Science.gov

Sample records for reliability geothermal experience

  1. Downwell pump reliability: Geothermal experience update: Final report

    SciTech Connect

    Ellis, P.F.

    1988-01-01

    Geothermal resources with temperatures between 250/sup 0/ and 360/sup 0/F (121/sup 0/C and 182/sup 0/C) are prime candidates for binary-cycle power generation, and constitute about 80% of the power-capable resources in the United States. The successful exploitation of these resources requires reliable high-capacity downwell brine production pumps, but earlier experience showed that high-capacity, high-temperature geothermal production pumps had many problems which resulted in a mean time-to-failure (MTTF) of less than 1000 h. However, steady progress has been made since 1981, and a large body of experience has been acquired by three geothermal binary plants. This survey of high-temperature geothermal downwell pump users and manufacturers updates a prior survey (AP-3572) completed in early 1983. This survey traces the development of lineshaft pump technology from the late 1970s to the present (mid-1987), detailing the advances in design, materials selection, and operating practices. Case histories of 72 lineshaft pumps installed at three geothermal binary plants since late 1981 are documented, including some detailed cause of failure reports. In the recent past, pump lives in excess of 7000 h have become common, but a high continuing rate of premature failures resulted in a mean time-to-failure (MTTF) of about 5000 h. Based on recent advances which appear likely to eliminate most premature failures, the estimated near-term MTTF will be on the order of 8000 h. The survey found almost no development of high-temperature geothermal electric submersible pumps (ESP's) or close-coupled downwell hydraulic turbopumps, and concluded that considerable development and demonstration will be needed before these technologies are able to compete with existing high-temperature geothermal lineshaft pump technology. 36 refs., 10 figs., 25 tabs.

  2. Experiments Demonstrate Geothermal Heating Process

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm…

  3. Geothermal FIT Design: International Experience and U.S. Considerations

    SciTech Connect

    Rickerson, W.; Gifford, J.; Grace, R.; Cory, K.

    2012-08-01

    Developing power plants is a risky endeavor, whether conventional or renewable generation. Feed-in tariff (FIT) policies can be designed to address some of these risks, and their design can be tailored to geothermal electric plant development. Geothermal projects face risks similar to other generation project development, including finding buyers for power, ensuring adequate transmission capacity, competing to supply electricity and/or renewable energy certificates (RECs), securing reliable revenue streams, navigating the legal issues related to project development, and reacting to changes in existing regulations or incentives. Although FITs have not been created specifically for geothermal in the United States to date, a variety of FIT design options could reduce geothermal power plant development risks and are explored. This analysis focuses on the design of FIT incentive policies for geothermal electric projects and how FITs can be used to reduce risks (excluding drilling unproductive exploratory wells).

  4. European Geothermal Drilling Experience-Problem Areas and Case Studies

    SciTech Connect

    Baron, G.; Ungemach, P.

    1981-01-01

    Geothermal drilling has long been restricted in Western Europe to the sole dry steam field of Larderello in Italy. In the last few years, a wider experience is building up as a consequence of intensified exploration and development programs carried out for evaluation and production of both low- and high-enthalpy geothermal resources. A sample of some 40 boreholes indicates the problem areas which are given.

  5. Italian Experience and Problems in Deep Geothermal Drilling

    SciTech Connect

    Cigni, U.; Del Gaudio, P.; Fabbri, F.

    1981-01-01

    Geothermal exploration at depth is being conducted in the Larderello area of Italy, in order to ascertain whether it is possible to extract geothermal fluids from the layers which underlie the reservoir now being exploited. The main operating problems are caused by the high thermality and the chemical corrosiveness of the fluids encountered; and by the practical problems involved in drilling without circulation to the surface in mainly hard but anhomogeneous fractured formations. The technology employed for deep geothermal well drilling plays an important role in this research. In deep geothermal well drilling it is essential that the equipment and the materials employed are suitable for use in areas which are characterized by high thermality and chemical corrosiveness. The results of the experiences gained in Italy concerning the materials and tools employed in deep geothermal exploration are presented. The various problems involved are described in detail and particular mention is made of drift control, fishing operations, cementation of the deep casing, control of the circulation fluid, and choice of the tubular materials.

  6. Raft River well stimulation experiments: geothermal reservoir well stimulation program

    SciTech Connect

    Not Available

    1980-08-01

    The Geothermal Reservoir Well Stimulation Program (GRWSP) performed two field experiments at the Raft River KGRA in 1979. Wells RRGP-4 and RRGP-5 were selected for the hydraulic fracture stimulation treatments. The well selection process, fracture treatment design, field execution, stimulation results, and pre- and post-job evaluations are presented.

  7. Geothermal well stimulation - program summary and the Beowawe field experiment

    SciTech Connect

    Verity, R.V.

    1983-12-01

    Republic Geothermal, Inc. and its subcontractors have planned and executed laboratory studies and eight well stimulation field experiments under the Geothermal Reservoir Well Stimulation Program (GRWSP). The program, begun in February 1979, has concentrated on extending petroleum industry stimulation technology for use by the geothermal industry. The most recent experiment was in a naturally fractured Chevron well at Beowawe and involved an acid stimulation of a damaged interval which yielded a 2.3-fold increase in injectivity. Overall results to date have shown that stimulation is viable where adequate reservoirs are penetrated by wells encountering formation damage or locally tight formations. However, wells in marginal naturally fractured reservoirs have not been saved by the types of well stimulation jobs performed thus far. A recent discovery is that many wells can possibly be made outstanding producers by widening and propping compliant natural fractures. Confirmation of this constitutes unfinished business of the GRWSP, adn offers one of the greatest potential opportunities for enhancing the economics of geothermal power production.

  8. Apollo experience report: Reliability and quality assurance

    NASA Technical Reports Server (NTRS)

    Sperber, K. P.

    1973-01-01

    The reliability of the Apollo spacecraft resulted from the application of proven reliability and quality techniques and from sound management, engineering, and manufacturing practices. Continual assessment of these techniques and practices was made during the program, and, when deficiencies were detected, adjustments were made and the deficiencies were effectively corrected. The most significant practices, deficiencies, adjustments, and experiences during the Apollo Program are described in this report. These experiences can be helpful in establishing an effective base on which to structure an efficient reliability and quality assurance effort for future space-flight programs.

  9. Software reliability experiments data analysis and investigation

    NASA Technical Reports Server (NTRS)

    Walker, J. Leslie; Caglayan, Alper K.

    1991-01-01

    The objectives are to investigate the fundamental reasons which cause independently developed software programs to fail dependently, and to examine fault tolerant software structures which maximize reliability gain in the presence of such dependent failure behavior. The authors used 20 redundant programs from a software reliability experiment to analyze the software errors causing coincident failures, to compare the reliability of N-version and recovery block structures composed of these programs, and to examine the impact of diversity on software reliability using subpopulations of these programs. The results indicate that both conceptually related and unrelated errors can cause coincident failures and that recovery block structures offer more reliability gain than N-version structures if acceptance checks that fail independently from the software components are available. The authors present a theory of general program checkers that have potential application for acceptance tests.

  10. Geothermal injection treatment: process chemistry, field experiences, and design options

    SciTech Connect

    Kindle, C.H.; Mercer, B.W.; Elmore, R.P.; Blair, S.C.; Myers, D.A.

    1984-09-01

    The successful development of geothermal reservoirs to generate electric power will require the injection disposal of approximately 700,000 gal/h (2.6 x 10/sup 6/ 1/h) of heat-depleted brine for every 50,000 kW of generating capacity. To maintain injectability, the spent brine must be compatible with the receiving formation. The factors that influence this brine/formation compatibility and tests to quantify them are discussed in this report. Some form of treatment will be necessary prior to injection for most situations; the process chemistry involved to avoid and/or accelerate the formation of precipitate particles is also discussed. The treatment processes, either avoidance or controlled precipitation approaches, are described in terms of their principles and demonstrated applications in the geothermal field and, when such experience is limited, in other industrial use. Monitoring techniques for tracking particulate growth, the effect of process parameters on corrosion and well injectability are presented. Examples of brine injection, preinjection treatment, and recovery from injectivity loss are examined and related to the aspects listed above.

  11. High power diode lasers reliability experiment

    NASA Astrophysics Data System (ADS)

    Lu, Guoguang; Xie, Shaofeng; Hao, Mingming; Huang, Yun; En, Yunfei

    2013-12-01

    In order to evaluate and obtain the actual lifetime data of high power laser diodes, an automated high power laser diodes reliability experiment was developed and reported in this paper. This computer controlled setup operates the laser diodes 24 hours a day, the parameters such as output power, wavelength were test once in one hour. The experiment has 60 work stations, the temperature control range is from 25°C to 70°C, and the output power of the aging device is beyond 20W.

  12. Geothermal energy and the environment - The global experience

    NASA Astrophysics Data System (ADS)

    Pasqualetti, M. J.

    1980-02-01

    The paper discusses the impact of environmental problems on the world's geothermal generating stations. The significant impacts include conflicts in land use, air pollution, subsidence, water pollution, induced seismicity, blowouts, and noise. Development of geothermal resources has been slowed down in some countries: in U.S., the emission of hydrogen sulfide produced a problem; in Japan, land use in national parks and waste-water disposal resulted in difficulties; and in El Salvador, waste-water disposal presented a difficulty. Geothermal development faces many regulations and difficulties, particularly in U.S., a country which could stimulate a global acceleration in this field with appropriately relaxed controls.

  13. Community Geothermal Technology Program: Cloth dyeing by geothermal steam. An experiment in technology transfer from Japan to Hawaii, Final report

    SciTech Connect

    Furumoto, A.S.

    1987-12-31

    This was an experiment to test whether cloth dyeing using geothermal steam (already proven in Japan) would be feasible in Hawaii. Results: Using a fabricated steam vat, cotton, silk, and synthetic can be dyed; the resulting material received high grades for steadfastness and permanency under dye testing. Techniques that were successful in Matsukawa, were replicated in Puna. However, attempts to embed leaf patterns on cloth using natural leaves and to extract natural dyes from Hawaiian plants were unsuccessful; the color of natural dyes deteriorated in hours. But chemical dyes gave brilliant hues or shades, in contrast to those in Japan where the steam there gave subdued tones. It is concluded that geothermal dyeing can be a viable cottage industry in Puna, Hawaii.

  14. Geothermal materials development

    SciTech Connect

    Kukacka, L.E.

    1982-01-01

    Among the most pressing problems constraining the development of geothermal energy is the lack of satisfactory component and system reliability. This is due to the unavailability, on a commercial scale, of cost-effective materials that can function in a wide range of geothermal environments and to the unavailability of a comprehensive body of directly relevant test data or materials selection experience. Suitable materials are needed for service in geothermal wells and in process plant equipment. For both situations, this requires materials that can withstand high-temperature, highly-corrosive, and scale-forming geothermal fluids. In addition to requiring a high degree of chemical and thermal resistance, the downhole environment places demands on the physical/mechanical properties of materials for components utilized in well drilling, completion, pumping, and logging. Technical and managerial assistance provided by Brookhaven in the program for studying these materials problems is described.

  15. Monitoring a shallow geothermal experiment in a sandy aquifer using electrical resistivity tomography: a feasibility study

    NASA Astrophysics Data System (ADS)

    Hermans, Thomas; Vandenbohede, Alexander; Nguyen, Frederic; Lebbe, Luc

    2010-05-01

    The use of low-enthalpy geothermal ressources is increasingly growing in Europe and around the world. This domain constitutes an essential field of research and development in the diversification of energy ressources to hinder global warming. The advantages of very low temperature systems are, first, that they are much more available than the geothermal high temperature, since the underground often contains important shallow aquifers (e.g. alluvial plains), and second, that their exploitation involve relatively low costs of implementation. Very low energy systems exhibit underground fluid with a temperature ranging from 5 to 30 ° C, which may be used for cooling or heating. The two main modes of exploitation of geothermal energy rely on the extraction of the hydrothermal fluid in the aquifer from wells and on the circulation of a heat transfer fluid in a closed and buried geothermal circuit. Underground heat exchange and overall exploitation system design may be undertaken in an optimized and sustainable fashion if the parameters governing the coupled heat transport and flow equations are know to a certain degree. As for many underground reservoir problems, sufficient knowledge on the distribution of the parameters of interests (e.g. thermal conductivity, thermal diffusivity, thermomechanic dispersitivity, effective porosity) must be obtained to perform reliable predictions. Designing novel experiments to estimate those parameters in-situ is therefore essential. In this framework, we examine the feasibility of a thermal tracer experiment similar to the ones performed in hydrogeology or hydrogeophysics. The test consists in following the evolution of a heat plume through the underground as it is injected in one well and pumped to another one. The thermal tracer evolution is followed by gathering electrical resistivity (ERT) images in a time-lapse framework over 10 days. In this contribution, we examine the potential of ERT to image such thermal plume and its

  16. Experiments in fault tolerant software reliability

    NASA Technical Reports Server (NTRS)

    Mcallister, David F.; Tai, K. C.; Vouk, Mladen A.

    1987-01-01

    The reliability of voting was evaluated in a fault-tolerant software system for small output spaces. The effectiveness of the back-to-back testing process was investigated. Version 3.0 of the RSDIMU-ATS, a semi-automated test bed for certification testing of RSDIMU software, was prepared and distributed. Software reliability estimation methods based on non-random sampling are being studied. The investigation of existing fault-tolerance models was continued and formulation of new models was initiated.

  17. On the basis of experience: Built in product reliability

    NASA Astrophysics Data System (ADS)

    1991-02-01

    Rolls Royce product reliability is considered based on experience in supporting commercial gas turbine engines and airline customers during the years of its existence. Reliability on return on investment is addressed. The meaning of 'reliability' and 'return on investment' is discussed.

  18. In situ experiments of geothermal well stimulation using gas fracturing technology

    SciTech Connect

    Chu, T.Y.; Warpinski, N.; Jacobson, R.D.

    1988-07-01

    The results of an experimental study of gas fracturing technology for geothermal well stimulation demonstrated that multiple fractures could be created to link water-filled boreholes with existing fractures. The resulting fracture network and fracture interconnections were characterized by mineback as well as flow tests. Commercial oil field fracturing tools were used successfully in these experiments. Simple scaling laws for gas fracturing and a brief discussion of the application of this technique to actual geothermal well stimulation are presented. 10 refs., 42 figs., 4 tabs.

  19. Geothermal non-power application: The PNOC experience

    SciTech Connect

    Chua, S.E.; Abito, G.F.; Berbano, M.C.

    1996-12-31

    A 1 MWth multi-crop dehydration plant using waste geothermal energy is being operated by the Philippine National Oil Company-Energy Development Corporation (PNOC-EDC) at one of the reinjection pads at the Southern Negros Geothermal Project (SNGP). The facility is composed of two heat exchange systems, seven modular dryers of three different designs, a processing and storage area, a laboratory for quality control tests and an office for general administration and other services. Products from the plant include copra (dried coconut meat), dried fruits, fish and squid, and other agricultural products. Pilot demonstration runs showed the techno-economic: viability of the drying plant. Calculated IRR for production of copra and fruits is 19.3 %, giving a payback period on capital investment of 4.2 years. Sustainability of the operation of the plant requires detailed logistical, production, and marketing plans for the assumed production mix. The facility, which is from a grant from the United Nations Development Programme, is proposed to be {open_quotes}turned over{close_quotes} to a PNOC-formed consortium of farmers cooperatives and associations for its continuous operation and management as a profitable business venture for the community.

