Science.gov

Sample records for ocean thermal energy

  1. Ocean thermal energy conversion

    SciTech Connect

    Avery, W.H.

    1983-03-17

    A brief explanation of the Ocean Thermal Energy Conversion (OTEC) concept and an estimate of the amount of energy that can be produced from the ocean resource without introducing environmental concerns are presented. Use of the OTEC system to generate electric power and products which can replace fossil fuels is shown. The OTEC program status and its prospects for the future are discussed.

  2. 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)

  3. 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)

  4. 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.

  5. 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.

  6. Ocean thermal energy conversion (OTEC)

    SciTech Connect

    Lockerby, R.W.

    1981-01-01

    Ocean thermal energy conversion (OTEC) is reviewed briefly. The two types of OTEC system (open and closed) are described and limitations are pointed out. A bibliography of 148 references on OTEC is given for the time period 1975 to 1980. Entries are arranged alphabetically according to the author's name. (MJJ)

  7. Energy from ocean thermal gradients

    NASA Astrophysics Data System (ADS)

    Cohen, R.

    1980-02-01

    Ocean Thermal Energy Conversion (OTEC) transforms the solar heating of the ocean surface into electrical energy, either transmitting it to shore or using it to manufacture energy-intensive products such as aluminum, ammonia, hydrogen or magnesium at sea. Open-cycle systems, requiring extremely large turbines and degasifiers, are not thought to be as advanced as closed-cycle systems which use heat exchangers (either shell-and-tube or plate) that are made of titanium, stainless steel or aluminum alloys, which must minimize corrosion and biofouling, and that use ammonia, propane or fluorocarbons as working fluids. OTEC platform configurations include ship shapes and submersibles, such as spar buoys, and require cold-water pipes 1,000 m long, made of such materials as elastomers, lightweight concrete and fiberglass-reinforced plastic.

  8. Ocean thermal-energy conversion

    NASA Astrophysics Data System (ADS)

    Ford, G.; Niblett, C.; Walker, L.

    1983-03-01

    The principles underlying ocean thermal-energy conversion (OTEC) are reviewed, and a schematic layout of a system is included. The two systems currently under study, the open system and the closed system, are described. The prospect now, it is noted, is that OTEC plants will not be commercially viable on a widespread basis, even in the tropics. This is especially true of the large-scale plants that have been envisioned. A strong possibility is seen, however, that smaller plants, generating about 40 megawatts of electrical power, can survive commercially. The following conditions would favor their success: placement on land rather than at sea; placement in areas (such as islands) where alternative energy supplies are at a premium; and designing the plant to operate in conjunction with either an aquaculture or a desalination plant.

  9. Ocean thermal energy conversion: An overview

    NASA Astrophysics Data System (ADS)

    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 U.S. 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. An overview of the OTEC technology is provided.

  10. 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.

  11. Ocean thermal energy conversion: Materials issues

    NASA Astrophysics Data System (ADS)

    Darby, J. B., Jr.

    The Ocean thermal Energy Conversion (OTEC) Program, in the Ocean Energy Technology Division of the U.S. Department of Energy, is concerned with the development of options that can be utilized to extract and distribute significant amounts of energy from the ocean. The biofouling control and materials portion of the program is concerned with the development of effective and environmentally acceptable methods to minimize biofouling and corrosion in high thermal conductivity materials suitable for use in heat exchangers and condensers. The mechanical and chemical techniques employed for biofouling control are reviewed and the recent success with chlorination is presented. The corrosion of aluminum alloys, copper alloys, stainless steel, stainless alloys, and titanium in near-surface warm and deep cold water is reviewed with emphasis on aluminum alloys. The major materials issues are reviewed with emphasis on lifetime and cost.

  12. Ocean engineering for ocean thermal energy conversion

    SciTech Connect

    Not Available

    1982-01-01

    The panel on OTEC Ocean Engineering of the National Research Council was formed to assess the state of ocean engineering knowledge, technology, and practice necessary to design, construct, and operate OTEC plants. The panel concentrated its study on platforms, moorings, and foundations; the cold water pipe; and submarine cables for electric power transmission. The panel did not address the design and engineering of power plants; institutional and management issues or the commercial feasibility of OTEC; or its environmental impacts. The panel focused instead on determining the state of development of several of the ocean engineering technologies needed to design and construct a 40-MWe OTEC plant; it also examined the technical feasibility and advantages of larger and smaller plants.

  13. Ocean Engineering for Ocean Thermal Energy Conversion

    DTIC Science & Technology

    1982-01-01

    California Julian H. Si~nguan A. Dudley Waff Maritime Institute for Remsearchr S Annapolis, Maryland and Industri ~l Development Washington, D. C... industry in the development of OTEC. . The panel focused its assessment of feasibility on a 40-megawatt oehctric (MWe) OTEC plant because, in the main...Importance*** Difficulty*** Platforms, Moorings, and Foundations 1. Integrate industrial process design requirements with Land/Shelf/ ocean

  14. Concrete for Ocean Thermal Energy, Conversion Structures.

    DTIC Science & Technology

    1976-08-01

    construction of massive floating structures to house ocean thermal energy conversion ( OTEC ) systems. The relevant capabilities and limitations of available...which reasonable improvements can be made in the near term to provide greater assurances of long-term safe and reliable operation of the OTEC systems and to provide lower cost structures. (Author)

  15. Environmental impacts of ocean thermal energy conversion

    SciTech Connect

    Not Available

    1986-04-01

    Ocean thermal energy conversion (OTEC) is a promising technology for production of energy and usable by-products from solar-generated temperature gradients in the world's oceans. Although considered benign compared to alternative forms of energy generation, deployment of OTEC plants will result in interactions with marine, terrestrial, and atmospheric environments and in socioeconomic interactions with surrounding areas. The Ocean Energy Technology Program of the Department of Energy has funded research to improve the understanding of these interactions. No insurmountable environmental obstacle to OTEC deployment has been uncovered. This document contains a summary of that research for entrepreneurs, utility engineers, and others interested in pursuing OTEC's potential. In addition, it provides a guide to permits, regulations, and licenses applicable to construction of an OTEC plant.

  16. 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.

  17. Ocean thermal energy conversion: Perspective and status

    SciTech Connect

    Thomas, A.; Hillis, D.L.

    1990-01-01

    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 be 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--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 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. 7 refs.

  18. 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.

  19. 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)

  20. 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.

  1. 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)

  2. Ocean thermal energy conversion: report to congress - fiscal year 1982

    SciTech Connect

    Not Available

    1983-03-31

    National Oceanic and Atmospheric Administration (NOAA) activities related to ocean thermal energy conversion (OTEC) during fiscal year 1982 are described. The agency focus has been in the areas of providing ocean engineering and technical assistance to the Department of Energy (DOE), in streamlining the administration of the Federal OTEC licensing system, and in environmental assistance.

  3. 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.…

  4. Quantitative evaluation of ocean thermal energy conversion (OTEC): executive briefing

    SciTech Connect

    Gritton, E.C.; Pei, R.Y.; Hess, R.W.

    1980-08-01

    Documentation is provided of a briefing summarizing the results of an independent quantitative evaluation of Ocean Thermal Energy Conversion (OTEC) for central station applications. The study concentrated on a central station power plant located in the Gulf of Mexico and delivering power to the mainland United States. The evaluation of OTEC is based on three important issues: resource availability, technical feasibility, and cost.

  5. Dimensional Analysis of Ocean Thermal Energy Conversion Heat Exchangers

    DTIC Science & Technology

    1977-06-30

    8217thIJt4IiTY CLASSIFICATION OF TWI4S PAG(E ona Dola t ern.r) 20. (continued) c-a• of factors having significance in OTEC (Ocean Thermal Energy Conversion...heat exchangers. Certain of these groups are then evaluated for a model and prototype OTEC -Type heat exchanger using the same working fluid and ex...Development Administration, and the U. S. Navy are brought out. Chapter II investigates the scaling problems of heat ex- changers in OTEC (Ocean Thermal

  6. Research and development on ocean thermal energy conversion in Japan

    SciTech Connect

    Uehara, H.

    1982-08-01

    The study of Ocean Thermal Energy Conversion (OTEC) in Japan has been conducted under the leadership of a team of the ''Sunshine Project'', a national new energy development project promoted by the Ministry of International Trade and Industries (MITI) since 1974. At present, two experimental OTEC power plants -Nauru's OTEC plant and Imari's OTEC plant are operating. In this paper, the review of research and development activity of these two OTEC plants in Japan is made.

  7. 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.

  8. 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.

  9. Data Analysis for Ocean Thermal Energy Conversion (otec)

    DTIC Science & Technology

    1979-11-01

    Unit Number 01. The author wishes to thank Mr. David Boswell of DTNSRDC, Annapolis, Maryland for his work on OTEC software development. The...assistance of Mr. Glenn Grannemann of Carnegie-Mellon University, Pittsburgh, Pennsylvania, in reviewing Panama City OTEC data analysis techniques is...FOR OCEAN THERMAL ENERGY Technical Memodnndum CONVERSION ( OTEC ) , * IERFORMING Ono, XCIPOOT mulesea 7. AUTNORf.) .. CONTRACT OR GRANT S411jbdb .ftf

  10. 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.

  11. 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.).

  12. 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.

  13. Heat transfer research for ocean thermal energy conversion

    SciTech Connect

    Kreith, F.; Bharathan, D.

    1988-02-01

    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.

  14. 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.

  15. 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.

  16. Shelf mounted ocean thermal energy conversion platform, revised preliminary report

    NASA Astrophysics Data System (ADS)

    1984-03-01

    This report relates model tests of a generic Ocean Thermal Energy Conversion (OTEC) platform. The objective of these tests is to aid in the evaluation of new OTEC designs and to present a data base for design purposes. The test plant has been designed to provide a data base for comparison with current and projected analytical tools as well as comparisons of results from one model configuration to another. The new conceptual OTEC designs are different from the typical offshore (jacket type) structure which is quite transparent to waves. The major difference is the addition of large submerged power production modules to the frame. These proposed modules offer a large surface area to obstruct the flow and thereby increase the global wave forces acting on the structure.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Production of desalinated water using ocean thermal energy

    NASA Astrophysics Data System (ADS)

    Rabas, T.; Panchal, C.

    This paper describes an Ocean Thermal Energy Conversion (OTEC) desalination plant that consists of a multistage flash evaporator (MSF), a closed-cycle OTEC power plant, and an appropriate seawater system depending if the desalination plant is land based or floating. OTEC desalination plants of this type are preferred because the production of desalinated water far exceeds that obtained from other OTEC plant types employing the same size seawater system. The focus of the paper is on the multistage flash evaporator. The similarities and differences between conventional MSF and OTEC multistage flash evaporators (OTEC-MSF) are first described. Then the details of the OTEC-MSF evaporator design are discussed and preliminary correlations are recommended for the three major elements: the flash chamber, the moisture removal device, and the condenser. Recent advances such as enhanced condenser tubes, condensers of the compact type, and corrugated-plate moisture separators are introduced into the design. Comparisons of the water production capability, evaporator shell volume, and material cost are then presented for state-of-the-art and the new design concepts.

  3. Production of desalinated water using ocean thermal energy

    SciTech Connect

    Rabas, T.; Panchal, C.

    1991-01-01

    This paper describes an Ocean Thermal Energy Conversion (OTEC) desalination plant that consists of a multistage flash evaporator (MSF), a closed-cycle OTEC power plant, and an appropriate seawater system depending if the desalination plant is land based or floating. OTEC desalination plants of this type are preferred because the production of desalinated water far exceeds that obtained from other OTEC plant types employing the same size seawater system. The focus of the paper is on the multistage flash evaporator. The similarities and differences between conventional MSF and OTEC multistage flash evaporators (OTEC-MSF) are first described. Then the details of the OTEC-MSF evaporator design are discussed and preliminary correlations are recommended for the three major elements: the flash chamber, the moisture removal device, and the condenser. Recent advances such as enhanced condenser tubes, condensers of the compact type, and corrugated-plate moisture separators are introduced into the design. Comparisons of the water production capability, evaporator shell volume, and material cost are then presented for state-of-the-art and the new design concepts. 20 refs., 11 figs., 5 tabs.

  4. 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)

  5. 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.

  6. 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

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    1982-01-01

    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. This Quarterly Report summarizes the work on the various tasks as of 31 December 1981.

  9. 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.

  10. Heat Exchanger Cleaning in Support of Ocean Thermal Energy Conversion (OTEC) - Mechanical Subsystem.

    DTIC Science & Technology

    1980-12-01

    Thermal E ergy Conversion ( OTEC ) - Mechanical 416ś Subsyste 7,6. AaM4-"GO. PAORT NUIBER 7. AUTHOR(*) 8. CONTRACT OR GRANT NUMBER(s) Daniel ott 9...for Ocean Thermal Energy Conversion ( OTEC ). Described in the report are the water supply and distribution and the flow driven brush, recirculating...Recirculating Sponge Rubber Balls .. .... ............. 17 Chlorination .. .............. ............. 19 OTEC MAINTENANCE PROCEDURES

  11. Waterborne Noise due to Ocean Thermal Energy Conversion Plants.

    DTIC Science & Technology

    1982-06-17

    ocean current. Nini -OTEC OTEC-1 TB V/ON Lockheed OTEC-I moor a, b correlation length Used, 2/b 300 150 50 3 1500 Aeoliani tone flow velocity (rn/sec...representative OTEC designs. Acoustic power in band Nini -OTEC OTEC-I TRW/GM Lockheed 10 Hz to 1 kHz (ao) For individual pumps cold-water 1.0 X 10-2

  12. 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.

  13. Initial Study Of Potency Thermal Energy Using OTEC (Ocean Thermal Energy Conversion) As A Renewable Energy For Halmahera Indonesia

    NASA Astrophysics Data System (ADS)

    Andrawina, Y. O.; Sugianto, D. N.; Alifdini, I.

    2017-02-01

    The Blue Energy is the one of renewable energy. Indonesia as a maritime country has many potention to implement this Blue energy, but it still an advance technology to convert this energy into the electricity. The concept of OTEC with Land Based System is to boost the cost effectiveness of ocean technology. OTEC Land based system which is integrated with the cooling system, water desalination systems, aquaculture, and agriculture. Geographically Halmahera district is located in the Eastern Province of North Maluku. Halmahera is the one of remote island in Indonesia that still lack of electricity. By processing the Argo Float data in 2013-2015 using ODV (Ocean Data View) software, shows the difference of ocean temperature in Halmahera sea surface the range is 29°C. In depth of 1000 m, the sea temperature ranging from 2°C. The Electrical potential of OTEC a long 55 km Halmahera beach are around 93,1% as potential source of OTEC technology. The electricity OTEC prediction is 5,12 MW. Capacity factor of OTEC is 0.857, means that Halmahera have electrical potential for applying OTEC for each year is 35,88 GWh/year.

  14. Ocean thermal plant

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1979-01-01

    Modular Ocean Thermal-Energy Conversion (OTEC) plant permits vital component research and testing and serves as operational generator for 100 megawatts of electric power. Construction permits evaporators and condensers to be tested in same environment in which they will be used, and could result in design specifications for most efficient plant facilities in future.

  15. Ocean thermal plant

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1979-01-01

    Modular Ocean Thermal-Energy Conversion (OTEC) plant permits vital component research and testing and serves as operational generator for 100 megawatts of electric power. Construction permits evaporators and condensers to be tested in same environment in which they will be used, and could result in design specifications for most efficient plant facilities in future.

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

    NASA Astrophysics Data System (ADS)

    An ocean thermal energy conversion (OTEC) pilot plant conceptual design review is given. OTEC methanol production from coal is discussed. A review of electrolyzer development programs and requirements is given. Financial and legal considerations in OTEC implementation, potential navy sites for GEOTEC system, hybrid geothermal-OTEC power plants, single-cycle performance estimates, and supervision of testing of a pneumatic wave energy conversion system 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. Ocean thermal energy conversion: environmental effects assessment program plan, 1981-85. [Monograph

    SciTech Connect

    Not Available

    1982-01-01

    The Ocean Thermal Energy Conversion (OTEC) Act of 1980 calls for a legal regime to encourage commercial OTEC while protecting the oceanic and coastal environments. The Act also requires a generic plan for assessing the environmental effects of OTEC development. The plan outlined in this report establishes a priority list of nine environmental effects and a research strategy for reducing uncertainties, with an emphasis on large-scale and long-term ecosystem implications and on the impacts of multiple facilities. 70 references, 4 figures, 4 tables. (DCK)

  1. Ocean thermal energy conversion report to congress: fiscal year 1981. public law 96-320

    SciTech Connect

    Not Available

    1982-02-01

    After a section on the background of Ocean Thermal Energy Conversion, which deals with the national interest and the nature of the industry, this report discusses OTEC technology, the legal regime, environmental considerations and the international impact and future of OTEC. At the current time no amendments to the ACT are recommended. NOAA is analyzing several areas in which technical amendments would clarify the original intent of the Act. The most significant of these relates to the specific requirements for issuance of OTEC licenses for facilities that are located partly on land and partly in ocean waters.

  2. 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

  3. Flexible retractable cold water pipe for an ocean thermal energy conversion system

    SciTech Connect

    Wenzel, J.G.; Trimble, L.C.

    1985-02-05

    A cold water pipe for an ocean thermal energy conversion (OTEC) system comprises a tubular membrane made of a fabric such as a canvas, which is substantially impervious to flowing water. A proximal end of the pipe is secured to a surface structure such as a ship, and a distal end of the pipe is extendible from the surface structure to a selected ocean depth. The pipe functions as a conduit through which cold water from the selected ocean depth can be drawn to the surface structure for use in a thermodynamic process of the OTEC system. The distal end of the pipe can be quickly retracted to the surface structure when it becomes desirable to move the surface structure.

  4. 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.

  5. 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

  6. Definitional mission: Ocean Thermal Energy Conversion, Republic of the Marshall Islands. Export trade information

    SciTech Connect

    Dean, S.R.; Ross, J.M.

    1990-09-01

    The objective of the study was to determine the commercial viability of an Ocean Thermal Energy Conversion (OTEC) electric power plant at the Majuro Atoll in the Marshall Islands. It was concluded that various technology improvements and economic factors have converged to present a feasible opportunity. United States industrial and research organizations are technically capable of developing a commercial OTEC industry for domestic and export markets. It is estimated that 100% of OTEC equipment and services could be supplied by United States firms. However, Japan has aggressively pursued OTEC development with an apparent goal of dominating the export market.

  7. Effects of Drake Passage on the Ocean's Thermal and Mechanical Energy Budget in a Coupled AOGCM

    NASA Astrophysics Data System (ADS)

    von der Heydt, A. S.; Viebahn, J. P.

    2016-12-01

    the Southern Ocean sub-polar gyres inevitably leads to widespread warming around Antarctica. Moreover, we provide a framework to characterise the ocean temperature response to a closed Drake Passage in terms of both the mechanical and thermal energy budget of the ocean.

  8. 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.

  9. Assessment of microbial fouling in an ocean thermal energy conversion experiment.

    PubMed

    Aftring, R P; Taylor, B F

    1979-10-01

    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 degrees 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 10 cells per cm. The ranges of mean areal densities for other biological components were: organic carbon, 18 to 27 mug/cm; organic nitrogen, 1.5 to 3.0 mug/cm; adenosine 5'-triphosphate, 4 to 28 ng/cm; carbohydrate (as glucose in the phenol assay), 3.8 to 7.0 mug/cm; chlorophyll a, 0.2 to 0.8 ng/cm. 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 1mum 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Ocean thermal energy at the Johns Hopkins University Applied Physics Laboratory, quarterly report. Report for Jan-Mar 82

    SciTech Connect

    Not Available

    1982-01-01

    The following are included: Ocean thermal energy conversion (OTEC)--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.

  15. Study of hydraulic air compression for Ocean Thermal Energy Conversion open-cycle application

    NASA Astrophysics Data System (ADS)

    Golshani, A.; Chen, F. C.

    1983-01-01

    A hydraulic air compressor, which requires no mechanical moving parts and operates in a nearly isothermal mode, can be an alternative for the noncondensible gas disposal of an Ocean Thermal Energy Conversion (OTEC) open-cycle power system. The compressor requires only a downward flow of water to accomplish air compression. An air compressor test loop was assembled and operated to obtain test data that would lead to the design of an OTEC hydraulic air compressor. A one dimensional, hydraulic gas compressor, computer model was employed to simulate the laboratory experiments, and it was tuned to fit the test results. A sensitivity study that shows the effects of various parameters on the applied head of the hydraulic air compression is presented.

  16. Potential impact of ocean thermal energy conversion (OTEC) on fisheries. Technical report

    SciTech Connect

    Myers, E.P.; Hoss, D.E.; Matsumoto, W.M.; Peters, D.S.; Seki, M.P.

    1986-06-01

    The commercial development of ocean thermal energy conversion (OTEC) operations will involve some environmental perturbations for which there is no precedent experience. The pumping of very large volumes of warm surface water and cold deep water and its subsequent discharge will result in the impingement, entrainment, and redistribution of biota. Additional stresses to biota will be caused by biocide usage and temperature depressions. However, the artificial upwelling of nutrients associated with the pumping of cold deep water, and the artificial reef created by an OTEC plant may have positive effects on the local environment. Although more detailed information is needed to assess the net effect of an OTEC operation on fisheries, certain assumptions and calculations are made, supporting the conclusion that the potential risk to fisheries is not signnificant enough to deter the early development of OTEC. It will be necessary to monitor a commercial-scale plant in order to remove many of the remaining uncertainties.

  17. Integration of ocean thermal energy conversion power plants with existing power systems

    SciTech Connect

    Arunasalam, N.

    1986-01-01

    The problem of integrating an Ocean Thermal Energy Conversion (OTEC) power plant with existing power systems is studied. A nonlinear model of an OTEC power system is developed. The dynamics of the large local induction motor load, and the coaxial cable connection to the mainland are included in the model. The effect of the motor load and the coaxial cable on the steady-state stability of the OTEC power plant is investigated using linearized analysis. The transient stability of the OTEC system is investigated through simulation. The contribution made by the motor load and the coaxial cable to the transient stability is studied. The occurrence of self excitation phenomena is analyzed using linear methods and simulation. The effects of wave and vessel motion on the electrical power output of the OTEC plant is investigated.

