermal energy is present to a lesser degree in the original scenario. They use this exaggeration strategy to track and conserve energy in dissipative scenarios.

  8. Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

    SciTech Connect

    Haas, Kevin

    2013-09-15

    Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States. This project created a national database of ocean current energy resources to help advance awareness and market penetration in ocean current energy resource assessment. The database, consisting of joint velocity magnitude and direction probability histograms, was created from data created by seven years of numerical model simulations. The accuracy of the database was evaluated by ORNL?s independent validation effort documented in a separate report. Estimates of the total theoretical power resource contained in the ocean currents were calculated utilizing two separate approaches. Firstly, the theoretical energy balance in the Gulf Stream system was examined using the two-dimensional ocean circulation equations based on the assumptions of the Stommel model for subtropical gyres with the quasi-geostrophic balance between pressure gradient, Coriolis force, wind stress and friction driving the circulation. Parameters including water depth, natural dissipation rate and wind stress are calibrated in the model so that the model can reproduce reasonable flow properties including volume flux and energy flux. To represent flow dissipation due to turbines additional turbine drag coefficient is formulated and included in the model. Secondly, to determine the reasonableness of the total power

  9. Enhancing low-grade thermal energy recovery in a thermally regenerative ammonia battery using elevated temperatures.

    PubMed

    Zhang, Fang; LaBarge, Nicole; Yang, Wulin; Liu, Jia; Logan, Bruce E

    2015-03-01

    A thermally regenerative ammonia battery (TRAB) is a new approach for converting low-grade thermal energy into electricity by using an ammonia electrolyte and copper electrodes. TRAB operation at 72 °C produced a power density of 236 ± 8 Wm(-2), with a linear decrease in power to 95 ± 5 Wm(-2) at 23 °C. The improved power at higher temperatures was due to reduced electrode overpotentials and more favorable thermodynamics for the anode reaction (copper oxidation). The energy density varied with temperature and discharge rates, with a maximum of 650 Wh m(-3) at a discharge energy efficiency of 54% and a temperature of 37 °C. The energy efficiency calculated with chemical process simulation software indicated a Carnot-based efficiency of up to 13% and an overall thermal energy recovery of 0.5%. It should be possible to substantially improve these energy recoveries through optimization of electrolyte concentrations and by using improved ion-selective membranes and energy recovery systems such as heat exchangers. PMID:25684619

  10. Some constraints on the thermal history of the lunar magma ocean

    NASA Technical Reports Server (NTRS)

    Herbert, F.; Drake, M. J.; Sonett, C. P.; Wiskerchen, M. J.

    1977-01-01

    If the accumulating evidence is accepted that the outer portion of the moon was molten for 100-200 million years, it is clear that a permanent insulating surface layer existed over nearly all of that epoch. Considerations of crustal stability against break-up and foundering lead to the view that this insulating blanket must have been an early-forming plagioclase-rich layer light enough to float on the hot magma. It is found that radiometric age-dating evidence implies a fairly specific history for the solidification of the lunar magma ocean. The possibility is anticipated that geochronological and petrological constraints will be sufficient to narrow the range of allowed geophysical and geochemical models. It is hoped that such a study will make it possible to deduce the original depth, and hence, the composition of the lunar magma ocean. If the moon accreted homogeneously, the composition of the magma ocean will also be that of the whole moon, and hence such models should allow estimation of the bulk lunar composition.

  11. Ocean energy systems. Quarterly report, July-September 1982

    SciTech Connect

    Not Available

    1982-09-30

    This quarterly report summarizes work on the following tasks as of September 30, 1982: (1) OTEC pilot plant conceptual design review; (2) OTEC methanol; (3) financial and legal considerations in OTEC implementation; (4) GEOTEC resource exploration at Adak, Alaska, and Lualualei, Hawaii; (5) preliminary GEOTEC plant cost estimates; and (6) supervision of testing of pneumatic wave energy conversion system.

  12. Sampling strategies for environmental data useful in design modification of ocean energy systems: an OTEC case study

    SciTech Connect

    Dengler, A.T.

    1983-01-01

    The Ocean Thermal Energy Conversion (OTEC) program is completing the conceptual design phase and entering the preliminary design phase of a 40 MWe pilot plant. During all design phases, there is a constructive feedback between the design of the plant and the body of data which describes the oceanographic and environmental setting of the plant. The design of the plant helps to define what data are gathered, and the data help refine the design of the plant. During conceptual design, development has proceeded on two baseline designs. Both designs are sited at the coast near Kahe Point, Oahu, Hawaii. The two designs are: (1) a shelf-seated artificial island, connected via a causeway to Oahu, using stainless steel heat exchangers, with the thermal resource enhanced by effluent from a near-by power plant, ammonia working fluid and biocide (chlorine) cleaning; and (2) a shelf-mounted tower 1 mile offshore using submerged aluminum heat exchangers, R-22 (freon) working fluid, and slurry cleaning with biocide (chlorine) backup. The designs are driven by engineering and socio-legal requirements which are in part defined using environmental and oceanographic data pertinent to the site. These requirements may be related to the data through four groupings of environmental concerns: (1) siting, design and operational criteria; (2) thermal resource evaluation and variability; (3) biological and chemical issues; and (4) regulatory requirements. The design, the requirements and the data are continually upgraded in concert.

  13. Advanced concepts in ground thermal energy storage systems

    NASA Astrophysics Data System (ADS)

    Woods, Kevin David

    In recent years, ground thermal energy storage has become a topic of interest in the energy community for solar thermal energy storage systems, ground sourced heat pump systems, and data center thermal management systems due to an increase in the energy efficiency of such systems utilizing the ground as a thermal reservoir. The most common method for transferring thermal energy to the ground formation is the geothermal borehole. This dissertation presents the state of the art in geothermal borehole modeling and derives novel analytical functions to model advanced concepts concerning their operation. The novel solutions derived allow a geothermal borehole designer to better understand and design ground energy storage systems. The state of the art in geothermal borehole modeling is the stationary line source solution which is limited to boreholes operating without groundwater flow. Novel solutions for modeling a geothermal borehole with groundwater advection are presented through derivation of a transient moving line source solution as well as a transient moving cylindrical surface source solution. These solutions are applied to model a specific type of open loop geothermal borehole called a standing column well with groundwater advection and are compared to empirical and numerical data for validation. The dissertation then moves into derivation of a property determination method for geothermal boreholes with groundwater advection. The traditional property determination method used to obtain ground formation properties is based on the stationary transient line source method and fails in the presence of groundwater flow. The proposed novel property determination method calculates the thermal conductivity, thermal diffusivity, and superficial flow velocity of groundwater within a ground formation. These methods and solutions are novel tools allowing for geothermal borehole designers to grasp a better understanding of the systems they are designing as well as open other

  14. Semi-transparent solar energy thermal storage device

    DOEpatents

    McClelland, John F.

    1985-06-18

    A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls, Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

  15. Semi-transparent solar energy thermal storage device

    DOEpatents

    McClelland, John F.

    1986-04-08

    A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls. Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

  16. Effect of topographic barriers on the rates of available potential energy conversion of the oceans

    NASA Astrophysics Data System (ADS)

    Stewart, K. D.; Saenz, J. A.; Hogg, A. McC.; Hughes, G. O.; Griffiths, R. W.

    2014-04-01

    Determining the energy budget of the oceans requires evaluating the rates of available potential energy conversion in the circulation. Calculating these conversion rates depends upon the definition of an appropriate “reference” state of the density field, but this definition is complicated in the oceans by the presence of bottom topography. The trapping of dense fluid by topographic barriers means that there are multiple definitions for the reference state. The approach taken in this paper is to examine the sensitivity of the available potential energy budget to several methods for defining the reference state. The first method makes allowances for restrictions imposed on the flow by topography, however it is computationally intensive. The second method is proposed as an inexpensive alternative to the first. These new methods are used to evaluate the energy budget of a model overturning circulation maintained by surface buoyancy forcing. The results are compared with those obtained from two existing methods; one which employs an adiabatic resorting procedure ignoring topography, and one which uses a reference profile developed from the horizontal average of the density field. In our model, the rates of available potential energy conversion are insensitive to the reference state definition providing the reference state is developed from an adiabatic resorting of the domain. These results suggest that any of the adiabatic resorting methods proposed here would be sufficient to evaluate the rates of energy conversion in the ocean.

  17. Efficient thermal energy harvesting using nanoscale magnetoelectric heterostructures

    NASA Astrophysics Data System (ADS)

    Etesami, S. R.; Berakdar, J.

    2016-02-01

    Thermomechanical cycles with a ferroelectric working substance convert heat to electrical energy. As shown here, magnetoelectrically coupled ferroelectric/ferromagnetic composites (also called multiferroics) allow for an efficient thermal energy harvesting at room temperature by exploiting the pyroelectric effect. By virtue of the magnetoelectric coupling, external electric and magnetic fields can steer the operation of these heat engines. Our theoretical predictions are based on a combination of Landau-Khalatnikov-Tani approach (with a Ginzburg-Landau-Devonshire potential) to simulate the ferroelectric dynamics coupled to the magnetic dynamics. The latter is treated via the electric-polarization-dependent Landau-Lifshitz-Gilbert equation. By performing an adapted Olsen cycle we show that a multiferroic working substance is potentially much more superior to the sole ferroelectrics, as far as the thermal energy harvesting using pyroelectric effect is concerned. Our proposal holds promise not only for low-energy consuming devices but also for cooling technology.

  18. Regolith thermal energy storage for lunar nighttime power

    NASA Technical Reports Server (NTRS)

    Tillotson, Brian

    1992-01-01

    A scheme for providing nighttime electric power to a lunar base is described. This scheme stores thermal energy in a pile of regolith. Any such scheme must somehow improve on the poor thermal conductivity of lunar regolith in vacuum. Two previous schemes accomplish this by casting or melting the regolith. The scheme described here wraps the regolith in a gas-tight bag and introduces a light gas to enhance thermal conductivity. This allows the system to be assembled with less energy and equipment than schemes which require melting of regolith. A point design based on the new scheme is presented. Its mass from Earth compares favorably with the mass of a regenerative fuel cell of equal capacity.

  19. On the spatial and temporal distribution of near-inertial energy in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Rath, Willi; Greatbatch, Richard J.; Zhai, Xiaoming

    2014-01-01

    We use an eddying realistic primitive-equation model of the Southern Ocean to examine the spatial and temporal distribution of near-inertial wind-power input (WPI) and near-inertial energy (NIE) in the Southern Ocean. We find that the modeled near-inertial WPI is almost proportional to inertial wind-stress variance (IWSV), while the modeled NIE is modulated by the inverse of the mixed-layer depth. We go on to assess recent decadal trends of near-inertial WPI from trends of IWSV based on reanalysis wind stress. Averaged over the Southern Ocean, annual-mean IWSV is found to have increased by 16% over the years 1979-2011. Part of the increase of IWSV is found to be related to the positive trend of the Southern-Annular Mode over the same period. Finally, we show that there are horizontal local maxima of NIE at depth that are almost exclusively associated with anticyclonic eddies.

  20. Fuels and chemicals from biomass using solar thermal energy

    NASA Astrophysics Data System (ADS)

    Giori, G.; Leitheiser, R.; Wayman, M.

    1981-05-01

    The significant nearer term opportunities for the application of solar thermal energy to the manufacture of fuels and chemicals from biomass are summarized, with some comments on resource availability, market potential and economics. Consideration is given to the production of furfural from agricultural residues, and the role of furfural and its derivatives as a replacement for petrochemicals in the plastics industry.

  1. Thermal energy storage subsystems. A collection of quarterly reports

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design, development, and progress toward the delivery of three subsystems is discussed. The subsystem used a salt hydrate mixture for thermal energy storage. The program schedules, technical data, and other program activities from October 1, 1976, through December 31, 1977 are presented.

  2. CALORSTOCK 1994: Thermal energy storage. Better economy, environment, technology

    NASA Astrophysics Data System (ADS)

    Kangas, M. T.; Lund, P. D.

    This publication is the second volume of the Proceedings of CALORSTOCK'94, the Sixth International Conference on Thermal Energy Storage held in Espoo, Finland on 22-25 Aug. 1994. This volume contains 51 presentations from the following six sessions: Chemical storage; Heat storage and environment; Central solar heating plants with seasonal storage; Water storage pits and tanks; Cooling; and National activities.

  3. Fuels and chemicals from biomass using solar thermal energy

    NASA Technical Reports Server (NTRS)

    Giori, G.; Leitheiser, R.; Wayman, M.

    1981-01-01

    The significant nearer term opportunities for the application of solar thermal energy to the manufacture of fuels and chemicals from biomass are summarized, with some comments on resource availability, market potential and economics. Consideration is given to the production of furfural from agricultural residues, and the role of furfural and its derivatives as a replacement for petrochemicals in the plastics industry.

  4. TECHNOLOGY ASSESSMENT OF SOLAR THERMAL ENERGY APPLICATIONS IN WASTEWATER TREATMENT

    EPA Science Inventory

    Three major areas were identified for which solar thermal energy usage has potential applicability in Publicly Owned Treatment Works. These areas include space and domestic water heating, anaerobic digester heating, and sludge drying. The report contains a detailed analysis of so...