  20. Reliability Centered Maintenance: the EDF's Experience

    SciTech Connect

    Huyart, Thierry; Degrave, Claude; Dubreuil-Chambardel, Alain

    2002-07-01

    In order to ensure safest possible operation and to get best overall economic performance of its Nuclear Power Plants, 10 years ago Electricite de France launched a Reliability Centered Maintenance (RCM) project (the so-called OMF Methodology in French) to optimize the preventive maintenance programs, while keeping safety at the right level required. The principles underlying the RCM approach are based on common sense: failures must be prevented by preventive maintenance operations in all cases when the repercussions for the installation could be serious or critical in term of safety, availability or maintenance costs. The new preventive maintenance programs are presently almost completed and progressively implemented. Here and now, the implementation of the RCM approach allows to emphasize some benefits in the fields of costs, safety availability and maintenance culture. (authors)

  1. Experiments in fault tolerant software reliability

    NASA Technical Reports Server (NTRS)

    Mcallister, David F.; Vouk, Mladen A.

    1989-01-01

    Twenty functionally equivalent programs were built and tested in a multiversion software experiment. Following unit testing, all programs were subjected to an extensive system test. In the process sixty-one distinct faults were identified among the versions. Less than 12 percent of the faults exhibited varying degrees of positive correlation. The common-cause (or similar) faults spanned as many as 14 components. However, a majority of these faults were trivial, and easily detected by proper unit and/or system testing. Only two of the seven similar faults were difficult faults, and both were caused by specification ambiguities. One of these faults exhibited variable identical-and-wrong response span, i.e. response span which varied with the testing conditions and input data. Techniques that could have been used to avoid the faults are discussed. For example, it was determined that back-to-back testing of 2-tuples could have been used to eliminate about 90 percent of the faults. In addition, four of the seven similar faults could have been detected by using back-to-back testing of 5-tuples. It is believed that most, if not all, similar faults could have been avoided had the specifications been written using more formal notation, the unit testing phase was subject to more stringent standards and controls, and better tools for measuring the quality and adequacy of the test data (e.g. coverage) were used.

  2. Reliability assessment at airline inspection facilities. Volume 2: Protocol for an eddy current inspection reliability experiment

    NASA Astrophysics Data System (ADS)

    Spencer, Floyd; Borgonovi, Giancarlo; Roach, Dennis; Schurman, Don; Smith, Ron

    1993-05-01

    The Aging Aircraft NDI Development and Demonstration Center (AANC) at Sandia National Laboratories is charged by the FAA to support technology transfer, technology assessment, and technology validation. A key task facing the center is the establishment of a consistent and systematic methodology to assess the reliability of inspections through field experiments. This task is divided into three major areas: reliability of eddy current lap splice inspections at transport aircraft maintenance facilities; reliability of inspection at commuter aircraft maintenance facilities; and reliability of inspection associated with visual inspection of aircraft structural parts. Volume 2 is the second document in a series of three describing the planning, execution, and results of an eddy current inspection field experiment. This document provides a detailed description of the experimental hardware and protocols. It also describes the methodology to be used in the analysis of the data.

  3. Insights From Laboratory Experiments On Simulated Faults With Application To Fracture Evolution In Geothermal Systems

    SciTech Connect

    Stephen L. Karner, Ph.D

    2006-06-01

    Laboratory experiments provide a wealth of information related to mechanics of fracture initiation, fracture propagation processes, factors influencing fault strength, and spatio-temporal evolution of fracture properties. Much of the existing literature reports on laboratory studies involving a coupling of thermal, hydraulic, mechanical, and/or chemical processes. As these processes operate within subsurface environments exploited for their energy resource, laboratory results provide insights into factors influencing the mechanical and hydraulic properties of geothermal systems. I report on laboratory observations of strength and fluid transport properties during deformation of simulated faults. The results show systematic trends that vary with stress state, deformation rate, thermal conditions, fluid content, and rock composition. When related to geophysical and geologic measurements obtained from engineered geothermal systems (e.g. microseismicity, wellbore studies, tracer analysis), laboratory results provide a means by which the evolving thermal reservoir can be interpreted in terms of physico-chemical processes. For example, estimates of energy release and microearthquake locations from seismic moment tensor analysis can be related to strength variations observed from friction experiments. Such correlations between laboratory and field data allow for better interpretations about the evolving mechanical and fluid transport properties in the geothermal reservoir – ultimately leading to improvements in managing the resource.

  4. Recirculation System for Geothermal Energy Recovery in Sedimentary Formations: Laboratory Experiments and Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Elkhoury, J. E.; Detwiler, R. L.; Serajian, V.; Bruno, M. S.

    2012-12-01

    Geothermal energy resources are more widespread than previously thought and have the potential for providing a significant amount of sustainable clean energy worldwide. In particular, hot permeable sedimentary formations provide many advantages over traditional geothermal recovery and enhanced geothermal systems in low permeability crystalline formations. These include: (1) eliminating the need for hydraulic fracturing, (2) significant reduction in risk for induced seismicity, (3) reducing the need for surface wastewater disposal, (4) contributing to decreases in greenhouse gases, and (5) potential use for CO2 sequestration. Advances in horizontal drilling, completion, and production technology from the oil and gas industry can now be applied to unlock these geothermal resources. Here, we present experimental results from a laboratory scale circulation system and numerical simulations aimed at quantifying the heat transfer capacity of sedimentary rocks. Our experiments consist of fluid flow through a saturated and pressurized sedimentary disc of 23-cm diameter and 3.8-cm thickness heated along its circumference at a constant temperature. Injection and production ports are 7.6-cm apart in the center of the disc. We used DI de-aired water and mineral oil as working fluids and explored temperatures from 20 to 150 oC and flow rates from 2 to 30 ml/min. We performed experiments on sandstone samples (Castlegate and Kirby) with different porosity, permeability and thermal conductivity to evaluate the effect of hydraulic and thermal properties on the heat transfer capacity of sediments. The producing fluid temperature followed an exponential form with time scale transients between 15 and 45 min. Steady state outflow temperatures varied between 60% and 95% of the set boundary temperature, higher percentages were observed for lower temperatures and flow rates. We used the flow and heat transport simulator TOUGH2 to develop a numerical model of our laboratory setting. Given

  5. Qualification Users' Perceptions and Experiences of Assessment Reliability

    ERIC Educational Resources Information Center

    Chamberlain, Suzanne

    2013-01-01

    This paper presents the findings of a study designed to explore qualification users' perceptions and experiences of reliability in the context of national assessment outcomes in England. The study consisted of 17 focus groups conducted across six sectors of qualification users: students, teachers, trainee teachers, job-seekers, employers and…

  6. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    SciTech Connect

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  7. An Approach to Studying the Reliability of Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Thaggard, Michael; Morilak, Daniel P.

    1994-01-01

    The identification of key factors that influence the nonsuccess of experiments conducted under microgravity conditions will aid in the planning, design, and implementation of future space shuttle experiments, as well as other microgravity experiments (i.e., experiments conducted on the space station). Similarly, knowledge of the experiments' reliability will assist in forecasting the success of forthcoming experiments. Since a relatively large number of space shuttle experiments have been conducted to date, a substantial pool of data exists for assessing the possible causes or factors which influence experiment nonsuccesses. This report details the task being undertaken at NASA Lewis Research Center (LeRC) to measure the space shuttle experiments' nonsuccess trends and identify causes that significantly affect their performance. It addresses the activities associated with correlating experiment macro-factors with experiment nonsuccesses. The development and implementation of a microgravity database to be used for tracking and correlating experiment nonsuccess factors, as well as the criteria for measuring experiment success and nonsuccess, are also discussed.

  8. Initial results of the CD-1 reliable multicast experiment

    SciTech Connect

    Agarwal, D.; Stead, R.; Coan, B.; Burns, J. E.; Shah, N.; Kyriakopoulos, N.

    2000-09-29

    During the past year, an experiment has been underway to test use of reliable multicast capabilities for transmission of continuous data in the Global Communication Infrastructure. For the experiment a version of the CD-1 protocol was multicast enabled. The experiment has demonstrated the feasibility of transmitting data in a multicast mode over the GCI. In the case of the Comprehensive Nuclear Test-Ban Treaty the sender could be the station and the receivers the International Data Center (IDC) and one or more National Data Centers (NDC). The potential advantages of multicasting include (a) the timely receipt of the data by the IDC and the host NDC and (b) the simultaneous availability of the raw station data at, at least, two locations. The latter, by introducing redundant data paths, decreases the probability of loss of station data due to a potential failure of a single data receiver. This experiment is only one element of a needed more thorough assessment of the reliability and cost-effectiveness of introducing redundancies in the data transmission paths and the data sinks of the IMS. The next stage of the multicast experiment planned is installation of the multicast-enabled CD-1 software at the GERES IMS station, at the German NDC and at the IDC for further experiments with actual IMS station data. This stage of the experiment is waiting on installation of a GCI link to the German NDC. Negotiations regarding price for this installation have been on going between the Global Communication Infrastructure (GCI) contractor and the German NDC with no resolution. Current development of the CD-x protocol is proceeding in two complementary directions. Along with the work on a multicast enabled version of CD-1 there is also work to develop CD-1.1, which will add end-to-end reliability to the CD-1 protocol among other things. A possible future activity would be to combine the reliable multicast and the end-to-end reliability mechanisms into one CD-x protocol version.

  9. Addendum to material selection guidelines for geothermal energy-utilization systems. Part I. Extension of the field experience data base. Part II. Proceedings of the geothermal engineering and materials (GEM) program conference (San Diego, CA, 6-8 October 1982)

    SciTech Connect

    Smith, C.S.; Ellis, P.F. II

    1983-05-01

    The extension of the field experience data base includes the following: key corrosive species, updated field experiences, corrosion of secondary loop components or geothermal binary power plants, and suitability of conventional water-source heat pump evaporator materials for geothermal heat pump service. Twenty-four conference papers are included. Three were abstracted previously for EDB. Separate abstracts were prepared for twenty-one. (MHR)

  10. Geothermal Gases--Community Experiences, Perceptions, and Exposures in Northern California.

    PubMed

    Chiu, Cindy H; Lozier, Matthew J; Bayleyegn, Tesfaye; Tait, Karen; Barreau, Tracy; Copan, Lori; Roisman, Rachel; Jackson, Rebecca; Smorodinsky, Svetlana; Kreutzer, Richard A; Yip, Fuyuen; Wolkin, Amy

    2015-12-01

    Lake County, California, is in a high geothermal-activity area. Over the past 30 years, the city of Clearlake has reported health effects and building evacuations related to geothermal venting. Previous investigations in Clearlake revealed hydrogen sulfide at levels known to cause health effects and methane at levels that can cause explosion risks. The authors conducted an investigation in multiple cities and towns in Lake County to understand better the risk of geothermal venting to the community. They conducted household surveys and outdoor air sampling of hydrogen sulfide and methane and found community members were aware of geothermal venting and some expressed concerns. The authors did not, however, find hydrogen sulfide above the California Environmental Protection Agency air quality standard of 30 parts per billion over one hour or methane above explosive thresholds. The authors recommend improving risk communication, continuing to monitor geothermal gas effects on the community, and using community reports and complaints to monitor and document geothermal venting incidents.

  11. Geothermal energy program overview

    NASA Astrophysics Data System (ADS)

    1991-12-01

    The mission of the Geothermal Energy Program is to develop the science and technology necessary for tapping our nation's tremendous heat energy sources contained within the Earth. Geothermal energy is a domestic energy source that can produce clean, reliable, cost-effective heat and electricity for our nation's energy needs. Geothermal energy - the heat of the Earth - is one of our nation's most abundant energy resources. In fact, geothermal energy represents nearly 40 percent of the total U.S. energy resource base and already provides an important contribution to our nation's energy needs. Geothermal energy systems can provide clean, reliable, cost-effective energy for our nation's industries, businesses, and homes in the form of heat and electricity. The U.S. Department of Energy's (DOE) Geothermal Energy Program sponsors research aimed at developing the science and technology necessary for utilizing this resource more fully. Geothermal energy originates from the Earth's interior. The hottest fluids and rocks at accessible depths are associated with recent volcanic activity in the western states. In some places, heat comes to the surface as natural hot water or steam, which have been used since prehistoric times for cooking and bathing. Today, wells convey the heat from deep in the Earth to electric generators, factories, farms, and homes. The competitiveness of power generation with lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma (the four types of geothermal energy), still depends on the technical advancements sought by DOE's Geothermal Energy Program.

  12. Geothermal handbook

    USGS Publications Warehouse

    1976-01-01

    presented which will allow the Service to provide input to the federal leasing process. As an impact information source by which to judge the appropriateness of a specific activity at a specific site, a discussion of activities-impacts is provided on a phase by phase basis. Mitigation and possible enhancement techniques are also presented so that the impacts of the development can be dealt with and the fish and wildlife situation improved. The Service can achieve its objective only if biological input is made throughout the entire process of geothermal development, from exploration to testing to full field operation. A discussion of geothermal leasing procedures emphasizes the timing and nature of Service participation in current interagency lease processing, and there is a provision for the utilization of new knowledge, techniques, and responses as experience is accumulated.

  13. Stanford Geothermal Program

    SciTech Connect

    R. Horn

    1999-06-30

    Reliable measurement of steam-water relative permeability functions is of great importance for geothermal reservoir performance simulation. Despite their importance, these functions are poorly known due to the lack of fundamental understanding of steam-water flows, and the difficulty of making direct measurements. The Stanford Geothermal Program has used an X-ray CT (Computer Tomography) scanner to obtain accurate saturation profiles by direct measurement. During the last five years, the authors have carried out experiments with nitrogen-water flow and with steam-water flow, and examined the effects of heat transfer and phase change by comparing these sets of results. In porous rocks, it was found that the steam-water relative permeabilities follow Corey type relationships similar to those in nitrogen-water flow, but that the irreducible gas phase saturation is smaller for steam than for nitrogen. The irreducible saturations represent substantial fractions of the recoverable energy in place yet are hard to determine in the field. Understanding the typical magnitude of irreducible saturations will lead to a much clearer forecast of geothermal field performance. In fracture flow, indirect measurements suggested that the relative permeabilities follow a linear (or ''X-curve'') behavior - but there is still considerable uncertainty in the knowledge of this behavior.

  14. Lost circulation in geothermal wells: survey and evaluation of industry experience

    SciTech Connect

    Goodman, M.A.

    1981-07-01

    Lost circulation during drilling and completion of geothermal wells can be a severe problem, particularly in naturally fractured and/or vugular formations. Geothermal and petroleum operators, drilling service companies, and independent consultants were interviewed to assess the lost circulation problem in geothermal wells and to determine general practices for preventing lost circulation. This report documents the results and conclusions from the interviews and presents recommendations for needed research. In addition, a survey was also made of the lost circulation literature, of currently available lost circulation materials, and of existing lost circulation test equipment.