  18. 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{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 US 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 US Department of Energy. An overview of all the programs is available, entitled Programs in Renewable Energy.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Open-cycle ocean thermal energy conversion surface-condenser design analysis and computer program

    SciTech Connect

    Panchal, C.B.; Rabas, T.J.

    1991-05-01

    This report documents a computer program for designing a surface condenser that condenses low-pressure steam in an ocean thermal energy conversion (OTEC) power plant. The primary emphasis is on the open-cycle (OC) OTEC power system, although the same condenser design can be used for conventional and hybrid cycles because of their highly similar operating conditions. In an OC-OTEC system, the pressure level is very low (deep vacuums), temperature differences are small, and the inlet noncondensable gas concentrations are high. Because current condenser designs, such as the shell-and-tube, are not adequate for such conditions, a plate-fin configuration is selected. This design can be implemented in aluminum, which makes it very cost-effective when compared with other state-of-the-art vacuum steam condenser designs. Support for selecting a plate-fin heat exchanger for OC-OTEC steam condensation can be found in the sizing (geometric details) and rating (heat transfer and pressure drop) calculations presented. These calculations are then used in a computer program to obtain all the necessary thermal performance details for developing design specifications for a plate-fin steam condenser. 20 refs., 5 figs., 5 tabs.

  4. A resource assessment of Southeast Florida as related to ocean thermal energy

    NASA Astrophysics Data System (ADS)

    Leland, Anna E.

    2009-11-01

    An assessment of the thermal resource in the Straits of Florida was performed to estimate the Ocean Thermal Energy Conversion (OTEC) potential. Direct measurements of the temperature profile across the Florida Straits were taken from nearshore Southeast Florida to the Exclusive Economic Zone boundary along four evenly spaced transects perpendicular to Florida's Southeast coast, spanning 160 km. Along the southern transects in summer, nearshore cold and warm water resources meet or exceed the average 20°C temperature difference required for OTEC. In winter, the nearshore average Delta T of 17.76°C can produce 59-75% design net power and 70-86% in spring with DeltaT averaging 18.25°C. Offshore along the southern transects, a high steady DeltaT from 18.5-24°C creates an annual average net power of 120-125MW. Along the northern transects, the nearshore resource does not exist, but a consistent OTEC resource is present offshore, providing 70-80% design net power in winter, and 100-158% in spring and summer.

  5. 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.

  6. 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.

  7. Open-cycle ocean thermal energy conversion surface-condenser design analysis and computer program

    NASA Astrophysics Data System (ADS)

    Panchal, C. B.; Rabas, T. J.

    1991-05-01

    This report documents a computer program for designing a surface condenser that condenses low-pressure steam in an ocean thermal energy conversion (OTEC) power plant. The primary emphasis is on the open-cycle (OC) OTEC power system, although the same condenser design can be used for conventional and hybrid cycles because of their highly similar operating conditions. In an OC-OTEC system, the pressure level is very low (deep vacuums), temperature differences are small, and the inlet noncondensable gas concentrations are high. Because current condenser designs, such as the shell-and-tube, are not adequate for such conditions, a plate-fin configuration is selected. This design can be implemented in aluminum, which makes it very cost-effective when compared with other state-of-the-art vacuum steam condenser designs. Support for selecting a plate-fin heat exchanger for OC-OTEC steam condensation can be found in the sizing (geometric details) and rating (heat transfer and pressure drop) calculations presented. These calculations are then used in a computer program to obtain all the necessary thermal performance details for developing design specifications for a plate-fin steam condenser.

  8. Innovative turbine concepts for open-cycle OTEC (Ocean Thermal Energy Conversion)

    NASA Astrophysics Data System (ADS)

    1989-12-01

    The results are summarized of preliminary studies conducted to identify and evaluate three innovative concepts for an open cycle ocean thermal energy conversion (OTEC) steam turbine that could significantly reduce the cost of OTEC electrical power plants. The three concepts are: (1) a crossflow turbine, (2) a vertical axis, axial flow turbine, and (3) a double flow, radial inflow turbine with mixed flow blading. In all cases, the innovation involves the use of lightweight, composite plastic blading and a physical geometry that facilitates efficient fluid flow to and from the other major system components and reduces the structural requirements for both the turbine or the system vacuum enclosure, or both. The performance, mechanical design, and cost of each of the concepts are developed to varying degrees but in sufficient detail to show that the potential exists for cost reductions to the goals established in the U.S. Department of Energy's planning documents. Specifically, results showed that an axial turbine operating with 33 percent higher steam throughput and 7 percent lower efficiency than the most efficient configuration provides the most cost effective open-cycle OTEC system. The vacuum enclosure can be significantly modified to reduce costs by establishing better interfaces with the system.

  9. Innovative turbine concepts for open-cycle OTEC (ocean thermal energy conversion)

    SciTech Connect

    Not Available

    1989-12-01

    This report summarizes the results of preliminary studies conducted to identify and evaluate three innovative concepts for an open-cycle ocean thermal energy conversion (OTEC) steam turbine that could significantly reduce the cost of OTEC electrical power plants. The three concepts are (1) a crossflow turbine, (2) a vertical-axis, axial-flow turbine, and (3) a double-flow, radial-inflow turbine with mixed-flow blading. In all cases, the innovation involves the use of lightweight, composite plastic blading and a physical geometry that facilitates efficient fluid flow to and from the other major system components and reduces the structural requirements for both the turbine or the system vacuum enclosure, or both. The performance, mechanical design, and cost of each of the concepts are developed to varying degrees but in sufficient detail to show that the potential exists for cost reductions to the goals established in the US Department of Energy's planning documents. Specifically, results showed that an axial turbine operating with 33% higher steam throughput and 7% lower efficiency than the most efficient configuration provides the most cost-effective open-cycle OTEC system. The vacuum enclosure can be significantly modified to reduce costs by establishing better interfaces with the system. 33 refs., 26 figs., 11 tabs.

  10. Experiments on oxygen desorption from surface warm seawater under open-cycle ocean thermal energy conversion

    SciTech Connect

    Pesaran, A.A. )

    1992-11-01

    This paper presents the results of scoping deaeration experiments conducted with warm surface seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions. Concentrations of dissolved oxygen in seawater at three locations (in the supply water, water leaving the predeaerator, and discharge water from an evaporator) were measured and used to estimate oxygen desorption levels. The results suggest that 7 percent to 60 percent of the dissolved oxygen in the supply water was desorbed from seawater in the predeaerator for pressures ranging from 35 to 9 kPa. Bubble injection in the upcomer increased the oxygen desorption rate by 20 percent to 60 percent. The data also indicated that at typical OC-OTEC evaporator pressures, when flash evaporation in the evaporator occurred, 75 percent to 95 percent of the dissolved oxygen was desorbed overall from the warm seawater. The results were used to find the impact of a single-stage predeaeration scheme on the power to remove noncondensable gases in an OC-OTEC plant.

  11. Technology development plan: Geotechnical survey systems for OTEC (Ocean Thermal Energy Conversion) cold water pipes

    NASA Astrophysics Data System (ADS)

    Valent, Philip J.; Riggins, Michael

    1989-04-01

    An overview is given 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 deg and in water depths to 1300 m.

  12. 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.

  13. 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.

  14. Identification of types of businesses with potential interest in operating and/or exporting ocean thermal energy conversion (OTEC) plants

    SciTech Connect

    Not Available

    1982-09-01

    This study describes the characteristics of three selected Ocean Thermal Energy Conversion (OTEC)-based lines of business, examines other lines of business and identifies those with similar characteristics, and indicates the types of businesses/corporations that could be expected to have potential interest in operating and/or exporting OTEC plants. An OTEC line of business model is developed to assist companies in making an internal corporate assessment as to whether OTEC should be in their business plan.

  15. 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.

  16. A quantitative evaluation of closed-cycle ocean thermal energy conversion (OTEC) technology in central station applications

    NASA Astrophysics Data System (ADS)

    Gritton, E. C.; Pei, R. Y.; Aroesty, J.; Balaban, M. M.; Gazley, C.; Hess, R. W.; Krase, W. H.

    1980-05-01

    An evaluation of a closed cycle Ocean Thermal Energy Conversion (OTEC) system for delivery of electric power to the United States is presented. Performance and costs of complete commercial OTEC systems are analyzed at the system level using inputs from component analyses and thermal resource data in the Gulf of Mexico. Such sites could feed the Gulf Coast from the west coast of Florida to the New Orleans area. By exploiting the temperature difference between warm surface waters and cold water from the depths to operate a thermodynamic cycle to generate electricity, OTEC acts as a heat engine that taps the surface waters of tropical and subtropical oceans as a heat source and the cold water originating in the polar regions as a heat sink. Results of the engineering analysis indicate that the system and platform appear to be within the state-of-the-art.

  17. 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.

  18. 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.

  19. Far-field model of the regional influence of affluent plumes from Ocean Thermal Energy Conversion (OTEC) plants

    NASA Astrophysics Data System (ADS)

    Wang, D. P.

    1985-07-01

    Ocean thermal energy conversion (OTEC) plants discharge large volumes of cold water into the upper ocean. A three-dimensional, limited-area model was developed to investigate the regional influence of the far-field effluent plume created by the negatively buoyant discharge. The model was applied to discharges from a 40-MW sub e OTEC plant into coastal waters characterized by various ambient ocean conditions. A typical ambient temperature structure and nutrient distribution, as well as the behavior of the effluent plume itself, were strongly modified by the discharge-induced circulation. Although temperature perturbations in the plume were small, upward entrainment of nutrients from below the thermocline was significant. The regional influence of discharges from an 80-MW sub e OTEC plant, the interactions between the discharges from two adjacent 40-MW sub e OTEC plants, and the effects of coastal boundary and bottom discharge were examined with respect to the regional influence of a 40-MW sub e OTEC plant located in deep water off a coast (base case).

  20. Far-field model of the regional influence of effluent plumes from ocean thermal energy conversion (OTEC) plants

    SciTech Connect

    Wang, D.P.

    1985-07-01

    Ocean thermal energy conversion (OTEC) plants discharge large volumes of cold water into the upper ocean. A three-dimensional, limited-area model was developed to investigate the regional influence of the far-field effluent plume created by the negatively buoyant discharge. The model was applied to discharges from a 40-MW/sub e/ OTEC plant into coastal waters characterized by various ambient ocean conditions. A typical ambient temperature structure and nutrient distribution, as well as the behavior of the effluent plume itself, were strongly modified by the discharge-induced circulation. Although temperature perturbations in the plume were small, upward entrainment of nutrients from below the thermocline was significant. The regional influence of discharges from an 80-MW/sub e/ OTEC plant, the interactions between the discharges from two adjacent 40-MW/sub e/ OTEC plants, and the effects of coastal boundary and bottom discharge were examined with respect to the regional influence of a 40-MW/sub e/ OTEC plant located in deep water off a coast (base case).

  1. Ocean Thermal Energy Conversion: The Potential Impact of Bottom Water Discharge at Subsurface on Microphytoplankton in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    de la Broise, D.; Giraud, M.; Garcon, V.; Boye, M.

    2016-02-01

    Mélanie Giraud1,2,3, Véronique Garçon3, Marie Boye11LEMAR - UMR 6539 Plouzané France, 2France Energies Marines Brest France, 3LEGOS/CNRS Toulouse -France 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. The OTEC installed off the Caribbean coast of Martinique is expected to pump approximately 100 000 m3/h of deep seawater for its functioning. The resulting impact of this cold nutrient-rich deep seawater discharge on the phytoplankton community of the nutrient depleted surface water is not fully understood. Therefore, a study was initiated before the installation of the pilot plant. The vertical and horizontal seawater plume dispersion of the deep seawater upwelling was described using the Regional Ocean Modeling System (ROMS). Field data allowed describing the expected chemical characteristics of the resulting mixed seawaters. The potential impact on the phytoplankton community was evaluated by in situ microcosm experiments. Two deep seawater ratio (2% and 10%) and two incubation depths (deep chlorophyll maximum and euphotic layer deep limit) were tested, showing a larger impact at the deep chlorophyll maximum and for the higher deep seawater concentration (10%). The microcosm enrichment by 10% of deep seawater induced a significant shift in the phytoplankton assemblage, supporting diatoms development, whereas the enrichment by 2% of deep seawater only showed a small shift in phytoplankton population. Experimental and modelling results were combined in order to identify the deep seawater discharge depth exhibiting the

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. Development of a demonstration power plant by ocean thermal energy conversion (OTEC)

    SciTech Connect

    Ito, F.; Takazawa, K.; Terayama, T.

    1984-01-01

    At the opening ceremony, the system was praised by leading figures invited from the Oceanic non-oil-producing countries. The power generation test of the OTEC demonstration plant was completed with many new records attained. As engineers who have participated in this project, the authors believe that they have gained confidence in their ability to construct a first-stage commercial OTEC plant of the built-on-land type, though admitting that there still remain some points to be improved. Subjects requiring further study are improvements of material and installation methods enabling the use of water intake piping with larger diameters, further improvement of heat transfer performance at the seawater side (tube inside) of the heat transfer tubes, etc. Since the commercialization of an OTEC system depends mainly on the economical level of the system, cost reduction in the manufacture of equipment and construction is also required.

  9. Coupling Ocean Thermal Energy Conversion technology (OTEC) with nuclear power plants

    SciTech Connect

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

    1981-01-01

    The prospects of utilizing an OTEC Related Bottoming Cycle to recover waste heat generated by a large nuclear (or fossil) power plant are examined. With such improvements, OTEC can become a major energy contributor. 12 refs.

  10. 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.

  11. Study to develop an inspection, maintenance, and repair plan for OTEC (Ocean Thermal Energy Conversion) modular experiment plants. Final report

    SciTech Connect

    Not Available

    1980-04-01

    The inspection, maintenance and repair (IM and R) of the Ocean Thermal Energy Conversion (OTEC) Modular Experiment Plant (Pilot Plant) have been studied in two phases: Task I and Task II. Task I phase developed IM and R identification forms, identified requirements for routine and post casualty IM and R, and categorized and outlined potential procedures to perform IM and R activities. The efforts of the Task II phase have been directed to meet the following objectives: to provide feedback to the OTEC marine systems designs to assure that such designs reflect appropriate consideration of IM and R methods and unit costs, resulting in designs with reduced life cycle costs; to include technical information concerning OTEC IM and R possibilities to NOAA/DOE; to outline a basis in which the anticipated IM and R contributions to life cycle costs can be developed for any specific OTEC plant design; to identify IM and R methods within the state-of-the-art in the offshore industry; to determine the application of potential IM and R procedures for the commercial operation of OTEC 10/40 Pilot Plant(s); and input into the US government formulation of statutory and regulatory IM and R requirements for OTEC plants.

  12. Experiments on oxygen desorption from surface warm seawater under Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) conditions

    NASA Astrophysics Data System (ADS)

    Pesaran, Ahmad 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 pct to 60 pct 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 pct to 60 pct. 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 pct to 95 pct 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Ocean Energy Technology assessment

    SciTech Connect

    Not Available

    1983-07-01

    The Department of Energy Ocean Energy Technology (OET) program is assessed. A summary of OET program activities during the period FY 1980 through FY 1983 documents the most significant findings of DOE-sponsored research and development in each of six program elements: Advanced Power Systems Development, Closed-Cycle Power Systems Development, Alternative Energy Systems Development, Environmental Research, Ocean Engineering, and Engineering Development. The summary is based on extensive review of technical documentation and discussions with DOE and field organization personnel. The result is a concise, comprehensive description of all significant OET activities during the period. Assessment of the current state of ocean technologies is documented through the use of matrices which relate elements of the current ocean technology WBS to a nine-level scale which defines technology status ranging from preliminary feasibility through off-the-shelf availability. These Technical Progress Matrices (TPMs) were developed for each of four ocean system configurations by integrating inputs from seven OET participating field organizations. An evaluation of the critical technical unknowns which would form the basis for future ocean energy public and private research and development activities is presented. This evaluation was accomplished using an accepted technique for group interaction and consensus formation in a meeting of knowledgeable program participants. The results of this meeting are presented in the form of forty minimum essential unknowns (MEUs). An analysis of the correlation of this list of unknowns with DOE policy and selection criteria for acceptable federally-sponsored R and D revealed significant research needs in the areas defined as the primary federal role.

  20. Heat transfer in ocean thermal energy conversion (OTEC) systems. Proceedings of the wanter mnnual Meeting, Chicago, IL, November 16-21, 1980

    SciTech Connect

    Owens, W.L.

    1980-01-01

    Among the topics discussed are: condensation heat transfer on long vertical, axially ridged tubes tests of the Applied Physics Laboratory of Johns Hopkins University (APL/JHU) folded-tube, Ocean Thermal Energy Conversion (OTEC) heat exchanger the design of a 1.0-MW OTEC heat exchanger for ocean testing and convective vaporization and condensation in serrated-fin channels. Also considered are: heat tranfer studies of an improved heat transfer monitor for OTEC an analysis of the mist lift process for mist flow, open-cycle OTEC the heat transfer characteristics of working fluids for OTEC and a comparison of major OTEC power system characteristics.

  1. 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

  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

    2010-08-11

    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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Ocean Modulation of the Thermal Wind

    NASA Astrophysics Data System (ADS)

    Hester, R. E.

    2009-12-01

    Modification of the sea surface temperature is shown to effect atmospheric circulation in a low resolution atmospheric general circulation model. One hypothesis, not directly tested here, is that a change in oceanic deep mixing processes allows less ocean surface heat to be carried into the depths, and preferentially effects the lower latitudes. Here it is proposed that a specific pattern of excess sea surface heat, similar to the Pacific Decadal Oscillation pattern of sea surface temperature anomalies, is transferred to the atmosphere by radiation and evaporation, and contributes to an increased equator to pole atmospheric temperature gradient. We then apply the theory of the thermal wind, which uses first order dynamics of the global atmosphere to relate horizontal temperature gradients to vertical gradients in the geostrophic winds. Thermal wind theory is used here to predict the changes in atmospheric circulation that result from changes in the latitudinal distribution of sea surface temperature. The predictions are tested by low resolution computer simulations and found to agree within an order of magnitude. We speculate on the role of ocean circulation oscillations in decadal climate variability, and on an energy and dissipation accounting approach to begin to quantify how anthropogenic radiative forcing is effecting natural climate modes of variability.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Ocean thermal energy conversion preliminary data report for the November 1977 GOTEC-02 cruise to the Gulf of Mexico Mobile Site

    SciTech Connect

    Commins, M. L; Duncan, C. P.; Estrella, D. J.; Frisch, J. D.; Horne, A. J.; Jones, K.; Johnson, P. W.; Oldson, J. C.; Quinby-Hunt, M. S.; Ryan, C. J.; Sandusky, J. C.; Tatro, M.; Wilde, P.

    1980-03-01

    This is the second in a series of preliminary data reports from cruises to potential Ocean Thermal Energy Conversion (OTEC) sites in the Gulf of Mexico. The data are from the GOTEC-02 cruise to a site at approximately 29/sup 0/N, 88/sup 0/W, the Mobile Site. Twelve oceanographic stations were visited. Due to bad weather, the results are scanty. The reader will note that much of the data is questionable. Current meter results are presented elsewhere (Molinari, Hazelworth and Ortman, 1979). Determinations of the biomass indicators - chlorophyll a, phaeophytins and adenosine triphosphate - and zooplankton, are presented. Results were generally those that might have been predicted from previous studies in the area.

  15. 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.

  16. 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.

  17. Distribution of energy in the ocean and atmosphere as a result of their thermal and dynamic interactions

    NASA Technical Reports Server (NTRS)

    Gusev, A. M.; Alekseeyev, V. V.; Aleksandrov, A. A.

    1975-01-01

    A two dimensional stationary model of the ocean-atmosphere interaction is formulated that satisfies the thermohydrodynamic convection equations in a Boussinesq approximation of heat input from the sun.

  18. 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.

  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. 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.

  1. 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.

  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

    NASA Astrophysics Data System (ADS)

    Tomlinson, J. J.

    1992-03-01

    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 Oak Ridge National Laboratory's TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

  4. Thermal energy storage

    NASA Astrophysics Data System (ADS)

    Tomlinson, J. J.

    1991-03-01

    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 in development of TES for specific diurnal and industrial applications under Oak Ridge National Laboratory's TES program from April 1989 to March 1990 is reported.

  5. 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.

  6. 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.

  7. Commercialization and cost-sharing potential for Ocean Thermal Energy Conversion (OTEC) plantships and facilities by industry, utilities and government

    SciTech Connect

    Francis, E.J.

    1980-01-01

    Following the introduction and summary on the US energy situation and the potential for OTEC, the remaining chapters deal with the OTEC-ammonia model; legal aspects of OTEC commercialization; the formation of SOLARAMCO, a joint venture of ammonia companies; electric power from OTEC, fuel cells and direct cables, potential cost-sharing; and OTEC production of ammonia for fertilizer.

  8. On the thermally-driven ocean

    NASA Astrophysics Data System (ADS)

    Gjermundsen, Ada; LaCasce, Joseph Henry; Denstad, Liv

    2017-04-01

    How will the ocean circulation respond to extensive temperature change? Warming over the Arctic Ocean due to the loss of sea ice and snow cover will impact the surface air temperature (Serreze and Farncis, 2006; Screen and Simmonds, 2010) and thereby the Northern Hemisphere (NH) temperature gradient. The ocean circulation will respond, but freshwater from ice melting and shifting storm tracks make it hard to determine the ocean response to temperature changes alone. Attempts have been made to separate the impact of wind, thermal and freshwater forcings on the large scale ocean circulation (Cai, 1994; Saenko et al., 2002; Nycander et al. 2007), but our understanding remains incomplete. Here we examine numerical solutions of the global circulation with realistic bathymetry, driven solely by surface buoyancy forcing. Explicit wind forcing is excluded, although vertical mixing is retained. The character of the resulting flow is consistent in many ways with the observed ocean circulation,with inflow to and sinking in the Nordic Seas, baroclinic western boundary currents and an overturning streamfunction which closely resembles those obtained in full GCMs and in observations. The overturning circulation exhibits two thermally-driven cells: one in the Southern Ocean (SO) and one in the Atlantic. We investigate the inter-basin transports, the relative importance of the two overturning cells for the global ocean circulation, as well as the sensitivity of the ocean circulation to changes in buoyancy forcing. We find that reduced Atlantic overturning accelerates the SO circulation, while a reduced SO circulation strengthens the Atlantic overturning considerably. References: Cai, W. (1994). Circulation driven by observed surface thermohaline fields in a coarse resolution ocean general circulation model. J. Geophys. Res.: Oceans, 99, 10163-10181. Nycander, J. et al. (2007). Thermodynamic Analysis of Ocean Circulation, J. Phys. Oceanogr., 37, 2038-2052. Saenko, O. A. et al

  9. Initial screening of license applications for ocean thermal energy conversion (OTEC) plants with regard to their interaction with the environment

    SciTech Connect

    Paddock, R.A.; Ditmars, J.D.