  5. Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage

    SciTech Connect

    2012-01-01

    HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

  6. Characterization of Encapsulated Phase Change Materials for Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    Zhao, Weihuan

    Solar energy is receiving a lot of attentions at present since it is a kind of clean, renewable and sustainable energy. A major limitation however is that it is available for only about 2,000 hours a year in many places. One way to improve this situation is to use thermal energy storage (TES) system for the off hours. A novel method to store solar energy for large scale energy usage is using high melting temperature encapsulated phase change materials (EPCMs). The present work is a study of thermal energy storage systems with phase change materials (PCMs). It is hoped that this work is to help understand the storage capability and heat transfer processes in the EPCM capsules in order to help design large EPCM based thermoclines. A calorimeter system was built to test the energy stored in EPCM capsules and examine the storage capabilities and potential for storage deterioration in EPCM capsules to determine the types of EPCMs suitable for TES. To accomplish this, the heat transfer performances of the EPCMs are studied in detail. Factors which could affect the heat transfer performance including the properties of materials, the sizes of capsules, the types of heat transfer fluids, the gravity effect of solid PCM, the buoyancy-driven convection in the molten PCM, void space inside the capsule are given attention. Understanding these characteristics for heat transfer process could help build the EPCM based thermoclines to make energy storage economical for solar energy and other applications.

  7. The ocean's gravitational potential energy budget in a coupled climate model

    NASA Astrophysics Data System (ADS)

    Butler, E. D.; Oliver, K. I.; Gregory, J. M.; Tailleux, R.

    2013-10-01

    This study examines, in a unified fashion, the budgets of ocean gravitational potential energy (GPE) and available gravitational potential energy (AGPE) in the control simulation of the coupled atmosphere-ocean general circulation model HadCM3. Only AGPE can be converted into kinetic energy by adiabatic processes. Diapycnal mixing supplies GPE but not AGPE, whereas the reverse is true of the combined effect of surface buoyancy forcing and convection. Mixing and buoyancy forcing thus play complementary roles in sustaining the large-scale circulation. However, the largest globally integrated source of GPE is resolved advection (+0.57 TW) and the largest sink is through parameterized eddy transports (-0.82 TW). The effect of these adiabatic processes on AGPE is identical to their effect on GPE, except for perturbations to both budgets due to numerical leakage exacerbated by nonlinearities in the equation of state.

  8. High Energy Density Thermal Batteries: Thermoelectric Reactors for Efficient Automotive Thermal Storage

    SciTech Connect

    2011-11-15

    HEATS Project: Sheetak is developing a new HVAC system to store the energy required for heating and cooling in EVs. This system will replace the traditional refrigerant-based vapor compressors and inefficient heaters used in today’s EVs with efficient, light, and rechargeable hot-and-cold thermal batteries. The high energy density thermal battery—which does not use any hazardous substances—can be recharged by an integrated solid-state thermoelectric energy converter while the vehicle is parked and its electrical battery is being charged. Sheetak’s converters can also run on the electric battery if needed and provide the required cooling and heating to the passengers—eliminating the space constraint and reducing the weight of EVs that use more traditional compressors and heaters.

  9. Experimental measurements of thermal properties of high-temperature refractory materials used for thermal energy storage

    NASA Astrophysics Data System (ADS)

    El-Leathy, Abdelrahman; Jeter, Sheldon; Al-Ansary, Hany; Abdel-Khalik, Said; Golob, Matthew; Danish, Syed Noman; Saeed, Rageh; Djajadiwinata, Eldwin; Al-Suhaibani, Zeyad

    2016-05-01

    This paper builds on studies conducted on thermal energy storage (TES) systems that were built as a part of the work performed for a DOE-funded SunShot project titled "High Temperature Falling Particle Receiver". In previous studies, two small-scale TES systems were constructed for measuring heat loss at high temperatures that are compatible with the falling particle receiver concept, both of which had shown very limited heat loss. Through the course of those studies, it became evident that there was a lack of information about the thermal performance of some of the insulating refractory materials used in the experiments at high temperatures, especially insulating firebrick and perlite concrete. This work focuses on determining the thermal conductivities of those materials at high temperatures. The apparatus consists of a prototype cylindrical TES bin built with the same wall construction used in previous studies. An electric heater is placed along the centerline of the bin, and thermocouples are used to measure temperature at the interfaces between all layers. Heat loss is measured across one of the layers whose thermal conductivity had already been well established using laboratory experiments. This value is used to deduce the thermal conductivity of other layers. Three interior temperature levels were considered; namely, 300°C, 500°C, and 700°C. Results show that the thermal conductivity of insulating firebrick remains low (approximately 0.22 W/m.K) at an average layer temperature as high as 640°C, but it was evident that the addition of mortar had an impact on its effective thermal conductivity. Results also show that the thermal conductivity of perlite concrete is very low, approximately 0.15 W/m.K at an average layer temperature of 360°C. This is evident by the large temperature drop that occurs across the perlite concrete layer. These results should be useful for future studies, especially those that focus on numerical modeling of TES bins.

  10. Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab Hyas araneus

    NASA Astrophysics Data System (ADS)

    Walther, K.; Sartoris, F. J.; Bock, C.; Pörtner, H. O.

    2009-03-01

    Future scenarios project combined developments of elevated CO2 concentrations and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of CO2 accumulation on thermal tolerance of the cold-eurythermal spider crab Hyas araneus. Animals were exposed to present day normocapnia (380 ppm CO2), CO2 levels expected towards 2100 (710 ppm) and beyond (3000 ppm). Heart rate and haemolymph PO2 (PeO2) were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling with highest values reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc) was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

  11. Onset of the Paleocene-Eocene Thermal Maximum in the southern Pacific Ocean (DSDP Site 277, Campbell Plateau)

    NASA Astrophysics Data System (ADS)

    Hollis, C. J.; Hines, B. R.; Littler, K.; Villasante-Marcos, V.; Kulhanek, D. K.; Strong, C. P.; Zachos, J. C.; Eggins, S. M.; Northcote, L.; Phillips, A.

    2015-02-01

    Re-examination of a sediment core collected by the Deep Sea Drilling Project (DSDP Site 277) on the western margin of the Campbell Plateau, Southwest Pacific Ocean (paleolatitude of ∼ 65° S), has identified an intact Paleocene-Eocene (P-E) boundary overlain by a 34 cm-thick record of the initial phase of the Paleocene-Eocene Thermal Maximum (PETM) within nannofossil chalk. The upper part of the PETM is truncated, either due to drilling disturbance or a sedimentary hiatus. An intact record of the onset of the PETM is indicated by a gradual decrease in δ13C values over 20 cm, followed by a 14 cm interval in which δ13C is 2‰ lighter than uppermost Paleocene values. After accounting for effects of diagenetic alteration, we use δ18O and Mg/Ca values from foraminiferal tests to determine that intermediate and surface waters warmed by ∼ 6° at the onset of the PETM prior to the full development of the negative δ13C excursion. After this initial warming, sea temperatures were relatively stable through the PETM, but declined abruptly across the unconformity that truncates the event at this site. Mg/Ca analysis of foraminiferal tests indicate peak intermediate and surface water temperatures of ∼ 19 and ∼ 32 °C, respectively. These temperatures may be influenced by enhanced poleward ocean heat transport during the PETM and surface water values may also be biased towards warm season temperatures.

  12. Thermal modeling with solid/liquid phase change of the thermal energy storage experiment

    NASA Technical Reports Server (NTRS)

    Skarda, J. Raymond Lee

    1991-01-01

    A thermal model which simulates combined conduction and phase change characteristics of thermal energy storage (TES) materials is presented. Both the model and results are presented for the purpose of benchmarking the conduction and phase change capabilities of recently developed and unvalidated microgravity TES computer programs. Specifically, operation of TES-1 is simulated. A two-dimensional SINDA85 model of the TES experiment in cylindrical coordinates was constructed. The phase change model accounts for latent heat stored in, or released from, a node undergoing melting and freezing.

  13. High-temperature molten salt thermal energy storage systems

    NASA Technical Reports Server (NTRS)

    Petri, R. J.; Claar, T. D.; Tison, R. R.; Marianowski, L. G.

    1980-01-01

    The results of comparative screening studies of candidate molten carbonate salts as phase change materials (PCM) for advanced solar thermal energy storage applications at 540 to 870 C (1004 to 1600 F) and steam Rankine electric generation at 400 to 540 C (752 to 1004 F) are presented. Alkali carbonates are attractive as latent heat storage materials because of their relatively high storage capacity and thermal conductivity, low corrosivity, moderate cost, and safe and simple handling requirements. Salts were tested in 0.1 kWhr lab scale modules and evaluated on the basis of discharge heat flux, solidification temperature range, thermal cycling stability, and compatibility with containment materials. The feasibility of using a distributed network of high conductivity material to increase the heat flux through the layer of solidified salt was evaluated. The thermal performance of an 8 kWhr thermal energy storage (TES) module containing LiKCO3 remained very stable throughout 5650 hours and 130 charge/discharge cycles at 480 to 535 C (896 to 995 F). A TES utilization concept of an electrical generation peaking subsystem composed of a multistage condensing steam turbine and a TES subsystem with a separate power conversion loop was defined. Conceptual designs for a 100 MW sub e TES peaking system providing steam at 316 C, 427 C, and 454 C (600 F, 800 F, and 850 F) at 3.79 million Pa (550 psia) were developed and evaluated. Areas requiring further investigation have also been identified.

  14. Artificial ocean upwelling utilizing the energy of surface waves

    NASA Astrophysics Data System (ADS)

    Soloviev, Alexander

    2016-04-01

    Artificial upwelling can bring cold water from below the thermocline to the sea surface. Vershinsky, Pshenichnyy, and Soloviev (1987) developed a prototype device, utilizing the energy of surface waves to create an upward flow of water in the tube. This is a wave-inertia pump consisting of a vertical tube, a valve, and a buoy to keep the device afloat. An outlet valve at the top of the unit synchronizes the operation of the device with surface waves and prevents back-splashing. A single device with a 100 m long and 1.2 m diameter tube is able to produce up to 1 m3s‑1 flow of deep water to the surface. With a 10 oC temperature difference over 100 m depth, the negative heat supply rate to the sea surface is 42 MW, which is equivalent to a 42 Wm‑2 heat flux, if distributed over 1 km2 area. Such flux is comparable to the average net air-sea flux. A system of artificial upwelling devices can cool down the sea surface, modify climate on a regional scale and possibly help mitigate hurricanes. The cold water brought from a deeper layer, however, has a larger density than the surface water and therefore has a tendency to sink back down. In this work, the efficiency of wave-inertia pumps and climatic consequences are estimated for different environmental conditions using a computational fluid dynamics model.

  15. Ultra high energy neutrinos: absorption, thermal effects and signatures

    SciTech Connect

    Lunardini, Cecilia; Sabancilar, Eray; Yang, Lili E-mail: Eray.Sabancilar@asu.edu

    2013-08-01

    We study absorption of ultra high energy neutrinos by the cosmic neutrino background, with full inclusion of the effect of the thermal distribution of the background on the resonant annihilation channel. For a hierarchical neutrino mass spectrum (with at least one neutrino with mass below ∼ 10{sup −2} eV), thermal effects are important for ultra high energy neutrino sources at z∼>16. The neutrino transmission probability shows no more than two separate suppression dips since the two lightest mass eigenstates contribute as a single species when thermal effects are included. Results are applied to a number of models of ultra high energy neutrino emission. Suppression effects are strong for sources that extend beyond z ∼ 10, which can be realized for certain top down scenarios, such as superheavy dark matter decays, cosmic strings and cosmic necklaces. For these, a broad suppression valley should affect the neutrino spectrum at least in the energy interval 10{sup 12}−10{sup 13} GeV — which therefore is disfavored for ultra high energy neutrino searches — with only a mild dependence on the neutrino mass spectrum and hierarchy. The observation of absorption effects would indicate a population of sources beyond z ∼ 10, and favor top-down mechanisms; it would also be an interesting probe of the physics of the relic neutrino background in the unexplored redshift interval z ∼ 10–100.

  16. Value of Concentrating Solar Power and Thermal Energy Storage

    SciTech Connect

    Sioshansi, R.; Denholm, P.

    2010-02-01

    This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant?s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry cooling of the CSP plant. We also discuss the value of CSP plants and TES net of capital costs.

  17. Overview of the US industrial thermal energy storage program

    NASA Astrophysics Data System (ADS)

    Olszewski, M.

    1981-02-01

    Thermal energy storage can contribute to industrial conservation efforts directed at saving premium (gas and oil) fuels, which is a priority national need. This can be done by using storage to allow the recycling of industrial reject heat to reduce primary energy consumption or to allow alternate fuels to replace gas and oil. Industrial thermal energy storage efforts include three major areas: in-plant reuse of industrial reject heat; external reuse of industrial reject heat for applications in the industrial or buildings sector; and use of alternate fuels to replace gas and oil. The program currently includes engineering field tests in the brick and aluminum industries. In addition, technology transfer activities are underway in the pulp and paper industry.