  15. Geothermal Energy.

    ERIC Educational Resources Information Center

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

    An introduction to geothermal energy is provided in this discussion of: (1) how a geothermal reservoir works; (2) how to find geothermal energy; (3) where it is located; (4) electric power generation using geothermal energy; (5) use of geothermal energy as a direct source of heat; (6) geopressured reservoirs; (7) environmental effects; (8)…

  16. Effects of Water Injection into Fractured Geothermal Reservoirs: A Summary of Experience Worldwide

    SciTech Connect

    Horne, Roland N.

    1982-06-01

    Reinjection of water into fractured geothermal reservoirs holds potential both for improvement and degradation of total energy recovery. The replacement of reservoir fluid can mean support of placement of reservoir pressures and also more efficient thermal energy recovery, but at the same time the premature invasion of reinjected water back into production wells through high permeability fractures can reduce discharge enthalpy and hence deliverability and useful energy output. Increases in reservoir pressure and maintenance of field output have been observed in operating fields, but unfortunately so too have premature thermal breakthroughs. The design of reinjection schemes, therefore, requires careful investigation into the likely effects, using field experimentation. This paper summarizes field experience with reinjection around the world, with the intention of elucidating characteristics of possible problems. The results summarized in this paper fall into three categories of interest: permeability changes dye to injection (both increases and decreases); the path followed by injected water (as indicated by tracer tests); and the thermal and hydraulic influences of injection on the reinjection well itself and on surrounding producers. [DJE-2005

  17. Optimal reliability-based planning of experiments for POD curves

    SciTech Connect

    Soerensen, J.D.; Faber, M.H.; Kroon, I.B.

    1995-12-31

    Optimal planning of crack detection tests is considered. The tests are used to update the information on the reliability of inspection techniques modeled by probability of detection (P.O.D.) curves. It is shown how cost-optimal and reliability-based test plans can be obtained using First Order Reliability Methods in combination with life-cycle cost-optimal inspection and maintenance planning. The methodology is based on preposterior analyses from Bayesian decisions theory. An illustrative example is shown.

  18. What Makes Marking Reliable? Experiments with UK Examinations

    ERIC Educational Resources Information Center

    Baird, Jo-Anne; Greatorex, Jackie; Bell, John F.

    2004-01-01

    Marking reliability is purported to be produced by having an effective community of practice. No experimental research has been identified which attempts to verify empirically the aspects of a community of practice that have been observed to produce marking reliability. This research outlines what that community of practice might entail and…

  19. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments.

    PubMed

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4(+)) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4(+) onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20°C to 60°C in order to determine the transport parameters and transformation mechanism of NH4(+) in the studied matrix. The results showed that the adsorption process of NH4(+) onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4(+) onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014cm/h, only a little part of NH4(+) could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20°C to 60°C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  20. Adsorption and transformation of ammonium ion in a loose-pore geothermal reservoir: Batch and column experiments

    NASA Astrophysics Data System (ADS)

    Zhao, Li; Li, Yanli; Wang, Shidong; Wang, Xinyi; Meng, Hongqi; Luo, Shaohe

    2016-09-01

    Adsorption kinetics and transformation process of ammonium ion (NH4+) were investigated to advance the understanding of N cycle in a low-temperature loose-pore geothermal reservoir. Firstly, batch experiments were performed in order to determine the sorption capacity and the kinetic mechanism of NH4+ onto a loose-pore geothermal reservoir matrix. Then column experiments were carried out at temperatures from 20 °C to 60 °C in order to determine the transport parameters and transformation mechanism of NH4+ in the studied matrix. The results showed that the adsorption process of NH4+ onto the porous media well followed the pseudo-second-order model. No obvious variation of hydrodynamic dispersion coefficient (D) and retardation factor (R) was observed at different transport distances at a Darcy's flux of 2.27 cm/h, at which nitrification could be neglected. The simulated D obtained by the CDE model in CXTFIT2.1 increased with temperature while R decreased with temperature, indicating that the adsorption capacity of NH4+ onto the matrix decreased with the increasing of temperature. When the Darcy's flux was decreased to 0.014 cm/h, only a little part of NH4+ could be transformed to nitrate, suggesting that low density of nitrifiers existed in the simulated loose-pore geothermal reservoir. Although nitrification rate increased with temperature in the range of 20 °C to 60 °C, it was extremely low and no accumulation of nitrite was observed under the simulated low-temperature geothermal conditions without addition of biomass and oxygen.

  1. Experiences with Two Reliability Data Collection Efforts (Presentation)

    SciTech Connect

    Sheng, S.; Lantz, E.

    2013-08-01

    This presentation, given by NREL at the Wind Reliability Experts Meeting in Albuquerque, New Mexico, outlines the causes of wind plant operational expenditures and gearbox failures and describes NREL's efforts to create a gearbox failure database.

  2. Fluidized-bed potato waste drying experiments at the Raft River Geothermal Test Site

    SciTech Connect

    Cole, L.T.; Schmitt, R.C.

    1980-06-01

    A fluidized-bed dryer was built and operated at the Raft River Geothermal Test Site in south central Idaho to test the feasibility of using low-temperature (145/sup 0/C or lower) geothermal fluids as an energy source for drying operations. The dryer performed successfully on two potato industry waste products that had a solid content of 5 to 13%. The dried product was removed as a sand-like granular material or as fines with a flour-like texture. Test results, observations, and design recommendations are presented. Also presented is an economic evaluation for commercial-scale drying plants using either geothermal low-temperature water or oil as a heat source.

  3. Using High Pressure Thermal Vessel For Mineral Solubility Experiments in Geothermal System

    NASA Astrophysics Data System (ADS)

    Liu, H. L.; Huang, Y. H.; Chen, H. F.; Song, S. R.

    2014-12-01

    Due to the serious scaling problems of the production in pipeline, Qingshui geothermal power plants closed after 12 years in the past. Because the pressure reduced in the process of upwelling, the hot spring from the reservoir will scaling CaCO3 immediately by large CO2 escape. This result will cause the space of pipeline reduced. On the other hand, as the temperature decreases, the SiO2 scaled in the part of heat exchanger. This study chose the Hongchailin and Qingshui IC-21 well as objects to simulate, and the Szeleng sandstone and the Lushan slate are the target layer of drilling well, respectively. We use pure water and saturated water pressure in our experiments. Besides, the previous studies showed that temperature of reservoir in Qingshui site was not over 300℃, so we set 300℃ as the upper limit temperature. The pressure was less than 800 bar by calculated the rock density of target layer. The original rock sample were placed in first autoclave, and added pure water in the second autoclave. Then we heat the first autoclave to reach the target temperature, and make the pressure saturated over water vapor pressure. After 72 hours the saturated water were leaked into the second autoclave. As the temperature cooling down, we removed the water from second autoclave and diluted the water. Finally, the Na+, K+, Mg+2, Ca+2 ions were analyzed by ICP. We want to get the maximum solubility of calcite and amorphous silica in equilibrium with sandstone and slate, and then check whether the method of geothermometer calculated is reasonable or not by calculated the concentration of Na+, K+, Si+4 in hot spring.

  4. A cost assessment of reliability requirements for shuttle-recoverable experiments

    NASA Technical Reports Server (NTRS)

    Campbell, J. W.

    1975-01-01

    The relaunching of unsuccessful experiments or satellites will become a real option with the advent of the space shuttle. An examination was made of the cost effectiveness of relaxing reliability requirements for experiment hardware by allowing more than one flight of an experiment in the event of its failure. Any desired overall reliability or probability of mission success can be acquired by launching an experiment with less reliability two or more times if necessary. Although this procedure leads to uncertainty in total cost projections, because the number of flights is not known in advance, a considerable cost reduction can sometimes be achieved. In cases where reflight costs are low relative to the experiment's cost, three flights with overall reliability 0.9 can be made for less than half the cost of one flight with a reliability of 0.9. An example typical of shuttle payload cost projections is cited where three low reliability flights would cost less than $50 million and a single high reliability flight would cost over $100 million. The ratio of reflight cost to experiment cost is varied and its effect on the range in total cost is observed. An optimum design reliability selection criterion to minimize expected cost is proposed, and a simple graphical method of determining this reliability is demonstrated.

  5. Geothermal pipeline

    SciTech Connect

    1997-08-01

    The Geothermal Pipeline is a progress and development update from the Geothermal Progress Monitor and includes brief descriptions of various geothermal projects around the world. The following topics are covered: The retirement of Geo-Heat Center Director Paul Lienau, announcement of two upcoming geothermal meetings, and a proposed geothermal power plant project in the Medicine Lake/Glass Mountain area of California. Also included is an article about the Bonneville Power Administration`s settlements with two California companies who had agreed to build geothermal power plants on the federal agency`s behalf, geothermal space heating projects and use of geothermal energy for raising red crayfish in Oregon, and some updates on geothermal projects in Minnesota, Pennsylvania, and China.

  6. Geothermal Energy.

    ERIC Educational Resources Information Center

    Reed, Marshall J.

    1979-01-01

    During 1978, exploration for geothermal energy continued at the same moderately low level of the past few years in most countries. The U.S. is the only country where the development of geothermal energy depends on private industry. (BB)

  7. Geothermal Energy

    SciTech Connect

    Steele, B.C.; Harman, G.; Pitsenbarger, J.

    1996-02-01

    Geothermal Energy Technology (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production.

  8. Westinghouse BWR Fuel Reliability - Recent Experience and Analyses

    SciTech Connect

    Ryttersson, Kristina; Helmersson, Sture; Wright, Jonathan; Hallstadius, Lars

    2007-07-01

    Fuel reliability and failure free fuel has always been one of the most important objectives in the development work at Westinghouse Electric Sweden. An important step in tailoring remedies against both primary and secondary fuel failures is to understand the failure mechanisms. Studies of the mechanisms behind both primary and secondary failures have been performed. For primary failures the recent efforts have been focused on debris fretting failures, since this has been the only mechanism that causes failures in Westinghouse BWR fuel for several years. A statistical analysis of debris fretting failures was performed. The results showed a strong dependency on flow velocity which could be related to a working hypothesis coupling to the excitation of vibrations and the pressure drop over an object in a flow. To increase the understanding of the secondary degradation mechanism, two test reactor studies have been performed. Also, trends related to residence time in core, burnup and power have been evaluated based on the Westinghouse fuel failure database. No clear trends could be seen regarding residence time or burnup up to {approx}40 MWd/kgU. Beyond {approx}40 MWd/kgU the secondary degradation seems to be less severe. One trend that could be identified was an increase in the severity of secondary degradation with increasing rod power. (authors)

  9. Geothermal systems

    NASA Technical Reports Server (NTRS)

    Mohl, C.

    1978-01-01

    Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

  10. Idaho Geothermal Commercialization Program. Idaho geothermal handbook

    SciTech Connect

    Hammer, G.D.; Esposito, L.; Montgomery, M.

    1980-03-01

    The following topics are covered: geothermal resources in Idaho, market assessment, community needs assessment, geothermal leasing procedures for private lands, Idaho state geothermal leasing procedures - state lands, federal geothermal leasing procedures - federal lands, environmental and regulatory processes, local government regulations, geothermal exploration, geothermal drilling, government funding, private funding, state and federal government assistance programs, and geothermal legislation. (MHR)

  11. Software reliability: Additional investigations into modeling with replicated experiments

    NASA Technical Reports Server (NTRS)

    Nagel, P. M.; Schotz, F. M.; Skirvan, J. A.

    1984-01-01

    The effects of programmer experience level, different program usage distributions, and programming languages are explored. All these factors affect performance, and some tentative relational hypotheses are presented. An analytic framework for replicated and non-replicated (traditional) software experiments is presented. A method of obtaining an upper bound on the error rate of the next error is proposed. The method was validated empirically by comparing forecasts with actual data. In all 14 cases the bound exceeded the observed parameter, albeit somewhat conservatively. Two other forecasting methods are proposed and compared to observed results. Although demonstrated relative to this framework that stages are neither independent nor exponentially distributed, empirical estimates show that the exponential assumption is nearly valid for all but the extreme tails of the distribution. Except for the dependence in the stage probabilities, Cox's model approximates to a degree what is being observed.

  12. Basin-scale geothermal model calibration: experience from the Perth Basin, Australia

    NASA Astrophysics Data System (ADS)

    Wellmann, Florian; Reid, Lynn

    2014-05-01

    The calibration of large-scale geothermal models for entire sedimentary basins is challenging as direct measurements of rock properties and subsurface temperatures are commonly scarce and the basal boundary conditions poorly constrained. Instead of the often applied "trial-and-error" manual model calibration, we examine here if we can gain additional insight into parameter sensitivities and model uncertainty with a model analysis and calibration study. Our geothermal model is based on a high-resolution full 3-D geological model, covering an area of more than 100,000 square kilometers and extending to a depth of 55 kilometers. The model contains all major faults (>80 ) and geological units (13) for the entire basin. This geological model is discretised into a rectilinear mesh with a lateral resolution of 500 x 500 m, and a variable resolution at depth. The highest resolution of 25 m is applied to a depth range of 1000-3000 m where most temperature measurements are available. The entire discretised model consists of approximately 50 million cells. The top thermal boundary condition is derived from surface temperature measurements on land and ocean floor. The base of the model extents below the Moho, and we apply the heat flux over the Moho as a basal heat flux boundary condition. Rock properties (thermal conductivity, porosity, and heat production) have been compiled from several existing data sets. The conductive geothermal forward simulation is performed with SHEMAT, and we then use the stand-alone capabilities of iTOUGH2 for sensitivity analysis and model calibration. Simulated temperatures are compared to 130 quality weighted bottom hole temperature measurements. The sensitivity analysis provided a clear insight into the most sensitive parameters and parameter correlations. This proved to be of value as strong correlations, for example between basal heat flux and heat production in deep geological units, can significantly influence the model calibration procedure

  13. Geothermal Energy.

    ERIC Educational Resources Information Center

    Bufe, Charles Glenn

    1983-01-01

    Major activities, programs, and conferences in geothermal energy during 1982 are highlighted. These include first comprehensive national assessment of U.S. low-temperature geothermal resources (conducted by U.S. Geological Survey and Department of Energy), map production by U.S. Geological Survey, geothermal plant production, and others. (JN)

  14. Experiments on different materials (polyamide, stainless & galvanized steel) influencing geothermal CaCO3 scaling formation: Polymorphs & elemental incorporation

    NASA Astrophysics Data System (ADS)

    Wedenig, Michael; Dietzel, Martin; Boch, Ronny; Hippler, Dorothee

    2016-04-01

    Thermal water is increasingly used for heat and electric power production providing base-load capable renewable and virtually unlimited geothermal energy. Compared to other energy sources geothermal facilities are less harmful to the environment, i.e. chemically and visually. In order to promote the economic viability of these systems compared to other traditional and renewable energy sources, production hindering processes such as corrosion and scaling of components arising from the typically high salinity thermal waters have to be considered as important economic factors. In this context, using proper materials being in contact with the thermal water is crucial and a playground for further improvements. Aim of the study presented, are basic experiments and observations of scaling and corrosive effects from hydrothermal water interacting with different materials and surfaces (stainless steel, polyamide, galvanized steel) and in particular the nucleation and growth effects of these materials regarding the precipitation of solid carbonate phases. The incorporation of Mg, Sr and Ba cations into the carbonate scalings are investigated as environmental proxy. For this purpose, hydrothermal carbonate precipitating experiments were initialized by mixing NaHCO3 and Ca-Mg-Sr-Ba-chloride solutions at temperatures ranging from 40 to 80 °C in glass reactors hosting artificial substrates of the above mentioned materials. The experiments show a strong dependence of the precipitation behaviour of calcium carbonate polymorphs on the particular material being present. Stainless steel and polyamide seem to restrict aragonite formation, whereas galvanized steel supports aragonite nucleation. Vaterite formation is promoted by polyamide surfaces. Importantly, vaterite is more soluble (less stable) compared to the other anhydrous calcium carbonate polymorphs, i.e. vaterite can be more easily re-dissolved. Thus, the use of polyamide components might reduce the amount and durability of

  15. Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1980-August 31, 1981

    SciTech Connect

    Aki, K.