    1983-02-01

    Presented is a three-step initial screening procedure to help NOAA assess the completeness and adequacy of the application with regard to the interaction of the OTEC plant with the environment. The three steps are (1) characterize the plant and site, (2) characterize the seawater intake and discharge flow fields, and (3) consider the major environmental issues associated with plant operation. The first step ensures that the application fully characterizes the proposed plant and site. The second step qualitatively describes the intake and discharge flow fields and then quantifies those descriptions. The third step identifies the major environmental issues and addresses them in light of the estimated behavior of the intake and discharge flow fields. The major issues are thermal resource utilization and recirculation; biota attraction and avoidance, entrainment, and impingement; biocide and other toxic chemical release; and nutrient redistribution. After completing the initial screening procedure, NOAA must evaluate the environmental monitoring program proposed by the applicant and prepare an environmental impact statement (EIS) that fulfills the requirements of all concerned federal agencies.

  10. 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.

  11. OTEC (Ocean Thermal Energy Conversion) Cold Water Pipe At-Sea Test Program Data Analysis Project: Users guide for the NOAA/ROTECF and NOAA/TRW computer models

    NASA Astrophysics Data System (ADS)

    Vega, L. A.; Nihous, G. C.

    1985-06-01

    Additional guidelines for the use of the Cold-Water-Pipe computer models NOAA/TRW and NOAA/ROTECF are provided. The primary intent is to correct and upgrade the user manuals with errata sheets and to provide an updated listing of the source codes. It is recommended that users be familiar with the hydrodynamic and structural aspects of floating vessels and the representation of ocean thermal energy conversion pipes as beams of equivalent structural properties.

  12. 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.

  13. 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.

  14. Thermal energy storage material

    SciTech Connect

    Kent, P.J.; Page, J.K.

    1980-06-24

    A thermal energy storage material is disclosed that is comprised of at least one hydrated inorganic salt having a transition temperature to the anhydrous or a less hydrated form in the range 10/sup 0/ to 100/sup 0/ C (for example, sodium sulphate decahydrate), the salt being dispersed and suspended in a water-insoluble hydrogel formed from a water-soluble synthetic polymer having pendant carboxylic or sulphonic acid groups cross-linked with cations of a polyvalent metal (For example, aluminium or magnesium).

  15. 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.

  16. Ocean atmosphere thermal decoupling in the eastern equatorial Indian ocean

    NASA Astrophysics Data System (ADS)

    Joseph, Sudheer; Ravichandran, M.; Kumar, B. Praveen; Jampana, Raju V.; Han, Weiqing

    2016-09-01

    Eastern equatorial Indian ocean (EEIO) is one of the most climatically sensitive regions in the global ocean, which plays a vital role in modulating Indian ocean dipole (IOD) and El Niño southern oscillation (ENSO). Here we present evidences for a paradoxical and perpetual lower co-variability between sea-surface temperature (SST) and air-temperature (Tair) indicating instantaneous thermal decoupling in the same region, where signals of the strongly coupled variability of SST anomalies and zonal winds associated with IOD originate at inter-annual time scale. The correlation minimum between anomalies of Tair and SST occurs in the eastern equatorial Indian ocean warm pool region (≈70°E-100°E, 5°S-5°N), associated with lower wind speeds and lower sensible heat fluxes. At sub-monthly and Madden-Julian oscillation time scales, correlation of both variables becomes very low. In above frequencies, precipitation positively contributes to the low correlation by dropping Tair considerably while leaving SST without any substantial instant impact. Precipitation is led by positive build up of SST and post-facto drop in it. The strong semi-annual response of SST to mixed layer variability and equatorial waves, with the absence of the same in the Tair, contributes further to the weak correlation at the sub-annual scale. The limited correlation found in the EEIO is mainly related to the annual warming of the region and ENSO which is hard to segregate from the impacts of IOD.

  17. Ocean atmosphere thermal decoupling in the eastern equatorial Indian ocean

    NASA Astrophysics Data System (ADS)

    Joseph, Sudheer; Ravichandran, M.; Kumar, B. Praveen; Jampana, Raju V.; Han, Weiqing

    2017-07-01

    Eastern equatorial Indian ocean (EEIO) is one of the most climatically sensitive regions in the global ocean, which plays a vital role in modulating Indian ocean dipole (IOD) and El Niño southern oscillation (ENSO). Here we present evidences for a paradoxical and perpetual lower co-variability between sea-surface temperature (SST) and air-temperature (Tair) indicating instantaneous thermal decoupling in the same region, where signals of the strongly coupled variability of SST anomalies and zonal winds associated with IOD originate at inter-annual time scale. The correlation minimum between anomalies of Tair and SST occurs in the eastern equatorial Indian ocean warm pool region (≈70°E-100°E, 5°S-5°N), associated with lower wind speeds and lower sensible heat fluxes. At sub-monthly and Madden-Julian oscillation time scales, correlation of both variables becomes very low. In above frequencies, precipitation positively contributes to the low correlation by dropping Tair considerably while leaving SST without any substantial instant impact. Precipitation is led by positive build up of SST and post-facto drop in it. The strong semi-annual response of SST to mixed layer variability and equatorial waves, with the absence of the same in the Tair, contributes further to the weak correlation at the sub-annual scale. The limited correlation found in the EEIO is mainly related to the annual warming of the region and ENSO which is hard to segregate from the impacts of IOD.

  18. 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.

  19. 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.

  20. 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.

  1. Thermal Energy Briefing with FPL

    NASA Image and Video Library

    2017-02-17

    Ismael H. Otero, NASA Kennedy Space Center's project manager on the thermal energy program, addresses the news media and NASA Social about the new Thermal Energy Storage (TES) tank Feb. 17. The TES tank works like a giant battery and is saving the center utility cost. These savings will be applied to new sustainable projects at Kennedy.

  2. Contribution of Surface Thermal Forcing to Mixing in the Ocean

    NASA Astrophysics Data System (ADS)

    Wang, F.; Huang, S. D.; Xia, K. Q.

    2016-12-01

    The mixing rate in convective flows driven by surface temperature gradient is investigated laboratorially to understand the contribution of surface thermal forcing (STF) to mixing in ocean. We found that either increasing Rayleigh number Ra or lateral aspect ratio Г can individually enhance the mixing. It is the depth ratio, defined by the ratio of thermocline thickness to sea depth, that substantially determines the contribution of STF to mixing in ocean. If the ocean circulation is purely driven by STF, the mixing rate and mixing efficiency will be O(10-6 m2/s) and 0.95, which are far from the real values, O(10-5 m2/s) and 0.17, in ocean. The meridional heat transport will also be two orders smaller than the real value 2 PW nowadays. These suggest that the mixing in real ocean is not dominated by STF and the meridional heat transport is conveyor belt powered by other energy source like wind stress.

  3. Thermal structure of oceanic transform faults

    USGS Publications Warehouse

    Behn, M.D.; Boettcher, M.S.; Hirth, G.

    2007-01-01

    We use three-dimensional finite element simulations to investigate the temperature structure beneath oceanic transform faults. We show that using a rheology that incorporates brittle weakening of the lithosphere generates a region of enhanced mantle upwelling and elevated temperatures along the transform; the warmest temperatures and thinnest lithosphere are predicted to be near the center of the transform. Previous studies predicted that the mantle beneath oceanic transform faults is anomalously cold relative to adjacent intraplate regions, with the thickest lithosphere located at the center of the transform. These earlier studies used simplified rheologic laws to simulate the behavior of the lithosphere and underlying asthenosphere. We show that the warmer thermal structure predicted by our calculations is directly attributed to the inclusion of a more realistic brittle rheology. This temperature structure is consistent with a wide range of observations from ridge-transform environments, including the depth of seismicity, geochemical anomalies along adjacent ridge segments, and the tendency for long transforms to break into small intratransform spreading centers during changes in plate motion. ?? 2007 Geological Society of America.

  4. Ocean floor mounting of wave energy converters

    DOEpatents

    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.

  5. 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.

  6. Thermal state of continental and oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Hasterok, Derrick P.

    The thermal state of the continental and oceanic lithosphere is reassessed on the basis of new databases for global heat flow and lithospheric heat production, recent advances in thermophysical properties measurements of minerals at high pressures and temperatures, and a better understanding of convective heat loss in young seafloor. The updated global heat flow database incorporates >60,000 records with >44,800 heat flow determinations. The update significantly increases the quantity and spatial coverage of global heat flow data since the last update in 1993. A new family of continental geotherms is proposed that is parametric in surface heat flow and takes advantage of thermophysical property data. The range of geotherms is constrained by xenolith P--T estimates; a cratonic geotherm consistent with a surface heat flow of 40 mW/m2 is particularly well constrained. Upper crustal heat production represents ˜26% of the total surface heat flow. Average heat production for the continental lower crust and mantle are 0.4 muW/m3 and 0.02 muW/m3, respectively. Recent controversy about the interpretation of heat flow observations in young seafloor is resolved by careful filtering of data based on sediment thickness and distance from seamounts and weighting marine studies where the environment of heat flow measurements is carefully documented. Oceanic geotherms, fit to bathymetry and heat flow data, are produced for a plate model with 7 km thick crust, a plate thickness of 95 km, and mantle potential temperature of 1425°C. While the current estimate of global heat loss (44 TW) is reasonable, these new reference models will be instrumental in refining and estimating uncertainty in the solid Earth's global heat loss.

  7. Energy cycling and hypothetical organisms in Europa's ocean.

    PubMed

    Schulze-Makuch, Dirk; Irwin, Louis N

    2002-01-01

    While Europa has emerged as a leading candidate for harboring extraterrestrial life, the apparent lack of a source of free energy for sustaining living systems has been argued. In this theoretical analysis, we have quantified the amount of energy that could in principle be obtained from chemical cycling, heat, osmotic gradients, kinetic motion, magnetic fields, and gravity in Europa's subsurface ocean. Using reasonable assumptions based on known organisms on Earth, our calculations suggest that chemical oxidation-reduction cycles in Europa's subsurface ocean could support life. Osmotic and thermal gradients, as well as the kinetic energy of convection currents, also represent plausible alternative sources of energy for living systems at Europa. Organisms thriving on these gradients could interact with each other to form the complex energy cycling necessary for establishing a stable ecosystem.

  8. 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.

  9. 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.

  10. 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... Interior is renewing the Ocean Energy Safety Advisory Committee. The Ocean Energy Safety Advisory...

  11. 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.

  12. 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.

  13. Hemispheric energy balance from an ocean perspective

    NASA Astrophysics Data System (ADS)

    Hakuba, M. Z.; Stephens, G. L.

    2016-12-01

    Although the Earth's energy balance has been studied for many decades, a number of challenges still remain in quantifying it globally and in understanding its behavior regionally. The recent advances in satellite-based radiation products allow to estimate the top-of-atmosphere (TOA) energy budget with unprecedented accuracy. In contrast, no equivalent data record exists for the energy balance at the surface with associated uncertainties being much larger than the small imbalance of 0.6 Wm-2 inferred from changes in ocean heat content. Recent studies combine the total and atmospheric heat budgets derived from satellite-based TOA irradiances and atmospheric reanalysis to infer the hemispheric surface heat budget as their residual. Here, we propose an approach that takes the perspective of the ocean, deriving the multi-annual surface net heat flux as the residual of the hemispheric ocean heat storage (OHS) and cross-equatorial ocean heat transport (OHT). The latter is taken from ocean model solutions (i.e. ECCOv4), while the OHS is derived from in-situ temperature profiles covering the ARGO period 2005-2015. Notable features of the hemispheric energy balance portrayed here are the dominance of the Southern hemispheric oceans in taking up heat (0.9 Wm-2) and the slight inter-hemispheric energy imbalance that leads to a net cross-equatorial heat transport from the Southern to the Northern hemisphere. This is achieved by the oceans transporting about 0.45 PW northward across the equator, accompanied by a southward transport of heat by the atmosphere (0.2-0.3 PW). The hemispheric turbulent heat fluxes, calculated as the residual of the net balance at the surface and satellite-derived surface radiative flux (CERES EBAF), differ by about 3 Wm-2, which is largely in line with the hemispheric contrast in precipitation according to GPCP data.

  14. Ocean Wave Energy Harvesting Devices

    DTIC Science & Technology

    2007-04-01

    coupled to a suitable buoy platform. 2. The approach of designing a device which meets the requirements for mounting on dogfish and generating...used on the tail of a marine life such as dogfish to harvest energy as it swims. The output power can be used to trickle charge battery packs to power...to be mounted to a dogfish to harvest energy from its motion. Due to the small fish size (approximate 40-50 inches, 25 pounds), the device was

  15. Thermal Energy Briefing with FPL

    NASA Image and Video Library

    2017-02-17

    Bart Gaetjens, Florida Power & Light's FPL area external affairs manager, addresses the news media and NASA Social about the new Thermal Energy Storage (TES) tank Feb. 17. The TES tank works like a giant battery and is saving the center utility cost. These savings will be applied to new sustainable projects at Kennedy.

  16. Thermal Energy Briefing with FPL

    NASA Image and Video Library

    2017-02-17

    Sustainability Team Lead Dan Clark addresses the news media and NASA Social about the new Thermal Energy Storage (TES) tank at NASA's Kennedy Space Center Feb. 17. The TES tank works like a giant battery and is saving the center utility cost. These savings will be applied to new sustainable projects at Kennedy.

  17. 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

  18. Significant sink of ocean eddy energy near western boundaries and its potential influence on the large scale ocean circulation

    NASA Astrophysics Data System (ADS)

    Zhai, X.; Johnson, H. L.; Marshall, D. P.; Saenko, O. A.

    2012-04-01

    Ocean eddies generated through instability of the mean flow play a vital role in balancing the energy budget of the global ocean. In equilibrium, the sources and sinks of eddy energy have to be balanced. However, where and how eddy energy is removed remains a large source of uncertainty. Ocean eddies are observed to propagate westward at speeds similar to the phase speeds of classical Rossby waves, but what happens to the eddies when they encounter the western boundary is unclear. Using a simple reduced-gravity model and satellite altimetry data, we show that the western boundary acts as a ``graveyard'' for the westward-propagating ocean eddies. We estimate a convergence of eddy energy near the western boundary of approximately 0.1~0.3 terawatts, poleward of 10 degree of latitude. This energy is most likely scattered into high-wavenumber vertical modes, resulting in energy dissipation and diapycnal mixing. A set of sensitivity experiments are conducted using an ocean general circulation model to investigate the effect of this eddy energy sink on ocean stratification and large-scale circulation, through the impact of energy dissipation on diapycnal mixing. It is found that with the addition of the eddy energy sink, the deep ocean thermal structure becomes closer to that observed, and the overturning circulation and stratification in the abyss become stronger. The Drake Passage transport also increases and becomes closer to its observational estimates.

  19. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    NASA Astrophysics Data System (ADS)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  20. 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.

  1. 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.

  2. 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.

  3. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    DOEpatents

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  4. 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.

  5. The Impact of Coastal Phytoplankton Blooms on Ocean-Atmosphere Thermal Energy Exchange: Evidence from a Two-Way Coupled Numerical Modeling System

    DTIC Science & Technology

    2012-12-25

    distribu- tion of nutrients in the coastal transition zone off Northern California: Effects on primary production , phytoplankton biomass and species com...chlorophyll-a product ; the inner nest ocean model domain is indicated by the red box. (c) Bathymetry map for Monterey Bay, California with reference...pixel in the composite product averages all clear observations ofthat pixel over the 4-month period. The two-dimensional surface chlo- rophyll

  6. Geographical variation in thermal tolerance within Southern Ocean marine ectotherms.

    PubMed

    Morley, Simon A; Hirse, Timo; Pörtner, Hans-Otto; Peck, Lloyd S

    2009-06-01

    Latitudinal comparisons of the Southern Ocean limpet, Nacella concinna, and clam, Laternula elliptica, acclimated to 0.0 degrees C, were used to assess differences in thermal response to two regimes, 0.0, 5.1 to 10.0 degrees C and 2.5, 7.5 to 12.5 degrees C, raised at 5.0 degrees C per week. At each temperature, tissue energy status was measured through a combination of O(2) consumption, intracellular pH, cCO(2), citrate synthase (CS) activity, organic acids (succinate, acetate, propionate), adenylates (ATP, ADP, AMP, ITP, PLA (phospho-L-arginine)) and heart rate. L. elliptica from Signy (60 degrees S) and Rothera (67 degrees S), which experience a similar thermal regime (-2 to +1 degrees C) had the same lethal (7.5-10.0 degrees C), critical (5.1-7.5 degrees C) and pejus (<5.1 degrees C;=getting worse) limits with only small differences in biochemical response. N. concinna, which experiences a wider thermal regime (-2 to +15.8 degrees C), had higher lethal limits (10.0-12.5 degrees C). However, at their Northern geographic limit N. concinna, which live in a warmer environment (South Georgia, 54 degrees S), had a lower critical limit (5.1-10.0 degrees C; O(2), PLA and organic acids) than Rothera and Signy N. concinna (10.0-12.5 degrees C). This lower limit indicates that South Georgia N. concinna have different biochemical responses to temperatures close to their thermal limit, which may make them more vulnerable to future warming trends.

  7. 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.

  8. 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.

  9. 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.

  10. Trends in Southern Ocean Eddy Kinetic Energy

    NASA Astrophysics Data System (ADS)

    Chambers, Don

    2016-04-01

    A recent study by Hogg et al. (JGR, 2015) has demonstrated a 20-year trend in eddy kinetic energy (EKE) computed from satellite altimetry data. However, this estimate is based on an averaging over large spatial areas. In this study, we use the same methods to examine regional EKE trends throughout the Southern Ocean, from 1993-2015. We do find significant positive trends in several areas of the Southern Ocean, mainly in regions with high mean EKE associated with interactions between jets and bathymetry. At the same time, however, there are also regions with significant negative trends. Overall, EKE in the majority of the Southern Ocean has not changed. These results suggest that the estimates of Hogg et al. may have been biased by these regional extremes, and that more work is needed to quantify climatic changes in EKE.

  11. 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.

  12. 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.

  13. 77 FR 32994 - Bureau of Ocean Energy Management

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ... 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 Management... Environment (MS 5410), Bureau of Ocean Energy Management, Gulf of Mexico OCS Region, 1201 Elmwood Park...

  14. Interplay of variable thermal conductivity and expansivity on the thermal structure of oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Honda, S.; Yuen, D. A.

    The sensitivity of pressure- and temperature-dependent thermal conductivity (k: W/m/K) and the thermal expansivity (α:1/K) on the thermal structure of the oceanic plate is investigated parametrically by comparing the ocean floor depth and heat flux calculated by one-dimensional conduction model with those of GDH1, a theoretical thermal model of the oceanic lithosphere. We find that an optimum fit is obtained, when the value of thermal expansivity is ˜ 3 × 10-5, while those associated with the thermal conductivity have many possibilities. The estimates, which give an equally good fit to the GDH1 model, of the plate thickness D (km) and the temperature at the base of the plate Tm (°C) may be given by Tm ˜ 1450-(k0-4.5) × 100-(α-3.0 × 10-5) × 105×100, D ˜ 90 + (k0-4.5) × 20 - (α-3.0 × 10-5) × 105 × 20 where k0 (W/m/K) is the lattice thermal conductivity at the ocean floor. A similar relation is obtained for constant thermal conductivity.

  15. Thermal Energy Transfer Through All Ceramic Restorations

    DTIC Science & Technology

    2016-06-01

    1 THERMAL ENERGY TRANSFER THROUGH ALL CERAMIC RESTORATIONS by Christopher D. Parks Lieutenant Commander, Dental Corps United...material in the manuscript titled: THERMAL E ERGY TRANSFER THROUGH ALL CERAMIC RESTORATIONS is appropriately acknowledged and, beyond brief excerpts...Naval Postgraduate Dental School JUN 2016 NAVAL POSTGRADUATE DENTAL SCHOOL CHRISTOPHER D. PARKS 2016 4 5 THERMAL ENERGY TRANSFER THROUGH ALL

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. High-energy thermal synchrotron emission

    NASA Technical Reports Server (NTRS)

    Imamura, J. N.; Epstein, R. I.; Petrosian, V.

    1985-01-01

    It is shown how the thermal synchrotron emission spectrum is modified when the photon energy is greater than the mean energy of the radiating particles. The effect if applying this energy conservation constraint is to produce spectra which have less high-energy photon emission than had been previously estimated. The thermal synchrotron spectra provide satisfactory fits to recently observed very high energy gamma ray spectra of certain burst sources.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Thermal cooling of the oceanic lithosphere from geoid height data

    NASA Technical Reports Server (NTRS)

    Cazenae, A.

    1985-01-01

    Another type of geophysical observation has proved to be very useful in the study of thermal cooling of the oceanic lithosphere. It is the geoid height derivative with respect to plate age, a quantity computed from the short wavelength geoid step across fracture zones measured by altimeter satellites. Two categories of simples models are proposed to describe cooling and contraction of the oceanic lithosphere with age. Both plate model and half space model, give almost similar results up to ages of 50 to 70 ma, but predict quite distinct behavior of seafloor depth, heat flow and other parameters in old basins. Tests of thermal models are based on heat flow and topography data. However, heat flow is not very sensitive to the form of the thermal model. Large areas of the ocean floor are particularly shallow, and as a result topography data may not be very appropriate to discriminate between plate and half space models, and no clear concensus on a preferred model yet exists.