  18. Anomaly transform methods based on total energy and ocean heat content norms for generating ocean dynamic disturbances for ensemble climate forecasts

    NASA Astrophysics Data System (ADS)

    Romanova, Vanya; Hense, Andreas

    2015-04-01

    In our study we use the anomaly transform, a special case of ensemble transform method, in which a selected set of initial oceanic anomalies in space, time and variables are defined and orthogonalized. The resulting orthogonal perturbation patterns are designed such that they pick up typical balanced anomaly structures in space and time and between variables. The metric used to set up the eigen problem is taken either as the weighted total energy with its zonal, meridional kinetic and available potential energy terms having equal contributions, or the weighted ocean heat content in which a disturbance is applied only to the initial temperature fields. The choices of a reference state for defining the initial anomalies are such that either perturbations on seasonal timescales and or on interannual timescales are constructed. These project a-priori only the slow modes of the ocean physical processes, such that the disturbances grow mainly in the Western Boundary Currents, in the Antarctic Circumpolar Current and the El Nino Southern Oscillation regions. An additional set of initial conditions is designed to fit in a least square sense data from global ocean reanalysis. Applying the AT produced sets of disturbances to oceanic initial conditions initialized by observations of the MPIOM-ESM coupled model on T63L47/GR15 resolution, four ensemble and one hind-cast experiments were performed. The weighted total energy norm is used to monitor the amplitudes and rates of the fastest growing error modes. The results showed minor dependence of the instabilities or error growth on the selected metric but considerable change due to the magnitude of the scaling amplitudes of the perturbation patterns. In contrast to similar atmospheric applications, we find an energy conversion from kinetic to available potential energy, which suggests a different source of uncertainty generation in the ocean than in the atmosphere mainly associated with changes in the density field.

  19. Experimental investigation of a packed bed thermal energy storage system

    NASA Astrophysics Data System (ADS)

    Cascetta, Mario; Cau, Giorgio; Puddu, Pierpaolo; Serra, Fabio

    2015-11-01

    In this work experimental investigations on a thermal energy storage system with a solid material as storage media and air as heat transfer fluid will be presented. The experimental test rig, installed at the DIMCM of the University of Cagliari, consists of a carbon steel tank filled with freely poured alumina beads that allows investigations of heat transfer phenomena in packed beds. The aim of this work is to show the influence of the operating conditions and physical parameters on thermocline formation and, in particular, the thermal behaviour of the thermal energy storage for repeated charging and discharging cycles. Better charging efficiency is obtained for lower values of mass flow rate and maximum air temperature and for increasing aspect ratio. A decreasing influence of the metal wall with continuous operation is also highlighted. In conclusion, the analysis focuses on the thermal hysteresis phenomenon, which causes degradation of the thermocline and the reduction of the energy that can be stored by the accumulator as the repeated number of cycles increases.

  20. Simulation and evaluation of latent heat thermal energy storage

    NASA Technical Reports Server (NTRS)

    Sigmon, T. W.

    1980-01-01

    The relative value of thermal energy storage (TES) for heat pump storage (heating and cooling) as a function of storage temperature, mode of storage (hotside or coldside), geographic locations, and utility time of use rate structures were derived. Computer models used to simulate the performance of a number of TES/heat pump configurations are described. The models are based on existing performance data of heat pump components, available building thermal load computational procedures, and generalized TES subsystem design. Life cycle costs computed for each site, configuration, and rate structure are discussed.

  1. Nanoparticles for heat transfer and thermal energy storage

    DOEpatents

    Singh, Dileep; Cingarapu, Sreeram; Timofeeva, Elena V.; Moravek, Michael

    2015-07-14

    An article of manufacture and method of preparation thereof. The article of manufacture and method of making the article includes an eutectic salt solution suspensions and a plurality of nanocrystalline phase change material particles having a coating disposed thereon and the particles capable of undergoing the phase change which provides increase in thermal energy storage. In addition, other articles of manufacture can include a nanofluid additive comprised of nanometer-sized particles consisting of copper decorated graphene particles that provide advanced thermal conductivity to heat transfer fluids.

  2. Solar thermal energy contract list, fiscal year 1990

    SciTech Connect

    Not Available

    1991-09-01

    The federal government has conducted the national Solar Thermal Technology Program since 1975. Its purpose is to provide focus, direction, and funding for the development of solar thermal technology as an energy option for the United States. This year's document is more concise than the summaries of previous years. The FY 1990 contract overview comprises a list of all subcontracts begun, ongoing, or completed during FY 1990 (October 1, 1989, through September 30, 1990). Under each managing laboratory projects are listed alphabetically by project area and then by subcontractor name. Amount of funding milestones are listed.

  3. Government-sponsored research in thermal energy storage

    SciTech Connect

    Tomlinson, J.J.

    1990-01-01

    Responding to energy supply disruptions during the last decade, the US Government began a program to research and develop thermal energy storage (TES) media and systems that could used to shift fuel use from imported oil and gas to other indigenous energy resources including renewables. Due to its flexibility in matching time-varying energy supplies with demand and capturing low availability waste heat, TES offers a means of increasing the efficiency of many heating and cooling systems for the industrial and commercial sectors. Today, a Federal presence in TES research and development is continuing to help resolve national and global issues such as energy-related environmental problems, growing reliance on imported oil, a projected electrical capacity shortfall, and flagging US competitiveness in international markets. This Federal role in TES research is described; results of research, development, and evaluation of TES technologies that reduce energy consumption and facilitate electric load management are also presented. 7 refs., 2 figs.

  4. Information-to-free-energy conversion: Utilizing thermal fluctuations

    PubMed Central

    Toyabe, Shoichi; Muneyuki, Eiro

    2013-01-01

    Maxwell’s demon is a hypothetical creature that can convert information to free energy. A debate that has lasted for more than 100 years has revealed that the demon’s operation does not contradict the laws of thermodynamics; hence, the demon can be realized physically. We briefly review the first experimental demonstration of Maxwell’s demon of Szilard’s engine type that converts information to free energy. We pump heat from an isothermal environment by using the information about the thermal fluctuations of a Brownian particle and increase the particle’s free energy. PMID:27493548

  5. Electrical characterization of a buckling thermal energy harvester

    NASA Astrophysics Data System (ADS)

    Trioux, E.; Rufer, L.; Monfray, S.; Skotnicki, T.; Muralt, P.; Basrour, S.

    2015-12-01

    This paper presents the electrical characterizations of a novel concept for thermal energy harvesting at micro scale. The devices presented here are based on a two-step transduction combining thermo-mechanical and piezoelectric conversion. The piezoelectric layer is directly integrated into a buckling bilayer plate made of aluminium and aluminium nitride. For the first time, we have characterized the structures electrically and we have investigated their output power during the buckling. Firstly, we have used an insulating tip to make the plate buckle in order to have an estimation of the output power due to piezoelectric contribution only, and to eliminate any pyroelectric contribution that might be present during the thermal actuation. Then, we heated up the structure and we collected the output signal with an instrumentation amplifier in order to measure the voltage generated during the buckling. The output power during the mechanical and the thermal buckling is compared in the paper.

  6. Ocean Wave Energy Estimation Using Active Satellite Imagery as a Solution of Energy Scarce in Indonesia Case Study: Poteran Island's Water, Madura

    NASA Astrophysics Data System (ADS)

    Nadzir, Z. A.; Karondia, L. A.; Jaelani, L. M.; Sulaiman, A.; Pamungkas, A.; Koenhardono, E. S.; Sulisetyono, A.

    2015-10-01

    Ocean wave energy is one of the ORE (Ocean Renewable Energies) sources, which potential, in which this energy has several advantages over fossil energy and being one of the most researched energy in developed countries nowadays. One of the efforts for mapping ORE potential is by computing energy potential generated from ocean wave, symbolized by Watt per area unit using various methods of observation. SAR (Synthetic Aperture Radar) is one of the hyped and most developed Remote Sensing method used to monitor and map the ocean wave energy potential effectively and fast. SAR imagery processing can be accomplished not only in remote sensing data applications, but using Matrices processing application as well such as MATLAB that utilizing Fast Fourier Transform and Band-Pass Filtering methods undergoing Pre-Processing stage. In this research, the processing and energy estimation from ALOSPALSAR satellite imagery acquired on the 5/12/2009 was accomplished using 2 methods (i.e Magnitude and Wavelength). This resulted in 9 potential locations of ocean wave energy between 0-228 W/m2, and 7 potential locations with ranged value between 182-1317 W/m2. After getting through buffering process with value of 2 km (to facilitate the construction of power plant installation), 9 sites of location were estimated to be the most potential location of ocean wave energy generation in the ocean with average depth of 8.058 m and annual wind speed of 6.553 knot.

  7. Overview of the Thermal Energy Storage (TES) Program

    NASA Astrophysics Data System (ADS)

    Gurevich, M.

    1981-03-01

    The program promotes energy savings and fuel substitution by developing and helping to commercialize technologies for storing heat or cold, with shot investment payback periods as a cost goal. The sources of energy include industrial and utility waste heat as well as primary sources such as solar, geothermal, nuclear and fossil fuels. The primary source of "cold" for seasonal storage is winter chilled air. The program emphasizes near-term (1980's) approaches to energy conservation and displacement of natural gas and oil. It also provides for development of technologies which will allow use of renewable resources such as solar-thermal energy during the mid-term (1990's) and advanced energy storage and transport techniques for the far-term (beyond 2000).

  8. Thermal Energy in Carbon Nanotube and Graphene Composite Materials

    NASA Astrophysics Data System (ADS)

    Schiffres, Scott N.

    Low-dimensional materials, like carbon nanotubes (CNTs) and graphene, possess extraordinary properties---higher thermal conductivity than any bulk material, mechanical strength 10-100 times greater than steel on a mass basis, and electrical current capacity 1000 times greater than copper. While composites incorporating these low-dimensional materials promise solutions to global sustainability challenges, significant transport barriers exist at the matrix interface that influence the composite properties. My PhD research sought to address this knowledge gap. I've experimentally explored how CNTs and graphene impact thermal conductivity when added in small volume fractions to gases, liquids and solids through the study of CNT aerogels (ultra lightweight, 8 kg/m3, 99.6% void space), and phase change nanocomposites (hexadecane-graphene). I measured the thermal conductivity of the CNT aerogel with various filling gases versus pressure using a novel technique that targeted ultralow thermal conductivity materials, called metal-coated 3o. I observed amplified energy transport length scales resulting from low gas accommodation, which is a general feature of carbon based nanoporous materials. Our evidence also shows that despite the high thermal conductivity of CNTs, thermal conduction through the CNT network is limited by the high thermal boundary resistance at van der Waals bonded CNT junctions. In the second system, I studied thermal and electrical conductivity of hexadecane- multi-layered-graphene (MLG) phase change nanocomposites to understand how morphology of the MLG network impacts transport. By adjusting the freezing rate, the electrical conductivity in the solid phase can be tuned between 1 and 5 orders-of-magnitude and the solid-liquid thermal conductivity ratio can be varied between 2.6 to 3.0. This research has yielded interesting insights into the tunability of nanocomposites and the physics underlying it, including evidence to indicate that the presence of

  9. Thermal transport measurements in high-energy-density matter

    NASA Astrophysics Data System (ADS)

    Ping, Yuan

    2015-11-01

    Thermal conductivity is one of the most fundamental physical properties of matter. It determines the heat transport rate and has an enormous impact on a variety of mechanical, electrical, chemical, and nuclear systems. Thermal conduction is important in high energy density (HED) matter such as laboratory fusion plasmas, planetary cores, compact stars, and other celestial objects. Examples are in the ablation and instability growth in inertial confinement fusion (ICF) capsules, in energy loss from ICF hot spot, and in the evolution of Earth's core-mantle boundary. Despite the importance of thermal conductivity in HED systems, experimental measurements under relevant conditions are scarce and challenging. We have developed a method of differential heating for thermal conductivity measurements. In this talk, experimental designs will be described for four different platforms: optical laser heating, proton heating, laser-generated x-ray heating and XFEL heating. Data from various facilities will be presented and comparison with models will be discussed. This work was performed under DOE contract DE-AC52-07NA27344 with support from OFES Early Career program and LLNL LDRD program.

  10. High temperature thermal energy storage in steel and sand

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1979-01-01

    The technical and economic potential for high temperature (343 C, 650 F) thermal energy storage in hollow steel ingots, pipes embedded in concrete, and for pipes buried in sand was evaluated. Because it was determined that concrete would separate from pipes due to thermal stresses, concrete was replaced by sand, which is free from thermal stresses. Variations of the steel ingot concept were not cost effective compared to the sand-pipe approach, therefore, the sand-pipe thermal storage unit (TSU) was evaluated in depth to assess the approximate tube spacing requirements consistent with different system performance characteristics and also attendant system costs. For large TSUs which do not require fast response times, the sand-pipe approach offers attractive possibilities. A pipe diameter about 9 cm (3.5 in) and pipe spacing of approximately 25 cm (10 in), with sand filling the interspaces, appears appropriate. Such a TSU system designed for 8 hours charge/discharge cycle has an energy unit storage cost (CE) of $2.63/kWhr-t and a power unit storage cost (Cp) of $42/kW-t (in 1977 dollars).