    1981-09-01

    Progress is reported on the following: interpretation of seismic data from hydraulic fracturing experiments at the Fenton Hill Hot Dry Rock Geothermal Site, interpretation of 3-D velocity anomalies in the western US with special attention to geothermal areas, theoretical and observational studies of scattering and attenuation of high-frequency seismic waves, theoretical and observational studies of volcanic tremors in relation to magma transport mechanisms, and deployment and maintenance of 9 event-recorders around Mt. St. Helens. Abstracts of papers submitted for publication are included. (MHR)

  16. Using Information from Operating Experience to Inform Human Reliability Analysis

    SciTech Connect

    Bruce P. Hallbert; David I. Gertman; Julie Marble; Erasmia Lois; Nathan Siu

    2004-06-01

    This paper reports on efforts being sponsored by the U.S. NRC and performed by INEEL to develop a technical basis and perform work to extract information from sources for use in HRA. The objectives of this work are to: 1) develop a method for conducting risk-informed event analysis of human performance information that stems from operating experience at nuclear power plants and for compiling and documenting the results in a structured manner; 2) provide information from these analyses for use in risk-informed and performance-based regulatory activities; 3) create methods for information extraction and a repository for this information that, likewise, support HRA methods and their applications.

  17. Geothermal flux through palagonitized tephra, Surtsey, Iceland - The Surtsey temperature-data-relay experiment via Landsat-1

    NASA Technical Reports Server (NTRS)

    Friedman, J. D.; Preble, D. M.; Jakobsson, S.

    1976-01-01

    The net geothermal flux through palagonitized basaltic tephra rims of the Surtur I and Surtur II craters at Surtsey, Iceland, in 1972, is estimated at 780 plus or minus 325 microcal/sq cm/s, indicating a decline since 1969 when a flux of 1500 microcal/sq cm/s was estimated. Heat flux in this range characterizes the postvolcanic environment on Surtsey in which the subaerial polagonitization of basaltic tephra is associated with mass transfer of hydrothermal vapor, either of meteoric or sea-water origin, only a few years after cessation of eruptive activity. The flux estimation is the result of the Surtsey data-relay experiment via Landsat-1 which was carried out in several phases. Temperature data were transmitted for a 38-day period in November and December 1972. A near-surface vertical gradient of 69.4 C/m was obtained, suggesting a mixed mechanism of heat transfer, partitioned between conduction and convection.

  18. Electrical conductivity of Icelandic deep geothermal reservoirs: insight from HT-HP laboratory experiments

    NASA Astrophysics Data System (ADS)

    Nono, Franck; Gibert, Benoit; Loggia, Didier; Parat, Fleurice; Azais, Pierre; Cichy, Sarah

    2016-04-01

    Although the Icelandic geothermal system has been intensively investigated over the years, targeting increasingly deeper reservoirs (i.e. under supercritical conditions) requires a good knowledge of the behaviour of physical properties of the host rock in order to better interpret large scale geophysical observations. In particular, the interpretation of deep electrical soundings remains controversial as only few studies have investigated the influence of altered minerals and pore fluid properties on electrical properties of rocks at high temperature and pressure. In this study, we investigate the electrical conductivity of drilled samples from different Icelandic geothermal fields at elevated temperature, confining pressure and pore pressure conditions (100°C < T < 600°C, confining pressure up to 100 MPa and pore pressure up to 35 MPa). The investigated rocks are composed of hyaloclastites, dolerites and basalts taken from depths of about 800 m for the hyaloclastites, to almost 2500 m for the dolerites. They display different porosity structures, from vuggy and intra-granular to micro-cracked porosities, and have been hydrothermally alterated in the chlorite to amphibolite facies. Electrical conductivity measurements are first determined at ambient conditions as a function of pore fluid conductivity in order to establish their relationships with lithology and pore space topology, prior to the high pressure and temperature measurements. Cementation factor varies from 1.5 for the dolerites to 2.83 for the basalt, reflecting changes in the shape of the conductive channels. The surface conductivities, measured at very low fluid conductivity, increases with the porosity and is correlated with the cation exchange capacity. At high pressure and temperature, we used the two guard-ring electrodes system. Measurements have been performed in dry and saturated conditions as a function of temperature and pore pressure. The supercritical conditions have been investigated and

  19. Interrater reliability of quantitative ultrasound using force feedback among examiners with varied levels of experience

    PubMed Central

    Ismail, Catheeja; Monfaredi, Reza; Hernandez, Haniel J.; Pennington, Donte; Woletz, Paula; McIntosh, Valerie; Adams, Bernadette; Blackman, Marc R.

    2016-01-01

    Background. Quantitative ultrasound measures are influenced by multiple external factors including examiner scanning force. Force feedback may foster the acquisition of reliable morphometry measures under a variety of scanning conditions. The purpose of this study was to determine the reliability of force-feedback image acquisition and morphometry over a range of examiner-generated forces using a muscle tissue-mimicking ultrasound phantom. Methods. Sixty material thickness measures were acquired from a muscle tissue mimicking phantom using B-mode ultrasound scanning by six examiners with varied experience levels (i.e., experienced, intermediate, and novice). Estimates of interrater reliability and measurement error with force feedback scanning were determined for the examiners. In addition, criterion-based reliability was determined using material deformation values across a range of examiner scanning forces (1–10 Newtons) via automated and manually acquired image capture methods using force feedback. Results. All examiners demonstrated acceptable interrater reliability (intraclass correlation coefficient, ICC = .98, p < .001) for material thickness measures obtained using force feedback. Individual examiners exhibited acceptable reliability with the criterion-based reference measures (ICC > .90, p < .001), independent of their level of experience. The measurement error among all examiners was 1.5%–2.9% across all applied stress conditions. Conclusion. Manual image capture with force feedback may aid the reliability of morphometry measures across a range of examiner scanning forces, and allow for consistent performance among examiners with differing levels of experience. PMID:27366647

  20. Fluid-rock interactions in CO2-saturated, granite-hosted geothermal systems: Implications for natural and engineered systems from geochemical experiments and models

    NASA Astrophysics Data System (ADS)

    Lo Ré, Caroline; Kaszuba, John P.; Moore, Joseph N.; McPherson, Brian J.

    2014-09-01

    Hydrothermal experiments were conducted and geochemical models constructed to evaluate the geochemical and mineralogical response of fractured granite and granite + epidote in contact with thermal water, with and without supercritical CO2, at 250 °C and 25-45 MPa. Illite ± smectite ± zeolite(?) precipitate as secondary minerals at the expense of K-feldspar, oligoclase, and epidote. Illite precipitates in experiments reacting granite and granite + epidote with water; metastable smectite forms in the experiments injected with supercritical CO2. Waters are supersaturated with respect to quartz and saturated with respect to chalcedony in CO2-charged experiments, but neither mineral formed. Carbonate formation is predicted for experiments injected with supercritical CO2, but carbonate only formed during cooling and degassing of the granite + epidote + CO2 experiment. Experimental results provide insight into the buffering capacity of granites as well as the drivers of clay formation. Metastable smectite in the experiments is attributed to high water-rock ratios, high silica activities, and high CO2 and magnesium-iron concentrations. Smectite precipitation in supercritical CO2-bearing geothermal systems may affect reservoir permeability. Silicate formation may create or thicken caps within or on the edges of geothermal reservoirs. Carbonate formation, as desired for carbon sequestration projects coinciding with geothermal systems, may require extended periods of time; cooling and degassing of CO2-saturated waters leads to carbonate precipitation, potentially plugging near-surface production pathways.

  1. National Geothermal Data System

    NASA Astrophysics Data System (ADS)

    Anderson, A. F.; Cuyler, D.; Snyder, W. S.; Allison, M. L.; Blackwell, D. D.; Williams, C. F.

    2011-12-01

    The goal of the U.S. Department of Energy's National Geothermal Data System is to design, build, implement, deploy and populate a national, sustainable, distributed, interoperable network of data and service (application) providers. These providers will develop, collect, serve, and maintain geothermal-relevant data that operates as an integral component of NGDS. As a result the geothermal industry, the public, and policy makers will have access to consistent and reliable data, which in turn, reduces the amount of staff time devoted to finding, retrieving, integrating, and verifying information. With easier access to information, the high cost and risk of geothermal power projects (especially exploration drilling) is reduced. Five separate NGDS projects provide the data support, acquisition, and access to cyber infrastructure necessary to reduce cost and risk of the nation's geothermal energy strategy and US DOE program goals focused on the production and utilization of geothermal energy. The U.S DOE Office of Energy Efficiency and Renewable Energy Geothermal Technologies Program is developing the knowledge and data foundation necessary for discovery and development of large-scale energy production while the Buildings Technology Program is focused on other practical applications such as direct use and residential/commercial ground source heat pumps. The NGDS provides expanded reference and resource data for research and development activities (a subset of the US DOE goals) and includes data from across all fifty states and the nation's leading academic geothermal centers. Thus, the project incorporates not only high-temperature potential but also moderate and low-temperature locations incorporating US DOE's goal of adding more geothermal electricity to the grid. The program, through its development of data integration cyberinfrastructure, will help lead to innovative exploration technologies through increased data availability on geothermal energy capacity. Finally

  2. Recover Act. Verification of Geothermal Tracer Methods in Highly Constrained Field Experiments

    SciTech Connect

    Becker, Matthew W.

    2014-05-16

    The prediction of the geothermal system efficiency is strong linked to the character of the flow system that connects injector and producer wells. If water flow develops channels or “short circuiting” between injection and extraction wells thermal sweep is poor and much of the reservoir is left untapped. The purpose of this project was to understand how channelized flow develops in fracture geothermal reservoirs and how it can be measured in the field. We explored two methods of assessing channelization: hydraulic connectivity tests and tracer tests. These methods were tested at a field site using two verification methods: ground penetrating radar (GPR) images of saline tracer and heat transfer measurements using distributed temperature sensing (DTS). The field site for these studies was the Altona Flat Fractured Rock Research Site located in northeastern New York State. Altona Flat Rock is an experimental site considered a geologic analog for some geothermal reservoirs given its low matrix porosity. Because soil overburden is thin, it provided unique access to saturated bedrock fractures and the ability image using GPR which does not effectively penetrate most soils. Five boreholes were drilled in a “five spot” pattern covering 100 m2 and hydraulically isolated in a single bedding plane fracture. This simple system allowed a complete characterization of the fracture. Nine small diameter boreholes were drilled from the surface to just above the fracture to allow the measurement of heat transfer between the fracture and the rock matrix. The focus of the hydraulic investigation was periodic hydraulic testing. In such tests, rather than pumping or injection in a well at a constant rate, flow is varied to produce an oscillating pressure signal. This pressure signal is sensed in other wells and the attenuation and phase lag between the source and receptor is an indication of hydraulic connection. We found that these tests were much more effective than constant

  3. Traveling-wave tube reliability estimates, life tests, and space flight experience

    NASA Technical Reports Server (NTRS)

    Lalli, V. R.; Speck, C. E.

    1977-01-01

    Infant mortality, useful life, and wearout phase of twt life are considered. The performance of existing developmental tubes, flight experience, and sequential hardware testing are evaluated. The reliability history of twt's in space applications is documented by considering: (1) the generic parts of the tube in light of the manner in which their design and operation affect the ultimate reliability of the device, (2) the flight experience of medium power tubes, and (3) the available life test data for existing space-qualified twt's in addition to those of high power devices.

  4. Geothermal Energy.

    ERIC Educational Resources Information Center

    Nemzer, Marilyn; Page, Deborah

    This curriculum unit describes geothermal energy in the context of the world's energy needs. It addresses renewable and nonrenewable energy sources with an in-depth study of geothermal energy--its geology, its history, and its many uses. Included are integrated activities involving science, as well as math, social studies, and language arts.…

  5. Geothermal Energy

    SciTech Connect

    Steele, B.C.; Pichiarella, L.S.; Kane, L.S.; Henline, D.M.

    1995-01-01

    Geothermal Energy (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past two months.

  6. Hydraulic Fracture Stimulation Treatments at East Mesa, Well 58-30; Geothermal Reservoir Well Stimulation Program; Experiment 3 and 4

    SciTech Connect

    1982-02-01

    The tests reported were part of the DOE Geothermal Reservoir Well Stimulation Program. This East Mesa (Imperial Valley, CA) well was successfully stimulated with two fracture treatments, a dendritic fracture and a planar fracture. The natural flow production of the well increased 114 percent, to 197,900 lb/hr. These tests were among the few successful attempts of this program to increase flow from geothermal production wells. The general belief is that these tests worked OK primarily because the formation was sedimentary rock (similar to rock in most oil and gas wells that have been stimulated successfully. Similar tests in geothermal hard rock reservoirs did not work very well. (DJE 2005)

  7. Impact of observers' experience and training on reliability of observations for a manual handling task.

    PubMed

    Denis, Denys; Lortie, Monique; Bruxelles, Mélanie

    2002-05-15

    Observation reliability (agreement percentage and kappa coefficients) for six experienced ergonomists and six untrained participants was computed. Participants were first tested after a training session and 1 week later after an additional practice session. Two formats were used: free practice and directed exercise. Reliability was tested for 17 variables and 20 sequences using photographic and video supports. The participants were asked to indicate whether they were confident about their answer, to rate this confidence on a scale of 1 to 10, and when the confidence rating was below 8, to provide a reason for this. Experience and additional practices had no clear impact on reliability, which was excellent overall. The main reason given was that the event to be observed took place at the borderline between two classes. The observers' rating on the scale appeared to be tied to the subsequent reliability computed. The use of a confidence scale appeared to be a useful tool for forecasting observation problems.