  9. 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

  10. 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.

  11. Geoid data and thermal structure of the oceanic lithosphere

    SciTech Connect

    Richardson, W.P.; Stein, S.; Stein, C.A.

    1995-07-15

    A long-standing question is whether old oceanic lithosphere continues cooling as the boundary layer of a halfspace or approaches thermal equilibrium as modeled by a finite thickness plate. Although the latter is the most direct inference from seafloor depths and heat flow, other explanations have been proposed. We investigate this issue using published results for the derivative of the oceanic geoid with age estimated from geoid offsets across fracture zones. Such data have not been used extensively in analyses of the thermal evolution of the lithosphere, primarily because they are inconsistent with two commonly used thermal models; a halfspace or a 125-km-thick plate. Recent studies, however, find that depth and heat flow data are better fit by a thinner (95 km) plate model. We thus compile published geoid slope results, and find that these data, though scattered, can discriminate between the models. Geoid slope changes with age, rather than being constant as predicted for a cooling halfspace. This variation is greater than predicted for a thick plate and is better fit by a thin plate. Geoid data should thus be useful for improving thermal models of the lithosphere. 30 refs., 4 figs., 1 tab.

  12. 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.

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

    USGS Publications Warehouse

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

    1989-01-01

    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. -from Authors

  14. Thermal Shunts in Thermoelectric Energy Scavengers

    NASA Astrophysics Data System (ADS)

    Leonov, V.

    2009-07-01

    The necessity for an additional component in thermoelectric generators and low-dimensional thermopiles for improving the efficiency of energy scavengers is discussed. Energy scavengers usually work at a small temperature difference and high thermal resistance of the heat source and sink, i.e., of the environment. The name “thermal shunt” is given to this component because, firstly, it is connected thermally in parallel to a certain zone of the environment in the vicinity of a thermopile and, secondly, it shunts this zone thermally. As a result, the heat flow through the thermopile increases, improving its performance characteristics.

  15. 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.

  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. Interplay of variable thermal conductivity and expansivity on the thermal structure of oceanic lithosphere II

    NASA Astrophysics Data System (ADS)

    Honda, S.; Yuen, D. A.

    2004-04-01

    We have extended our previous analysis of the effects of constant vs. variable, i.e., pressure and temperature dependent thermal conductivity (k) and constant thermal expansivity (a) on the thermal structure of the oceanic lithosphere. We apply our analysis to the actual data set including information on the geoid slope. The heat flow and ocean floor depth data constrain the thermal expansivity (a ≍ 3 × 10-5 1/°C). Including geoid slope data may loosely constrain both the thermal expansivity and the thermal conductivity. The probable value of thermal conductivity is ≍ 3 W/m/°C for the constant k case and ≍ 4 W/m/°C (at ambient conditions) for the variable k case. These a and k are generally consistent with laboratory data of appropriate lithospheric materials. Our analysis supports the plate model with thin lithosphere and high bottom temperature, such as GDH1 (95 km; 1450°C). Variable k case requires slightly thinner and higher temperature lithosphere (≍ 85 km and ≍ 1500°C) and gives a slightly better fit to the geoid slope data.

  18. Thermal evolution of the lithosphere near oceanic hotspots and the subaerial lifespan of volcanic ocean islands

    NASA Astrophysics Data System (ADS)

    Huppert, K.; Perron, J. T.; Royden, L.

    2016-12-01

    Vertical motions of the Earth's surface driven by heat flow, surface loading, and mantle buoyancy generate topography and constrain the rheology and dynamics of the Earth's interior. At oceanic hotspots, these processes interact to modify the bathymetry, and paleoshorelines on hotspot volcanoes record changes in seafloor depth over various timescales. The seafloor surrounding oceanic hotspots is typically 0.5-2 km shallower than expected for its age over areas hundreds to >1000 km wide. The origin of this shallow bathymetry is uncertain; excess heat in the upper mantle, dynamic pressure at the base of the lithosphere, thinning of the lithosphere, or some combination of these processes may generate uplift. If bathymetric swells are produced by thinning of the lithosphere, their subsidence should mimic the subsidence of young oceanic lithosphere. We use a spatial median filter to separate regional and residual bathymetry at various oceanic hotspots. Considering the end-member case of purely thermal swell compensation, we model the thermal evolution of the lithosphere along the swell crest parallel to plate motion. We test various combinations of upper mantle temperature anomalies and extents of lithospheric thinning that produce the observed swell uplift. Comparing the model to regional bathymetry, we find that predicted thermal subsidence is significantly slower than observed subsidence, suggesting a dynamic contribution to swell uplift. This is consistent with global observations of island subsidence; because lithospheric thinning makes a minor contribution to swell uplift, hotspot islands subside definitively as they are transported away from a sublithospheric source of swell uplift. We estimate island residence times atop swell topography (swell wavelength/plate velocity) and find a correspondence to the age at which islands typically drown to form atolls and guyots in various hotspot chains.

  19. 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.

  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. 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.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. Efficient hybrid electric and thermal energy generation

    NASA Astrophysics Data System (ADS)

    Xia, X. Winston; Parfenov, Alexander V.; Aye, Tin M.; Shih, Min-Yi

    2011-10-01

    We demonstrate a novel hybrid solar photovoltaic electrical and thermal energy cogeneration system with high efficiency, at potentially reduced overall weight and size compared with current solar energy systems. The new system is based on highly efficient photovoltaic solar cells and tubular water thermal receivers, incorporating holographic spectral beam light guide concentrators resulting in a more cost-effective solution. Details of fabrication and preliminary experimental testing results are presented.

  7. 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

  8. Energy Saving in Thermal Vacuum Test

    NASA Astrophysics Data System (ADS)

    Ascani, M.

    2004-08-01

    When the shrouds of a thermal vacuum chamber must reach temperatures lower than 200 K, the thermoregulation of these ones is usually carried out by the circulation of gaseous nitrogen or flooding with liquid nitrogen; in this second case, using heaters (calrod), it is possible to modulate the thermal flow. Both modes imply a high consumption of liquid nitrogen and of power energy. It is explained a modality of test performed with a thermal vacuum chamber that permits a considerable energy saving compared to the tests available. Following we will call this modality as partially flooded mode.

  9. Ocean energy resources: the impact of OTEC

    SciTech Connect

    Ditmars, J.D.

    1980-01-01

    The status of OTEC technological development is summarized with emphasis on the potential impacts of OTEC power production on the ocean environment, including implications for impacts to climate. (MHR)

  10. 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.

  11. Where do we need abyssal ocean observations to estimate planetary energy imbalance from ocean heat content?

    NASA Astrophysics Data System (ADS)

    Garry, F. K.; Roberts, C. D.; Frajka-Williams, E.; McDonagh, E.; Blaker, A.; King, B.

    2016-02-01

    The oceans absorb the vast majority of heat accumulating in the climate system and so ocean heat content (OHC) estimates reflect global climate change. The sparseness and infrequency of ocean temperature measurements below 2000 m hinders precise evaluation of full depth OHC and change. We use global climate simulations from the Coupled Model Intercomparison Project 5 (CMIP5) to reveal the regions where below 2000 m temperature observations are necessary to accurately estimate OHC and adequately resolve the planetary energy imbalance over the twenty-first century (under the RCP 8.5 forcing scenario). Consistent with available observations, we find that OHC variability and the emergent patterns of climate change in the deep oceans (2000 - 4000 m) are dominated by signals in the Southern Ocean and Atlantic Ocean. We estimate the bias in OHC estimates when sampling to specific depths compared to full depth OHC and quantify how these biases evolve during the twenty-first century. Our results highlight that current observing strategies must be rapidly extended to include sampling below 2000 m as heat penetrates ever deeper into the oceans. For the purposes of constraining the planetary energy imbalance over the coming decades, 2000 - 4000 m ocean observations should initially be focused in the Southern and Atlantic oceans.

  12. Mesoscale Atmosphere-Ocean Coupling Enhances the Transfer of Wind Energy into the Ocean.

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    Ocean eddies receive their energy mainly from the atmospheric energy input at large scales, while it is thought that direct atmosphere-ocean interactions at this scale contribute little to the eddies' energy balance. If anything, the prevailing view is that mesoscale atmosphere-ocean interactions lead to a reduction of the energy transfer from the atmosphere to the ocean. From satellite observations, modelling studies and theory, we present results in contrast to this. Specifically, we describe a novel mechanism that provides a new energy pathway from the atmosphere into the ocean that directly injects energy at the mesoscale, shortcutting the classical main pathway from the larger scales. Our hypothesis is based upon recent evidence that the `coupling strength' i.e., the magnitude of the atmospheric response to underlying sea surface temperature anomalies associated with eddies, is dependent upon the background wind speed. We argue that ocean eddies rarely live in an area of constant background wind, particularly not in the Southern Ocean, and that the horizontal gradients in the wind across ocean eddies lead to an increased/decreased work on one side of the eddy that is not compensated for on the other. Essentially, this asymmetry provides a `spin up' or a `spin down' forcing such that the net result is an increase in kinetic energy for both warm and cold core eddies that reside in a negative wind gradient and a decrease in kinetic energy when they are located in a positive wind gradient. This result has strong implications for the Southern Ocean, where large regions of positive and negative wind gradients exist on both sides of the wind maximum. We show from diagnosing the local eddy scale and domain wide energy balance in a high-resolution coupled atmosphere-ocean regional model in the South Atlantic, there are different energy transfers in the two regions and due to the different eddy abundances that this mechanism increases the net kinetic energy contained in

  13. 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.

  14. 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.

  15. The Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes

    NASA Astrophysics Data System (ADS)

    Wong, Elizabeth Wing-See

    -or-less fixed. The surplus energy, from absorbing increasing levels of infrared radiation, is found to adjust the curvature of the thermal skin layer such that there is a smaller gradient at the interface between the thermal skin layer and the mixed layer beneath. The vertical conduction of heat from the mixed layer to the surface is therefore hindered while the additional energy within the thermal skin layer is supporting the gradient changes of the skin layer's temperature profile. This results in heat beneath the thermal skin layer, which is a product of the absorption of solar radiation during the day, to be retained and cause an increase in upper ocean heat content. The accuracy of four published skin layer models were evaluated by comparison with the field results. The results show a need to include radiative effects, which are currently absent, in such models as they do not replicate the findings from the field data and do not elucidate the effects of the absorption of infrared radiation.

  16. Ocean energy systems at the Johns Hopkins University Applied Physics Laboratory, April-June 1983. Quarterly report

    SciTech Connect

    Not Available

    1983-06-01

    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 geo-thermal-OTEC (GEOTEC) plants. The Laboratory also has a technical advisory role with respect to DOE/DOET's management of the conceptual design activities of two industry teams who have been designing offshore OTEC pilot plants. Since the conceptual designs were completed, one of the teams, headed by Ocean Thermal Corporation, was selected to continue with preliminary design. 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.

  17. 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.

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

    PubMed

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

    2016-06-13

    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.

  19. 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

  20. 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.

  1. Thermal energy in Robertson-Walker universes

    NASA Astrophysics Data System (ADS)

    Ruiz, Fernando Ruiz

    1989-03-01

    The covariant functional Schrödinger formalism is used to study thermal equilibrium for a scalar field in Robertson-Walker spacetimes. It is found that thermal equilibrium can be maintained for field masses, coupling constants and geometries satisfying a given differential equation, of which the massless conformally coupled case is a solution, but not the only one. The thermal energy is computed; it contains a term which for particular geometries, such as de Sitter spacetime, grows in time. On leave of absence from Departamento de Física Teórica, Universidad Complutense, 28040 Madrid 3, Spain.

  2. 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)

  3. 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)

  4. Thermal energy harvesting plasmonic based chemical sensors.

    PubMed

    Karker, Nicholas; Dharmalingam, Gnanaprakash; Carpenter, Michael A

    2014-10-28

    Detection of gases such as H2, CO, and NO2 at 500 °C or greater requires materials with thermal stability and reliability. One of the major barriers toward integration of plasmonic-based chemical sensors is the requirement of multiple components such as light sources and spectrometers. In this work, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The combination of a plasmonic-based energy harvesting sensing paradigm with PCA analysis offers a novel path toward simplification and integration of plasmonic-based sensing methods.

  5. Spatial distribution of thermal energy in equilibrium.

    PubMed

    Bar-Sinai, Yohai; Bouchbinder, Eran

    2015-06-01

    The equipartition theorem states that in equilibrium, thermal energy is equally distributed among uncoupled degrees of freedom that appear quadratically in the system's Hamiltonian. However, for spatially coupled degrees of freedom, such as interacting particles, one may speculate that the spatial distribution of thermal energy may differ from the value predicted by equipartition, possibly quite substantially in strongly inhomogeneous or disordered systems. Here we show that for systems undergoing simple Gaussian fluctuations around an equilibrium state, the spatial distribution is universally bounded from above by 1/2k(B)T. We further show that in one-dimensional systems with short-range interactions, the thermal energy is equally partitioned even for coupled degrees of freedom in the thermodynamic limit and that in higher dimensions nontrivial spatial distributions emerge. Some implications are discussed.

  6. Cost-Effective Solar Thermal Energy Storage: Thermal Energy Storage With Supercritical Fluids

    SciTech Connect

    2011-02-01

    Broad Funding Opportunity Announcement Project: UCLA and JPL are creating cost-effective storage systems for solar thermal energy using new materials and designs. A major drawback to the widespread use of solar thermal energy is its inability to cost-effectively supply electric power at night. State-of-the-art energy storage for solar thermal power plants uses molten salt to help store thermal energy. Molten salt systems can be expensive and complex, which is not attractive from a long-term investment standpoint. UCLA and JPL are developing a supercritical fluid-based thermal energy storage system, which would be much less expensive than molten-salt-based systems. The team’s design also uses a smaller, modular, single-tank design that is more reliable and scalable for large-scale storage applications.

  7. Aquifer thermal energy (heat and chill) storage

    NASA Astrophysics Data System (ADS)

    Jenne, E. A.

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference (IECEC), held in San Diego, California, 3 - 7 Aug. 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.

  8. 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.

  9. Thermal energy recycling fuel cell arrangement

    DOEpatents

    Hanrahan, Paul R.

    2017-04-11

    An example fuel cell arrangement includes a fuel cell stack configured to receive a supply fluid and to provide an exhaust fluid that has more thermal energy than the supply fluid. The arrangement also includes an ejector and a heat exchanger. The ejector is configured to direct at least some of the exhaust fluid into the supply fluid. The heat exchanger is configured to increase thermal energy in the supply fluid using at least some of the exhaust fluid that was not directed into the supply fluid.

  10. 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.

  11. 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.

  12. 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.

  13. Significant sink of ocean-eddy energy near western boundaries

    NASA Astrophysics Data System (ADS)

    Zhai, Xiaoming; Johnson, Helen L.; Marshall, David P.

    2010-09-01

    Ocean eddies generated through instability of the mean flow are a vital component of the energy budget of the global ocean. In equilibrium, the sources and sinks of eddy energy have to be balanced. However, where and how eddy energy is removed remains uncertain. Ocean eddies are observed to propagate westwards at speeds similar to the phase speeds of classical Rossby waves, but what happens to the eddies when they encounter the western boundary is unclear. Here we use a simple reduced-gravity model along with satellite altimetry data to show that the western boundary acts as a `graveyard' for the westward-propagating ocean eddies. We estimate a convergence of eddy energy near the western boundary of approximately 0.1-0.3TW, poleward of 10° in latitude. This energy is most probably scattered into high-wavenumber vertical modes, resulting in energy dissipation and diapycnal mixing. If confirmed, this eddy-energy sink will have important implications for the ocean circulation.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Energy from Ocean Waves, River Currents, and Wind

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2006-03-01

    The Earth we live in is surrounded by fluids, which are in perpetual motion. The air in the atmosphere and water found in lakes, ocean, and rivers form our natural environment. Much of the fluid medium is in constant motion. The kinetic energy of this moving fluid is astronomical in magnitude. Over the years, I have considered methods of converting a fraction of the vast reserve of this kinetic energy into electro-mechanical energy. I have conceived a few schemes of such conversions. The fluids whose kinetic energy can be converted into electro-mechanical energy are the following: ocean waters, river currents and atmospheric air. In a book to be published in the spring of 2006, I have described different techniques of energy conversion. In the upcoming APS meeting, I plan to discuss some of these techniques.

  5. Energy from Ocean Waves, River Currents, and Wind

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2006-05-01

    The earth we live in is surrounded by fluids, which are in perpetual motion. There is air in the atmosphere, water in lakes, oceans and rivers. The air and water around us form our natural environment. Much of the fluid medium is in constant motion. The kinetic energy of this moving fluid is astronomical in magnitude. Over the years, I considered methods of converting a fraction of the vast reserve of this kinetic energy into electro-mechanical energy. I conceived a few schemes of such conversion. The fluids whose kinetic energy can be converted into electro-mechanical energy are: ocean waters, river current and atmospheric air. In a book to be published in 2006, I have described different techniques of energy conversion. In the APS meeting, I plan to discuss some of these techniques.

  6. 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.

  7. Energy-optimal path planning in the coastal ocean

    NASA Astrophysics Data System (ADS)

    Subramani, Deepak N.; Haley, Patrick J.; Lermusiaux, Pierre F. J.

    2017-05-01

    We integrate data-driven ocean modeling with the stochastic Dynamically Orthogonal (DO) level-set optimization methodology to compute and study energy-optimal paths, speeds, and headings for ocean vehicles in the Middle-Atlantic Bight (MAB) region. We hindcast the energy-optimal paths from among exact time-optimal paths for the period 28 August 2006 to 9 September 2006. To do so, we first obtain a data-assimilative multiscale reanalysis, combining ocean observations with implicit two-way nested multiresolution primitive-equation simulations of the tidal-to-mesoscale dynamics in the region. Second, we solve the reduced-order stochastic DO level-set partial differential equations (PDEs) to compute the joint probability of minimum arrival time, vehicle-speed time series, and total energy utilized. Third, for each arrival time, we select the vehicle-speed time series that minimize the total energy utilization from the marginal probability of vehicle-speed and total energy. The corresponding energy-optimal path and headings are obtained through the exact particle-backtracking equation. Theoretically, the present methodology is PDE-based and provides fundamental energy-optimal predictions without heuristics. Computationally, it is 3-4 orders of magnitude faster than direct Monte Carlo methods. For the missions considered, we analyze the effects of the regional tidal currents, strong wind events, coastal jets, shelfbreak front, and other local circulations on the energy-optimal paths. Results showcase the opportunities for vehicles that intelligently utilize the ocean environment to minimize energy usage, rigorously integrating ocean forecasting with optimal control of autonomous vehicles.

  8. 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

  9. Model Scaling of Hydrokinetic Ocean Renewable Energy Systems

    NASA Astrophysics Data System (ADS)

    von Ellenrieder, Karl; Valentine, William

    2013-11-01

    Numerical simulations are performed to validate a non-dimensional dynamic scaling procedure that can be applied to subsurface and deeply moored systems, such as hydrokinetic ocean renewable energy devices. The prototype systems are moored in water 400 m deep and include: subsurface spherical buoys moored in a shear current and excited by waves; an ocean current turbine excited by waves; and a deeply submerged spherical buoy in a shear current excited by strong current fluctuations. The corresponding model systems, which are scaled based on relative water depths of 10 m and 40 m, are also studied. For each case examined, the response of the model system closely matches the scaled response of the corresponding full-sized prototype system. The results suggest that laboratory-scale testing of complete ocean current renewable energy systems moored in a current is possible. This work was supported by the U.S. Southeast National Marine Renewable Energy Center (SNMREC).

  10. 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.

  11. 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.

  12. 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.

  13. Aquifer thermal energy storage: a survey

    SciTech Connect

    Tsang, C.F.; Hopkins, D.; Hellstroem, G.

    1980-01-01

    The disparity between energy production and demand in many power plants has led to increased research on the long-term, large-scale storage of thermal energy in aquifers. Field experiments have been conducted in Switzerland, France, the United States, Japan, and the People's Republic of China to study various technical aspects of aquifer storage of both hot and cold water. Furthermore, feasibility studies now in progress include technical, economic, and environmental analyses, regional exploration to locate favorable storage sites, and evaluation and design of pilot plants. Several theoretical and modeling studies are also under way. Among the topics being studied using numerical models are fluid and heat flow, dispersion, land subsidence or uplift, the efficiency of different injection/withdrawal schemes, buoyancy tilting, numerical dispersion, the use of compensation wells to counter regional flow, steam injection, and storage in narrow glacial deposits of high permeability. Experiments to date illustrate the need for further research and development to ensure successful implementation of an aquifer storage system. Some of the areas identified for further research include shape and location of the hydrodynamic and thermal fronts, choice of appropriate aquifers, thermal dispersion, possibility of land subsidence or uplift, thermal pollution, water chemistry, wellbore plugging and heat exchange efficiency, and control of corrosion.

  14. 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.

  15. 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

  16. Operational experience from solar thermal energy projects

    NASA Astrophysics Data System (ADS)

    Cameron, C. P.

    1984-03-01

    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.

  17. 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.

  18. 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.

  19. Energy, Power and Thermal Research Overview

    DTIC Science & Technology

    2010-09-01

    Research Overview Rick Fingers, Ph.D. Chief Energy/Power/Thermal Division Propulsion Directorate Air Force Research ... Air Vehicles Sensors AFOSR 5 AFRL People & Facilities • 10 Major R&D Sites across US • 40 Sites World-Wide • $40B Real Property & Capital throughout... AFRL • 5,764 Government Employees – 4570 Air Force Civilian – 1194 Military • 3,844 Onsite Contractors 6 Propulsion Directorate’s Strategic

  20. The effects of volcanic eruptions on simulated ocean heat content and thermal expansion

    NASA Astrophysics Data System (ADS)

    Gleckler, P.; Achutarao, K.; Barnett, T.; Gregory, J.; Pierce, D.; Santer, B.; Taylor, K.; Wigley, T.