  11. Role of random thermal perturbations in the magmatic segmentation of mid-oceanic ridges: Insights from numerical simulations

    NASA Astrophysics Data System (ADS)

    Sarkar, Shamik; Baruah, Amiya; Dutta, Urmi; Mandal, Nibir

    2014-12-01

    Using a random thermal perturbation (RTP) model this study investigates the process of magmatic segmentation along mid-oceanic ridge (MOR) axes as a function of the upwelling dynamics, controlled by coupled solidification-melting processes. The RTP model suggests that the variation in along-axis velocity (VL) fields constitutes the underlying mechanism of segmentation in natural MORs, showing temperature variations within a steady-state range, irrespective of large initial thermal perturbations imposed at the model base. The VL patterns are initially transient, characterized by multi-order segments, but attain a stable configuration with dominantly large segments (average size ~ 100 km) within a time scale of 2.3 Ma. Buoyant-melt driven thermal convection explains this transient segmentation. Small scale convection cells are found to be progressively consumed by larger cells, resulting in a stable convection structure over a similar time scale. Slow- and fast-spreading ridges (SSR and FSR) undergo upwelling with contrasting melt flow patterns. SSRs involve melt feeding into the ridge axis by horizontal flows from segment centers, trailing into large-scale conduits at an early stage. With time, vertical upwelling occurs throughout the segment. In the case of FSRs, both melt supply avenues prevail throughout their development. We also evaluate the variation of the across-axis flow velocity (VT) to investigate the mode of geometric evolution of MORs. Time series VT maps suggest that a ridge structure develops through localization of discrete axes (VT = 0) with offsets varying up to 15 km, which coalesce with one another to form a single axis. The matured ridge, however, retains higher-order offsets (up to 9 km).

  12. On thermal properties of hard rocks as a host environment of an underground thermal energy storage

    NASA Astrophysics Data System (ADS)

    Novakova, L.; Hladky, R.; Broz, M.; Novak, P.; Lachman, V.; Sosna, K.; Zaruba, J.; Metelkova, Z.; Najser, J.

    2013-12-01

    With increasing focus on environmentally friendly technologies waste heat recycling became an important issue. Under certain circumstances subsurface environment could be utilized to accommodate relatively large quantity of heat. Industrial waste heat produced during warm months can be stored in an underground thermal energy storage (UTES) and used when needed. It is however a complex task to set up a sustainable UTES for industrial scale. Number of parameters has to be studied and evaluated by means of thermohydromechanical and chemical coupling (THMC) before any UTES construction. Thermal characteristics of various rocks and its stability under thermal loading are amongst the most essential. In the Czech Republic study two complementary projects THMC processes during an UTES operation. The RESEN project (www.resen.cz) employs laboratory tests and experiments to characterise thermal properties of hard rocks in the Bohemian Massif. Aim of the project is to point out the most suitable rock environment in the Bohemian Massif for moderate to ultra-high temperature UTES construction (Sanyal, 2005). The VITA project (www.geology.cz/mokrsko) studies THM coupling in non-electrical temperature UTES using long term in-situ experiment. In both projects thermal properties of rocks were studied. Thermal conductivity and capacity were measured on rock samples. In addition an influence of increasing temperature and moisture content was considered. Ten hard rocks were investigated. The set included two sandstones, two ignibrites, a melaphyr, a syenite, two granites, a gneiss and a serpentinite. For each rock there were measured thermal conductivity and capacity of at least 54 dried samples. Subsequently, the samples were heated up to 380°C in 8 hours and left to cool down. Thermal characteristics were measured during the heating period and after the sample reached room temperature. Heating and cooling cycle was repeated 7 to 10 times to evaluate possible UTES-like degradation of

  13. An assessment methodology for thermal energy storage evaluation

    NASA Astrophysics Data System (ADS)

    Brown, D. R.; Dirks, J. A.; Drost, M. K.; Spanner, G. E.; Williams, T. A.

    1987-11-01

    This report documents an assessment methodology for evaluating the cost, performance, and overall economic feasibility of thermal energy storage (TES) concepts. The methodology was developed by Thermal Energy Storage Evaluation Program personnel at Pacific Northwest Laboratory (PNL) for use by PNL and other TES concept evaluators. The methodology is generically applicable to all TES concepts; however, specific analyses may require additional or more detailed definition of the ground rules, assumptions, and analytical approach. The overall objective of the assessment methodology is to assist in preparing equitable and proper evaluations of TES concepts that will allow developers and end-users to make valid decisions about research and development (R and D) and implementation. The methodology meets this objective by establishing standard approaches, ground rules, assumptions, and definitions that are analytically correct and can be consistently applied by concept evaluators.

  14. An assessment methodology for thermal energy storage evaluation

    SciTech Connect

    Brown, D.R.; Dirks, J.A.; Drost, M.K.; Spanner, G.E.; Williams, T.A.

    1987-11-01

    This report documents an assessment methodology for evaluating the cost, performance, and overall economic feasibility of thermal energy storage (TES) concepts. The methodology was developed by Thermal Energy Storage Evaluation Program personnel at Pacific Northwest Laboratory (PNL) for use by PNL and other TES concept evaluators. The methodology is generically applicable to all TES concepts; however, specific analyses may require additional or more detailed definition of the ground rules, assumptions, and analytical approach. The overall objective of the assessment methodology is to assist in preparing equitable and proper evaluations of TES concepts that will allow developers and end-users to make valid decisions about research and development (R and D) and implementation. The methodology meets this objective by establishing standard approaches, ground rules, assumptions, and definitions that are analytically correct and can be consistently applied by concept evaluators. 15 refs., 4 figs., 13 tabs.

  15. Ocean thermal conversion (OTEC) project bottom cable protection study: environmental characteristics and hazards analysis

    SciTech Connect

    Chern, C.; Tudor, W.

    1981-10-01

    Seafloor cable-protection criteria and technology as applied to the four proposed OTEC plant sites and cable routes at Hawaii, Puerto Rico, Guam and Florida were examined. Study of environmental characteristics for each site covered: (A) natural factors of location, tide and currents, wind and wave, bottom soil type and seafloor movement; and (B) man-made factors such as ship traffic, fishing activities, ocean mining, government regulations. These characteristics were studied to determine the hazards which are potential sources of damage to a cable system. Hazards include: chafe and corrosion, hydrodynamic forces due to wave and current action, mudslides, earthquakes, trawler and/or dredge action and ship anchors. An analysis of the history of submarine-cable failures was conducted. Included are the probabilities of damage related to water depth. Probabilities become minimal for all hazards in water depths of 1500 feet and more. Chafe and corrosion had the highest probability of causing damage to a seafloor cable compared to the other hazards. Because of the hazards present at all sites, cable burial is recommended as the best means of protection.

  16. An ocean kinetic energy converter for low-power applications using piezoelectric disk elements

    NASA Astrophysics Data System (ADS)

    Viñolo, C.; Toma, D.; Mànuel, A.; del Rio, J.

    2013-09-01

    The main problem facing long-term electronic system deployments in the sea, is to find a feasible way to supply them with the power they require. Harvesting mechanical energy from the ocean wave oscillations and converting it into electrical energy, provides an alternative method for creating self-contained power sources. However, the very low and varying frequency of ocean waves, which generally varies from 0.1 Hz to 2 Hz, presents a hurdle which has to be overcome if this mechanical energy is to be harvested. In this paper, a new sea wave kinetic energy converter is described using low-cost disk piezoelectric elements, which has no dependence on their excitement frequency, to feed low-consumption maritime-deployed electronic devices. The operating principles of the piezoelectric device technique are presented, including analytical formulations describing the transfer of energy. Finally, a prototypical design, which generates electrical energy from the motion of a buoy, is introduced. The paper concludes with the the behavior study of the piezoelectric prototype device as a power generator.

  17. Dish concentrators for solar thermal energy: Status and technology development

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.

    1982-01-01

    Point-focusing concentrators under consideration for solar thermal energy use are reviewed. These concentrators differ in such characteristics as optical configuration, optical materials, structure for support of the optical elements and of the receiver, mount, foundation, drive, controls and enclosure. Concentrator performance and cost are considered. Technology development is outlined, including wind loads and aerodynamics; precipitation, sand, and seismic considerations; and maintenance and cleaning.

  18. DE-EE0000319 Final Technical Report [National Open-ocean Energy Laboratory

    SciTech Connect

    Skemp, Susan

    2013-12-29

    Under the authorization provided by Section 634 of the Energy Independence and Security Act of 2007 (P.L. 110-140), in 2009 FAU was awarded U.S. Congressionally Directed Program (CDP) funding through the U.S. Department of Energy (DOE) to investigate and develop technologies to harness the energy of the Florida Current as a source of clean, renewable, base-load power for Florida and the U.S. A second CDP award in 2010 provided additional funding in order to enhance and extend FAU’s activities. These two CDPs in 2009 and 2010 were combined into a single DOE grant, DE-EE0000319, and are the subject of this report. Subsequently, in July 2010 funding was made available under a separate contract, DE-EE0004200. Under that funding, DOE’s Wind and Water Power Program designated FAU’s state of Florida marine renewable energy (MRE) center as the Southeast National Marine Renewable Energy Center (SNMREC). This report discusses SNMREC activities funded by the DE-EE0000319 grant, but will make reference, as appropriate, to activities that require further investigation under the follow-on grant. The concept of extracting energy from the motions of the oceans has a long history. However, implementation on large scales of the technologies to effect renewable energy recovery from waves, tides, and open-ocean currents is relatively recent. DOE’s establishment of SNMREC recognizes a significant potential for ocean current energy recovery associated with the (relatively) high-speed Florida Current, the reach of the Gulf Stream System flowing through the Straits of Florida, between the Florida Peninsula and the Bahamas Archipelago. The proximity of the very large electrical load center of southeast Florida’s metropolitan area to the resource itself makes this potential all the more attractive. As attractive as this potential energy source is, it is not without its challenges. Although the technology is conceptually simple, its design and implementation in a commercially

  19. Flexible hybrid energy cell for simultaneously harvesting thermal, mechanical, and solar energies.

    PubMed

    Yang, Ya; Zhang, Hulin; Zhu, Guang; Lee, Sangmin; Lin, Zong-Hong; Wang, Zhong Lin

    2013-01-22

    We report the first flexible hybrid energy cell that is capable of simultaneously or individually harvesting thermal, mechanical, and solar energies to power some electronic devices. For having both the pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based nanogenerator (NG) was used to harvest thermal and mechanical energies. Using aligned ZnO nanowire arrays grown on the flexible polyester (PET) substrate, a ZnO-poly(3-hexylthiophene) (P3HT) heterojunction solar cell was designed for harvesting solar energy. By integrating the NGs and the solar cells, a hybrid energy cell was fabricated to simultaneously harvest three different types of energies. With the use of a Li-ion battery as the energy storage, the harvested energy can drive four red light-emitting diodes (LEDs). PMID:23199138

  20. Environmental risk assessment for aquifer thermal energy storage

    SciTech Connect

    Hall, S.H.

    1993-01-01

    This report has been prepared by Pacific Northwest Laboratory at the request of the International Energy Agency (IEA). The US Department of Energy represents the United States in the IEA for Annex IV, the IEA task for research and development in aquifer thermal energy storage (ATES). Installation and operation of an ATES system is necessarily intrusive to ground-water resources. Therefore, governmental authorities usually require an environmental risk assessment to be performed before permission to construct an ATES system is granted. Writing an accurate statement of risk presupposes a knowledge of aquifer and ground-water characteristics and that an engineering feasibility study has taken place. Effective and logical presentation of the results of the risk assessment can expedite the grant of approval. Introductory remarks should address questions regarding why the ATES project has been proposed, what it is expected to accomplish, and what the expected benefits are. Next, the system configuration, including the aquifer, ATES plant, and well field, should be described in terms of size and location, design components, and thermal and hydraulic capacity. The final element of system design, the predicted annual operating cycle, needs to be described in sufficient detail to allow the reviewer to appreciate the net hydraulic, thermal, and hydrochemical effects imposed on the aquifer. Risks may be environmental or legal. Only after a reviewer has been introduced to the proposed system`s design, operation, and scale can risk issues can be identified and weighed against the benefits of the proposed ATES system.

  1. Environmental risk assessment for aquifer thermal energy storage

    SciTech Connect

    Hall, S.H.

    1993-01-01

    This report has been prepared by Pacific Northwest Laboratory at the request of the International Energy Agency (IEA). The US Department of Energy represents the United States in the IEA for Annex IV, the IEA task for research and development in aquifer thermal energy storage (ATES). Installation and operation of an ATES system is necessarily intrusive to ground-water resources. Therefore, governmental authorities usually require an environmental risk assessment to be performed before permission to construct an ATES system is granted. Writing an accurate statement of risk presupposes a knowledge of aquifer and ground-water characteristics and that an engineering feasibility study has taken place. Effective and logical presentation of the results of the risk assessment can expedite the grant of approval. Introductory remarks should address questions regarding why the ATES project has been proposed, what it is expected to accomplish, and what the expected benefits are. Next, the system configuration, including the aquifer, ATES plant, and well field, should be described in terms of size and location, design components, and thermal and hydraulic capacity. The final element of system design, the predicted annual operating cycle, needs to be described in sufficient detail to allow the reviewer to appreciate the net hydraulic, thermal, and hydrochemical effects imposed on the aquifer. Risks may be environmental or legal. Only after a reviewer has been introduced to the proposed system's design, operation, and scale can risk issues can be identified and weighed against the benefits of the proposed ATES system.