  8. Students' and Teacher's Experiences of the Validity and Reliability of Assessment in a Bioscience Course

    ERIC Educational Resources Information Center

    Räisänen, Milla; Tuononen, Tarja; Postareff, Liisa; Hailikari, Telle; Virtanen, Viivi

    2016-01-01

    This case study explores the assessment of students' learning outcomes in a second-year lecture course in biosciences. The aim is to deeply explore the teacher's and the students' experiences of the validity and reliability of assessment and to compare those perspectives. The data were collected through stimulated recall interviews. The results…

  9. Templating in uncemented total hip arthroplasty—on intra- and interobserver reliability and professional experience

    PubMed Central

    Strøm, Nils J.; Pripp, Are Hugo; Reikerås, Olav

    2017-01-01

    Background This study examines the intra-, and interobserver reliability of digital templating in uncemented total hip arthroplasty (THA), and assesses whether these values are dependent on professional experience. Methods Three independent observers retrospectively examined digital X-rays of 34 consecutive hips scheduled for uncemented THA. These were templated using templating software. Evaluations were carried out on two occasions at least 6 weeks apart. Findings were compared to each surgeon’s own findings, and then to the other surgeons’ findings. Data underwent statistical analysis to assess and describe reliability. Results The intraobserver reliability of the method was found to be good. The intra-class correlation coefficient (ICC) for individual surgeons ranged from 0.81 to 0.87 for acetabular components and 0.74 to 0.91 for femoral components. However, it was somewhat lower for neck length with kappa statistics (κ) from 0.41 to 0.51 with agreement in about 70% of the cases. Interobserver reliability was similar, with an ICC of 0.87 for the acetabular component and 0.79 for the femoral component, but somewhat lower for neck length with κ of 0.27 and agreement in 41% of the cases. We found no association between increasing experience and increasing precision, as the least experienced observer showed the highest intraobserver reliability. Conclusions The reliability of digital templating of uncemented THA is good for acetabular and femoral components, but inferior for neck length. Precision does not rely on professional experience. Digital templating provides surgeons with a valuable tool for preoperative planning, but cannot supersede the intraoperative assessment and final decision. PMID:28251122

  10. Factor structure, reliability, and validity of the Chinese version of the School Bullying Experience Questionnaire.

    PubMed

    Yen, Cheng-Fang; Kim, Young-Shin; Tang, Tze-Chun; Wu, Yu-Yu; Cheng, Chung-Ping

    2012-09-01

    The aims of this study were to examine the factor structure, internal consistency, 1-month test-retest reliability, and congruent validity of the Chinese version of the School Bullying Experience Questionnaire (C-SBEQ). Study 1, in which 5751 Taiwanese adolescents in Southern Taiwan participated, examined the adequacy of the original four-factor structure of the C-SBEQ using confirmatory factor analysis (CFA) and internal-consistency reliability using Cronbach α. Study 2, in which 108 adolescents in Southern Taiwan participated, examined the 1-month test-retest reliability using intraclass correlation coefficients (ICCs). We examined the congruent validity of the C-SBEQ by examining the consistency between self-reported and teacher- and classmate-nominated experiences of bullying involvement in Study 2. The results of CFA supported the four-factor structure of the C-SBEQ in Taiwanese adolescents. The test-retest and internal reliability values of all subscales of the C-SBEQ were at acceptable to satisfactory levels. Nominated adolescents had significantly higher self-reported scores on three C-SBEQ subscales than non-nominated ones, and the levels of agreement between self-reported and nominated victims were moderate. The results of this study indicate that the C-SBEQ is appropriate for assessing bullying experiences in Taiwanese adolescents.

  11. Corrosion reference for geothermal downhole materials selection

    SciTech Connect

    Ellis, P.F. II, Smith, C.C.; Keeney, R.C.; Kirk, D.K.; Conover, M.F.

    1983-03-01

    Geothermal downhole conditions that may affect the performance and reliability of selected materials and components used in the drilling, completion, logging, and production of geothermal wells are reviewed. The results of specific research and development efforts aimed at improvement of materials and components for downhole contact with the hostile physicochemical conditions of the geothermal reservoir are discussed. Materials and components covered are tubular goods, stainless steels and non-ferrous metals for high-temperature downhole service, cements for high-temperature geothermal wells, high-temperature elastomers, drilling and completion tools, logging tools, and downhole pumps. (MHR)

  12. Health impacts of geothermal energy

    SciTech Connect

    Layton, D.W.; Anspaugh, L.R.

    1981-06-15

    The focus is on electric power production using geothermal resources greater than 150/sup 0/C because this form of geothermal energy utilization has the most serious health-related consequences. Based on measurements and experience at existing geothermal power plants, atmospheric emissions of noncondensing gases such as hydrogen sulfide and benzene pose the greatest hazards to public health. Surface and ground waters contaminated by discharges of spent geothermal fluids constitute another health hazard. It is shown that hydrogen sulfide emissions from most geothermal power plants are apt to cause odor annoyances among members of the exposed public - some of whom can detect this gas at concentrations as low as 0.002 parts per million by volume. A risk assessment model is used to estimate the lifetime risk of incurring leukemia from atmospheric benzene caused by 2000 MW(e) of geothermal development in California's Imperial Valley. The risk of skin cancer due to the ingestion of river water in New Zealand that is contaminated by waste geothermal fluids containing arsenic is also assessed. Finally, data on the occurrence of occupational disease in the geothermal industry are summarized briefly.

  13. Geothermal heating

    SciTech Connect

    Aureille, M.

    1982-01-01

    The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.

  14. An Experiment to Test Geophysical Methods For Monitoring Fluid Re-Injection at the Wairakei Geothermal Field, New Zealand

    NASA Astrophysics Data System (ADS)

    Jiracek, G. R.; Bowles-Martinez, E.; Feucht, D. W.; Ryan, J.; Caldwell, T. G.; Bannister, S. C.; Bertrand, T.; Bennie, S.; Bourguignon, S.

    2010-12-01

    The National Science Foundation (NSF) is supporting US students to participate in GNS Science’s geothermal research program supported by the New Zealand Government. The NSF international program aims to quick-start a new generation of geothermal-oriented US geophysics students who will be poised to be active participants and leaders in US geothermal energy development. This year’s project evaluated joint passive seismic and magnetotelluric (MT) field measurements to determine three-dimensional (3-D) reservoir characteristics during fluid withdrawal and re-injection. A preliminary test of the ability to achieve repeatable MT data in high noise locations was carried out in the Wairakei geothermal field using a 14-site base-line MT survey and repeat occupations at four sites. Different data processing schemes identified MT frequency bands where impedance phase tensor data were most sensitive to known variables such as daily solar source variations, wind, and drilling operations. Other frequency bands were identified where good MT repeatability will allow further tests. A streamlined method was developed for visualizing 3-D earthquake focal mechanisms resulting from production changes in geothermal reservoirs. The computer program allows spatial sorting of seismic events and thus subsurface fracture identification.

  15. Shaker Table Experiments with Rare Earth Elements Sorption from Geothermal Brine

    DOE Data Explorer

    Gary Garland

    2015-07-21

    This dataset described shaker table experiments ran with sieved -50 +100 mesh media #1 in brine #1 that have 2ppm each of the 7 REE metals at different starting pH's of 3.5, 4.5, and 5.5. The experimental conditions are 2g media to 150mL of REE solution, at 70C.

  16. Tracing Injection Fluids in Engineered Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Rose, P. E.; Leecaster, K.; Mella, M.; Ayling, B.; Bartl, M. H.

    2011-12-01

    The reinjection of produced fluids is crucial to the effective management of geothermal reservoirs, since it provides a mechanism for maintaining reservoir pressures while allowing for the disposal of a toxic byproduct. Tracers are essential to the proper location of injection wells since they are the only known tool for reliably characterizing the flow patterns of recirculated fluids. If injection wells are placed too close to production wells, then reinjected fluids do not have sufficient residence time to extract heat from the reservoir and premature thermal breakthrough results. If injection wells are placed too far away, then the reservoir risks unacceptable pressure loss. Several thermally stable compounds from a family of very detectable fluorescent organic compounds (the naphthalene sulfonates) were characterized and found to be effective for use as geothermal tracers. Through batch-autoclave reactions, their Arrhenius pseudo-first-order decay-rate constants were determined. An analytical method was developed that allows for the laboratory determination of concentrations in the low parts-per-trillion range. Field experiments in numerous geothermal reservoirs throughout the world have confirmed the laboratory findings. Whereas conservative tracers such as the naphthalene sulfonates are effective tools for indicating interwell flow patterns and for measuring reservoir pore volumes, 'reactive' tracers can be used to constrain fracture surface area, which is the effective area for heat extraction. This is especially important for engineered geothermal system (EGS) wells, since reactive tracers can be used to measure fracture surface area immediately after drilling and while the well stimulation equipment is still on site. The reactive properties of these tracers that can be exploited to constrain fracture surface area are reversible sorption, contrasting diffusivity, and thermal decay. Laboratory batch- and flow-reactor experiments in combination with numerical

  17. Heat deliverability of homogeneous geothermal reservoirs

    SciTech Connect

    Iglesias, Eduardo R.; Moya, Sara L.

    1991-01-01

    For the last two decades, the petroleum industry has been successfully using simple inflow performance relationships (IPR's) to predict oil deliverability. In contrast, the geothermal industry lacked a simple and reliable method to estimate geothermal wells' heat deliverability. To address this gap in the standard geothermal-reservoir-assessment arsenal, we developed generalized dimensionless geothermal inflow performance relationships (GIPR's). These ''reference curves'' may be regarded as an approximate general solution of the equations describing the practically important case of radial 2-phase inflow. Based on this approximate solution, we outline a straightforward approach to estimate the reservoir contribution to geothermal wells heat and mass deliverability for 2-phase reservoirs. This approach is far less costly and in most cases as reliable as numerically modeling the reservoir, which is the alternative for 2-phase inflow.

  18. Geothermal Information Dissemination and Outreach

    SciTech Connect

    Ted J. Clutter

    2005-02-18

    Project Purpose. To enhance technological and topical information transfer in support of industry and government efforts to increase geothermal energy use in the United States (power production, direct use, and geothermal groundsource heat pumps). Project Work. GRC 2003 Annual Meeting. The GRC convened the meeting on Oct. 12-15, 2003, at Morelia's Centro de Convenciones y ExpoCentro in Mexico under the theme, International Collaboration for Geothermal Energy in the Americas. The event was also sponsored by the Comision Federal de Electricidad. ~600 participants from more than 20 countries attended the event. The GRC convened a Development of Geothermal Projects Workshop and Geothermal Exploration Techniques Workshop. GRC Field Trips included Los Azufres and Paricutin Volcano on Oct. 11. The Geothermal Energy Association (Washington, DC) staged its Geothermal Energy Trade Show. The Annual Meeting Opening Session was convened on Oct. 13, and included the governor of Michoacan, the Mexico Assistant Secretary of Energy, CFE Geothermal Division Director, DOE Geothermal Program Manager, and private sector representatives. The 2003 Annual Meeting attracted 160 papers for oral and poster presentations. GRC 2004. Under the theme, Geothermal - The Reliable Renewable, the GRC 2004 Annual Meeting convened on Aug. 29-Sept. 1, 2004, at the Hyatt Grand Champions Resort at Indian Wells, CA. Estimated total attendance (including Trade Show personnel, guests and accompanying persons) was ~700. The event included a workshop, Geothermal Production Well Pump Installation, Operation and Maintenance. Field trips went to Coso/Mammoth and Imperial Valley/Salton Sea geothermal fields. The event Opening Session featured speakers from the U.S. Department of Energy, U.S. Department of the Interior, and the private sector. The Geothermal Energy Association staged its Geothermal Energy Trade Show. The Geothermal Education Office staged its Geothermal Energy Workshop. Several local radio and TV

  19. An experiment in software reliability: Additional analyses using data from automated replications

    NASA Technical Reports Server (NTRS)

    Dunham, Janet R.; Lauterbach, Linda A.

    1988-01-01

    A study undertaken to collect software error data of laboratory quality for use in the development of credible methods for predicting the reliability of software used in life-critical applications is summarized. The software error data reported were acquired through automated repetitive run testing of three independent implementations of a launch interceptor condition module of a radar tracking problem. The results are based on 100 test applications to accumulate a sufficient sample size for error rate estimation. The data collected is used to confirm the results of two Boeing studies reported in NASA-CR-165836 Software Reliability: Repetitive Run Experimentation and Modeling, and NASA-CR-172378 Software Reliability: Additional Investigations into Modeling With Replicated Experiments, respectively. That is, the results confirm the log-linear pattern of software error rates and reject the hypothesis of equal error rates per individual fault. This rejection casts doubt on the assumption that the program's failure rate is a constant multiple of the number of residual bugs; an assumption which underlies some of the current models of software reliability. data raises new questions concerning the phenomenon of interacting faults.

  20. Geothermal energy

    NASA Astrophysics Data System (ADS)

    Manzella, A.

    2015-08-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

  1. Geothermal pipeline

    SciTech Connect

    Not Available

    1992-12-01

    A number of new ideas for geothermal power development and use have been proposed or initiated. British engineers have proposed using North Sea oil rigs as geothermal power stations. These stations would use the low temperature heat from the water that now occupies the former oil reservoirs to generate electricity. NASA recently retrofitted its engine test facility to enable it to use warm water from an underground aquifer as source water in a heat pump. A major policy guideline regarding electricity is issued by the California Energy Commission (CEC) every two years. This year, CEC appears to be revising its method for determining the total societal cost of various electricity supply options. The change may impact geothermal energy usage in a positive way. Virtually untapped geothermal resources in Preston, Idaho will be utilized for warm water catfish farming. Stockton State College in New Jersey will be the site of one of the nation's largest geothermal projects when it is completed in 1993. It is designed to satisfy the college's energy requirements at an estimated cost savings of $300,000 per year. Aquaculture projects using thermal springs are under consideration in Utah and Washington State. Utah may be the site of an alligator farm and Washington State is being considered for raising golden tilapia, a food fish.

  2. Designing Fault-Injection Experiments for the Reliability of Embedded Systems

    NASA Technical Reports Server (NTRS)

    White, Allan L.

    2012-01-01

    This paper considers the long-standing problem of conducting fault-injections experiments to establish the ultra-reliability of embedded systems. There have been extensive efforts in fault injection, and this paper offers a partial summary of the efforts, but these previous efforts have focused on realism and efficiency. Fault injections have been used to examine diagnostics and to test algorithms, but the literature does not contain any framework that says how to conduct fault-injection experiments to establish ultra-reliability. A solution to this problem integrates field-data, arguments-from-design, and fault-injection into a seamless whole. The solution in this paper is to derive a model reduction theorem for a class of semi-Markov models suitable for describing ultra-reliable embedded systems. The derivation shows that a tight upper bound on the probability of system failure can be obtained using only the means of system-recovery times, thus reducing the experimental effort to estimating a reasonable number of easily-observed parameters. The paper includes an example of a system subject to both permanent and transient faults. There is a discussion of integrating fault-injection with field-data and arguments-from-design.