    2006-12-01

    We examine the ocean heat content in a recent suite of coupled ocean-atmosphere model simulations of the 20th Century. Our results suggest that 20th Century increases in ocean heat content and sea-level (via thermal expansion) were substantially reduced by the 1883 eruption of Krakatoa. The volcanically-induced cooling of the ocean surface is subducted into deeper ocean layers, where it persists for decades. Temporary reductions in ocean heat content associated with the comparable eruptions of El Chichon (1982) and Pinatubo (1991) were much shorter lived because they occurred relative to a non-stationary background of large, anthropogenically-forced ocean warming. To understand the response of these simulations to volcanic loadings, we focus on multiple realizations of the 20th Century experiment with three models (NCAR CCSM3, GFDL 2.0, and GISS HYCOM). By comparing these runs to control simulations of each model, we track the three dimensional oceanic response to Krakatoa using S/N analysis. Inter-model differences in the oceanic thermal response to Krakatoa are large and arise from differences in external forcing, model physics, and experimental design. Our results suggest that inclusion of the effects of Krakatoa (and perhaps even earlier eruptions) is important for reliable simulation of 20th century ocean heat uptake and thermal expansion. Systematic experimentation will be required to quantify the relative importance of these factors.

  1. 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.

  2. 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.

  3. 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.

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

    NASA Astrophysics Data System (ADS)

    Collins, R. E.

    1980-08-01

    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.

  5. Seasonal variability of eddy kinetic energy in a global high-resolution ocean model

    NASA Astrophysics Data System (ADS)

    Rieck, Jan K.; Böning, Claus W.; Greatbatch, Richard J.; Scheinert, Markus

    2015-11-01

    A global ocean model with 1/12° horizontal resolution is used to assess the seasonal cycle of surface eddy kinetic energy (EKE). The model reproduces the salient features of the observed mean surface EKE, including amplitude and phase of its seasonal cycle in most parts of the ocean. In all subtropical gyres of the Pacific and Atlantic, EKE peaks in summer down to a depth of ˜350 m, below which the seasonal cycle is weak. Investigation of the possible driving mechanisms reveals the seasonal changes in the thermal interactions with the atmosphere to be the most likely cause of the summer maximum of EKE. The development of the seasonal thermocline in spring and summer is accompanied by stronger mesoscale variations in the horizontal temperature gradients near the surface which corresponds, by thermal wind balance, to an intensification of mesoscale velocity anomalies toward the surface.

  6. The energy balance over land and oceans: An assessment based on direct observations and CMIP5 climate models

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris; Hakuba, Maria; Schär, Christoph; Seneviratne, Sonia; Kato, Seiji; Rutan, David; Ammann, Christof; Wood, Eric; König-Langlo, Gert

    2015-04-01

    The energy budgets over land and oceans are still afflicted with considerable uncertainties, despite their key importance for terrestrial and maritime climates. We evaluate these budgets as represented in 43 CMIP5 climate models with direct observations from both surface and space and identify substantial biases, particularly in the surface fluxes of downward solar and thermal radiation. These flux biases in the various models are then linearly related to their respective land and ocean means to infer best estimates for present day downward solar and thermal radiation over land and oceans. Over land, 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. 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/latent heat flux magnitudes, estimated here near 32/38 Wm-2 over land, and 16/100 Wm-2 over oceans. Estimated uncertainties are on the order of 10 and 5 Wm-2 for most surface and TOA fluxes, respectively. By combining these surface budgets with satellite-determined TOA budgets we quantify the atmospheric energy budgets as residuals (including ocean to land transports), and revisit the global mean energy balance. This study has recently been published online in Climate Dynamics.

  7. 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.

  8. Thermal stress depletes energy reserves in Drosophila

    PubMed Central

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P.

    2016-01-01

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting “memory effect” on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness. PMID:27641694

  9. Thermal stress depletes energy reserves in Drosophila.

    PubMed

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P

    2016-09-19

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting "memory effect" on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness.

  10. 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

  11. Observations of Upper-Ocean Thermal Structure in the Tropical Atlantic Ocean during Hurricane Danny and Tropical Storm Erika (2015)

    NASA Astrophysics Data System (ADS)

    Ridinger, S.; Jesse, J. A.; Sanabia, E.; Jayne, S. R.; Swick, W. A.

    2016-02-01

    In August 2015, Hurricane Danny and Tropical Storm Erika formed in close proximity within the Main Development Region over the tropical Atlantic Ocean. The westward tropical cyclone tracks remained within 1.5° latitude for more than 1500 km before reaching the Lesser Antilles. The upper-ocean thermal structure beneath these two tropical systems is investigated using AXBT, ALAMO, and Argo float observations, and changes over time are analyzed. The 59 AXBT and 12 ALAMO floats deployed from USAFR WC-130J aircraft as part of the USNA TROPIC program and AXBT Demonstration Project, along with the Argo floats, provide insight into temporal and spatial scales of the impact of wind-stress on the upper ocean. Several observations are highlighted and observed changes in the mixed layer are compared to theoretical results obtained using the Price-Weller-Pinkel ocean mixed layer model.

  12. Aquifer thermal-energy-storage modeling

    NASA Astrophysics Data System (ADS)

    Schaetzle, W. J.; Lecroy, J. E.

    1982-09-01

    A model aquifer was constructed to simulate the operation of a full size aquifer. Instrumentation to evaluate the water flow and thermal energy storage was installed in the system. Numerous runs injecting warm water into a preconditioned uniform aquifer were made. Energy recoveries were evaluated and agree with comparisons of other limited available data. The model aquifer is simulated in a swimming pool, 18 ft by 4 ft, which was filled with sand. Temperature probes were installed in the system. A 2 ft thick aquifer is confined by two layers of polyethylene. Both the aquifer and overburden are sand. Four well configurations are available. The system description and original tests, including energy recovery, are described.

  13. 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.

  14. 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.

  15. Attenuation of Scattered Thermal Energy Atomic Oxygen

    NASA Astrophysics Data System (ADS)

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

    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.

  16. 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.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1993-06-01

    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.

  19. On the dynamics of a novel ocean wave energy converter

    NASA Astrophysics Data System (ADS)

    Orazov, B.; O'Reilly, O. M.; Savaş, Ö.

    2010-11-01

    Buoy-type ocean wave energy converters are designed to exhibit resonant responses when subject to excitation by ocean waves. A novel excitation scheme is proposed which has the potential to improve the energy harvesting capabilities of these converters. The scheme uses the incident waves to modulate the mass of the device in a manner which amplifies its resonant response. To illustrate the novel excitation scheme, a simple one-degree of freedom model is developed for the wave energy converter. This model has the form of a switched linear system. After the stability regime of this system has been established, the model is then used to show that the excitation scheme improves the power harvesting capabilities by 25-65 percent even when amplitude restrictions are present. It is also demonstrated that the sensitivity of the device's power harvesting capabilities to changes in damping becomes much smaller when the novel excitation scheme is used.

  20. 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.

  1. 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.

  2. Dish concentrators for solar thermal energy

    NASA Astrophysics Data System (ADS)

    Jaffe, L. D.

    1983-08-01

    Comparisons are presented of point-focusing, or 'dish' solar concentrator system features, development status, and performance levels demonstrated to date. In addition to the requirements of good optical efficiency and high geometric concentration ratios, the most important future consideration in solar thermal energy dish concentrator design will be the reduction of installed and lifetime costs, as well as the materials and labor costs of production. It is determined that technology development initiatives are needed in such areas as optical materials, design wind speeds and wind loads, structural configuration and materials resistance to prolonged exposure, and the maintenance of optical surfaces. The testing of complete concentrator systems, with energy-converting receivers and controls, is also necessary. Both reflector and Fresnel lens concentrator systems are considered.

  3. 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.

  4. 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.

  5. Demonstration of EnergyNest thermal energy storage (TES) technology

    NASA Astrophysics Data System (ADS)

    Hoivik, Nils; Greiner, Christopher; Tirado, Eva Bellido; Barragan, Juan; Bergan, Pâl; Skeie, Geir; Blanco, Pablo; Calvet, Nicolas

    2017-06-01

    This paper presents the experimental results from the EnergyNest 2 × 500 kWhth thermal energy storage (TES) pilot system installed at Masdar Institute of Science & Technology Solar Platform. Measured data are shown and compared to simulations using a specially developed computer program to verify the stability and performance of the TES. The TES is based on a solid-state concrete storage medium (HEATCRETE®) with integrated steel tube heat exchangers cast into the concrete. The unique concrete recipe used in the TES has been developed in collaboration with Heidelberg Cement; this material has significantly higher thermal conductivity compared to regular concrete implying very effective heat transfer, at the same time being chemically stable up to 450 °C. The demonstrated and measured performance of the TES matches the predictions based on simulations, and proves the operational feasibility of the EnergyNest concrete-based TES. A further case study is analyzed where a large-scale TES system presented in this article is compared to two-tank indirect molten salt technology.

  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. 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.

  8. 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

  9. STEP - A temperature profiler for measuring the oceanic thermal boundary layer at the ocean-air interface

    SciTech Connect

    Mammen, T.C.; Von bosse, N. Salzgitter Elektronik GmbH, Flintbek, )

    1990-04-01

    A fast measuring system has been designed and built to determine the oceanic thermal microstructure at the ocean-air interface. The system consists of a profiler sonde, which ascends through the uppermost few meters of the ocean with a speed of typically 1 m/s and carries a fast temperature sensor with a time constant of 0.5 ms and a surface detector. The data rate is 8000 measurements per second and the achieved resolution in temperature is 0.01 K. The instrument has been designed for rough off-shore treatment and to avoid any disturbance of the boundary layer during measurements. Some measurements of the cool skin are shown from in situ experiments. 26 refs.

  10. Krakatoa lives: The effect of volcanic eruptions on ocean heat content and thermal expansion

    NASA Astrophysics Data System (ADS)

    Gleckler, P. J.; AchutaRao, K.; Gregory, J. M.; Santer, B. D.; Taylor, K. E.; Wigley, T. M. L.

    2006-09-01

    A suite of climate model experiments indicates that 20th Century increases in ocean heat content and sea-level (via thermal expansion) were substantially reduced by the 1883 eruption of Krakatoa. The volcanically-induced cooling of the ocean surface is subducted into deeper ocean layers, where it persists for decades. Temporary reductions in ocean heat content associated with the comparable eruptions of El Chichón (1982) and Pinatubo (1991) were much shorter lived because they occurred relative to a non-stationary background of large, anthropogenically-forced ocean warming. Our results suggest that inclusion of the effects of Krakatoa (and perhaps even earlier eruptions) is important for reliable simulation of 20th century ocean heat uptake and thermal expansion. Inter-model differences in the oceanic thermal response to Krakatoa are large and arise from differences in external forcing, model physics, and experimental design. Systematic experimentation is required to quantify the relative importance of these factors. The next generation of historical forcing experiments may require more careful treatment of pre-industrial volcanic aerosol loadings.

  11. 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.

  12. 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.

  13. 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.

  14. The total energy flux leaving the ocean's mixed layer

    NASA Astrophysics Data System (ADS)

    Rimac, Antonija; von Storch, Jin-Song; Eden, Carsten

    2017-04-01

    Interior density mixing contributes to drive the large-scale ocean circulation. The energy needed for this mixing is believed to be supplied predominantly by the tidal and wind forcing. In this study, we focus on the wind-power input to three different types of motions, that is, near-inertial waves, sub-inertial fluctuations, and time-mean flows. Surface winds can generate near-inertial waves which propagate freely into the ocean's interior and after escaping the mixed layer contribute to interior mixing. Winds also input power into the ocean to maintain the time-mean circulation and to generate sub-inertial fluctuations, either by the vertical or horizontal shear instability of the large-scale flows, or directly via wind induced fluctuations at the ocean surface. The energy of both the sub-inertial fluctuations and the time-mean flow will be eventually dissipated (or transferred to the internal gravity wave field or small scale turbulence). However, the exact portion of the power that escapes the turbulent mixed layer and that can potentially affect the interior mixing, is still unknown. The total energy flux leaving the ocean's spatially and seasonally varying mixed layer is estimated using a global 1/10° ocean general circulation model. From the total wind-power input of 3.33 TW into near-inertial waves (0.35 TW) sub-inertial fluctuations (0.87 TW), and the time-mean circulation (2.11 TW), 0.92 TW leave the mixed layer; with 0.04 TW (11.4%) due to near-inertial motions, 0.07 TW (8.3%) due to sub-inertial fluctuations, and 0.81 TW (38.4%) due to time-mean motions. Of the 0.81 TW from the time-mean motions, 0.5 TW result from the projection of the horizontal flux onto the sloped bottom of the mixed layer. This projection is negligible for the transient fluxes. The spatial structure of the vertical flux is determined principally by the wind stress curl. The mean and sub-inertial fluxes leaving the mixed layer are approximately 40-50% smaller than the respective

  15. Effects of hypoxia and ocean acidification on the upper thermal niche boundaries of coral reef fishes.

    PubMed

    Ern, Rasmus; Johansen, Jacob L; Rummer, Jodie L; Esbaugh, Andrew J

    2017-07-01

    Rising ocean temperatures are predicted to cause a poleward shift in the distribution of marine fishes occupying the extent of latitudes tolerable within their thermal range boundaries. A prevailing theory suggests that the upper thermal limits of fishes are constrained by hypoxia and ocean acidification. However, some eurythermal fish species do not conform to this theory, and maintain their upper thermal limits in hypoxia. Here we determine if the same is true for stenothermal species. In three coral reef fish species we tested the effect of hypoxia on upper thermal limits, measured as critical thermal maximum (CTmax). In one of these species we also quantified the effect of hypoxia on oxygen supply capacity, measured as aerobic scope (AS). In this species we also tested the effect of elevated CO2 (simulated ocean acidification) on the hypoxia sensitivity of CTmax We found that CTmax was unaffected by progressive hypoxia down to approximately 35 mmHg, despite a substantial hypoxia-induced reduction in AS. Below approximately 35 mmHg, CTmax declined sharply with water oxygen tension (PwO2). Furthermore, the hypoxia sensitivity of CTmax was unaffected by elevated CO2 Our findings show that moderate hypoxia and ocean acidification do not constrain the upper thermal limits of these tropical, stenothermal fishes. © 2017 The Author(s).

  16. 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.

  17. Development of MEMS based pyroelectric thermal energy harvesters

    SciTech Connect

    Hunter, Scott Robert; Lavrik, Nickolay V; Bannuru, Thirumalesh; Mostafa, Salwa; Rajic, Slobodan; Datskos, Panos G

    2011-01-01

    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.

  18. Thermal regime along the Antilles subduction zone: Influence of the oceanic lithosphere materials subducted in the oceanic crust

    NASA Astrophysics Data System (ADS)

    Biari, Youssef; Marcaillou, Boris; Klingelhoefer, Frauke; Francis, Lucazeau; Fréderique, Rolandone; Arnauld, Heuret; Thibaud, Pichot; Hélène, Bouquerel

    2017-04-01

    Heat-flow measurements acquired during the Antithesis Cruise in the Northern Lesser Antilles reveal an atypical heat-flow trend, from the trench to the margin forearc, where the subducting crust consists of exhumed and serpentinized mantle rocks (see Marcaillou et al. same session). We investigate the thermal structure of the Lesser Antilles subduction zone along two transects perpendicular to the margin located off Antigua and Martinique Islands. We perform 2-D steady-state finite elements thermal modelling constrained by newly-recorded and existing data: heat flow measurements, deep multichannel reflection and wide angle seismic data as well as earthquake hypocenters location at depth. Along the Martinique profile, the heat-flow decreases from the trench (45 mW.m-2) to minimum in the outer fore-arc (30 mW.m-2) and increases to a plateau (50 mW.m-2) toward the back-arc area. These trend and values are typical for the subduction of a steep 80-MYr old oceanic plate beneath an oceanic margin. As a result, the 150°-350°C temperature range along the interplate contact, commonly associated to the thermally-defined seismogenic zone, is estimated to be located between 200 - 350km from the trench. In contrast, along the Antigua profile, the heat-flow shows an atypical "flat" trend at 40 ± 15 mW.m-2 from the trench to the inner forearc. Purely conductive thermal models fail at fitting both the measured values and the flat trend. We propose that the subducting crust made of serpentinized exhumed mantle rock strongly affecting the heat-flow at the surface and the margin thermal structure. The geothermal gradient in the 5-km-thick serpentinized layer is expected to be low compared to "normal" oceanic crust because of cold water percolation and peridotite alteration. Moreover, from 50km depth, serpentine dehydration reactions provide significant amounts of hot water expelled toward the upper plate, generated heat beneath the forearc. As a result, in our preferred model: 1/ A

  19. MEMS based pyroelectric thermal energy harvester

    DOEpatents

    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.

  20. 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.

  1. 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.

  2. Multistable chain for ocean wave vibration energy harvesting

    NASA Astrophysics Data System (ADS)

    Harne, R. L.; Schoemaker, M. E.; Wang, K. W.

    2014-03-01

    The heaving of ocean waves is a largely untapped, renewable kinetic energy resource. Conversion of this energy into electrical power could integrate with solar technologies to provide for round-the-clock, portable, and mobile energy supplies usable in a wide variety of marine environments. However, the direct drive conversion methodology of gridintegrated wave energy converters does not efficiently scale down to smaller, portable architectures. This research develops an alternative power conversion approach to harness the extraordinarily large heaving displacements and long oscillation periods as an excitation source for an extendible vibration energy harvesting chain. Building upon related research findings and engineering insights, the proposed system joins together a series of dynamic cells through bistable interfaces. Individual impulse events are generated as the inertial mass of each cell is pulled across a region of negative stiffness to induce local snap through dynamics; the oscillating magnetic inertial mass then generates current in a coil which is connected to energy harvesting circuitry. It is shown that linking the cells into a chain transmits impulses through the system leading to cascades of vibration and enhancement of electrical energy conversion from each impulse event. This paper describes the development of the multistable chain and ways in which realistic design challenges were addressed. Numerical modeling and corresponding experiments demonstrate the response of the chain due to slow and large amplitude input motion. Lastly, experimental studies give evidence that energy conversion efficiency of the chain for wave energy conversion is much higher than using an equal number of cells without connections.

  3. Satellite and Ocean Model Analysis of Thermal Conditions Affecting Coral Reefs in the Western Indian Ocean

    NASA Astrophysics Data System (ADS)

    Perez Delgado, Z.; Ummenhofer, C.; Swales, D. J.

    2016-02-01

    Corals are thought to be one of the smallest yet most productive ecosystems in the world. They have great economic and ecological value, but are increasingly affected by anthropogenic, biological and physical threats, such as a rise in sea surface temperature (SST) and ocean acidification due to an increase in CO2 in the atmosphere, among other factors. Here, specific events are investigated that likely exerted significant stress on corals, focusing particularly on unusual climatic conditions in the Western Indian Ocean during the 2001 to 2007 period as reflected by anomalies in degree heating weeks, hotspots and SST. Anomalous conditions in subsurface temperatures and mixed layer depth across the Indian Ocean region are also examined. We do this by using monthly, year-to-date, and annual composites of twice-weekly 50-km satellite coral bleaching monitoring products from the NOAA Coral Reef Watch and complementing it with output from a high-resolution global ocean model hindcast (1948-2007) forced with observed atmospheric forcing. Two years stand out in our analysis for the satellite data and model output: 2003 and 2005 exhibit strong warming in the Western Indian Ocean and cooling in the East. To establish the physical mechanisms giving rise to the unusual conditions and hotspot origins in 2003 and 2005 we also evaluate regional circulation changes in the Western Indian Ocean.

  4. Ocean acidification narrows the acute thermal and salinity tolerance of the Sydney rock oyster Saccostrea glomerata.

    PubMed

    Parker, Laura M; Scanes, Elliot; O'Connor, Wayne A; Coleman, Ross A; Byrne, Maria; Pörtner, Hans-O; Ross, Pauline M

    2017-09-15

    Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO2-induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15-33°C) and salinity (34.2-20) treatments. Oysters acclimated to elevated CO2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. What limits photosynthetic energy conversion efficiency in nature? Lessons from the oceans.

    PubMed

    Falkowski, Paul G; Lin, Hanzhi; Gorbunov, Maxim Y

    2017-09-26

    Constraining photosynthetic energy conversion efficiency in nature is challenging. In principle, two yield measurements must be made simultaneously: photochemistry, fluorescence and/or thermal dissipation. We constructed two different, extremely sensitive and precise active fluorometers: one measures the quantum yield of photochemistry from changes in variable fluorescence, the other measures fluorescence lifetimes in the picosecond time domain. By deploying the pair of instruments on eight transoceanic cruises over six years, we obtained over 200 000 measurements of fluorescence yields and lifetimes from surface waters in five ocean basins. Our results revealed that the average quantum yield of photochemistry was approximately 0.35 while the average quantum yield of fluorescence was approximately 0.07. Thus, closure on the energy budget suggests that, on average, approximately 58% of the photons absorbed by phytoplankton in the world oceans are dissipated as heat. This extraordinary inefficiency is associated with the paucity of nutrients in the upper ocean, especially dissolved inorganic nitrogen and iron. Our results strongly suggest that, in nature, most of the time, most of the phytoplankton community operates at approximately half of its maximal photosynthetic energy conversion efficiency because nutrients limit the synthesis or function of essential components in the photosynthetic apparatus.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  6. 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.

  7. Subsurface Thermal Energy Storage for Improved Air Conditioning Efficiency

    DTIC Science & Technology

    2016-11-01

    EW-201013) Subsurface Thermal Energy Storage for Improved Air Conditioning Efficiency November 2016 This document has been cleared for public...December 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 10-C-0027-A Cost and Performance Report. Subsurface Thermal Energy Storage for Improved...distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT This project involved a field demonstration of subsurface thermal energy storage for

  8. 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.

  9. 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.

  10. Coupled Modeling of Hydrodynamics and Sound in Coastal Ocean for Renewable Ocean Energy Development

    SciTech Connect

    Long, Wen; Jung, Ki Won; Yang, Zhaoqing; Copping, Andrea; Deng, Z. Daniel

    2016-03-01

    An underwater sound model was developed to simulate sound propagation from marine and hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite difference methods were developed to solve the 3D Helmholtz equation for sound propagation in the coastal environment. A 3D sparse matrix solver with complex coefficients was formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method was applied to solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model was then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities, such as construction of OSW turbines or tidal stream turbine operations, in a range-dependent setting. As a proof of concept, initial validation of the solver is presented for two coastal wedge problems. This sound model can be useful for evaluating impacts on marine mammals due to deployment of MHK devices and OSW energy platforms.