  2. Thermal energy conversion by coupled shape memory and piezoelectric effects

    NASA Astrophysics Data System (ADS)

    Zakharov, Dmitry; Lebedev, Gor; Cugat, Orphee; Delamare, Jerome; Viala, Bernard; Lafont, Thomas; Gimeno, Leticia; Shelyakov, Alexander

    2012-09-01

    This work gives experimental evidence of a promising method of thermal-to-electric energy conversion by coupling shape memory effect (SME) and direct piezoelectric effect (DPE) for harvesting quasi-static ambient temperature variations. Two original prototypes of thermal energy harvesters have been fabricated and tested experimentally. The first is a hybrid laminated composite consisting of TiNiCu shape memory alloy (SMA) and macro fiber composite piezoelectric. This composite comprises 0.1 cm3 of active materials and harvests 75 µJ of energy for each temperature variation of 60 °C. The second prototype is a SME/DPE ‘machine’ which uses the thermally induced linear strains of the SMA to bend a bulk PZT ceramic plate through a specially designed mechanical structure. The SME/DPE ‘machine’ with 0.2 cm3 of active material harvests 90 µJ over a temperature increase of 35 °C (60 µJ when cooling). In contrast to pyroelectric materials, such harvesters are also compatible with both small and slow temperature variations.

  3. Product suitable for the storage and conveyance of thermal energy

    SciTech Connect

    Babin, L.; Clausse, D.

    1981-09-01

    This invention concerns the storage and conveyance of thermal energy at low temperature, by using the latent heat produced by a substance during changes of state. This substance consists of a salt producing considerable latent heat during change of state, such as NA/sub 2/SO/sub 4/, 10 H/sub 2/O, combined closely with a nucleating agent such as borax and dispersed in an oil to which an emulsifying agent has been added. This product is particularly suitable for storage of solar energy at low temperature and for heating of enclosed areas.

  4. United States Department of Energy Thermally Activated Heat Pump Program

    SciTech Connect

    Fiskum, R.J.; Adcock, P.W.; DeVault, R.C.

    1996-06-01

    The US Department of Energy (DOE) is working with partners from the gas heating and cooling industry to improve energy efficiency using advance absorption technologies, to eliminate chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), to reduce global warming through more efficient combustion of natural gas, and to impact electric peak demand of air conditioning. To assist industry in developing these gas heating and cooling absorption technologies, the US DOE sponsors the Thermally Activated Heat Pump Program. It is divided into five key activities, addressing residential gas absorption heat pumps, large commercial chillers, advanced absorption fluids, computer-aided design, and advanced ``Hi-Cool`` heat pumps.

  5. The upgrading of the energy of biomass by thermal methods

    SciTech Connect

    Deglise, X.; Lede, J.

    1982-10-01

    A survey is given of various thermal processes for upgrading biomass as a source of energy or chemical raw materials. Estimates are made of the quantity of biomass available and the types best suited to the various processes. The reactions and their yields are discussed. The different types of reactors and means of supplying heat are reviewed for the case of gasification, with special attention to the advantages of concentrated solar energy. Uses are proposed for the products and recommendations are made for future research.

  6. Energy storage and thermal control system design status

    NASA Technical Reports Server (NTRS)

    Simons, Stephen N.; Willhoite, Bryan C.; Vanommering, Gert

    1989-01-01

    The Space Station Freedom electric power system (EPS) will initially rely on photovoltaics for power generation and Ni/H2 batteries for electrical energy storage. The current design for and the development status of two major subsystems in the PV Power Module is discussed. The energy storage subsystem comprised of high capacity Ni/H2 batteries and the single-phase thermal control system that rejects the excess heat generated by the batteries and other components associated with power generation and storage is described.

  7. Thermal energy storage for industrial waste heat recovery

    NASA Technical Reports Server (NTRS)

    Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

    1978-01-01

    The potential is examined for waste heat recovery and reuse through thermal energy storage in five specific industrial categories: (1) primary aluminum, (2) cement, (3) food processing, (4) paper and pulp, and (5) iron and steel. Preliminary results from Phase 1 feasibility studies suggest energy savings through fossil fuel displacement approaching 0.1 quad/yr in the 1985 period. Early implementation of recovery technologies with minimal development appears likely in the food processing and paper and pulp industries; development of the other three categories, though equally desirable, will probably require a greater investment in time and dollars.

  8. S. 1109: a Bill to authorize the Department of Energy to initiate a cooperative research program in ocean energy. Introduced in the Senate of the United States, Ninety-Ninth Congress, First Session, May 8, 1985

    SciTech Connect

    Not Available

    1985-01-01

    The intent of S.1109 is to initiate a joint DOE/Pacific International Center for High Technology Research program that will apply data on design methods developed by the DOE and other international research organizations to the development of a 200 kW integrated open-cycle ocean thermal energy conversion (OTEC) experimental system at the National Energy Laboratory of Hawaii. The Bill authorizes $500,000 for fiscal year 1986, $2 million for 1987, $3.5 million for 1988, $3 million for 1989, and $1 million for 1990.

  9. THERMAL-ENERGY STORAGE IN A DEEP SANDSTONE AQUIFER IN MINNESOTA: FIELD OBSERVATIONS AND THERMAL ENERGY-TRANSPORT MODELING.

    USGS Publications Warehouse

    Miller, R.T.

    1986-01-01

    A study of the feasibility of storing heated water in a deep sandstone aquifer in Minnesota is described. The aquifer consists of four hydraulic zones that are areally anisotropic and have average hydraulic conductivities that range from 0. 03 to 1. 2 meters per day. A preliminary axially symmetric, nonisothermal, isotropic, single-phase, radial-flow, thermal-energy-transport model was constructed to investigate the sensitivity of model simulation to various hydraulic and thermal properties of the aquifer. A three-dimensional flow and thermal-energy transport model was constructed to incorporate the areal anisotropy of the aquifer. Analytical solutions of equations describing areally anisotropic groundwater flow around a doublet-well system were used to specify model boundary conditions for simulation of heat injection. The entire heat-injection-testing period of approximately 400 days was simulated. Model-computed temperatures compared favorably with field-recorded temperatures, with differences of no more than plus or minus 8 degree C. For each test cycle, model-computed aquifer thermal efficiency, defined as total heat withdrawn divided by total heat injected, was within plus or minus 2% of the field-calculated values.

  10. Optical and thermal energy discharge from tritiated solid hydrogen

    SciTech Connect

    Magnotta, F.; Mapoles, E.R.; Collins, G.W.; Souers, P.C.

    1991-04-02

    The authors are investigating mechanisms of energy storage and release in tritiated solid hydrogens, by a variety of techniques including ESR, NMR and thermal and optical emission. The nuclear decay of a triton in solid hydrogen initiates the conversion of nuclear energy into stored chemical energy by producing unpaired hydrogen atoms which are trapped within the molecular lattice. The ability to store large quantities of atoms in this manner has been demonstrated and can serve as a basis for new forms of high energy density materials. This paper presents preliminary results of a study of the optical emission from solid hydrogen containing tritium over the visible and near infrared (NIR) spectral regions. Specifically, they have studied optical emission from DT and T{sub 2} using CCD, silicon diode and germanium diode arrays. 8 refs., 6 figs.

  11. Flexible ocean upwelling pipe

    DOEpatents

    Person, Abraham

    1980-01-01

    In an ocean thermal energy conversion facility, a cold water riser pipe is releasably supported at its upper end by the hull of the floating facility. The pipe is substantially vertical and has its lower end far below the hull above the ocean floor. The pipe is defined essentially entirely of a material which has a modulus of elasticity substantially less than that of steel, e.g., high density polyethylene, so that the pipe is flexible and compliant to rather than resistant to applied bending moments. The position of the lower end of the pipe relative to the hull is stabilized by a weight suspended below the lower end of the pipe on a flexible line. The pipe, apart from the weight, is positively buoyant. If support of the upper end of the pipe is released, the pipe sinks to the ocean floor, but is not damaged as the length of the line between the pipe and the weight is sufficient to allow the buoyant pipe to come to a stop within the line length after the weight contacts the ocean floor, and thereafter to float submerged above the ocean floor while moored to the ocean floor by the weight. The upper end of the pipe, while supported by the hull, communicates to a sump in the hull in which the water level is maintained below the ambient water level. The sump volume is sufficient to keep the pipe full during heaving of the hull, thereby preventing collapse of the pipe.

  12. Numerical Modeling of a Shallow Borehole Thermal Energy Storage System

    NASA Astrophysics Data System (ADS)

    Catolico, N.; Ge, S.; Lu, N.; McCartney, J. S.

    2014-12-01

    Borehole thermal energy storage (BTES) combined with solar thermal energy harvesting is an economic technological system to garner and store energy as well as an environmentally-sustainable alternative for the heating of buildings. The first community-scale BTES system in North America was installed in 2007 in the Drake Landing Solar Community (DLSC), about 35 miles south of Calgary, Canada. The BTES system involves direct circulation of water heated from solar thermal panels in the summer into a storage tank, after which it is circulate within an array of 144 closed-loop geothermal heat exchangers having a depth of 35 m and a spacing of 2.5 m. In the winter the circulation direction is reversed to supply heat to houses. Data collection over a six year period indicates that this system can supply more than 90% of the winter heating energy needs for 52 houses in the community. One major challenge facing the BTES system technology is the relatively low annual efficiency, i.e., the ratio of energy input and output is in the range of 15% to 40% for the system in Drake Landing. To better understand the working principles of BTES and to improve BTES performance for future applications at larger scales, a three-dimensional transient coupled fluid and heat transfer model is established using TOUGH2. The time-dependent injection temperatures and circulation rate measured over the six years of monitoring are used as model input. The simulations are calibrated using soil temperature data measured at different locations over time. The time-dependent temperature distributions within the borehole region agree well with the measured temperatures for soil with an intrinsic permeability of 10e-19 m2, an apparent thermal conductivity of 2.03 W/m°C, and a volumetric heat capacity of 2.31 MJ/m-3°C. The calibrated model serves as the basis for a sensitivity analysis of soil and operational parameters on BTES system efficiency preformed with TOUGH2. Preliminary results suggest 1) BTES

  13. Accelerating Ocean Energy to the Marketplace – Environmental Research at the U.S. Department of Energy National Laboratories

    SciTech Connect

    Copping, Andrea E.; Cada, G. F.; Roberts, Jesse; Bevelhimer, Mark

    2010-10-06

    The U.S. Department of Energy (US DOE) has mobilized its National Laboratories to address the broad range of environmental effects of ocean and river energy development. The National Laboratories are using a risk-based approach to set priorities among environmental effects, and to direct research activities. Case studies will be constructed to determine the most significant environmental effects of ocean energy harvest for tidal systems in temperate estuaries, for wave energy installations in temperate coastal areas, wave installations in sub-tropical waters, and riverine energy installations in large rivers. In addition, the National Laboratories are investigating the effects of energy removal from waves, tides and river currents using numerical modeling studies. Laboratory and field research is also underway to understand the effects of electromagnetic fields (EMF), acoustic noise, toxicity from anti-biofouling coatings, effects on benthic habitats, and physical interactions with tidal and wave devices on marine and freshwater organisms and ecosystems. Outreach and interactions with stakeholders allow the National Laboratories to understand and mitigate for use conflicts and to provide useful information for marine spatial planning at the national and regional level.

  14. Numerical modeling of Thermal Response Tests in Energy Piles

    NASA Astrophysics Data System (ADS)

    Franco, A.; Toledo, M.; Moffat, R.; Herrera, P. A.

    2013-05-01

    Nowadays, thermal response tests (TRT) are used as the main tools for the evaluation of low enthalpy geothermal systems such as heat exchangers. The results of TRT are used for estimating thermal conductivity and thermal resistance values of those systems. We present results of synthetic TRT simulations that model the behavior observed in an experimental energy pile system, which was installed at the new building of the Faculty of Engineering of Universidad de Chile. Moreover, we also present a parametric study to identify the most influent parameters in the performance of this type of tests. The modeling was developed using the finite element software COMSOL Multiphysics, which allows the incorporation of flow and heat transport processes. The modeled system consists on a concrete pile with 1 m diameter and 28 m deep, which contains a 28 mm diameter PEX pipe arranged in a closed circuit. Three configurations were analyzed: a U pipe, a triple U and a helicoid shape implemented at the experimental site. All simulations were run considering transient response in a three-dimensional domain. The simulation results provided the temperature distribution on the pile for a set of different geometry and physical properties of the materials. These results were compared with analytical solutions which are commonly used to interpret TRT data. This analysis demonstrated that there are several parameters that affect the system response in a synthetic TRT. For example, the diameter of the simulated pile affects the estimated effective thermal conductivity of the system. Moreover, the simulation results show that the estimated thermal conductivity for a 1 m diameter pile did not stabilize even after 100 hours since the beginning of the test, when it reached a value 30% below value used to set up the material properties in the simulation. Furthermore, we observed different behaviors depending on the thermal properties of concrete and soil. According to the simulations, the thermal

  15. Thermal management in inertial fusion energy slab amplifiers

    NASA Astrophysics Data System (ADS)

    Sutton, Steven B.; Albrecht, George F.

    1995-12-01

    As the technology associated with the development of solid-state drivers for inertial fusion energy (IFE) has evolved, increased emphasis has been placed on the development of an efficient approach for managing the waste heat generated in the laser media. This paper addresses the technical issues associated with the gas cooling of large aperture slabs, where the laser beam propagates through the cooling fluid. It is shown that the major consequence of proper thermal management is the introduction of simple wedge, or beam steering, into the system. Achieving proper thermal management requires careful consideration of the geometry, cooling fluid characteristics, cooling flow characteristics, as well as the thermal/mechanical/optical characteristics of the laser media. Particularly important are the effects of cooling rate variation and turbulent scattering on the system optical performance. Helium is shown to have an overwhelming advantage with respect to turbulent scattering losses. To mitigate cooling rate variations, we introduce the concept of flow conditioning. Finally, optical path length variations across the aperture are calculated. A comparison of two laser materials (S-FAP and YAG) shows the benefit of a nearly a-thermal material on optical variations in the system.