  3. Federal Geothermal Research Program Update Fiscal Year 2004

    SciTech Connect

    Not Available

    2005-03-01

    The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. The Geothermal Technologies Program (GTP) works in partnership with industry to establish geothermal energy as an economically competitive contributor to the U.S. energy supply. Geothermal energy production, a $1.5 billion a year industry, generates electricity or provides heat for direct use applications. The technologies developed by the Geothermal Technologies Program will provide the Nation with new sources of electricity that are highly reliable and cost competitive and do not add to America's air pollution or the emission of greenhouse gases. Geothermal electricity generation is not subject to fuel price volatility and supply disruptions from changes in global energy markets. Geothermal energy systems use a domestic and renewable source of energy. The Geothermal Technologies Program develops innovative technologies to find, access, and use the Nation's geothermal resources. These efforts include emphasis on Enhanced Geothermal Systems (EGS) with continued R&D on geophysical and geochemical exploration technologies, improved drilling systems, and more efficient heat exchangers and condensers. The Geothermal Technologies Program is balanced between short-term goals of greater interest to industry, and long-term goals of importance to national energy interests. The program's research and development activities are expected to increase the number of new domestic geothermal fields, increase the success rate of geothermal well drilling, and reduce the costs of constructing and operating geothermal power plants. These improvements will increase the quantity of economically viable geothermal resources, leading in turn to an increased number of geothermal power facilities serving more energy demand. These new geothermal projects will take advantage of geothermal resources in locations where development is not currently possible or

  4. Federal Geothermal Research Program Update - Fiscal Year 2004

    SciTech Connect

    Patrick Laney

    2005-03-01

    The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. The Geothermal Technologies Program (GTP) works in partnership with industry to establish geothermal energy as an economically competitive contributor to the U.S. energy supply. Geothermal energy production, a $1.5 billion a year industry, generates electricity or provides heat for direct use applications. The technologies developed by the Geothermal Technologies Program will provide the Nation with new sources of electricity that are highly reliable and cost competitive and do not add to America's air pollution or the emission of greenhouse gases. Geothermal electricity generation is not subject to fuel price volatility and supply disruptions from changes in global energy markets. Geothermal energy systems use a domestic and renewable source of energy. The Geothermal Technologies Program develops innovative technologies to find, access, and use the Nation's geothermal resources. These efforts include emphasis on Enhanced Geothermal Systems (EGS) with continued R&D on geophysical and geochemical exploration technologies, improved drilling systems, and more efficient heat exchangers and condensers. The Geothermal Technologies Program is balanced between short-term goals of greater interest to industry, and long-term goals of importance to national energy interests. The program's research and development activities are expected to increase the number of new domestic geothermal fields, increase the success rate of geothermal well drilling, and reduce the costs of constructing and operating geothermal power plants. These improvements will increase the quantity of economically viable geothermal resources, leading in turn to an increased number of geothermal power facilities serving more energy demand. These new geothermal projects will take advantage of geothermal resources in locations where development is not currently possible or

  5. Direct use of the geothermal energy at Los Azufres geothermal field, Mexico

    SciTech Connect

    Sanchez-Velasco, E.; Casimiro-Espinoza, E.

    1995-12-31

    The main object of Comision Federal de Electricidad (CFE`s) Geothermal Field at Los Azufres, is to generate geothermal electricity; however with the new politics in Mexico, CFE has designed a pilot project in order to profit from the geothermal residual energy and to attract national or foreign investors and convince them that direct use of geothermal energy is an attractive feasible and economical project. The object of this paper is to present the CFE experiences in different pilot projects applied to direct uses of geothermal energy.

  6. Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1979-August 31, 1980

    SciTech Connect

    Aki, K.

    1980-09-01

    Progress is reported in the following research areas: a synthesis of seismic experiments at the Fenton Hill Hot-Dry-Rock System; attenuation of high-frequency shear waves in the lithosphere; a new kinematic source model for deep volcanic tremors; ground motion in the near-field of a fluid-driven crack and its interpretation in the study of shallow volcanic tremor; low-velocity bodies under geothermal areas; and operation of event recorders in Mt. St. Helens and Newberry Peak with preliminary results from them. (MHR)

  7. Experience with modified aerospace reliability and quality assurance method for wind turbines

    NASA Technical Reports Server (NTRS)

    Klein, W. E.

    1982-01-01

    The SR&QA approach assures that the machine is not hazardous to the public or operating personnel, can operate unattended on a utility grid, demonstrates reliability operation, and helps establish the quality assurance and maintainability requirements for future wind turbine projects. The approach consisted of modified failure modes and effects analysis (FMEA) during the design phase, minimal hardware inspection during parts fabrication, and three simple documents to control activities during machine construction and operation. Five years experience shows that this low cost approach works well enough that it should be considered by others for similar projects.

  8. Geothermal Energy.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Described are the origin and nature of geothermal energy. Included is the history of its development as an energy source, technological considerations affecting its development as an energy source, its environmental effects, economic considerations, and future prospects of development in this field. Basic system diagrams of the operation of a…

  9. Development of concepts for the management of shallow geothermal resources in urban areas - Experience gained from the Basel and Zaragoza case studies

    NASA Astrophysics Data System (ADS)

    García-Gil, Alejandro; Epting, Jannis; Mueller, Matthias H.; Huggenberger, Peter; Vázquez-Suñé, Enric

    2015-04-01

    In urban areas the shallow subsurface often is used as a heat resource (shallow geothermal energy), i.e. for the installation and operation of a broad variety of geothermal systems. Increasingly, groundwater is used as a low-cost heat sink, e.g. for building acclimatization. Together with other shallow geothermal exploitation systems significantly increased groundwater temperatures have been observed in many urban areas (urban heat island effect). The experience obtained from two selected case study cities in Basel (CH) and Zaragoza (ES) has allowed developing concepts and methods for the management of thermal resources in urban areas. Both case study cities already have a comprehensive monitoring network operating (hydraulics and temperature) as well as calibrated high-resolution numerical groundwater flow and heat-transport models. The existing datasets and models have allowed to compile and compare the different hydraulic and thermal boundary conditions for both groundwater bodies, including: (1) River boundaries (River Rhine and Ebro), (2) Regional hydraulic and thermal settings, (3) Interaction with the atmosphere under consideration of urbanization and (4) Anthropogenic quantitative and thermal groundwater use. The potential natural states of the considered groundwater bodies also have been investigated for different urban settings and varying processes concerning groundwater flow and thermal regimes. Moreover, concepts for the management of thermal resources in urban areas and the transferability of the applied methods to other urban areas are discussed. The methods used provide an appropriate selection of parameters (spatiotemporal resolution) that have to be measured for representative interpretations of groundwater flow and thermal regimes of specific groundwater bodies. From the experience acquired from the case studies it is shown that understanding the variable influences of the specific geological and hydrogeological as well as hydraulic and thermal

  10. Magnetic force microscopy reveals meta-stable magnetic domain states that prevent reliable absolute palaeointensity experiments.

    PubMed

    de Groot, Lennart V; Fabian, Karl; Bakelaar, Iman A; Dekkers, Mark J

    2014-08-22

    Obtaining reliable estimates of the absolute palaeointensity of the Earth's magnetic field is notoriously difficult. The heating of samples in most methods induces magnetic alteration--a process that is still poorly understood, but prevents obtaining correct field values. Here we show induced changes in magnetic domain state directly by imaging the domain configurations of titanomagnetite particles in samples that systematically fail to produce truthful estimates. Magnetic force microscope images were taken before and after a heating step typically used in absolute palaeointensity experiments. For a critical temperature (250 °C), we observe major changes: distinct, blocky domains before heating change into curvier, wavy domains thereafter. These structures appeared unstable over time: after 1-year of storage in a magnetic-field-free environment, the domain states evolved into a viscous remanent magnetization state. Our observations qualitatively explain reported underestimates from otherwise (technically) successful experiments and therefore have major implications for all palaeointensity methods involving heating.

  11. Reliability Lessons Learned From GPU Experience With The Titan Supercomputer at Oak Ridge Leadership Computing Facility

    SciTech Connect

    Gallarno, George; Rogers, James H; Maxwell, Don E

    2015-01-01

    The high computational capability of graphics processing units (GPUs) is enabling and driving the scientific discovery process at large-scale. The world s second fastest supercomputer for open science, Titan, has more than 18,000 GPUs that computational scientists use to perform scientific simu- lations and data analysis. Understanding of GPU reliability characteristics, however, is still in its nascent stage since GPUs have only recently been deployed at large-scale. This paper presents a detailed study of GPU errors and their impact on system operations and applications, describing experiences with the 18,688 GPUs on the Titan supercom- puter as well as lessons learned in the process of efficient operation of GPUs at scale. These experiences are helpful to HPC sites which already have large-scale GPU clusters or plan to deploy GPUs in the future.

  12. Geothermal tomorrow 2008

    SciTech Connect

    None, None

    2009-01-18

    Contributors from the Geothermal Technologies Program and the geothermal community highlight the current status and activities of the Program and the development of the global resource of geothermal energy.

  13. Geothermal Technologies Program: Utah

    SciTech Connect

    Not Available

    2005-06-01

    Geothermal Technologies Program Utah fact sheet describes the geothermal areas and use in Utah, focusing on power generation as well as direct use, including geothermally heated greenhouses, swimming pools, and therapeutic baths.

  14. Combining water-rock interaction experiments with reaction path and reactive transport modelling to predict reservoir rock evolution in an enhanced geothermal system

    NASA Astrophysics Data System (ADS)

    Kuesters, Tim; Mueller, Thomas; Renner, Joerg

    2016-04-01

    Reliably predicting the evolution of mechanical and chemical properties of reservoir rocks is crucial for efficient exploitation of enhanced geothermal systems (EGS). For example, dissolution and precipitation of individual rock forming minerals often result in significant volume changes, affecting the hydraulic rock properties and chemical composition of fluid and solid phases. Reactive transport models are typically used to evaluate and predict the effect of the internal feedback of these processes. However, a quantitative evaluation of chemo-mechanical interaction in polycrystalline environments is elusive due to poorly constrained kinetic data of complex mineral reactions. In addition, experimentally derived reaction rates are generally faster than reaction rates determined from natural systems, likely a consequence of the experimental design: a) determining the rate of a single process only, e.g. the dissolution of a mineral, and b) using powdered sample materials and thus providing an unrealistically high reaction surface and at the same time eliminating the restrictions on element transport faced in-situ for fairly dense rocks. In reality, multiple reactions are coupled during the alteration of a polymineralic rocks in the presence of a fluid and the rate determining process of the overall reactions is often difficult to identify. We present results of bulk rock-water interaction experiments quantifying alteration reactions between pure water and a granodiorite sample. The rock sample was chosen for its homogenous texture, small and uniform grain size (˜0.5 mm in diameter), and absence of pre-existing alteration features. The primary minerals are plagioclase (plg - 58 vol.%), quartz (qtz - 21 vol.%), K-feldspar (Kfs - 17 vol.%), biotite (bio - 3 vol.%) and white mica (wm - 1 vol.%). Three sets of batch experiments were conducted at 200 ° C to evaluate the effect of reactive surface area and different fluid path ways using (I) powders of the bulk rock with

  15. Geothermal probabilistic cost study

    NASA Astrophysics Data System (ADS)

    Orren, L. H.; Ziman, G. M.; Jones, S. C.; Lee, T. K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-08-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined.

  16. Geothermal probabilistic cost study

    NASA Technical Reports Server (NTRS)

    Orren, L. H.; Ziman, G. M.; Jones, S. C.; Lee, T. K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-01-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined.

  17. Geothermal development opportunities in developing countries

    SciTech Connect

    Kenkeremath, D.C.

    1989-11-16

    This report is the proceedings of the Seminar on geothermal development opportunities in developing countries, sponsored by the Geothermal Division of the US Department of Energy and presented by the National Geothermal Association. The overall objectives of the seminar are: (1) Provide sufficient information to the attendees to encourage their interest in undertaking more geothermal projects within selected developing countries, and (2) Demonstrate the technological leadership of US technology and the depth of US industry experience and capabilities to best perform on these projects.

  18. Materials selection guidelines for geothermal energy utilization systems

    SciTech Connect

    Ellis, P.F. II; Conover, M.F.

    1981-01-01

    This manual includes geothermal fluid chemistry, corrosion test data, and materials operating experience. Systems using geothermal energy in El Salvador, Iceland, Italy, Japan, Mexico, New Zealand, and the United States are described. The manual provides materials selection guidelines for surface equipment of future geothermal energy systems. The key chemical species that are significant in determining corrosiveness of geothermal fluids are identified. The utilization modes of geothermal energy are defined as well as the various physical fluid parameters that affect corrosiveness. Both detailed and summarized results of materials performance tests and applicable operating experiences from forty sites throughout the world are presented. The application of various non-metal materials in geothermal environments are discussed. Included in appendices are: corrosion behavior of specific alloy classes in geothermal fluids, corrosion in seawater desalination plants, worldwide geothermal power production, DOE-sponsored utilization projects, plant availability, relative costs of alloys, and composition of alloys. (MHR)

  19. Near-surface groundwater responses to injection of geothermal wastes

    SciTech Connect

    Arnold, S.C.

    1984-06-01

    This report assesses the feasibility of injection as an alternative for geothermal wastewater disposal and analyzes hydrologic controls governing the upward migration of injected fluids. Injection experiences at several geothermal developments are presented including the following: Raft River Valley, Salton Sea, East Mesa, Otake, Hatchobaru, and Ahuachapan geothermal fields.

  20. Geothermometer calculations for geothermal assessment

    USGS Publications Warehouse

    Reed, M.J.; Mariner, R.H.

    2007-01-01

    Geothermal exploration programs have relied on the calculation of geothermometers from hot spring chemistry as an early estimation of geothermal reservoir temperatures. Calibration of the geothermometers has evolved from experimental determinations of mineral solubility as a function of temperature to calibration from analyses of water chemistry from known depths and temperatures in thermal wells. Most of the geothermometers were calibrated from analyses of sodium-chloride type waters, and the application of some geothermometers should be restricted to waters of the chemical types that were used in their calibration. Chemical analyses must be determined to be reliable before they are used to calculate geothermometers. The USGS Geothermal Resource Assessment will rely on the silica geothermometer developed by Giggenbach that approximates the transition between chalcedony at 20??C and quartz at 200??C. Above 200??C, the assessment will rely on the quartz geothermometer. In addition, the assessment will also rely on the potassium-magnesium geothermometer.

  1. Deep geothermal resources and energy: Current research and developments

    NASA Astrophysics Data System (ADS)

    Manzella, A.; Milsch, H.; Hahne, B.; van Wees, J. D.; Bruhn, D.