  11. 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.

  12. NEOTEC: Negative-CO2-Emissions Marine Energy With Direct Mitigation of Global Warming, Sea-Level Rise and Ocean Acidification

    NASA Astrophysics Data System (ADS)

    Rau, G. H.; Baird, J.; Noland, G.

    2016-12-01

    The vertical thermal energy potential in the ocean is a massive renewable energy resource that is growing due to anthropogenic warming of the surface and near-surface ocean. The conversion of this thermal energy to useful forms via Ocean Thermal Energy Conversion (OTEC) has been demonstrated over the past century, albeit at small scales. Because OTEC removes heat from the surface ocean, this could help directly counter ongoing, deleterious ocean/atmosphere warming. The only other climate intervention that could do this is solar radiation "geoengineering". Conventional OTEC requires energy intensive, vertical movement of seawater resulting in ocean and atmospheric chemistry alteration, but this can be avoided via more energy efficient, vertical closed-cycle heating and cooling of working fluid like CO2 or NH3. An energy carrier such as H2 is required to transport energy optimally extracted far offshore, and methods of electrochemically generating H2 while also consuming CO2 and converting it to ocean alkalinity have been demonstrated. The addition of such alkalinity to the ocean would provide vast, stable, carbon storage, while also helping chemically counter the effects of ocean acidification. The process might currently be profitable given the >$100/tonne CO2 credit offered by California's Low Carbon Fuel Standard for transportation fuels like H2. Negative-Emissions OTEC, NEOTEC, thus can potentially provide constant, cost effective, high capacity, negative-emissions energy while: a) reducing surface ocean heat load, b) reducing thermal ocean expansion and sea-level rise, c) utilizing a very large, natural marine carbon storage reservoir, and d) helping mitigate ocean acidification. The technology also avoids the biophysical and land use limitations posed by negative emissions methods that rely on terrestrial biology, such as afforestation and BECCS. NEOTEC and other marine-based, renewable energy and CO2 removal approaches could therefore greatly increase the

  13. 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.

  14. 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.

  15. Enhanced turbulence and energy dissipation at ocean fronts.

    PubMed

    D'Asaro, Eric; Lee, Craig; Rainville, Luc; Harcourt, Ramsey; Thomas, Leif

    2011-04-15

    The ocean surface boundary layer mediates air-sea exchange. In the classical paradigm and in current climate models, its turbulence is driven by atmospheric forcing. Observations at a 1-kilometer-wide front within the Kuroshio Current indicate that the rate of energy dissipation within the boundary layer is enhanced by one to two orders of magnitude, suggesting that the front, rather than the atmospheric forcing, supplied the energy for the turbulence. The data quantitatively support the hypothesis that winds aligned with the frontal velocity catalyzed a release of energy from the front to the turbulence. The resulting boundary layer is stratified in contrast to the classically well-mixed layer. These effects will be strongest at the intense fronts found in the Kuroshio Current, the Gulf Stream, and the Antarctic Circumpolar Current, all of which are key players in the climate system.

  16. How do Greenhouse Gases Warm the Ocean? Investigation of the Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes.

    NASA Astrophysics Data System (ADS)

    Wong, E.; Minnett, P. J.

    2016-12-01

    There is much evidence that the ocean is heating due to an increase in concentrations of greenhouse gases (GHG) in the atmosphere from human activities. GHGs absorbs infrared (IR) radiation and re-emits the radiation back to the ocean's surface which is subsequently absorbed resulting in a rise in the ocean heat content. However, the incoming longwave radiation, LWin, is absorbed within the top micrometers of the ocean's surface, where the thermal skin layer (TSL) exists and does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the TSL, which is directly influenced by the absorption and emission of IR radiation, the heat flow through the TSL adjusts to maintain the surface heat loss, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in LWin and analyzing retrieved TSL vertical profiles from a shipboard IR spectrometer from two research cruises. The data is limited to night-time, no precipitation and low winds of < 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of TSL disruption. The results show independence between the turbulent fluxes and radiative fluxes which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation. Instead, we observe the surplus energy, from absorbing increasing levels of LWin, adjusts the curvature of the TSL such that there is a lower gradient at the interface between the TSL and the mixed layer. The release of heat stored within the mixed layer is therefore hindered while the additional energy within the TSL is cycled back into the atmosphere. This results in heat beneath the TSL

  17. Experimental Constraints on Thermal Cracking of Peridotite at Mid-Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Demartin, B.; Hirth, G.; Evans, B.

    2002-12-01

    Fluid flow at oceanic spreading centers controls the cooling and rheology of oceanic lithosphere, the biological and chemical evolution of hydrothermal systems, and serpentinization of mantle peridotite. Faults provide conduits for focused flow at the ridges and likely provide the channels necessary to sustain high-temperature hydrothermal vents. However, dispersed fluid flow can be accommodated though a zone of thermally fractured rock and promote distributed serpentinization of the lithosphere at slow spreading ridges. Thermal fractures form in upwelling mantle peridotite due to both thermal expansion anisotropy and thermal expansion mismatch between mineral grains. To test the applicability of micromechanical models for thermal cracking in peridotite and determine the critical stress intensity factor necessary to initiate thermal cracking in the oceanic lithosphere, we have run controlled cooling rate experiments on hot-pressed olivine aggregates. During the experiments, we use a pore fluid monitoring technique to determine when cracking proceeds to an extent where an interconnected microcrack network develops. By varying grain size, cooling rate, and confining pressure during the experiments, we can either enhance or suppress thermal cracking within the olivine samples. Larger grain sizes (38 - 60 microns) or faster cooling rates (1oC/s) enhance microcrack formation. Based on our experiments, we estimate a critical stress intensity factor of ~0.65-0.75 MPa m1/2. The laboratory experiments can be scaled to the Earth using micromechanical models for the influence of grain size and cooling rate on the freezing temperature for viscous dissipation of thermal stresses (Evans and Clarke, 1980). The depth extent of thermal cracking can be estimated by coupling micromechanical models of stress intensity resulting from anisotropic thermal contraction with thermal models for upwelling mantle at oceanic spreading centers. Our analysis indicates that thermal cracking of

  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. 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.

  20. Near-Inertial and Thermal Upper Ocean Response to Atmospheric Forcing in the North Atlantic Ocean

    DTIC Science & Technology

    2010-06-01

    water is then subducted as the ocean restratifies during spring, and advected throughout the subtropical gyre by the large scale wind driven circulation...Luther, and W. C. Patzert, 1992: The heat budget in the north atlantic subtropical frontal zone . J. Geophys. Res., 97 (C11), 17 947–17 959. 131 Price, J

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

    PubMed Central

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-01-01

    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

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

    PubMed

    Chen, Jige; Chen, Shunda; Gao, Yi

    2016-07-07

    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.

  11. Thermal noise can facilitate energy conversion by a ratchet system.

    PubMed

    Takagi, F; Hondou, T

    1999-10-01

    Molecular motors in biological systems are expected to use ambient fluctuation. In a recent paper [Phys. Rev. Lett. 80, 5251 (1998)], it was shown that the following question was unanswered: Can thermal noise facilitate energy conversion by ratchet system? We consider it using stochastic energetics, and show that there exist systems where thermal noise helps the energy conversion.

  12. Renewable energy from the ocean - a guide to OTEC

    SciTech Connect

    Avery, W.H.; Wu, C.

    1994-01-01

    An enormous renewable energy resource exists in the tropical oceans. The authors of this book state that this resource could be exploited to produce a large fraction of the world's energy needs in the form of methanol or ammonia and that any associated deleterious environmental effects would be minimal. Careful analyses of potential problems, detailed designs of OTEC plant ships, and consideration of costs occupy most of the book. Part of it is devoted to some limited practical experience. With the knowledge set forth a 40-MWe seagoing pilot plant could be constructed. Cost would be about $200 million in 1990 dollars. Construction could be relatively rapid, since most of the components would be commercially available. The authors provide extensive evidence that with experience costs of OTEC would be substantially reduced and that ultimately production of methanol and ammonia by OTEC could be made cost-competitive.

  13. 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

  14. 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.

  15. Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications.

    PubMed

    Wang, Song; Cottrill, Anton L; Kunai, Yuichiro; Toland, Aubrey R; Liu, Pingwei; Wang, Wen-Jun; Strano, Michael S

    2017-05-24

    Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young's moduli larger than 11.5 MPa and 55.2 MPa above and below the melting transition point, respectively. Moreover, the composites show significant changes in thermal conductivity above and below the melting point of the constituent paraffin and rectification that is well-described by our previous theory and the Maxwell-Eucken model. Maximum thermal rectifications range from 1.18 to 1.34. We show that such devices perform reliably enough to operate in thermal diode bridges, dynamic thermal circuits capable of transforming oscillating temperature inputs into single polarity temperature differences - analogous to an electrical diode bridge with widespread implications for transient thermal energy harvesting and conservation. Overall, our approach yields mechanically robust, solid-state thermal diodes capable of engineering design from a mathematical model of phase change and thermal transport, with implications for energy harvesting.

  16. Impact of improved building thermal efficiency on residential energy demand

    SciTech Connect

    Adams, R.C.; Rockwood, A.D.

    1983-04-01

    The impact of improved building shell thermal efficiency on residential energy demand is explored in a theoretical framework. The important economic literature on estimating the price elasticity of residential energy demand is reviewed. The specification of the residential energy demand model is presented. The data used are described. The empirical estimation of the residential energy demand model is described. (MHR)

  17. Temperature Distribution and Thermal Performance of an Aquifer Thermal Energy Storage System

    NASA Astrophysics Data System (ADS)

    Ganguly, Sayantan

    2017-04-01

    Energy conservation and storage has become very crucial to make use of excess energy during times of future demand. Excess thermal energy can be captured and stored in aquifers and this technique is termed as Aquifer Thermal Energy Storage (ATES). Storing seasonal thermal energy in water by injecting it into subsurface and extracting in time of demand is the principle of an ATES system. Using ATES systems leads to energy savings, reduces the dependency on fossil fuels and thus leads to reduction in greenhouse gas emission. This study numerically models an ATES system to store seasonal thermal energy and evaluates the performance of it. A 3D thermo-hydrogeological numerical model for a confined ATES system is presented in this study. The model includes heat transport processes of advection, conduction and heat loss to confining rock media. The model also takes into account regional groundwater flow in the aquifer, geothermal gradient and anisotropy in the aquifer. Results show that thermal injection into the aquifer results in the generation of a thermal-front which grows in size with time. Premature thermal-breakthrough causes thermal interference in the system when the thermal-front reaches the production well and consequences in the fall of system performance and hence should be avoided. This study models the transient temperature distribution in the aquifer for different flow and geological conditions. This may be effectively used in designing an efficient ATES project by ensuring safety from thermal-breakthrough while catering to the energy demand. Based on the model results a safe well spacing is proposed. The thermal energy discharged by the system is determined and strategy to avoid the premature thermal-breakthrough in critical cases is discussed. The present numerical model is applied to simulate an experimental field study which is found to approximate the field results quite well.

  18. Thermal Energy Storage in Phase Change Material.

    DTIC Science & Technology

    1982-03-01

    Graphs of the exnerimental results follow: tney are groupea in the tree categories: tube cross flow, ricked bed, and tube parallel flow. A. Tube Cross... Riordan , Michael, "Thermal Storage: A Rtsic Guile to the Ptate of the Art", Solar Age, Aril, 1978, P. 10. 5. Telkes, Maria, "Thermal Lner y Storage in

  19. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

    PubMed

    Durgun, E; Grossman, Jeffrey C

    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.

  20. Investigating the Environmental Effects of Ocean Energy Generation (Invited)

    NASA Astrophysics Data System (ADS)

    Copping, A. E.; Anderson, R.; Schultz, I.; Woodruff, D.; Carlson, T.; Ward, J.; van Cleve, F.; Eere Mhk Environmental Effects

    2010-12-01

    The production of electricity from the moving waters of the ocean has the potential to be a viable addition to the portfolio of renewable energy sources worldwide. The marine and hydrokinetic (MHK) industry seeks to deploy and operate devices that harvest energy from the tides, waves, ocean currents and run of the river. Challenges facing the emerging industry include technology development, rigors of offshore deployments, and financing; however, the barrier most commonly cited by industry, regulators, and stakeholders is the uncertainty surrounding potential environmental effects of devices placed in the water and the permitting processes associated with those impacts. There is a need to evaluate the extensive list of potential interactions that may cause harm to marine organisms and ecosystems, to set priorities for regulatory triggers, and to direct future research. Project developers need information to understand how to minimize environmental effects; regulators need to know what monitoring targets are needed near ocean energy farms; and stakeholders need to know what mitigation strategies are effective in addressing unavoidable impacts. Scientists from Pacific Northwest National Laboratory (PNNL) are developing an Environmental Risk Evaluation System (ERES) to assess environmental effects associated with MHK technologies and projects through a systematic analytical process, with specific input from key stakeholder groups. The ERES development process provides the scientific structure to support risk characterization, comparison of tradeoffs, and risk-informed decision-making by project and technology developers, regulatory agencies, and other interested stakeholders. The PNNL team will determine the range and severity of environmental effects of MHK development, leading to the development of mitigation strategies where residual risk remains. Input to ERES draws from a wide range of marine and freshwater studies to understand which marine receptors may suffer

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

    SciTech Connect

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

    2016-06-15

    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.

  2. 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.

  3. 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.

  4. 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.

  5. On the response of northwest Greenland glaciers to ocean thermal forcing

    NASA Astrophysics Data System (ADS)

    Wood, M.; Rignot, E. J.; Menemenlis, D.; Fenty, I. G.; Millan, R.; van den Broeke, M. R.

    2016-12-01

    Over the past 25 years, the tidewater glaciers of northwest Greenland have exhibited widespread retreat synchronous with warming ocean temperatures in northeast Baffin Bay, yet we also observe different behaviors from one glacier to the next, sometimes within the same fjord. Here, we calculate the ocean-induced melt rate of glaciers in the northwest using simulations from the MITgcm ocean model for various water depths, ocean thermal forcing (TF) and subglacial water fluxes (SG). We use water depth from Ocean Melting Greenland (OMG) bathymetry, ocean thermal forcing from the Estimating the Circulation and Climate of the Ocean (Phase II, ECCO2) combined with CTD data from 2012 and 2015, and time series of subglacial water flux combining runoff production from the 1-km Regional Atmospheric Climate Model (RACMO2.3) with basal melt beneath land ice from the JPL/UCI ISSM model. Time series of melt rates are formed as a function of grounding line depth, SG flux and TF. We compare the results with the calving speed of the glaciers and history of retreat rate to assess the relative glacier control between calving rate and ice melt by the ocean over the past two and a half decades. In some cases, we find that the front position is highly modulated by ocean-induced melt. For example, the melt rates at Docker Smith Gletscher and the southern-most branch of Hayes Gletscher (Hayes SS) have been comparable to or have exceeded the frontal speeds since the late 1990's, which coincides with their 5-km and 2-km retreats, respectively, despite moving into water 100 m shallower than at the start of the retreat. In other, often adjacently positioned, cases such as Gade Gletscher or another sub-branch of Hayes Gletscher (Hayes M), the frontal speeds far exceeded ocean-induced melt rates, the glaciers are dominantly controlled by calving processes, and the glacier retreat has been minimal (<300m) in the past two decades. These results illustrate the sensitivity of northwestern glaciers

  6. Thermal energy dissipation and xanthophyll cycles beyond the Arabidopsis model.

    PubMed

    García-Plazaola, José Ignacio; Esteban, Raquel; Fernández-Marín, Beatriz; Kranner, Ilse; Porcar-Castell, Albert

    2012-09-01

    Thermal dissipation of excitation energy is a fundamental photoprotection mechanism in plants. Thermal energy dissipation is frequently estimated using the quenching of the chlorophyll fluorescence signal, termed non-photochemical quenching. Over the last two decades, great progress has been made in the understanding of the mechanism of thermal energy dissipation through the use of a few model plants, mainly Arabidopsis. Nonetheless, an emerging number of studies suggest that this model represents only one strategy among several different solutions for the environmental adjustment of thermal energy dissipation that have evolved among photosynthetic organisms in the course of evolution. In this review, a detailed analysis of three examples highlights the need to use models other than Arabidopsis: first, overwintering evergreens that develop a sustained form of thermal energy dissipation; second, desiccation tolerant plants that induce rapid thermal energy dissipation; and third, understorey plants in which a complementary lutein epoxide cycle modulates thermal energy dissipation. The three examples have in common a shift from a photosynthetically efficient state to a dissipative conformation, a strategy widely distributed among stress-tolerant evergreen perennials. Likewise, they show a distinct operation of the xanthophyll cycle. Expanding the list of model species beyond Arabidopsis will enhance our knowledge of these mechanisms and increase the synergy of the current studies now dispersed over a wide number of species.

  7. Equilibrium Ocean Thermal Expansion Depends Non-Linearly on the Forcing Level

    NASA Astrophysics Data System (ADS)

    Rugenstein, M.; Knutti, R.

    2015-12-01

    The ocean dominates the planetary heat budget and takes thousands of years to equilibrate to perturbedsurface conditions. We show two commonly held assumptions to be inaccurate: (a) A temperature perturbationin the atmosphere translates to a roughly uniform equilibrium ocean temperature anomaly.(b) Equilibrium global sea level rise due to thermal expansion is proportional to global surface warming.We analyze a vast range forcing levels and equilibration time scales of up to 10 000 years, for one model ofintermediate complexity and one state-of-the-art global climate model.The response time scales and regions of anomalous ocean heat storage depend non-linearly on the forcinglevel and equilibrium surface warming. The Atlantic Meridional Overturning Circulation is only proportionalto the forcing in its initial response, but not in its centennial to millennial recovery. In the SouthernOcean, water mass properties and surface air temperature response do not scale linearly with the forcinglevel. Interior and deep oceans warm very little compared to the surface layers for small perturbations, butdo so increasingly for higher forcing levels. The deep ocean temperature anomaly does not correspond toeither high or low latitude atmospheric surface temperature anomaly. Depending on where the excess heatis stored in the long term, the global sea level due to thermal expansion varies. We discuss the scalability ofequilibrium climate sensitivity between these simulations and their relation to different definitions of radiativeforcing.Two far reaching consequences are: (1) that one cannot deduce long term (centennial to millennial) fromshort term (decadal to centennial) behavior of ocean circulation and heat uptake. (2) The explanatory powerof deep sea proxies of past climate change to represent surface temperature perturbations, might be limiteddue to the uncertainty of the detailed forcing history.

  8. Numerical Modeling of Gravity, Geoid, and the Thermal Structure of Oceanic Lithosphere

    NASA Astrophysics Data System (ADS)

    Davis, D.; Grose, C. J.

    2010-12-01

    In order to better understand links between the thermal and density structure of oceanic lithosphere with its surface manifestations, we implement numerical techniques to predict both the thermal structure of oceanic lithosphere and the consequent gravity field and geoid height. The two principal problems of our potential field numerical algorithm are the transposition of density data in two-dimensional Cartesian space into a three-dimensional spherical shell model, and accurately quantifying deformation in the Cartesian grid associated with contraction and isostatic adjustment. Using this model we investigate anomalies in gravity and the geoid due to density heterogeneities associated with varying properties and boundary conditions of the oceanic lithosphere. Such sources of thermal and density structure include the impact of variable heat transport properties, lattice preferred orientation, mantle potential temperature and adiabate, plate thickness, and the composite mineral assemblage. Variable transport properties are known to result in substantial deviations in the geotherm relative to that expected from models with constant thermal parameters. Since the near-surface lithosphere is cooler, the impact on geoid height should be smaller and this is important for constraining the effective diffusivity of the lithosphere. In addition, composite mineralogy is important due to phase changes. In particular, the spinel-garnet transition rapidly elevates in lithosphere around ages of 20 to 40 Mya. Such a density anomaly is likely to be observable in the geoid height, and this may account for unexplained features of geoid slope at young ages.

  9. Impact of Parameterized Internal Wave Drag on the Semidiurnal Energy Balancein a Global Ocean Circulation Model

    DTIC Science & Technology

    2016-04-12

    Impact of Parameterized Internal Wave Drag on the Semidiurnal Energy Balance in a Global Ocean Circulation Model* MAARTENC. BUIJSMAN,1 JOSEPHK...of Southern Mississippi, Stennis Space Center, Mississippi #University of Michigan, Ann Arbor, Michigan @Center for Ocean -Atmospheric Prediction...parameterized linear internal wave drag on the semidiurnal barotropic and baroclinic energetics of a realistically forced, three-dimensional global ocean

  10. 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.

  11. Ocean acidification has little effect on developmental thermal windows of echinoderms from Antarctica to the tropics.

    PubMed

    Karelitz, Sam E; Uthicke, Sven; Foo, Shawna A; Barker, Mike F; Byrne, Maria; Pecorino, Danilo; Lamare, Miles D

    2017-02-01

    As the ocean warms, thermal tolerance of developmental stages may be a key driver of changes in the geographical distributions and abundance of marine invertebrates. Additional stressors such as ocean acidification may influence developmental thermal windows and are therefore important considerations for predicting distributions of species under climate change scenarios. The effects of reduced seawater pH on the thermal windows of fertilization, embryology and larval morphology were examined using five echinoderm species: two polar (Sterechinus neumayeri and Odontaster validus), two temperate (Fellaster zelandiae and Patiriella regularis) and one tropical (Arachnoides placenta). Responses were examined across 12-13 temperatures ranging from -1.1 °C to 5.7 °C (S. neumayeri), -0.5 °C to 10.7 °C (O. validus), 5.8 °C to 27 °C (F. zelandiae), 6.0 °C to 27.1 °C (P. regularis) and 13.9 °C to 34.8 °C (A. placenta) under present-day and near-future (2100+) ocean acidification conditions (-0.3 pH units) and for three important early developmental stages 1) fertilization, 2) embryo (prehatching) and 3) larval development. Thermal windows for fertilization were broad and were not influenced by a pH decrease. Embryological development was less thermotolerant. For O. validus, P. regularis and A. placenta, low pH reduced normal development, albeit with no effect on thermal windows. Larval development in all five species was affected by both temperature and pH; however, thermal tolerance was not reduced by pH. Results of this study suggest that in terms of fertilization and development, temperature will remain as the most important factor influencing species' latitudinal distributions as the ocean continues to warm and decrease in pH, and that there is little evidence of a synergistic effect of temperature and ocean acidification on the thermal control of species ranges. © 2016 John Wiley & Sons Ltd.