  16. Review of pyroelectric thermal energy harvesting and new MEMs-based resonant energy conversion techniques

    NASA Astrophysics Data System (ADS)

    Hunter, Scott R.; Lavrik, Nickolay V.; Mostafa, Salwa; Rajic, Slo; Datskos, Panos G.

    2012-06-01

    Harvesting electrical energy from thermal energy sources using pyroelectric conversion techniques has been under investigation for over 50 years, but it has not received the attention that thermoelectric energy harvesting techniques have during this time period. This lack of interest stems from early studies which found that the energy conversion efficiencies achievable using pyroelectric materials were several times less than those potentially achievable with thermoelectrics. More recent modeling and experimental studies have shown that pyroelectric techniques can be cost competitive with thermoelectrics and, using new temperature cycling techniques, has the potential to be several times as efficient as thermoelectrics under comparable operating conditions. This paper will review the recent history in this field and describe the techniques that are being developed to increase the opportunities for pyroelectric energy harvesting. The development of a new thermal energy harvester concept, based on temperature cycled pyroelectric thermal-to-electrical energy conversion, are also outlined. The approach uses a resonantly driven, pyroelectric capacitive bimorph cantilever structure that can be used to rapidly cycle the temperature in the energy harvester. The device has been modeled using a finite element multi-physics based method, where the effect of the structure material properties and system parameters on the frequency and magnitude of temperature cycling, and the efficiency of energy recycling using the proposed structure, have been modeled. Results show that thermal contact conductance and heat source temperature differences play key roles in dominating the cantilever resonant frequency and efficiency of the energy conversion technique. This paper outlines the modeling, fabrication and testing of cantilever and pyroelectric structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal

  17. Review of pyroelectric thermal energy harvesting and new MEMs based resonant energy conversion techniques

    SciTech Connect

    Hunter, Scott Robert; Lavrik, Nickolay V; Mostafa, Salwa; Rajic, Slobodan; Datskos, Panos G

    2012-01-01

    Harvesting electrical energy from thermal energy sources using pyroelectric conversion techniques has been under investigation for over 50 years, but it has not received the attention that thermoelectric energy harvesting techniques have during this time period. This lack of interest stems from early studies which found that the energy conversion efficiencies achievable using pyroelectric materials were several times less than those potentially achievable with thermoelectrics. More recent modeling and experimental studies have shown that pyroelectric techniques can be cost competitive with thermoelectrics and, using new temperature cycling techniques, has the potential to be several times as efficient as thermoelectrics under comparable operating conditions. This paper will review the recent history in this field and describe the techniques that are being developed to increase the opportunities for pyroelectric energy harvesting. The development of a new thermal energy harvester concept, based on temperature cycled pyroelectric thermal-to-electrical energy conversion, are also outlined. The approach uses a resonantly driven, pyroelectric capacitive bimorph cantilever structure that can be used to rapidly cycle the temperature in the energy harvester. The device has been modeled using a finite element multi-physics based method, where the effect of the structure material properties and system parameters on the frequency and magnitude of temperature cycling, and the efficiency of energy recycling using the proposed structure, have been modeled. Results show that thermal contact conductance and heat source temperature differences play key roles in dominating the cantilever resonant frequency and efficiency of the energy conversion technique. This paper outlines the modeling, fabrication and testing of cantilever and pyroelectric structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal

  18. Solar Thermal Power.

    ERIC Educational Resources Information Center

    McDaniels, David K.

    The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

  19. Energy metabolism among eukaryotic anaerobes in light of Proterozoic ocean chemistry.

    PubMed

    Mentel, Marek; Martin, William

    2008-08-27

    Recent years have witnessed major upheavals in views about early eukaryotic evolution. One very significant finding was that mitochondria, including hydrogenosomes and the newly discovered mitosomes, are just as ubiquitous and defining among eukaryotes as the nucleus itself. A second important advance concerns the readjustment, still in progress, about phylogenetic relationships among eukaryotic groups and the roughly six new eukaryotic supergroups that are currently at the focus of much attention. From the standpoint of energy metabolism (the biochemical means through which eukaryotes gain their ATP, thereby enabling any and all evolution of other traits), understanding of mitochondria among eukaryotic anaerobes has improved. The mainstream formulations of endosymbiotic theory did not predict the ubiquity of mitochondria among anaerobic eukaryotes, while an alternative hypothesis that specifically addressed the evolutionary origin of energy metabolism among eukaryotic anaerobes did. Those developments in biology have been paralleled by a similar upheaval in the Earth sciences regarding views about the prevalence of oxygen in the oceans during the Proterozoic (the time from ca 2.5 to 0.6 Ga ago). The new model of Proterozoic ocean chemistry indicates that the oceans were anoxic and sulphidic during most of the Proterozoic. Its proponents suggest the underlying geochemical mechanism to entail the weathering of continental sulphides by atmospheric oxygen to sulphate, which was carried into the oceans as sulphate, fueling marine sulphate reducers (anaerobic, hydrogen sulphide-producing prokaryotes) on a global scale. Taken together, these two mutually compatible developments in biology and geology underscore the evolutionary significance of oxygen-independent ATP-generating pathways in mitochondria, including those of various metazoan groups, as a watermark of the environments within which eukaryotes arose and diversified into their major lineages. PMID:18468979

  20. Applications of cogeneration with thermal energy storage technologies

    SciTech Connect

    Somasundaram, S.; Katipamula, S.; Williams, H.R.

    1995-03-01

    The Pacific Northwest Laboratory (PNL) leads the U.S. Department of Energy`s Thermal Energy Storage (TES) Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility-scale applications [utility thermal energy storage (UTES)]. Several of these storage technologies can be used in a new or an existing power generation facility to increase its efficiency and promote the use of the TES technology within the utility and the industrial sectors. The UTES project has included a study of both heat storage and cool storage systems for different utility-scale applications. The study reported here has shown that an oil/rock diurnal TES system, when integrated with a simple gas turbine cogeneration system, can produce on-peak power for $0.045 to $0.06 /kWh, while supplying a 24-hour process steam load. The molten salt storage system was found to be less suitable for simple as well as combined-cycle cogeneration applications. However, certain advanced TES concepts and storage media could substantially improve the performance and economic benefits. In related study of a chill TES system was evaluated for precooling gas turbine inlet air, which showed that an ice storage system could be used to effectively increase the peak generating capacity of gas turbines when operating in hot ambient conditions.

  1. Characterization of an energy storage capacitor in abnormal thermal environments

    SciTech Connect

    Edwards, L.R.; Chen, K.C.; Baron, R.V.

    2000-01-05

    There are applications of high-voltage, energy-storage, capacitors where it is desirable that the energy storage capability can be reliably and predictably negated in abnormal environments such as fire. This property serves as a safety feature to prevent events of unintended consequence. The present paper describes studies of the thermal response characteristics of a cylindrically wound, discrete Mylar film/foil capacitor design. The experimental setups that simulate fires will be presented. Three different heat input geometries were employed: uniform radial input, spot radial input, and axial input. Heat input was controlled via feedback system to maintain specific temperature ramp rates. Both capacitor voltage and current were monitored during the thermal excursion to ascertain the failure temperature, i.e. when the capacitor permanently shorts. Temperature of failure data is presented for the three heat input cases along with a statistical analysis of the results and application implications. The physics of failure will be described in terms of the thermal/mechanical properties of the Mylar.

  2. Sodium-based hydrides for thermal energy applications

    NASA Astrophysics Data System (ADS)

    Sheppard, D. A.; Humphries, T. D.; Buckley, C. E.

    2016-04-01

    Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH4) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH3- x F x , Na-based transition metal hydrides, NaBH4 and Na3AlH6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100 °C to more than 650 °C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

  3. Advanced Reactors Thermal Energy Transport for Process Industries

    SciTech Connect

    P. Sabharwall; S.J. Yoon; M.G. McKellar; C. Stoots; George Griffith

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as liquid fuel production, district heating, desalination, hydrogen production, and other process heat applications, etc. Some of the major technology challenges that must be overcome before the advanced reactors could be licensed on the reactor side are qualification of next generation of nuclear fuel, materials that can withstand higher temperature, improvement in power cycle thermal efficiency by going to combined cycles, SCO2 cycles, successful demonstration of advanced compact heat exchangers in the prototypical conditions, and from the process side application the challenge is to transport the thermal energy from the reactor to the process plant with maximum efficiency (i.e., with minimum temperature drop). The main focus of this study is on doing a parametric study of efficient heat transport system, with different coolants (mainly, water, He, and molten salts) to determine maximum possible distance that can be achieved.

  4. Design of a high temperature subsurface thermal energy storage system

    NASA Astrophysics Data System (ADS)

    Zheng, Qi

    Solar thermal energy is taking up increasing proportions of future power generation worldwide. Thermal energy storage technology is a key method for compensating for the inherent intermittency of solar resources and solving the time mismatch between solar energy supply and electricity demand. However, there is currently no cost-effective high-capacity compact storage technology available (Bakker et al., 2008). The goal of this work is to propose a high temperature subsurface thermal energy storage (HSTES) technology and demonstrate its potential energy storage capability by developing a solar-HSTES-electricity generation system. In this work, main elements of the proposed system and their related state-of-art technologies are reviewed. A conceptual model is built to illustrate the concept, design, operating procedure and application of such a system. A numerical base model is built within the TOUGH2-EOS1 multiphase flow simulator for the evaluation of system performance. Additional models are constructed and simulations are done to identify the effect of different operational and geological influential factors on the system performance. Our work shows that when the base model is run with ten years operation of alternate injection and production processes - each for a month - with a thermal power input of 10.85 MW, about 83% of the injected thermal energy could be recovered within each working cycle from a stabilized HSTES system. After the final conversion into electrical energy, a relative (compared with the direct use of hot water) electricity generation efficiency of 73% is obtained. In a typical daily storage scenario, the simulated thermal storage efficiency could exceed 78% and the relative electricity generation efficiency is over 66% in the long run. In a seasonal storage scenario, these two efficiencies reach 69% and 53% respectively by the end of the simulation period of 10 years. Additional simulations reveal a thinner storage aquifer with a higher

  5. Equilibrium statistical-thermal models in high-energy physics

    NASA Astrophysics Data System (ADS)

    Tawfik, Abdel Nasser

    2014-05-01

    We review some recent highlights from the applications of statistical-thermal models to different experimental measurements and lattice QCD thermodynamics that have been made during the last decade. We start with a short review of the historical milestones on the path of constructing statistical-thermal models for heavy-ion physics. We discovered that Heinz Koppe formulated in 1948, an almost complete recipe for the statistical-thermal models. In 1950, Enrico Fermi generalized this statistical approach, in which he started with a general cross-section formula and inserted into it, the simplifying assumptions about the matrix element of the interaction process that likely reflects many features of the high-energy reactions dominated by density in the phase space of final states. In 1964, Hagedorn systematically analyzed the high-energy phenomena using all tools of statistical physics and introduced the concept of limiting temperature based on the statistical bootstrap model. It turns to be quite often that many-particle systems can be studied with the help of statistical-thermal methods. The analysis of yield multiplicities in high-energy collisions gives an overwhelming evidence for the chemical equilibrium in the final state. The strange particles might be an exception, as they are suppressed at lower beam energies. However, their relative yields fulfill statistical equilibrium, as well. We review the equilibrium statistical-thermal models for particle production, fluctuations and collective flow in heavy-ion experiments. We also review their reproduction of the lattice QCD thermodynamics at vanishing and finite chemical potential. During the last decade, five conditions have been suggested to describe the universal behavior of the chemical freeze-out parameters. The higher order moments of multiplicity have been discussed. They offer deep insights about particle production and to critical fluctuations. Therefore, we use them to describe the freeze-out parameters

  6. Rapid warming at the Palaeocene-Eocene Thermal Maximum drives rapid hydrate dissociation but only modest and delayed methane release to the ocean

    NASA Astrophysics Data System (ADS)

    Minshull, Tim; Marin-Moreno, Hector; Wilson, Paul; Armstrong McKay, David

    2016-04-01

    During the Palaeocene-Eocene Thermal Maximum (PETM), the carbon isotopic signature δ13C of the ocean-atmosphere system decreased abruptly - the record in deep sea benthic foraminifera shows an excursion of at least 2.5 to 3.0 ‰ VPDB. This global carbon isotope excursion (CIE) has been attributed to large-scale methane hydrate dissociation in response to rapid ocean warming. There is increasing evidence for warming-induced hydrate dissociation in the modern ocean and the PETM may represent an analogue for this process. We ran a thermohydraulic modeling code to simulate hydrate dissociation due to ocean warming for a range of possible PETM scenarios. Our results show that hydrate dissociation in response to such warming is rapid but methane release to the ocean is modest, and delayed by hundreds to thousands of years by transport processes through the hydrate stability field. In our simulations most of the dissociated hydrate methane remains beneath the seabed, either in solution or as free gas below the irreducible gas saturation, and the small fraction (≤0.13) released to the ocean is delivered over several kyr. We conclude that hydrate dissociation cannot have been largely responsible for the CIE unless the late Palaeocene hydrate inventory greatly exceeded most current estimates.