    2012-04-01

    Energy from deep geothermal resources plays an increasing role in many European countries in their efforts to increase the proportion of renewables in their energy portfolio. Deep geothermal heat and electric power have a high load factor, are sustainable and environmentally friendly. However, the safe, sustainable, and economic development of deep geothermal resources, also in less favourable regions, faces a number of issues requiring substantial research efforts: (1) The probability of finding an unknown geothermal reservoir has to be improved. (2) Drilling methods have to be better adapted and developed to the specific needs of geothermal development. (3) The assessment of the geothermal potential should provide more reliable and clear guidelines for the development. (4) Stimulation methods for enhanced geothermal systems (EGS) have to be refined to increase the success rate and reduce the risk associated with induced seismicity. (5) Operation and maintenance in aggressive geothermal environments require specific solutions for corrosion and scaling problems. (6) Last but not least, emerging activities to harness energy from supercritical reservoirs would make significant progress with qualified input from research. In particular, sedimentary basins like e.g. the North German and Polish Basin, the Pannonian Basin, the Po Valley, the Bavarian Molasse Basin or the Upper Rhine Graben have a high geothermal potential, even if geothermal gradients are moderate. We will highlight projects that aim at optimizing exploration, characterization, and modeling prior to drilling and at a better understanding of physical, hydraulic and chemical processes during operation of a geothermal power plant. This includes geophysical, geological and geochemical investigations regarding potential geothermal reservoirs in sedimentary basins, as well as modelling of geothermally relevant reservoir parameters that influence the potential performance and long-term behavior of a future

  2. Influence of shutdown phases on the microbial community composition and their effects on the operational reliability in a geothermal plant in the North German Basin

    NASA Astrophysics Data System (ADS)

    Westphal, Anke; Lerm, Stephanie; Miethling-Graff, Rona; Seibt, Andrea; Wolfgramm, Markus; Würdemann, Hilke

    2014-05-01

    Microbial activity can influence the dissolution and/or precipitation of minerals, as well as corrosion phenomena that may lead to a lower efficiency of engineered systems. To enhance the understanding of these processes, the microbial biocenosis in fluids produced from the cold well of a deep geothermal heat store located in the North German Basin (NGB) was characterized during normal plant operation and immediately after plant downtime phases. The microbial community composition was dominated by three different genera of sulphate reducing bacteria (SRB) and fermentative Halanaerobiaceae in the 46 ° C tempered fluids during regular operation, whereas after shut down phases sequences of sulphur oxidizing bacteria (SOB) were additionally detected. The detection of SOB is regarded as an indication of oxygen introduction into the well during the downtime phase. This corresponded to the higher redox potential of fluids taken directly after the restart of fluid production in the cold well. In addition to an extremely high particle loading rate after plant restart, a higher DNA content as well as an increase of specific gene copy numbers of SRB and SOB by a factor of 104 and 105 respectively were observed. Obviously stagnant conditions favored the enrichment of biomass and particles in the well. This is supported by the determination of a higher sulphate and hydrogen sulphide content in the fluids taken initially after plant restart. With increasing fluid production during the restart, SRB specific gene copy numbers decreased much slower than SOB specific gene copy numbers, which led to the assumption that SOB abundance is limited to the near wellbore area. Besides the absence of particle removal by fluid flow and the deposition of particles by sedimentation during the shut down phase, oxygen introduction and subsequent activity of SOB may also have favored microbial induced formation of precipitates in the well. It is quite likely that the interaction of SRB and SOB

  3. The seed bank longevity index revisited: limited reliability evident from a burial experiment and database analyses

    PubMed Central

    Saatkamp, Arne; Affre, Laurence; Dutoit, Thierry; Poschlod, Peter

    2009-01-01

    Background and Aims Seed survival in the soil contributes to population persistence and community diversity, creating a need for reliable measures of soil seed bank persistence. Several methods estimate soil seed bank persistence, most of which count seedlings emerging from soil samples. Seasonality, depth distribution and presence (or absence) in vegetation are then used to classify a species' soil seed bank into persistent or transient, often synthesized into a longevity index. This study aims to determine if counts of seedlings from soil samples yield reliable seed bank persistence estimates and if this is correlated to seed production. Methods Seeds of 38 annual weeds taken from arable fields were buried in the field and their viability tested by germination and tetrazolium tests at 6 month intervals for 2·5 years. This direct measure of soil seed survival was compared with indirect estimates from the literature, which use seedling emergence from soil samples to determine seed bank persistence. Published databases were used to explore the generality of the influence of reproductive capacity on seed bank persistence estimates from seedling emergence data. Key Results There was no relationship between a species' soil seed survival in the burial experiment and its seed bank persistence estimate from published data using seedling emergence from soil samples. The analysis of complementary data from published databases revealed that while seed bank persistence estimates based on seedling emergence from soil samples are generally correlated with seed production, estimates of seed banks from burial experiments are not. Conclusions The results can be explained in terms of the seed size–seed number trade-off, which suggests that the higher number of smaller seeds is compensated after germination. Soil seed bank persistence estimates correlated to seed production are therefore not useful for studies on population persistence or community diversity. Confusion of soil

  4. Geothermal Progress Monitor 12

    SciTech Connect

    1990-12-01

    Some of the more interesting articles in this GPM are: DOE supporting research on problems at The Geysers; Long-term flow test of Hot Dry Rock system (at Fenton Hill, NM) to begin in Fiscal Year 1992; Significant milestones reached in prediction of behavior of injected fluids; Geopressured power generation experiment yields good results. A number of industry-oriented events and successes are reported, and in that regard it is noteworthy that this report comes near the end of the most active decade of geothermal power development in the U.S. There is a table of all operating U.S. geothermal power projects. The bibliography of research reports at the end of this GPM is useful. (DJE 2005)

  5. Utility company views of geothermal development

    NASA Technical Reports Server (NTRS)

    Hinrichs, T. C.

    1974-01-01

    The views of geothermal development from a utility company standpoint are presented. The impediments associated with such developments as required reliability and identification of risks are discussed. The utility industry historically is not a risk-taking industry. Support of rapid geothermal development by the utility industry requires identification and elimination of risks or absorption of the risks by other agencies. Suggestions as to the identification and minimization of risks are made.

  6. Geothermal Research and Development Program

    SciTech Connect

    Not Available

    1993-01-25

    Results are reported on adsorption of water vapor on reservoir rocks, physics of injection of water into vapor-dominated geothermal reservoirs, earth-tide effects on downhole pressures, injection optimization at the Geysers, effects of salinity in adsorption experiments, interpreting multiwell pressure data from Ohaaki, and estimation of adsorption parameters from transient experiments.

  7. Direct utilization of geothermal resources field experiments at Monroe, Utah. Final report, July 14, 1978-July 13, 1981

    SciTech Connect

    Blair, C.K.; Owen, L.B.

    1982-12-01

    The City of Monroe, Utah undertook a project to demonstrate the economic and technical viability of utilizing a low temperature geothermal resource to provide space and hot water heating to commercial, municipal, and domestic users within the community. During the course of the project, resource development and assessment, including drilling of a production well, was successfully completed. Upon completion of the field development and assessment phase of the program and of a preliminary design of the district heating system, it was determined that the project as proposed was not economically viable. This was due to: (1) a significant increase in estimated capital equipment costs resulting from the general inflation in construction costs, the large area/low population density in Monroe, and a more remote fluid disposal well site than planned, could not balance increased construction costs, (2) a lower temperature resource than predicted, and (3) due to predicted higher pumping and operating costs. After a thorough investigation of alternatives for utilizing the resource, further project activities were cancelled because the project was no longer economical and an alternative application for the resource could not be found within the constraints of the project. The City of Monroe, Utah is still seeking a beneficial use for the 600 gpm, 164/sup 0/F geothermal well. A summary of project activities included.

  8. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  9. Promoting Geothermal Energy: Air Emissions Comparison and Externality Analysis

    SciTech Connect

    Kagel, Alyssa; Gawell, Karl

    2005-09-01

    When compared to fossil fuel energy sources such as coal and natural gas, geothermal emerges as one of the least polluting forms of energy, producing virtually zero air emissions. Geothermal offers a baseload source of reliable power that compares favorably with fossil fuel power sources. But unless legislative changes are enacted, geothermal energy will continue to be produced at only a fraction of its potential.

  10. Microbiological monitoring in geothermal plants

    NASA Astrophysics Data System (ADS)

    Alawi, M.; Lerm, S.; Vetter, A.; Vieth, A.; Seibt, A.; Wolfgramm, M.; Würdemann, H.

    2009-12-01

    In times of increasing relevance of alternative energy resources the utilization of geothermal energy and subsurface energy storage gains importance and arouses increasing interest of scientists. The research project “AquiScreen” investigates the operational reliability of geothermally used groundwater systems under microbial, geochemical, mineralogical and petrological aspects. Microbiological analyses based on fluid and solid phases of geothermal systems are conducted to evaluate the impact of microbial populations on these systems. The presentation focuses on first results obtained from microbiological monitoring of geothermal plants located in two different regions of Germany: the North German Basin and the Molasse Basin in the southern part characterized by different salinities and temperatures. Fluid and filter samples taken during regular plant operation were investigated using genetic fingerprinting based on PCR-amplified 16S rRNA genes to characterize the microbial biocenosis of the geothermal aquifer. Sequencing of dominant bands of the fingerprints and the subsequent comparison to 16S rRNA genes from public databases enables a correlation to metabolic classes and provides information about the biochemical processes in the deep biosphere. The genetic profiles revealed significant differences in microbiological community structures of geothermal aquifers investigated. Phylogenetic analyses indicate broad metabolical diversity adapted to the specific conditions in the aquifers. Additionally a high amount of so far uncultivated microorganisms was detected indicating very specific indigenous biocenosis. However, in all geothermal plants bacteria were detected despite of fluid temperatures from 45° to 120°C. The identified microorganisms are closely related to thermophilic and hyperthermophilic species detectable in hot wells and hot springs, like Thermus scotoductus and Thermodesulfovibrio yellowstonii, respectively. Halophilic species were detected in

  11. Geothermal reservoir simulation to enhance confidence in predictions for nuclear waste disposal

    SciTech Connect

    Kneafsey, Timothy J.; Pruess, Karsten; O'Sullivan, Michael J.; Bodvarsson, Gudmundur S.

    2002-06-15

    Numerical simulation of geothermal reservoirs is useful and necessary in understanding and evaluating reservoir structure and behavior, designing field development, and predicting performance. Models vary in complexity depending on processes considered, heterogeneity, data availability, and study objectives. They are evaluated using computer codes written and tested to study single and multiphase flow and transport under nonisothermal conditions. Many flow and heat transfer processes modeled in geothermal reservoirs are expected to occur in anthropogenic thermal (AT) systems created by geologic disposal of heat-generating nuclear waste. We examine and compare geothermal systems and the AT system expected at Yucca Mountain, Nevada, and their modeling. Time frames and spatial scales are similar in both systems, but increased precision is necessary for modeling the AT system, because flow through specific repository locations will affect long-term ability radionuclide retention. Geothermal modeling experience has generated a methodology, used in the AT modeling for Yucca Mountain, yielding good predictive results if sufficient reliable data are available and an experienced modeler is involved. Codes used in geothermal and AT modeling have been tested extensively and successfully on a variety of analytical and laboratory problems.

  12. Systematic study of cell isolation from bovine nucleus pulposus: Improving cell yield and experiment reliability.

    PubMed

    Lee, Juliana T Y; Cheung, Kenneth M C; Leung, Victor Y L

    2015-12-01

    Differences in matrix compositions in human nucleus pulposus (NP) clinical samples demand different cell isolation protocols for optimal results but there is no clear guide about this to date. Sub-optimal protocols may result in low cell yield, limited reliability of results or even failure of experiments. Cell yield, viability and attachment of cells isolated from bovine NP tissue with different protocols were estimated by cell counting, Trypan blue staining and cell culturing respectively. RNA was extracted from isolated cells and quantified by Nanodrop spectrometry and RT-qPCR. Higher collagenase concentration, longer digestion duration and pronase pre-treatment increased the cell yield. Cell viability remained high (<5% dead cells) even after 0.2% collagenase treatment for overnight. NP cells remained to have high ACAN, COL2A1, CDH2, KRT18, and KRT19 expression compared to muscle cells for different cell isolation conditions tested. Digestion by collagenase alone without the use of pronase could isolate cells from human degenerated NP tissue but clusters of cells were observed. We suggest the use of the disappearance of tissue as an indirect measure of cells released. This study provides a guide for researchers to decide the parameters involved in NP cell isolation for optimal outcome.

  13. Wood and fruit drying in Los Azufres geothermal field, Mexico

    SciTech Connect

    Casimiro, E.; Pastrana, E.

    1996-12-31

    The main object of Comision Federal de Electricidad (CFE`s) Geothermal Field at Los Azufres, is to generate geothermal electricity; however with the new politics in Mexico CFE has built a pilot project in order to profit from the geothermal residual energy and to attract national or foreign investors and convince them that direct-use of geothermal energy is an attractive feasible and economical possibility. The object of this paper is to present the CFE experiences in wood and fruit drying using geothermal energy.

  14. Reliability of sensory predictions determines the experience of self-agency.

    PubMed

    Gentsch, Antje; Kathmann, Norbert; Schütz-Bosbach, Simone

    2012-03-17

    This study examines the neurocognitive mechanisms underlying the sense of agency, that is, the experience of causing and controlling events in our environment. Specifically, we tested the hypothesis that the sense of agency depends on an optimal integration of different anticipatory signals, generated by motor and nonmotor systems. An established marker of pre-reflective agency experience is the suppression of cortical responses to actively generated feedback as compared to passively observed feedback, which was measured here by event-related potentials (ERPs). Sensory expectations based on motor-related and unrelated signals were induced by varying the probabilistic contingency between action and feedback, and by priming the feedback prior to the action. Moreover, simultaneous conscious agency judgments were assessed. A reduction of visual N1 response was found to self- as compared to externally generated feedback. In addition, the N1 was modulated by accurate anticipations based on prime stimuli, independent of the precision of motor predictions. Conscious agency judgments, in contrast, were enhanced by prime stimuli only in situations where no precise motor predictions of the action feedback were available. These results indicate that anticipatory signals arising from motor and nonmotor systems are integrated differently depending on the level of agency processing. Our findings suggest that, at a pre-reflective level, the brain's agency system relies on both embodied signals and nonmotor sensory expectations. At higher cognitive levels, motor and nonmotor cues are weighted differently depending on their relative reliability in a given context, thereby providing a basis for robust agentive self-awareness.

  15. Resource assessment for geothermal direct use applications

    SciTech Connect

    Beer, C.; Hederman, W.F. Jr.; Dolenc, M.R.; Allman, D.W.

    1984-04-01

    This report discusses the topic geothermal resource assessment and its importance to laymen and investors for finding geothermal resources for direct-use applications. These are applications where the heat from lower-temperature geothermal fluids, 120 to 200/sup 0/F, are used directly rather than for generating electricity. The temperatures required for various applications are listed and the various types of geothermal resources are described. Sources of existing resource data are indicated, and the types and suitability of tests to develop more data are described. Potential development problems are indicated and guidance is given on how to decrease technical and financial risk and how to use technical consultants effectively. The objectives of this report are to provide: (1) an introduction low-temperature geothermal resource assessment; (2) experience from a series of recent direct-use projects; and (3) references to additional information.

  16. Guidebook to Geothermal Finance

    SciTech Connect

    Salmon, J. P.; Meurice, J.; Wobus, N.; Stern, F.; Duaime, M.