  12. 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.

  13. 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.

  14. Analysis on energy consumption index system of thermal power plant

    NASA Astrophysics Data System (ADS)

    Qian, J. B.; Zhang, N.; Li, H. F.

    2017-05-01

    Currently, the increasingly tense situation in the context of resources, energy conservation is a realistic choice to ease the energy constraint contradictions, reduce energy consumption thermal power plants has become an inevitable development direction. And combined with computer network technology to build thermal power “small index” to monitor and optimize the management system, the power plant is the application of information technology and to meet the power requirements of the product market competition. This paper, first described the research status of thermal power saving theory, then attempted to establish the small index system and build “small index” monitoring and optimization management system in thermal power plant. Finally elaborated key issues in the field of small thermal power plant technical and economic indicators to be further studied and resolved.

  15. 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.

  16. 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…

  17. 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.

  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. Flexible operation of thermal plants with integrated energy storage technologies

    NASA Astrophysics Data System (ADS)

    Koytsoumpa, Efthymia Ioanna; Bergins, Christian; Kakaras, Emmanouil

    2017-08-01

    The energy system in the EU requires today as well as towards 2030 to 2050 significant amounts of thermal power plants in combination with the continuously increasing share of Renewables Energy Sources (RES) to assure the grid stability and to secure electricity supply as well as to provide heat. The operation of the conventional fleet should be harmonised with the fluctuating renewable energy sources and their intermittent electricity production. Flexible thermal plants should be able to reach their lowest minimum load capabilities while keeping the efficiency drop moderate as well as to increase their ramp up and down rates. A novel approach for integrating energy storage as an evolutionary measure to overcome many of the challenges, which arise from increasing RES and balancing with thermal power is presented. Energy storage technologies such as Power to Fuel, Liquid Air Energy Storage and Batteries are investigated in conjunction with flexible power plants.

  20. Making Heat Visible: Promoting Energy Conservation Behaviors Through Thermal Imaging.

    PubMed

    Goodhew, Julie; Pahl, Sabine; Auburn, Tim; Goodhew, Steve

    2015-12-01

    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 (n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 (n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation.

  1. 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.

  2. Ocean engineering and the environment (Conference record)

    SciTech Connect

    Not Available

    1985-01-01

    This book present the papers given at a conference on offshore operations. Topics considered include ocean engineering and the environment, marine information systems, oil spill cleanup, economic potential, the design and analysis of offshore structures, water current measurements, ocean thermal energy conversion, ocean thermal power plants, corrosion, materials testing, biofouling, and aquaculture.

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. 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.

  8. Design Considerations of a Solid State Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    Janbozorgi, Mohammad; Houssainy, Sammy; Thacker, Ariana; Ip, Peggy; Ismail, Walid; Kavehpour, Pirouz

    2016-11-01

    With the growing governmental restrictions on carbon emission, renewable energies are becoming more prevalent. A reliable use of a renewable source however requires a built-in storage to overcome the inherent intermittent nature of the available energy. Thermal design of a solid state energy storage has been investigated for optimal performance. The impact of flow regime, laminar vs. turbulent, on the design and sizing of the system is also studied. The implications of low thermal conductivity of the storage material are discussed and a design that maximizes the round trip efficiency is presented. This study was supported by Award No. EPC-14-027 Granted by California Energy Commission (CEC).

  9. 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.

  10. 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.

  11. 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.

  12. The OTEC (Ocean Thermal Energy Conversion) mooring technology

    NASA Astrophysics Data System (ADS)

    Shields, D. R.; Wendt, R. L.; Johnson, B. A.

    1982-12-01

    Existing technology for mooring components which may be suitable for OTEC use is summarized. Due to the platform size, depth of water, and length of design life required for an operational OTEC plant, only large and high capacity mooring components were investigated. Engineering, test, and manufacturer's data on wire rope, synthetic rope (nylon, polyester and Kevlar), anchors, deck fittings and machinery, and design concepts for tension leg platform mooring systems are included. A significant portion of the effort was directed to the assessment of synthetic rope technology and its application to moorings.

  13. 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.

  14. 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

  15. 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

    2015-10-30

    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.

  16. Phase-change thermal energy storage: Final subcontract report

    SciTech Connect

    Not Available

    1989-11-01

    The research and development described in this document was conducted within the US Department of Energy's Solar Thermal Technology Program. 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{degree}C in low-temperature troughs to over 1500{degree}C in dish and central receiver systems. 12 refs., 119 figs., 4 tabs.

  17. Hot Thermal Storage in a Variable Power, Renewable Energy System

    DTIC Science & Technology

    2014-06-01

    characteristics and may not necessarily be available in all cases. Types of direct heat energy systems include solar thermal, waste heat, and geothermal ...the amount of energy absorbed in heating to the maximum temperature. These are conservative estimates of cost per kilowatt hour, gravimetric energy ...STORAGE IN A VARIABLE POWER, RENEWABLE ENERGY SYSTEM by Themba D. Hinke June 2014 Thesis Advisor: Anthony J. Gannon Co-Advisor: Anthony G

  18. 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... Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE); Cancellation of Oil and Gas... Mexico (GOM) AGENCY: Bureau of Ocean Energy Management, Regulation, and Enforcement, Interior....

  19. 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,......

  20. 77 FR 5817 - Ocean Renewable Power Company, Tidal Energy Project, Cobscook Bay, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... SECURITY Coast Guard Ocean Renewable Power Company, Tidal Energy Project, Cobscook Bay, ME AGENCY: Coast... five turbine generator units secured to the ocean floor, used for generating electricity from tidal...: Background and Purpose ORPC's tidal energy project involves installation of five underwater turbines on the...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

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

    SciTech Connect

    Regnier, Cindy

    2012-08-01

    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. Thermal Energy Corporation in Houston, Texas Earns ENERGY STAR Award for Carbon Pollution Reductions

    EPA Pesticide Factsheets

    DALLAS - (June 29, 2015) The U.S. Environmental Protection Agency (EPA) recently recognized Thermal Energy Corporation (TECO) of Houston, Texas with the ENERGY STAR Combined Heat and Power (CHP) Award. TECO substantially reduced emissions of carbon

  7. Rapid charging of thermal energy storage materials through plasmonic heating.

    PubMed

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

    2014-09-01

    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.

  8. 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

  9. Investigation of lithium sulphate for high temperature thermal energy storage

    NASA Astrophysics Data System (ADS)

    Bayon, Alicia; Liu, Ming; Bruno, Frank; Hinkley, Jim

    2017-06-01

    Lithium sulphate (Li2SO4) was evaluated as a solid-solid PCM material to be coupled with concentrated solar power (CSP) technologies. The energy is stored in a cubic crystalline phase that is formed at temperatures above 576°C and can potentially be discharged at temperatures as low as 150°C, providing both sensible and latent thermal energy storage in a hybrid sensible-latent system. These operational conditions are appropriate for current CSP technologies based on subcritical steam Rankine power cycles. Results from thermal cycling experiments in air showed no change in energy storage capacity after 15 cycles. There was up to a 5% reduction in latent thermal capacity and 0.95% in total thermal capacity after 150 cycles in air. In our paper, we evaluate a hybrid sensible-latent thermal energy storage system based on lithium sulphate from an economic and technical performance point of view, demonstrating its potential as a high temperature thermal energy storage material.

  10. 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.

  11. 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

  12. Nanoscale Based ThermalMagnetic Energy Harvesting

    DTIC Science & Technology

    2012-07-30

    Superparamagnetic size ~20 nm ? Multiferroic Energy Transfer Spaldin and Fiebig, Science, 2005 PMN-PT,PZN-PT, PZT …… Ferroelectric Ni, Gd, Terfenol-D...Si substrate Covering layer for FIB Magnetocrystalline , function of temp. x y XRD: Textured crystal structure a) T < TSR b) T > TSR Easy...to spin-reorientation harvesting 2012 Textured Gd Thin Flims: UCLA Change of MCA energy in Gd • The easy axis of magnetization is dependent on

  13. Thermal effects on isoscalar giant resonance energies in hot nuclei

    SciTech Connect

    Wen, W.; Dai, G.; Jin, G.

    1995-07-01

    The thermal effects on the energies of the isoscalar giant multipole resonances of hot nuclei are discussed and an approximate formula for the energy as a function of temperature is derived via a hydrodynamic theory. The energy difference between the isoscalar giant multipole resonance of a hot nucleus and its ground-state resonance depends on the competition between the volume expansion and the increase of the average kinetic energy per nucleon of hot nuclei, which lower and raise the resonance energy, respectively, and nearly counteract each other in magnitude. The variaiton of the isoscalar giant resonance energy with temperature is very small.

  14. 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.

  15. ENERGY PARTITIONS AND EVOLUTION IN A PURELY THERMAL SOLAR FLARE

    SciTech Connect

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E.

    2015-04-01

    This paper presents a solely thermal flare, which we detected in the microwave range from the thermal gyro- and free–free emission it produced. An advantage of analyzing thermal gyro emission is its unique ability to precisely yield the magnetic field in the radiating volume. When combined with observationally deduced plasma density and temperature, these magnetic field measurements offer a straightforward way of tracking evolution of the magnetic and thermal energies in the flare. For the event described here, the magnetic energy density in the radio-emitting volume declines over the flare rise phase, then stays roughly constant during the extended peak phase, but recovers to the original level over the decay phase. At the stage where the magnetic energy density decreases, the thermal energy density increases; however, this increase is insufficient, by roughly an order of magnitude, to compensate for the magnetic energy decrease. When the magnetic energy release is over, the source parameters come back to nearly their original values. We discuss possible scenarios to explain this behavior.

  16. 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.

  17. 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.

  18. Survey of EPA facilities for solar thermal energy applications

    NASA Technical Reports Server (NTRS)

    Nelson, E. V.; Overly, P. T.; Bell, D. M.

    1980-01-01

    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/facility combinations were ranked on the basis of greatest cost effectiveness.

  19. Anisotropy of thermal contraction controls deep hydrothermal circulation at oceanic ridges

    NASA Astrophysics Data System (ADS)

    Boudier, F.; Nicolas, A.; Mainprice, D.; Baronnet, A.

    2003-04-01

    A deep and high-T (up to 1000^oC) hydrothermal contamination of the oceanic crust at the ridge axis has been documented in the Oman ophiolite. In the deep and hot gabbros, the main water channels are submillimetric microcracks with a dominantly vertical attitude (Nicolas et al, in press). Sr and O isotopic investigations point to seawater as the most likely hydrothermal contaminant (Bosch et al. submitted). We propose that the mechanism allowing seawater ingression at temperatures above 700^oC is anisotropy of thermal contraction, opening microcracks that are controlled by fabric. The exceptionally large anisotropy of thermal contraction of single crystal of calcic plagioclase, when introduced in the strong lattice fabrics in the lower gabbros results in finding the maximum thermal contraction direction parallel to maximum crystals elongation L1. This direction in the oceanic ridge referential is horizontal and perpendicular to microcracks dominant orientation. This high-T hydrothermal alteration in gabbros reaches the Moho. In the underlying peridotites, preliminary Sr isotopic data on clinopyroxene from wehrlites suggest that seawater was able to ingress at crystallization temperature for clinopyroxene. Interestingly, in these peridotites with horizontal foliation, thermal contraction, calculated as above from fabrics and thermal expansion coefficients in olivine, is vertical, being responsible for subhorizontal cracking, as deduced from serpentine dominant veining. Thus, during off-axis drifting of newly accreted lithosphere, thermal contraction opens vertical cracks, favoring seawater ingression down to the Moho. Below, in peridotites, the horizontal microcrack system would favor closing of hydrothermal circuit at Moho level.

  20. Thermal energy recovery in gas turbine engine test cells

    NASA Astrophysics Data System (ADS)

    Kodres, C. A.

    1983-11-01

    The economics of thermal energy recovery in jet engine test cells is examined. A numerical model to simulate the test cell augmenter tube is developed. This model is employed to determine the feasibility of installing heat exchangers along the augmenter or at the augmenter exit and using these heat exchangers to generate steam or electricity from the thermal energy in the jet exhaust. In general, energy recovery is not practical. The exhaust is quickly diluted by the entrained augmentation air, decreasing temperature gradients necessary for heat transfer. Most test cells are used too infrequently to warrant the cost of the hardware.

  1. Energy Aspects of Thermal Molecular Switching: Molecular Thermal Hysteresis of Helicene Oligomers.

    PubMed

    Shigeno, Masanori; Kushida, Yo; Yamaguchi, Masahiko

    2015-07-20

    Molecular switching is a phenomenon by which a molecule reversibly changes its structure and state in response to external stimuli or energy. Herein, molecular switching is discussed from thermodynamic and kinetic aspects in terms of energy supply with an emphasis on the thermal switching exhibited by helicene oligomers. It includes the inversion of relative thermodynamic stability induced by temperature changes and molecular thermal hysteresis in a closed system. The thermal phenomenon associated with the oligomers involves population/concentration changes between metastable states under nonequilibrium thermodynamic control.

  2. 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.

  3. Validation and Application of Altimetry-Derived Upper Ocean Thermal Structure in the Western North Pacific Ocean for Typhoon-Intensity Forecast

    DTIC Science & Technology

    2007-06-01

    structure and causes a large under- estimation of the tropical cyclone heat potential ( TCHP ) by up to 60 kJ/cml. After validation, the derived upper ocean...self-induced cooling and the during-typhoon TCHP , are the most sensitive parameters (with R1 - 0.7) to the 6-h intensity change of Dianmu during the...upper heat potential ( TCHP ) by up to 60 kJ/cm2 . After validation, ocean termal profile. the derived upper ocean thermal profiles are used to study the

  4. Mechanism of seasonal eddy kinetic energy variability in the eastern equatorial Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Wang, Minyang; Du, Yan; Qiu, Bo; Cheng, Xuhua; Luo, Yiyong; Chen, Xiao; Feng, Ming

    2017-04-01

    Enhanced mesoscale eddy activities or tropical instability waves (TIWs) exist along the northern front of the cold tongue in the eastern equatorial Pacific Ocean. In this study, we investigate seasonal variability of eddy kinetic energy (EKE) over this region and its associated dynamic mechanism using a global, eddy-resolving ocean general circulation model (OGCM) simulation, the equatorial mooring data, and satellite altimeter observations. The seasonal-varying enhanced EKE signals are found to expand westward from 100°W in June to 180°W in December between 0°N and 6°N. This westward expansion in EKE is closely connected to the barotropically-baroclinically unstable zonal flows that are in thermal-wind balance with the seasonal-varying thermocline trough along 4°N. By adopting an 1½-layer reduced-gravity model, we confirm that the seasonal perturbation of the thermocline trough is dominated by the anticyclonic wind stress curl forcing, which develops due to southerly winds along 4°N from June to December.

  5. 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.

  6. 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.

  7. Thermal Convection in High-Pressure Ice Layers Beneath a Buried Ocean within Titan and Ganymede

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Deep interiors of large icy satellites such as Titan and Ganymede probably harbor a buried ocean sandwiched between low pressure ice and high-pressure ice layers. The nature and location of the lower interface of the ocean involves equilibration of heat and melt transfer in the HP ices and is ultimately controlled by the amount heat transferred through the surface ice Ih layer. Here, we perform 3D simulations of thermal convection, using the OEDIPUS numerical tool (Choblet et al. GJI 2007), to determine the efficiency of heat and mass transfer through these HP ice mantles. In a first series of simulations with no melting, we show that a significant fraction of the HP layer reaches the melting point. Using a simple description of water production and transport, our simulations demonstrate that the melt generation in the outermost part of the HP ice layer and its extraction to the overlying ocean increase the efficiency of heat transfer and reduce strongly the internal temperature. structure and the efficiency of the heat transfer. Scaling relationships are proposed to describe the cooling effect of melt production/extraction and used to investigate the consequences of internal melting on the thermal history of Titan and Ganymede's interior.

  8. Satellite-derived Ocean Thermal Structure for the North Atlantic Hurricane Season

    NASA Astrophysics Data System (ADS)

    Pun, I. F.; Price, J.; Jayne, S. R.

    2016-02-01

    This paper describes a new model (method) called SNAP (Satellite-derived North Atlantic Profiles) that seeks to provide a high resolution, near real-time ocean thermal field to aid TC forecasting. The heart of the method is a regression of sea surface height anomaly upon the depth of ocean isotherms. Using about 139000 profiles from Argo floats and historical in situ observations, a spatially-dependent regression model is developed for the North Atlantic Ocean during the hurricane season, June to November. A new step introduced in this work is that the daily mixed layer depth (MLD) is derived from the output of a one-dimensional Price-Weller-Pinkel ocean mixed layer model with time-dependent wind and radiation forcing. The surface layer temperature and thickness of a SNAP temperature profile is a satellite-observed sea surface temperature and this model-computed MLD. The accuracy of SNAP is assessed by comparison to 10761 independent Argo profiles from the hurricane seasons of 2011 and 2012. The root-mean-squared differences (RMSDs) of the SNAP-estimated isotherm depths are found to be 10-20 m for upper thermocline isotherms (29°C to 20°C), 35-55 m for middle isotherms (18°C to 11°C), and 60-90 m for lower isotherms (6°C to 4°C). The primary error sources for SNAP-derived isotherm depths include SSHA uncertainty, high frequency fluctuations of isotherm depths, salinity effects and the barotropic component of SSHA. These account for roughly 29%, 25%, 19% and 10% of the overall estimated isotherm depth errors, respectively. The RMSDs of TC-related ocean parameters, upper ocean heat content and averaged temperature of the upper 100 m, are 10 kJ cm-2 and 0.82°C, respectively.

  9. 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.

  10. 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.

  11. 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.

  12. Using the shield for thermal energy storage in PULSAR

    SciTech Connect

    Sager, G.T.; Wong, C.P.C.; Sze, D.K.

    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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Electrical Energy Harvesting from Thermal Energy with Converged Infrared Light

    NASA Astrophysics Data System (ADS)

    Goh, S. Y.; Kok, S. L.

    2017-06-01

    Photovoltaics (PV) cell is a common energy harvester that had been used to harvest solar energy and convert it into electrical energy. However, the vast energy from the spectrum of sunlight is not fully harvested. Therefore, thermoelectric (TE) module that harvest electrical energy from heat is being proposed in this paper. Generally, the part of the sunlight spectrum that induce heat is in the spectrum band of infrared (IR). For the experimental set-up in this paper, infrared (IR) light bulb was being used to simulate the IR spectrum band of the sunlight. In order to maximize the heat energy collection, a convex lens was being used to converge the IR light and therefore focused the heat on an aluminium sheet and heat sink which was placed on top of the hot side of the TE module. The distance between convex lens and IR light bulb is varying in between 10cm and 55cm and the reading was taken at an interval of 5cm. Firstly, the temperature of the IR light and converged IR light were recorded and plotted in graph. The graph showed that the temperature of the converged IR light bulb is higher than the IR light bulb. Lastly, the voltage and power output of the TE module with different heat source was compared. The output voltage and power of the TE module increased inverse proportional to the distance between IR light bulb and TE module.

  18. 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.

  19. 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)

  20. 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)...

  1. 33 CFR 140.101 - Inspection by Coast Guard marine inspectors or Bureau of Ocean Energy Management, Regulation and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... inspectors or Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. 140.101 Section 140... Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. (a) Each unit engaged in OCS... facility engaged in OCS activities is subject to inspection by the Bureau of Ocean Energy Management...

  2. 33 CFR 140.101 - Inspection by Coast Guard marine inspectors or Bureau of Ocean Energy Management, Regulation and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... inspectors or Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. 140.101 Section 140... Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. (a) Each unit engaged in OCS... facility engaged in OCS activities is subject to inspection by the Bureau of Ocean Energy Management...

  3. 33 CFR 140.101 - Inspection by Coast Guard marine inspectors or Bureau of Ocean Energy Management, Regulation and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... inspectors or Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. 140.101 Section 140... Bureau of Ocean Energy Management, Regulation and Enforcement inspectors. (a) Each unit engaged in OCS... facility engaged in OCS activities is subject to inspection by the Bureau of Ocean Energy Management...

  4. Phonon Surface Scattering and Thermal Energy Distribution in Superlattices.

    PubMed

    Kothari, Kartik; Maldovan, Martin

    2017-07-17

    Thermal transport at small length scales has attracted significant attention in recent years and various experimental and theoretical methods have been developed to establish the reduced thermal conductivity. The fundamental understanding of how phonons move and the physical mechanisms behind nanoscale thermal transport, however, remains poorly understood. Here we move beyond thermal conductivity calculations and provide a rigorous and comprehensive physical description of thermal phonon transport in superlattices by solving the Boltzmann transport equation and using the Beckman-Kirchhoff surface scattering theory with shadowing to precisely describe phonon-surface interactions. We show that thermal transport in superlattices can be divided in two different heat transport modes having different physical properties at small length scales: layer-restricted and extended heat modes. We study how interface conditions, periodicity, and composition can be used to manipulate the distribution of thermal energy flow among such layer-restricted and extended heat modes. From predicted frequency and mean free path spectra of superlattices, we also investigate the existence of wave effects. The results and insights in this paper advance the fundamental understanding of heat transport in superlattices and the prospects of rationally designing thermal systems with tailored phonon transport properties.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Metal hydride-based thermal energy storage systems

    DOEpatents

    Vajo, John J.; Fang, Zhigang

    2017-10-03

    The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

  11. Thermal energy storage technical progress report, April 1990--March 1991

    SciTech Connect

    Tomlinson, J.J.