  7. Development of thermal energy storage materials for biomedical applications.

    PubMed

    Shukla, A; Sharma, Atul; Shukla, Manjari; Chen, C R

    2015-01-01

    The phase change materials (PCMs) have been utilized widely for solar thermal energy storage (TES) devices. The quality of these materials to remain at a particular temperature during solid-liquid, liquid-solid phase transition can also be utilized for many biomedical applications as well and has been explored in recent past already. This study reports some novel PCMs developed by them, along with some existing PCMs, to be used for such biomedical applications. Interestingly, it was observed that the heating/cooling properties of these PCMs enhance the quality of a variety of biomedical applications with many advantages (non-electric, no risk of electric shock, easy to handle, easy to recharge thermally, long life, cheap and easily available, reusable) over existing applications. Results of the present study are quite interesting and exciting, opening a plethora of opportunities for more work on the subject, which require overlapping expertise of material scientists, biochemists and medical experts for broader social benefits. PMID:26103988

  8. A survey of manufacturers of solar thermal energy systems

    NASA Technical Reports Server (NTRS)

    Levine, N.; Slonski, M. L.

    1982-01-01

    Sixty-seven firms that had received funding for development of solar thermal energy systems (STES) were surveyed. The effect of the solar thermal technology systems program in accelerating (STES) were assessed. The 54 firms still developing STES were grouped into a production typology comparing the three major technologies with three basic functions. It was discovered that large and small firms were developing primarily central receiver systems, but also typically worked on more than one technology. Most medium-sized firms worked only on distributed systems. Federal support of STES was perceived as necessary to allow producers to take otherwise unacceptable risks. Approximately half of the respondents would drop out of STES if support were terminated, including a disproportionate number of medium-sized firms. A differentiated view of the technology, taking into account differing firm sizes and the various stages of technology development, was suggested for policy and planning purposes.

  9. Thermal energy storage. [by means of chemical reactions

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.

    1975-01-01

    The principles involved in thermal energy storage by sensible heat, chemical potential energy, and latent heat of fusion are examined for the purpose of evolving selection criteria for material candidates in the low ( 0 C) and high ( 100 C) temperature ranges. The examination identifies some unresolved theoretical considerations and permits a preliminary formulation of an energy storage theory. A number of candidates in the low and high temperature ranges are presented along with a rating of candidates or potential candidates. A few interesting candidates in the 0 to 100 C region are also included. It is concluded that storage by means of reactions whose reversibility can be controlled either by product removal or by catalytic means appear to offer appreciable advantages over storage with reactions whose reversability cannot be controlled. Among such advantages are listed higher heat storage capacities and more favorable options regarding temperatures of collection, storage, and delivery. Among the disadvantages are lower storage efficiencies.

  10. The transfer between electron bulk kinetic energy and thermal energy in collisionless magnetic reconnection

    SciTech Connect

    Lu, San; Lu, Quanming; Huang, Can; Wang, Shui

    2013-06-15

    By performing two-dimensional particle-in-cell simulations, we investigate the transfer between electron bulk kinetic and electron thermal energy in collisionless magnetic reconnection. In the vicinity of the X line, the electron bulk kinetic energy density is much larger than the electron thermal energy density. The evolution of the electron bulk kinetic energy is mainly determined by the work done by the electric field force and electron pressure gradient force. The work done by the electron gradient pressure force in the vicinity of the X line is changed to the electron enthalpy flux. In the magnetic island, the electron enthalpy flux is transferred to the electron thermal energy due to the compressibility of the plasma in the magnetic island. The compression of the plasma in the magnetic island is the consequence of the electromagnetic force acting on the plasma as the magnetic field lines release their tension after being reconnected. Therefore, we can observe that in the magnetic island the electron thermal energy density is much larger than the electron bulk kinetic energy density.

  11. Solar Energy - An Option for Future Energy Production

    ERIC Educational Resources Information Center

    Glaser, Peter E.

    1972-01-01

    Discusses the exponential growth of energy consumption and future consequences. Possible methods of converting solar energy to power such as direct energy conversion, focusing collectors, selective rediation absorbers, ocean thermal gradient, and space solar power are considered. (DF)

  12. US Department of Energy Solar Thermal Energy Systems Program. An overview presentation, August 1979

    SciTech Connect

    Braun, G W

    1980-06-01

    Intended as both a position paper and a progress report to industry, this document provides a comprehensive overview of the US Department of Energy's Solar Thermal Program. Cost goals, systems design parameters, applications considerations, and the potential for industry involvement in solar thermal development and commercialization are described in detail. Decentralized management of R and D functions is linked to priorities and strategies of the evolving program.

  13. Conceptual design of thermal energy storage systems for near-term electric utility applications

    NASA Technical Reports Server (NTRS)

    Hall, E. W.

    1980-01-01

    Promising thermal energy storage systems for midterm applications in conventional electric utilities for peaking power generation are evaluated. Conceptual designs of selected thermal energy storage systems integrated with conventional utilities are considered including characteristics of alternate systems for peaking power generation, viz gas turbines and coal fired cycling plants. Competitive benefit analysis of thermal energy storage systems with alternate systems for peaking power generation and recommendations for development and field test of thermal energy storage with a conventional utility are included. Results indicate that thermal energy storage is only marginally competitive with coal fired cycling power plants and gas turbines for peaking power generation.

  14. Thermal Energy Corporation Combined Heat and Power Project

    SciTech Connect

    Turner, E. Bruce; Brown, Tim; Mardiat, Ed

    2011-12-31

    To meet the planned heating and cooling load growth at the Texas Medical Center (TMC), Thermal Energy Corporation (TECO) implemented Phase 1 of a Master Plan to install an additional 32,000 tons of chilled water capacity, a 75,000 ton-hour (8.8 million gallon) Thermal Energy Storage (TES) tank, and a 48 MW Combined Heat and Power (CHP) system. The Department of Energy selected TMC for a $10 million grant award as part of the Financial Assistance Funding Opportunity Announcement, U.S. Department of Energy National Energy Technology, Recovery Act: Deployment of Combined Heat and Power (CHP) Systems, District Energy Systems, Waste Energy Recovery Systems, and Efficiency Industrial Equipment Funding Opportunity Number: DE-FOA-0000044 to support the installation of a new 48 MW CHP system at the TMC located just outside downtown Houston. As the largest medical center in the world, TMC is home to many of the nation's best hospitals, physicians, researchers, educational institutions, and health care providers. TMC provides care to approximately six million patients each year, and medical instruction to over 71,000 students. A medical center the size of TMC has enormous electricity and thermal energy demands to help it carry out its mission. Reliable, high-quality steam and chilled water are of utmost importance to the operations of its many facilities. For example, advanced medical equipment, laboratories, laundry facilities, space heating and cooling all rely on the generation of heat and power. As result of this project TECO provides this mission critical heating and cooling to TMC utilizing a system that is both energy-efficient and reliable since it provides the capability to run on power independent of the already strained regional electric grid. This allows the medical center to focus on its primary mission providing top quality medical care and instruction without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power

  15. Feasibility study of thermal energy harvesting using lead free pyroelectrics

    NASA Astrophysics Data System (ADS)

    Karim, Hasanul; Sarker, Md Rashedul H.; Shahriar, Shaimum; Arif Ishtiaque Shuvo, Mohammad; Delfin, Diego; Hodges, Deidra; (Bill Tseng, Tzu-Liang; Roberson, David; Love, Norman; Lin, Yirong

    2016-05-01

    Energy harvesting has significant potential for applications in energizing wireless sensors and charging energy storage devices. To date, one of the most widely investigated materials for mechanical and thermal energy harvesting is lead zirconate titanate (PZT). However, lead has detrimental effects on the environment and on health. Hence, alternative materials are required for this purpose. In this paper, a lead free material, lithium niobate (LNB) is investigated as a potential material for pyroelectric energy harvesting. Although its theoretical pyroelectric properties are lower compared to PZT, it has better properties than other lead free alternatives such as ZnO. In addition, LNB has a high Curie temperature of about 1142 °C, which makes it applicable for high temperature energy harvesting, where other pyroelectric ceramics are not suitable. Herein, an energy harvesting and storage system composed of a single crystal LNB and a porous carbon-based super-capacitor was investigated. It is found that with controlled heating and cooling, a single wafer of LNB (75 mm diameter and 0.5 mm thickness) could generate 437.72 nW cm–3 of power and it could be used to charge a super-capacitor with a charging rate of 2.63 mV (h cm3)–1.

  16. Evaluation of diurnal thermal energy storage combined with cogeneration systems

    NASA Astrophysics Data System (ADS)

    Somasundaram, S.; Brown, D. R.; Drost, M. K.

    1992-11-01

    This report describes the results of an evaluation of thermal energy storage (TES) integrated with simple gas turbine cogeneration systems. The TES system captures and stores thermal energy from the gas turbine exhaust for immediate or future generation of process heat. Integrating thermal energy storage with conventional cogeneration equipment increases the initial cost of the combined system; but, by decoupling electric power and process heat production, the system offers the following significant advantages: (1) electric power can be generated on demand, irrespective of the process heat load profile, thus increasing the value of the power produced; (2) although supplementary firing could be used to serve independently varying electric and process heat loads, this approach is inefficient. Integrating TES with cogeneration can serve the two independent loads while firing all fuel in the gas turbine. The study evaluated the cost of power produced by cogeneration and cogeneration/TES systems designed to serve a fixed process steam load. The value of the process steam was set at the levelized cost estimated for the steam from a conventional stand-alone boiler. Power costs for combustion turbine and combined-cycle power plants were also calculated for comparison. The results indicated that peak power production costs for the cogeneration/TES systems were between 25 and 40 percent lower than peak power costs estimated for a combustion turbine and between 15 and 35 percent lower than peak power costs estimated for a combined-cycle plant. The ranges reflect differences in the daily power production schedule and process steam pressure/temperature assumptions for the cases evaluated. Further cost reductions may result from optimization of current cogeneration/TES system designs and improvement in TES technology through future research and development.

  17. Mitigating Climate Change with Ocean Pipes: Influencing Land Temperature and Hydrology and Termination Overshoot Risk

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, L.; Caldeira, K.; Ricke, K.

    2014-12-01

    With increasing risk of dangerous climate change geoengineering solutions to Earth's climate problems have attracted much attention. One proposed geoengineering approach considers the use of ocean pipes as a means to increase ocean carbon uptake and the storage of thermal energy in the deep ocean. We use a latest generation Earth System Model (ESM) to perform simulations of idealised extreme implementations of ocean pipes. In our simulations, downward transport of thermal energy by ocean pipes strongly cools the near surface atmosphere - by up to 11°C on a global mean. The ocean pipes cause net thermal energy to be transported from the terrestrial environment to the deep ocean while increasing the global net transport of water to land. By cooling the ocean surface more than the land, ocean pipes tend to promote a monsoonal-type circulation, resulting in increased water vapour transport to land. Throughout their implementation, ocean pipes prevent energy from escaping to space, increasing the amount of energy stored in Earth's climate system despite reductions in surface temperature. As a consequence, our results indicate that an abrupt termination of ocean pipes could cause dramatic increases in surface temperatures beyond that which would have been obtained had ocean pipes not been implemented.

  18. Horizontal eddy energy flux in the world oceans diagnosed from altimetry data.

    PubMed

    Xu, Chi; Shang, Xiao-Dong; Huang, Rui Xin

    2014-01-01

    During the propagation of coherent mesoscale eddies, they directly or indirectly induce many effects and interactions at different scales, implying eddies are actually serving as a kind of energy carrier or energy source for these eddy-related dynamic processes. To quantify this dynamically significant energy flow, the multi-year averaged horizontal eddy energy fluxes (EEFs) were estimated by using satellite altimetry data and a two-layer model based on hydrographic climatology. There is a strong net westward transport of eddy energy estimated at the mean value of ~13.3 GW north of 5°N and ~14.6 GW at the band 5°S ~ 44°S in the Southern Hemisphere. However, poleward of 44°S east-propagating eddies carry their energy eastward with an averaged net flux of ~3.2 GW. If confirmed, it would signify that geostrophic eddies not only contain the most of oceanic kinetic energy (KE), but also carry and spread a significant amount of energy with them. PMID:24937401

  19. Survey of sensible and latent heat thermal energy storage projects

    NASA Astrophysics Data System (ADS)

    Baylin, F.; Merino, M.

    1981-05-01

    Ongoing and completed research projects on sensible and latent heat thermal enegy storage for low, intermediate, and high temperature applications are reviewed. Projects in the United States and abroad are included. Several research efforts are in the index although the project descriptions are absent. Project lists are organized into four sections: short term sensible heat storage; seasonal sensible heat storage; latent heat storage; and models, economic analysis, and support studies. The organization of the Department of Energy programs managing many of these projects is also outlined. Projects are presented in a standard format that includes laboratory; funding level and period; status; project description; technical and economic parameters; and applications.

  20. Analysis of dynamic effects in solar thermal energy conversion systems

    NASA Technical Reports Server (NTRS)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  1. Thermal energy storage systems using fluidized bed heat exchangers

    NASA Technical Reports Server (NTRS)

    Ramanathan, V.; Weast, T. E.; Ananth, K. P.

    1980-01-01

    The viability of using fluidized bed heat exchangers (FBHX) for thermal energy storage (TES) in applications with potential for waste heat recovery was investigated. Of the candidate applications screened, cement plant rotary kilns and steel plant electric arc furnaces were identified, via the chosen selection criteria, as having the best potential for successful use of FBHX/TES system. A computer model of the FBHX/TES systems was developed and the technical feasibility of the two selected applications was verified. Economic and tradeoff evaluations in progress for final optimization of the systems and selection of the most promising system for further concept validation are described.

  2. Bibliography of the seasonal thermal energy storage library

    SciTech Connect

    Prater, L.S.; Casper, G.; Kawin, R.A.

    1981-08-01

    The Main Listing is arranged alphabetically by the last name of the first author. Each citation includes the author's name, title, publisher, publication date, and where applicable, the National Technical Information Service (NTIS) number or other document number. The number preceding each citation is the identification number for that document in the Seasonal Thermal Energy Storage (STES) Library. Occasionally, one or two alphabetic characters are added to the identification number. These alphabetic characters indicate that the document is contained in a collection of papers, such as the proceedings of a conference. An Author Index and an Identification Number Index are included. (WHK)

  3. Solar-thermal-energy collection/storage-pond system

    DOEpatents

    Blahnik, D.E.

    1982-03-25

    A solar thermal energy collection and storage system is disclosed. Water is contained, and the water surface is exposed directly to the sun. The central part of an impermeable membrane is positioned below the water's surface and above its bottom with a first side of the membrane pointing generally upward in its central portion. The perimeter part of the membrane is placed to create a watertight boundary separating the water into a first volume which is directly exposable to the sun and which touches the membranes first side, and a second volumn which touches the membranes second side. A salt is dissolved in the first water volume.

  4. Electrochemical energy storage systems for solar thermal applications

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.; Frank, H.

    1980-01-01

    Existing and advanced electrochemical storage and inversion/conversion systems that may be used with terrestrial solar-thermal power systems are evaluated. The status, cost and performance of existing storage systems are assessed, and the cost, performance, and availability of advanced systems are projected. A prime consideration is the cost of delivered energy from plants utilizing electrochemical storage. Results indicate that the five most attractive electrochemical storage systems are the: iron-chromium redox (NASA LeRC), zinc-bromine (Exxon), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (EDA).

  5. Thermal energy harvesters with piezoelectric or electrostatic transducer

    NASA Astrophysics Data System (ADS)

    Prokaryn, Piotr; Domański, Krzysztof; Marchewka, Michał; Tomaszewski, Daniel; Grabiec, Piotr; Puscasu, Onoriu; Monfray, Stéphane; Skotnicki, Thomas

    2014-08-01

    This paper describes the idea of the energy harvester which converts thermal gradient present in environment into electricity. Two kinds of such devices are proposed and their prototypes are shown and discussed. The main parts of harvesters are bimetallic spring, piezoelectric transducer or electrostatic transducer with electret. The applied piezomembrane was commercial available product but electrets was made by authors. In the paper a fabrication procedure of electrets formed by the corona discharge process is described. Devices were compared in terms of generated power, charging current, and the voltage across a storage capacitor.

  6. Entropy versus APE production: On the buoyancy power input in the oceans energy cycle

    NASA Astrophysics Data System (ADS)

    Tailleux, R.

    2010-11-01

    This letter argues that the current controversy about whether Wbuoyancy, the power input due to the surface buoyancy fluxes, is large or small in the oceans stems from two distinct and incompatible views on how Wbuoyancy relates to the volume-integrated work of expansion/contraction B. The current prevailing view is that Wbuoyancy should be identified with the net value of B, which current theories estimate to be small. The alternative view, defended here, is that only the positive part of B, i.e., the one converting internal energy into mechanical energy, should enter the definition of Wbuoyancy, since the negative part of B is associated with the non-viscous dissipation of mechanical energy. Two indirect methods suggest that by contrast, the positive part of B is potentially large.

  7. Convective available potential energy in the environment of oceanic and continental clouds: Correction and comments

    NASA Technical Reports Server (NTRS)

    Lucas, Christopher; Zipser, Edward J.; Lemone, Margaret A.

    1994-01-01

    In 1980, Zipser and LeMone estimated the convective available potential energy (CAPE) for the Thunderstorm Project cumulonimbus environment to be about 3000 J per kg. By assuming the most adiabat reported by Byers and Braham (1949) to be that of an undilute parcel rather than a reference moist adiabat, a significant error was introduced. On the basis of recent calculations made under similar conditions in Oklahoma and Florida, CAPE is now estimated to be considerably lower. These lower CAPE estimates shed doubt on the suggestion that differences in CAPE account for differences in the vertical velocities in convective updrafts over land and over the ocean.

  8. A system for measuring thermal activation energy levels in silicon by thermally stimulated capacitance

    NASA Technical Reports Server (NTRS)

    Cockrum, R. H.

    1982-01-01

    One method being used to determine energy level(s) and electrical activity of impurities in silicon is described. The method is called capacitance transient spectroscopy (CTS). It can be classified into three basic categories: the thermally stimulated capacitance method, the voltage-stimulated capacitance method, and the light-stimulated capacitance method; the first two categories are discussed. From the total change in capacitance and the time constant of the capacitance response, emission rates, energy levels, and trap concentrations can be determined. A major advantage of using CTS is its ability to detect the presence of electrically active impurities that are invisible to other techniques, such as Zeeman effect atomic absorption, and the ability to detect more than one electrically active impurity in a sample. Examples of detection of majority and minority carrier traps from gold donor and acceptor centers in silicon using the capacitance transient spectrometer are given to illustrate the method and its sensitivity.

  9. Solar Energy.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  10. Thermal energy storage for cooling of commercial buildings

    SciTech Connect

    Akbari, H. ); Mertol, A. )

    1988-07-01

    The storage of coolness'' has been in use in limited applications for more than a half century. Recently, because of high electricity costs during utilities' peak power periods, thermal storage for cooling has become a prime target for load management strategies. Systems with cool storage shift all or part of the electricity requirement from peak to off-peak hours to take advantage of reduced demand charges and/or off-peak rates. Thermal storage technology applies equally to industrial, commercial, and residential sectors. In the industrial sector, because of the lack of economic incentives and the custom design required for each application, the penetration of this technology has been limited to a few industries. The penetration rate in the residential sector has been also very limited due to the absence of economic incentives, sizing problems, and the lack of compact packaged systems. To date, the most promising applications of these systems, therefore, appear to be for commercial cooling. In this report, the current and potential use of thermal energy storage systems for cooling commercial buildings is investigated. In addition, a general overview of the technology is presented and the applicability and cost-effectiveness of this technology for developed and developing countries are discussed. 28 refs., 12 figs., 1 tab.

  11. Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska final report

    SciTech Connect

    Wright, Bruce Albert

    2014-05-07

    The Aleutian Pribilof Islands Association was awarded a U.S. Department of Energy Tribal Energy Program grant (DE-EE0005624) for the Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska (Project). The goal of the Project was to perform a feasibility study to determine if a tidal energy project would be a viable means to generate electricity and heat to meet long-term fossil fuel use reduction goals, specifically to produce at least 30% of the electrical and heating needs of the tribally-owned buildings in False Pass. The Project Team included the Aleut Region organizations comprised of the Aleutian Pribilof Island Association (APIA), and Aleutian Pribilof Island Community Development Association (APICDA); the University of Alaska Anchorage, ORPC Alaska a wholly-owned subsidiary of Ocean Renewable Power Company (ORPC), City of False Pass, Benthic GeoScience, and the National Renewable Energy Laboratory (NREL). The following Project objectives were completed: collected existing bathymetric, tidal, and ocean current data to develop a basic model of current circulation at False Pass, measured current velocities at two sites for a full lunar cycle to establish the viability of the current resource, collected data on transmission infrastructure, electrical loads, and electrical generation at False Pass, performed economic analysis based on current costs of energy and amount of energy anticipated from and costs associated with the tidal energy project conceptual design and scoped environmental issues. Utilizing circulation modeling, the Project Team identified two target sites with strong potential for robust tidal energy resources in Isanotski Strait and another nearer the City of False Pass. In addition, the Project Team completed a survey of the electrical infrastructure, which identified likely sites of interconnection and clarified required transmission distances from the tidal energy resources. Based on resource and electrical data

  12. Estimation of the energy release and thermal properties of ejected clasts from explosive eruptions using a thermal imaging camera

    NASA Astrophysics Data System (ADS)

    De la Cruz-Reyna, S.; Cárdenas-Sánchez, E.

    2012-04-01

    Thermal images were obtained at Popocatépetl, central Mexico, during the period of high lava-dome destruction activity between 1998 and 2002. Similarly, thermal cameras have operated at Colima volcano, western Mexico during episodes of similar explosive activity in 2005 and 2007. We have developed a method to estimate the relative thermal energy release among explosions, and the degree of conversion into mechanical energy spent in the fragmentation of the ejecta, based on the cooling rate inferred from successive thermal images obtained immediately after each explosion. The thermal imaging cameras were located at about 11 km from the crater at Popocatépetl, and at about 6 km from the crater at Colima. The selected explosions threw significant amounts of hot debris on the volcano flanks. The cooling rate was then measured on selected pixels of the thermal images, and compared with different possible distributions of fragment sizes considering weighted averages of fragments in the pixels. The optimal fitting of fragment distributions reveals the degree of fragmentation of individual explosions, and along with a model for the cooling process, permitted to estimate the relative thermal energy release on the area covered by the image. Additionally, the results indicate that the radiative thermal conductivity plays a significant role on the outer shell of the fragments, suggesting a free mean path of thermal infrared photons that may reach several millimeters or even a few centimeters.

  13. Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

    PubMed

    Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

    2016-09-01

    The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency. PMID:27537862

  14. A novel application of concentrated solar thermal energy in foundries.

    PubMed

    Selvaraj, J; Harikesavan, V; Eshwanth, A

    2016-05-01

    Scrap preheating in foundries is a technology that saves melting energy, leading to economic and environmental benefits. The proposed method in this paper utilizes solar thermal energy for preheating scrap, effected through a parabolic trough concentrator that focuses sunlight onto a receiver which carries the metallic scrap. Scraps of various thicknesses were placed on the receiver to study the heat absorption by them. Experimental results revealed the pattern with which heat is gained by the scrap, the efficiency of the process and how it is affected as the scrap gains heat. The inferences from them gave practical guidelines on handling scraps for best possible energy savings. Based on the experiments conducted, preheat of up to 160 °C and a maximum efficiency of 70 % and a minimum efficiency of 40 % could be achieved across the time elapsed and heat gained by the scrap. Calculations show that this technology has the potential to save around 8 % of the energy consumption in foundries. Cumulative benefits are very encouraging: 180.45 million kWh of energy savings and 203,905 t of carbon emissions cut per year across the globe. This research reveals immense scope for this technology to be adopted by foundries throughout the world. PMID:26208658

  15. Microwave impregnation of porous materials with thermal energy storage materials

    DOEpatents

    Benson, D.K.; Burrows, R.W.

    1993-04-13

    A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

  16. Microwave impregnation of porous materials with thermal energy storage materials

    DOEpatents

    Benson, David K.; Burrows, Richard W.

    1993-01-01

    A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

  17. Thermal energy storage for the Stirling engine powered automobile

    NASA Technical Reports Server (NTRS)

    Morgan, D. T. (Editor)

    1979-01-01

    A thermal energy storage (TES) system developed for use with the Stirling engine as an automotive power system has gravimetric and volumetric storage densities which are competitive with electric battery storage systems, meets all operational requirements for a practical vehicle, and can be packaged in compact sized automobiles with minimum impact on passenger and freight volume. The TES/Stirling system is the only storage approach for direct use of combustion heat from fuel sources not suitable for direct transport and use on the vehicle. The particular concept described is also useful for a dual mode TES/liquid fuel system in which the TES (recharged from an external energy source) is used for short duration trips (approximately 10 miles or less) and liquid fuel carried on board the vehicle used for long duration trips. The dual mode approach offers the potential of 50 percent savings in the consumption of premium liquid fuels for automotive propulsion in the United States.

  18. A thermal approach to waveform-independent energy determination

    NASA Astrophysics Data System (ADS)

    Möhring, Tobias; Spiegel, Thomas; Funck, Torsten

    2014-08-01

    In this paper, a new device for power and rms value measurement is presented. Unlike the commercially available measurement equipment, this device is not limited to special waveforms. As a reaction to the increasing use of energy harvesters, which gather energy from the ambience to power low-power electronics, it is necessary to develop new measurement equipment that is not limited to sinusoidal signals (harvesters generally deliver nonsinusoidal signals). Therefore, a new device is presented based on an isothermal operating mode of a planar multijunction thermal converter (PMJTC). Unlike previous PMJTCs, this one is equipped with an additional gold heater and is operated by a regulating circuit, which is electrically isolated from the input. The output signal of the regulator is recorded and analyzed to determine the power and rms value of the input signal.

  19. Improvement of pyroelectric cells for thermal energy harvesting.

    PubMed

    Hsiao, Chun-Ching; Siao, An-Shen; Ciou, Jing-Chih

    2012-01-01

    This study proposes trenching piezoelectric (PZT) material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters. PMID:22368484

  20. Improvement of Pyroelectric Cells for Thermal Energy Harvesting

    PubMed Central

    Hsiao, Chun-Ching; Siao, An-Shen; Ciou, Jing-Chih

    2012-01-01

    This study proposes trenching piezoelectric (PZT) material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters. PMID:22368484