    1992-03-01

    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 Oak Ridge National Laboratory`s TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

  12. Thermal energy storage technical progress report, April 1990--March 1991

    SciTech Connect

    Tomlinson, J.J.

    1992-03-01

    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 Oak Ridge National Laboratory's TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

  13. Effects of ocean acidification increase embryonic sensitivity to thermal extremes in Atlantic cod, Gadus morhua.

    PubMed

    Dahlke, Flemming T; Leo, Elettra; Mark, Felix C; Pörtner, Hans-Otto; Bickmeyer, Ulf; Frickenhaus, Stephan; Storch, Daniela

    2017-04-01

    Thermal tolerance windows serve as a powerful tool for estimating the vulnerability of marine species and their life stages to increasing temperature means and extremes. However, it remains uncertain to which extent additional drivers, such as ocean acidification, modify organismal responses to temperature. This study investigated the effects of CO2 -driven ocean acidification on embryonic thermal sensitivity and performance in Atlantic cod, Gadus morhua, from the Kattegat. Fertilized eggs were exposed to factorial combinations of two PCO2 conditions (400 μatm vs. 1100 μatm) and five temperature treatments (0, 3, 6, 9 and 12 °C), which allow identifying both lower and upper thermal tolerance thresholds. We quantified hatching success, oxygen consumption (MO2 ) and mitochondrial functioning of embryos as well as larval morphometrics at hatch and the abundance of acid-base-relevant ionocytes on the yolk sac epithelium of newly hatched larvae. Hatching success was high under ambient spawning conditions (3-6 °C), but decreased towards both cold and warm temperature extremes. Elevated PCO2 caused a significant decrease in hatching success, particularly at cold (3 and 0 °C) and warm (12 °C) temperatures. Warming imposed limitations to MO2 and mitochondrial capacities. Elevated PCO2 stimulated MO2 at cold and intermediate temperatures, but exacerbated warming-induced constraints on MO2 , indicating a synergistic interaction with temperature. Mitochondrial functioning was not affected by PCO2 . Increased MO2 in response to elevated PCO2 was paralleled by reduced larval size at hatch. Finally, ionocyte abundance decreased with increasing temperature, but did not differ between PCO2 treatments. Our results demonstrate increased thermal sensitivity of cod embryos under future PCO2 conditions and suggest that acclimation to elevated PCO2 requires reallocation of limited resources at the expense of embryonic growth. We conclude that ocean acidification constrains

  14. Conversion of concentrated solar thermal energy into chemical energy.

    PubMed

    Tamaura, Yutaka

    2012-01-01

    When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500-2500 kW/m(2) is absorbed by an excess Frenkel defect formation. This non-equilibrium state defect is generated not by heating at a low heating-rate (30 K/min), but by irradiating high flux energy of concentrated solar beam rapidly at a high heating rate (200 K/min). The defect can be spontaneously converted to chemical energy of a cation-excess spinel structure (reduced-oxide form) at the temperature around 1773 K. Thus, the O(2) releasing reaction (α-O(2) releasing reaction) proceeds in two-steps; (1) high flux energy of concentrated solar beam absorption by formation of the non-equilibrium Frenkel defect and (2) the O(2) gas formation from the O(2-) in the Frenkel defect even in air atmosphere. The 2nd step proceeds without the solar radiation. We may say that the 1st step is light reaction, and 2nd step, dark reaction, just like in photosynthesis process.

  15. Advanced phase change composite by thermally annealed defect-free graphene for thermal energy storage.

    PubMed

    Xin, Guoqing; Sun, Hongtao; Scott, Spencer Michael; Yao, Tiankai; Lu, Fengyuan; Shao, Dali; Hu, Tao; Wang, Gongkai; Ran, Guang; Lian, Jie

    2014-09-10

    Organic phase change materials (PCMs) have been utilized as latent heat energy storage and release media for effective thermal management. A major challenge exists for organic PCMs in which their low thermal conductivity leads to a slow transient temperature response and reduced heat transfer efficiency. In this work, 2D thermally annealed defect-free graphene sheets (GSs) can be obtained upon high temperature annealing in removing defects and oxygen functional groups. As a result of greatly reduced phonon scattering centers for thermal transport, the incorporation of ultralight weight and defect free graphene applied as nanoscale additives into a phase change composite (PCC) drastically improve thermal conductivity and meanwhile minimize the reduction of heat of fusion. A high thermal conductivity of the defect-free graphene-PCC can be achieved up to 3.55 W/(m K) at a 10 wt % graphene loading. This represents an enhancement of over 600% as compared to pristine graphene-PCC without annealing at a comparable loading, and a 16-fold enhancement than the pure PCM (1-octadecanol). The defect-free graphene-PCC displays rapid temperature response and superior heat transfer capability as compared to the pristine graphene-PCC or pure PCM, enabling transformational thermal energy storage and management.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Energy dynamics of Chinook salmon as they migrate from rivers to the ocean

    NASA Astrophysics Data System (ADS)

    Martin, B.; Fiechter, J.; Nisbet, R. M.; Danner, E.

    2016-02-01

    During the migration from their freshwater habitats of rivers to the ocean, juvenile Chinook salmon encounter substantially different abiotic and biotic conditions. These differences in conditions in can have important consequences for growth, condition (lipid storage), and survival. We developed a generic energetic model based off Dynamic Energy Budget theory that characterizes growth and energy allocation dynamics as a function of biotic (food density) and abiotic (water temperature) conditions. We then linked the bioenergetics model with coupled physical-biological models of river, estuary, and ocean habitats to predict energy dynamics before, during, and after the transition to ocean environments. The analysis of our model yielded novel insights about energy partitioning between growth and storage lipids as a function of food density. Furthermore we used the model to identify physical conditions associated with fast growth and high survival in the first few months in the ocean, a critical transition in the salmon life cycle.

  3. 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.

  4. 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.

  5. High temperature latent heat thermal energy storage to augment solar thermal propulsion for microsatellites

    NASA Astrophysics Data System (ADS)

    Gilpin, Matthew R.

    Solar thermal propulsion (STP) offers an unique combination of thrust and efficiency, providing greater total DeltaV capability than chemical propulsion systems without the order of magnitude increase in total mission duration associated with electric propulsion. Despite an over 50 year development history, no STP spacecraft has flown to-date as both perceived and actual complexity have overshadowed the potential performance benefit in relation to conventional technologies. The trend in solar thermal research over the past two decades has been towards simplification and miniaturization to overcome this complexity barrier in an effort finally mount an in-flight test. A review of micro-propulsion technologies recently conducted by the Air Force Research Laboratory (AFRL) has identified solar thermal propulsion as a promising configuration for microsatellite missions requiring a substantial Delta V and recommended further study. A STP system provides performance which cannot be matched by conventional propulsion technologies in the context of the proposed microsatellite ''inspector" requiring rapid delivery of greater than 1500 m/s DeltaV. With this mission profile as the target, the development of an effective STP architecture goes beyond incremental improvements and enables a new class of microsatellite missions. Here, it is proposed that a bi-modal solar thermal propulsion system on a microsatellite platform can provide a greater than 50% increase in Delta V vs. chemical systems while maintaining delivery times measured in days. The realization of a microsatellite scale bi-modal STP system requires the integration of multiple new technologies, and with the exception of high performance thermal energy storage, the long history of STP development has provided "ready" solutions. For the target bi-modal STP microsatellite, sensible heat thermal energy storage is insufficient and the development of high temperature latent heat thermal energy storage is an enabling

  6. 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.

  7. 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.

  8. Assessment of great ocean currents as a source of renewable energy using recent OGCM simulations of the global ocean

    NASA Astrophysics Data System (ADS)

    Barnier, Bernard; Domina, Anastasiia; Maitre, Thierry; Molines, Jean-Marc; Penduff, Thierry; Le Sommer, Julien; Brasseur, Pierre; Gulev, Sergey

    2017-04-01

    The great wind-driven ocean currents (e.g. Gulf-Stream or Kuroshio) are relatively constant in strength and direction, and they carry a great deal of energy because of the density of water. Technologies are being developed to extract energy from those currents and convert it into a usable power. The paper presents a methodology used to select regions of the global ocean where the properties of the great ocean currents are favourable to the implementation of Turbine Power Plants (TPP) made of submerged rotors driven by the motion of water. The methodology relies on a state-of-the-art eddy-resolving global ocean general circulation model used for real-time ocean forecasting, in which the implementation of a large TPP is represented by an additional drag force applied locally. This system is able to simulate the flow changes induced by the implementation of a power plant in the current, and consequently provides an assessment of the renewable energy that could be recovered and of the possible environmental impact. Our results demonstrate that the flow changes induced by a large TPP (covering the area of a model grid size, i.e. a few km) are highly dependent on the details of local topography, leading to a reduction of the available power that can vary from 25% to 85% according to location. We shall also show that impact of a TPP on the flow can be felt a few 100 kilometres upstream and may in some cases not only impact the flow speed, but also induce a large shift of the main current path.

  9. 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.

  10. Dark energy in thermal equilibrium with the cosmological horizon?

    NASA Astrophysics Data System (ADS)

    Poitras, Vincent

    2014-03-01

    According to a generalization of black hole thermodynamics to a cosmological framework, it is possible to define a temperature for the cosmological horizon. The hypothesis of thermal equilibrium between the dark energy and the horizon has been considered by many authors. We find the restrictions imposed by this hypothesis on the energy transfer rate (Qi) between the cosmological fluids, assuming that the temperature of the horizon has the form T =b/2πR, where R is the radius of the horizon. We more specifically consider two types of dark energy: Chaplygin gas (CG) and dark energy with a constant equation of state parameter (wDE). In each case, we show that for a given radius R, there is a unique term Qde that is consistent with thermal equilibrium. We also consider the situation where, in addition to dark energy, other fluids (cold matter, radiation) are in thermal equilibrium with the horizon. We find that the interaction terms required for this will generally violate energy conservation (∑iQi=0).

  11. 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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dual Reciprocity Boundary Element Method for studying thermal flow in cooling Magma Oceans

    NASA Astrophysics Data System (ADS)

    Drombosky, T.; Hier-Majumder, S.

    2011-12-01

    Earth's early history is marked by a giant impact with a Mars-sized object which lead to the formation of the moon. This impact event likely led to a substantial amount of melting of the Earth's interior. Subsequent cooling of the Earth involved extensive crystallization in this "magma ocean" over a relatively short period of time. While chemical evidence from ancient sources provides some clues on the rate of cooling, computational models of such phenomena are sparse. Modeling the crystal settling behavior requires solving a coupled system of partial differential equations, specifically the Stokes flow equation coupled with the heat equation through an advection term. Our work uses the dual reciprocity boundary element method (DRBEM) to model such a system. DRBEM extends on the boundary element method (BEM) to solve the heat equation for a multiparticle system in an infinite suspension fluid while avoiding the expensive rediscretization inherit in other methods. In DRBEM, terms arising from the material time derivative of temperature are expanded in a series of function, known as radial basis functions. By modeling this system we are able to simulate thermal interactions among an arbitrary number of crystals settling in a magma ocean. The types of interactions include the enhanced cooling of the magma due to an advecting matrix of cold crystal particles. We are also able to observe the interactions of the crystals' thermal profiles. As a crystal settles, it leaves behind a trail of lower temperature suspension fluid, which then interacts with surrounding particles.

  13. 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.; 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.

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

    PubMed

    Sluijs, Appy; Schouten, Stefan; Pagani, Mark; Woltering, Martijn; Brinkhuis, Henk; Sinninghe Damsté, Jaap S; Dickens, Gerald R; Huber, Matthew; Reichart, Gert-Jan; Stein, Ruediger; Matthiessen, Jens; Lourens, Lucas J; Pedentchouk, Nikolai; Backman, Jan; Moran, Kathryn

    2006-06-01

    The Palaeocene/Eocene thermal maximum, approximately 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 degrees C to over 23 degrees 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 degrees 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.

  15. 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.

  16. 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.

  17. Thermal energy storage. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-09-01

    The cited reports of federally-funded research concern thermal energy storage. The citations cover the design of equipment, performance evaluation, theory, materials used, and experimental design. This updated bibliography contains 240 citations, 128 of which are new entries to the previous edition.

  18. 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.

  19. 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.

  20. Local thermal energy as a structural indicator in glasses

    NASA Astrophysics Data System (ADS)

    Zylberg, Jacques; Lerner, Edan; Bar-Sinai, Yohai; Bouchbinder, Eran

    2017-07-01

    Identifying heterogeneous structures in glasses—such as localized soft spots—and understanding structure-dynamics relations in these systems remain major scientific challenges. Here, we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change caused by thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses—an intrinsic signature of glassy frustration—anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal ω4ω4 density of states of quasilocalized low-frequency vibrational modes. When the spatial thermal energy field—a “softness field”—is considered, this power law tail manifests itself by highly localized spots, which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal modes-based approach. These results offer a general, system/model-independent, physical/observable-based approach to identify structural properties of quiescent glasses and relate them to glassy dynamics.

  1. Local thermal energy as a structural indicator in glasses.

    PubMed

    Zylberg, Jacques; Lerner, Edan; Bar-Sinai, Yohai; Bouchbinder, Eran

    2017-07-11

    Identifying heterogeneous structures in glasses-such as localized soft spots-and understanding structure-dynamics relations in these systems remain major scientific challenges. Here, we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change caused by thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses-an intrinsic signature of glassy frustration-anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal [Formula: see text] density of states of quasilocalized low-frequency vibrational modes. When the spatial thermal energy field-a "softness field"-is considered, this power law tail manifests itself by highly localized spots, which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal modes-based approach. These results offer a general, system/model-independent, physical/observable-based approach to identify structural properties of quiescent glasses and relate them to glassy dynamics.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. The ocean as a supplier of food and energy.

    PubMed

    Wilcox, H A

    1982-01-01

    This paper presents the concept of raising seaweeds and other valuable organisms with the aid of huge structures ('ocean farms') emplaced in the surface waters of the open oceans. Potential advantages from and difficulties to be expected in realizing the associated technologies are briefly set forth. Much of the published literature pertaining to the concept is referenced and summarized. Wave-powered upwelling of cool, nutrient-rich waters through vertical pipes extending to depths of 100-300 m is indicated as desirable. Technologies are outlined for using the harvested seaweeds to create foods and other valuable products such as animal feeds, fertilizers, fibers, plastics, synthetic natural gas (methane), and alcohol and gasoline fuels. Results from site selection studies and economic analyses are given. It appears that dynamically positioned farms orbiting with the surface current patterns typically found on the ocean will be most cost-effective. The general conclusion is stated that open ocean farming will become economically more feasible as the cheaper fossil fuels and food producing lands of the earth become increasingly consumed in the course of the next century.

  8. Thermal Energy Storage and Heat Transfer Support Program. Task 4. Thermionic Energy Conversion Studies. Volume 2

    DTIC Science & Technology

    1991-03-01

    AD-A-23 9 968 (J WRDC-TR-90-2121 Thermal Energy Storage and Heat Transfer Support Program Task 4 - Thermionic Energy Conversion Studies Mysore L...POOS IIiMINT NO NO. NOION5g No LI ght Patterson AFB, OH 45433-6563 62203F 3145 20 51 ’. ""." inCOu secunr Cdriecawo Thermal Energy Storage and Heat...Transfer Support Program ’Vol. II Task 4 - Thermionic Energy Conversion Studies 12. PERSONAL AUTmOR(S) I Ramalingam, _vsore L. 1U1. !YOE OF REPORT -..%ifE

  9. Subduction of young oceanic plates: A numerical study with application to aborted thermal-chemical plumes

    NASA Astrophysics Data System (ADS)

    Blanco-Quintero, Idael Francisco; Gerya, Taras V.; GarcíA-Casco, Antonio; Castro, Antonio

    2011-10-01

    We investigated numerical models of initiation and subsequent evolution of subduction of young (10-30 Myr) oceanic lithosphere. Systematic numerical experiments were carried out by varying the age of the subducting plate (10, 12.5, 15, 17.5, 20, 25 and 30 Myr), the rate of induced convergence (2, 4 and 5 cm/yr) and the degree of hydration (0 and 2 wt% H2O) of the pre-existing weak oceanic fracture zone along which subduction is initiated. Despite the prescribed plate forcing, spontaneously retreating oceanic subduction with a pronounced magmatic arc and a backarc basin was obtained in a majority of the experiments. It was also found that the younger age of oceanic lithosphere results in more intense dehydration and partial melting of the slab during and after the induced subduction initiation due to the shallow dispositions of the isotherms. Partial melting of the subducted young crust may create thermal-chemical instabilities (cold plumes) that ascend along the slab-mantle interface until they either freeze at depth or detach from the slab and penetrate the upper plate lithosphere contributing to the nucleation and growth of a volcanic arc. Freezing of the plumes in the slab-mantle interface is favored by subduction of very young lithosphere (i.e., 10 Myr) at moderate rate (4 cm/yr) of convergence. Such aborted plumes may correspond to Cretaceous partially melted MORB-derived slab material and associated adakitic tonalitic-trondhjemitic rocks crystallized at ca. 50 km depth in the slab-mantle interface and exhumed in a subduction channel (serpentinite mélanges) in eastern Cuba.

  10. Thermal energy storage - overview and specific insight into nitrate salts for sensible and latent heat storage.

    PubMed

    Pfleger, Nicole; Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

  11. The Impact of the Ocean Thermal Skin Layer on Air-Sea Interfacial Heat Fluxes

    NASA Astrophysics Data System (ADS)

    Minnett, P. J.; Wong, E.

    2015-12-01

    The upper ocean heat content has been observed to be increasing over the past few decades much of which has been attributed to anthropogenic effects resulting in an increase in greenhouse gases thereby increasing the amounts of incoming longwave (LWin) radiation impinging onto the ocean's surface. However, the penetration depth of LWin extends to micrometer scales, where the ocean's thermal skin layer (TSL) exists, and does not directly heat the upper few meters of the ocean thereby raising the conundrum of how does the upper ocean warm with increasing levels of infrared (IR) radiation. The TSL consists of a strong temperature gradient on the aqueous side of the interface that sustains the upward heat flux by molecular conduction. As such, we hypothesize the heat lost through the air-sea interface which is controlled by the TSL, modulates the amount of heat stored in the upper few meters of the ocean. An analysis of properties of the retrieved TSL profiles from a shipboard IR spectrometer with heat fluxes (specifically LWin) and wind speeds from two cruises limited to night-time data are presented. We also show a comparison between these properties with current published viscous layer models. The results indicate that the data have an inherent wind speed dependence with net flux thereby requiring a segregation of the data into wind speed bins to acknowledge the effects of wind-driven shear in the analysis. The temperature differences derived from the models indicates that at low wind speeds (<2 m/s), where wind-driven shear effects are negligible and buoyancy effects dominate, the TSL profile's gradient is decreasing with increased LWin which leads to a lowered net heat flux and is in agreement with our hypothesis. However our field results show an opposite effect (higher gradient at higher LWin) which is believed to be due to the formation of a thicker TSL at low winds. The presence of a thicker TSL suggests that more of the vertical temperature gradient lies

  12. 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).

  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. 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

  15. The Value of Concentrating Solar Power and Thermal Energy Storage

    DOE PAGES

    Sioshansi, Ramteen; Denholm, Paul

    2010-06-14

    Our paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in a number of regions in the southwestern United States. Our analysis also shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant's solar field to be used, 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 also analyze the sensitivity of this value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, andmore » dry cooling of the CSP plant, and also estimate the capacity value of a CSP plant with TES. We further discuss the value of CSP plants and TES net of capital costs.« less

  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. The Value of Concentrating Solar Power and Thermal Energy Storage

    SciTech Connect

    Sioshansi, Ramteen; Denholm, Paul

    2010-06-14

    Our paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in a number of regions in the southwestern United States. Our analysis also shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant's solar field to be used, 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 also analyze the sensitivity of this value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, and dry cooling of the CSP plant, and also estimate the capacity value of a CSP plant with TES. We further discuss the value of CSP plants and TES net of capital costs.

  18. Tsunami Energy, Ocean-Bottom Pressure, and Hydrodynamic Force from Stochastic Bottom Displacement

    NASA Astrophysics Data System (ADS)

    Ramadan, Khaled T.; Omar, M. A.; Allam, Allam A.

    2017-03-01

    Tsunami generation and propagation due to a randomly fluctuating of submarine earthquake modeled by vertical time-dependent of a stochastic bottom displacement are investigated. The increase in oscillations and amplitude in the free surface elevation are controlled by the noise intensity parameter of the stochastic bottom displacement. Evolution of kinetic and potential energy of the resulting waves by the stochastic bottom displacement is examined. Exchange between potential and kinetic energy was achieved in the propagation process. The dynamic ocean-bottom pressure during tsunami generation is investigated. As the vertical displacement of the stochastic bottom increases, the peak amplitude of the ocean-bottom pressure increases through the dynamic effect. Time series of the maximum tsunami wave amplitude, kinetic and potential energy, wave and ocean-bottom pressure gauges and the hydrodynamic force caused by the stochastic source model under the effect of the water depth of the ocean are investigated.

  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. Extreme subseasonal tropical air-sea interactions and their relation to ocean thermal stratification

    NASA Astrophysics Data System (ADS)

    Lloyd, Ian D.

    2011-12-01

    representation of warm core eddies and the loop current in the Gulf of Mexico, and a new parameterization of the drag coefficient. The 2006--2009 period contains more intense hurricanes (category 4 and 5) and the non-monotonic nature of the SST-intensity response is more similar to observations than in 2005. This result was attributed to weaker ocean thermal stratification in the Gulf of Mexico allowing for greater storm intensification. A very simple Conceptual Hurricane Intensity Model consisting of two coupled equations was formulated to account for the non-monotonic SST-intensity response. Finally, dynamical oceanic changes in the tropical North Atlantic under climate change were examined across a range of climate models. Given the sensitivity of hurricane intensity to stratification, large-scale ocean changes must be understood in order to make robust intensity predictions. The models' mean state contained significant biases, and it is not clear whether these mean state biases are reduced in models with higher resolution. However, climate change projections indicate a robust subsurface warming response in the tropical North Atlantic that could impact hurricane intensity. The non-local air-sea processes that account for water mass biases were highlighted as an area for future research.