    2011-03-01

    This guidebook is intended to facilitate further investment in conventional geothermal projects in the United States. It includes a brief primer on geothermal technology and the most relevant policies related to geothermal project development. The trends in geothermal project finance are the focus of this tool, relying heavily on interviews with leaders in the field of geothermal project finance. Using the information provided, developers and investors may innovate in new ways, developing partnerships that match investors' risk tolerance with the capital requirements of geothermal projects in this dynamic and evolving marketplace.

  17. City of El Centro geothermal energy utility core field experiment. Final report, February 16, 1979-November 30, 1984

    SciTech Connect

    Province, S.G.; Sherwood, P.B.

    1984-11-01

    The City of El Centro was awarded a contract in late 1978 to cost share the development of a low to moderate temperature geothermal resource in the City. The resource would be utilized to heat, cool and provide hot water to the nearby Community Center. In December 1981, Thermal 1 (injector) was drilled to 3970 feet. In January 1982, Thermal 2 (producer) was drilled to 8510 feet. Before testing began, fill migrated into both wells. Both wells were cleaned out. A pump was installed in the producer, but migration of fill again into the injector precluded injection of produced fluid. A short term production test was undertaken and results analyzed. Based upon the analysis, DOE decided that the well was not useful for commercial production due to a low flow rate, the potential problems of continued sanding and gasing, and the requirement to lower the pump setting depth and the associated costs of pumping. There was no commercial user found to take over the wells. Therefore, the wells were plugged and abandoned. The site was restored to its original condition.

  18. Measuring Educators' Attitudes and Beliefs about Evaluation: Construct Validity and Reliability of the Teacher Evaluation Experience Scale

    ERIC Educational Resources Information Center

    Reddy, Linda A.; Dudek, Christopher M.; Kettler, Ryan J.; Kurz, Alexander; Peters, Stephanie

    2016-01-01

    This study presents the reliability and validity of the Teacher Evaluation Experience Scale--Teacher Form (TEES-T), a multidimensional measure of educators' attitudes and beliefs about teacher evaluation. Confirmatory factor analyses of data from 583 teachers were conducted on the TEES-T hypothesized five-factor model, as well as on alternative…

  19. The Development of the Functional Literacy Experience Scale Based upon Ecological Theory (FLESBUET) and Validity-Reliability Study

    ERIC Educational Resources Information Center

    Özenç, Emine Gül; Dogan, M. Cihangir

    2014-01-01

    This study aims to perform a validity-reliability test by developing the Functional Literacy Experience Scale based upon Ecological Theory (FLESBUET) for primary education students. The study group includes 209 fifth grade students at Sabri Taskin Primary School in the Kartal District of Istanbul, Turkey during the 2010-2011 academic year.…

  20. Geothermal Technologies Program: Washington

    SciTech Connect

    Not Available

    2005-02-01

    This fact sheets provides a summary of geothermal potential, issues, and current development in Washington State. This fact sheet was developed as part of DOE's GeoPowering the West initiative, part of the Geothermal Technologies Program.

  1. GEOTHERM Data Set

    DOE Data Explorer

    DeAngelo, Jacob

    1983-01-01

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey.

  2. Geothermal exploration in Indonesia

    SciTech Connect

    Radja, V.T.

    1984-03-01

    Indonesia is blessed with geothermal resources. This fortunate aspect is directly related to the fact that the archipelago is an island arc created by a subduction zone. Evidence of geothermal activity is common throughout the Islands. Among the islands' many active volcanos are numerous geothermal phenomena. Almost half of the volcanic centers in Indonesia (88 out of 177 centers) contain fumarole and sulfatare features. A brief history of the exploration for geothermal energy in Indonesia is presented.

  3. Geothermal district G1

    SciTech Connect

    Not Available

    1988-12-01

    Geothermal District G1 includes 37 northeastern California counties and six geothermal fields: Lake City, Susanville, Litchfield, Wendel, Amedee, and Casa Diablo. Electrical generation from geothermal resources occurs in three of the fields: Wendel, Amedee, and Casa Diablo. Low-temperature geothermal projects are underway throughout the district and are described in a road log format. The ten projects described are located at Big Bend, Glass Mountain, Bieber, Alturas, Cedarville, Lake City, Honey Lake Valley, Greenville, and in Sierra and Mono Counties.

  4. South Dakota geothermal handbook

    SciTech Connect

    Not Available

    1980-06-01

    The sources of geothermal fluids in South Dakota are described and some of the problems that exist in utilization and materials selection are described. Methods of heat extraction and the environmental concerns that accompany geothermal fluid development are briefly described. Governmental rules, regulations and legislation are explained. The time and steps necessary to bring about the development of the geothermal resource are explained in detail. Some of the federal incentives that encourage the use of geothermal energy are summarized. (MHR)

  5. Microbiological Monitoring in Geothermal Plants

    NASA Astrophysics Data System (ADS)

    Alawi, M.; Lerm, S.; Linder, R.; Vetter, A.; Vieth-Hillebrand, A.; Miethling-Graff, R.; Seibt, A.; Wolfgramm, M.; Wuerdemann, H.

    2010-12-01

    In the scope of the research projects “AquiScreen” and “MiProTherm” we investigated geothermally used groundwater systems under microbial, geochemical, mineralogical and petrological aspects. On one side an enhanced process understanding of engineered geothermal systems is mandatory to optimize plant reliability and economy, on the other side this study provides insights into the microbiology of terrestrial thermal systems. Geothermal systems located in the North German Basin and the Molasse Basin were analyzed by sampling of fluids and solid phases. The investigated sites were characterized by different temperatures, salinities and potential microbial substrates. The microbial population was monitored by the use of genetic fingerprinting techniques and PCR-cloning based on PCR-amplified 16S rRNA and dissimilatory sulfite reductase (DSR) genes. DNA-sequences of fingerprints and cloned PCR-products were compared to public databases and correlated with metabolic classes to provide information about the biogeochemical processes. In all investigated geothermal plants, covering a temperature range from 5° to 120°C, microorganisms were found. Phylogenetic gene analyses indicate a broad diversity of microorganisms adapted to the specific conditions in the engineered system. Beside characterized bacteria like Thermus scotoductus, Siderooxidans lithoautotrophicus and the archaeon Methanothermobacter thermoautotrophicus a high number of so far uncultivated microorganisms was detected. As it is known that - in addition to abiotic factors - microbes like sulfate-reducing bacteria (SRB) are involved in the processes of corrosion and scaling in plant components, we identified SRB by specific analyses of DSR genes. The SRB detected are closely related to thermotolerant and thermophilic species of Desulfotomaculum, Thermodesulfovibrio, Desulfohalobium and Thermodesulfobacterium, respectively. Overall, the detection of microbes known to be involved in biocorrosion and the

  6. Hot Dry Rock; Geothermal Energy

    SciTech Connect

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  7. Geothermal energy in Nevada

    SciTech Connect

    Not Available

    1980-01-01

    The nature of goethermal resources in Nevada and resource applications are discussed. The social and economic advantages of utilizing geothermal energy are outlined. Federal and State programs established to foster the development of geothermal energy are discussed. The names, addresses, and phone numbers of various organizations actively involved in research, regulation, and the development of geothermal energy are included. (MHR)

  8. A systematic review of the reliability and validity of discrete choice experiments in valuing non-market environmental goods.

    PubMed

    Rakotonarivo, O Sarobidy; Schaafsma, Marije; Hockley, Neal

    2016-12-01

    While discrete choice experiments (DCEs) are increasingly used in the field of environmental valuation, they remain controversial because of their hypothetical nature and the contested reliability and validity of their results. We systematically reviewed evidence on the validity and reliability of environmental DCEs from the past thirteen years (Jan 2003-February 2016). 107 articles met our inclusion criteria. These studies provide limited and mixed evidence of the reliability and validity of DCE. Valuation results were susceptible to small changes in survey design in 45% of outcomes reporting reliability measures. DCE results were generally consistent with those of other stated preference techniques (convergent validity), but hypothetical bias was common. Evidence supporting theoretical validity (consistency with assumptions of rational choice theory) was limited. In content validity tests, 2-90% of respondents protested against a feature of the survey, and a considerable proportion found DCEs to be incomprehensible or inconsequential (17-40% and 10-62% respectively). DCE remains useful for non-market valuation, but its results should be used with caution. Given the sparse and inconclusive evidence base, we recommend that tests of reliability and validity are more routinely integrated into DCE studies and suggest how this might be achieved.

  9. Geothermal monitor report

    NASA Astrophysics Data System (ADS)

    1982-06-01

    Geothermal Progress Monitor Report No. 6 presents a state-by-state summary of the status of geothermal leasing, exploration, and development in major physiographic regions where geothermal resource potential has been identified. Recent state-specific activities are reported at the end of each state status report, while recent activities of a more general nature are summarized briefly in Part 2 of the report. A list of recent publications of potential interest to the geothermal community and a directory of contributors to the geothermal progress monitoring system are also included.

  10. Mono County geothermal activity

    SciTech Connect

    Lyster, D.L.

    1986-01-01

    Three geothermal projects have been proposed or are underway in Mono County, California. The Mammoth/Chance geothermal development project plans to construct a 10-MW geothermal binary power plant which will include 8 production and 3 injection wells. Pacific Lighting Energy Systems is also planning a 10-MW binary power plant consisting of 5 geothermal wells and up to 4 injection wells. A geothermal research project near Mammoth Lakes has spudded a well to provide a way to periodically measure temperature gradient, pressure, and chemistry of the thermal waters and to investigate the space-heating potential of the area in the vicinity of Mammoth Lakes. All three projects are briefly described.

  11. Hawaii geothermal project

    NASA Technical Reports Server (NTRS)

    Kamins, R. M.

    1974-01-01

    Hawaii's Geothermal Project is investigating the occurrence of geothermal resources in the archipelago, initially on the Island of Hawaii. The state's interest in geothermal development is keen, since it is almost totally dependent on imported oil for energy. Geothermal development in Hawaii may require greater participation by the public sector than has been true in California. The initial exploration has been financed by the national, state, and county governments. Maximization of net benefits may call for multiple use of geothermal resources; the extraction of by-products and the application of treated effluents to agricultural and aquacultural uses.

  12. Turbodrilling in the Geothermal Environment

    SciTech Connect

    Herbert, P.

    1981-01-01

    Geothermal drilling, historically, has presented what seemed to be insurmountable barriers to the efficient and extended use of downhole drilling motors, especially those containing elastomeric bearing or motor components. In addition to being damaging to rubber, the typical temperatures of 177 to 371 C (350 to 700 F) create other operating problems as well. Recent innovations, specifically in turbodrill design, have opened heretofore unrealized potentials and allowed, for the first time, extended downhole drilling of geothermal wells. A considerable amount of experience has been obtained both in The Geysers and Imperial County areas of California primarily in directional drilling applications using insert, diamond, and polycrystallines diamond compact bits. Other hot-hole applications are currently being drilled successfully or planned in other states, both onshore and offshore. The turbodrill is devoid of any elastomers or other temperature-sensitive materials, hence, its capabilities are closely matched to the requirements of the industry. The bearing assembly can withstand the rigors found in the drilling of typical geothermal formations and provide the performance necessary to stay in the hole, thus providing increased penetration rates and, hence, more economical drilling. This paper presents case histories of recent turbodrill performances in all areas where used. Furthermore, data will be presented showing the performance of insert, diamond, and polycrystalline diamond bits as they relate to the turbodrill, together with forecasts as to the potential that turbodrills have to offer in accelerating and controlling the drilling of geothermal wells.

  13. Modeling and Simulation of Reliability & Maintainability Parameters for Reusable Launch Vehicles using Design of Experiments

    NASA Technical Reports Server (NTRS)

    Unal, Resit; Morris, W. Douglas; White, Nancy H.; Lepsch, Roger A.

    2004-01-01

    This paper describes the development of a methodology for estimating reliability and maintainability distribution parameters for a reusable launch vehicle. A disciplinary analysis code and experimental designs are used to construct approximation models for performance characteristics. These models are then used in a simulation study to estimate performance characteristic distributions efficiently. The effectiveness and limitations of the developed methodology for launch vehicle operations simulations are also discussed.

  14. UP TO 100,000 RELIABLE STRONG GRAVITATIONAL LENSES IN FUTURE DARK ENERGY EXPERIMENTS

    SciTech Connect

    Serjeant, S.

    2014-09-20

    The Euclid space telescope will observe ∼10{sup 5} strong galaxy-galaxy gravitational lens events in its wide field imaging survey over around half the sky, but identifying the gravitational lenses from their observed morphologies requires solving the difficult problem of reliably separating the lensed sources from contaminant populations, such as tidal tails, as well as presenting challenges for spectroscopic follow-up redshift campaigns. Here I present alternative selection techniques for strong gravitational lenses in both Euclid and the Square Kilometre Array, exploiting the strong magnification bias present in the steep end of the Hα luminosity function and the H I mass function. Around 10{sup 3} strong lensing events are detectable with this method in the Euclid wide survey. While only ∼1% of the total haul of Euclid lenses, this sample has ∼100% reliability, known source redshifts, high signal-to-noise, and a magnification-based selection independent of assumptions of lens morphology. With the proposed Square Kilometre Array dark energy survey, the numbers of reliable strong gravitational lenses with source redshifts can reach 10{sup 5}.

  15. Experiences of discrimination: validity and reliability of a self-report measure for population health research on racism and health.

    PubMed

    Krieger, Nancy; Smith, Kevin; Naishadham, Deepa; Hartman, Cathy; Barbeau, Elizabeth M

    2005-10-01

    Population health research on racial discrimination is hampered by a paucity of psychometrically validated instruments that can be feasibly used in large-scale studies. We therefore sought to investigate the validity and reliability of a short self-report instrument, the "Experiences of Discrimination" (EOD) measure, based on a prior instrument used in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Study participants were drawn from a cohort of working class adults, age 25-64, based in the Greater Boston area, Massachusetts (USA). The main study analytic sample included 159 black, 249 Latino, and 208 white participants; the validation study included 98 African American and 110 Latino participants who completed a re-test survey two to four weeks after the initial survey. The main and validation survey instruments included the EOD and several single-item discrimination questions; the validation survey also included the Williams Major and Everyday discrimination measures. Key findings indicated the EOD can be validly and reliably employed. Scale reliability was high, as demonstrated by confirmatory factor analysis, Cronbach's alpha (0.74 or greater), and test-re-test reliability coefficients (0.70). Structural equation modeling demonstrated the EOD had the highest correlation (r=0.79) with an underlying discrimination construct compared to other self-report discrimination measures employed. It was significantly associated with psychological distress and tended to be associated with cigarette smoking among blacks and Latinos, and it was not associated with social desirability in either group. By contrast, single-item measures were notably less reliable and had low correlations with the multi-item measures. These results underscore the need for using validated, multi-item measures of experiences of racial discrimination and suggest the EOD may be one such measure that can be validly employed with working class African Americans and Latino Americans.

  16. Reference book on geothermal direct use

    SciTech Connect

    Lienau, P.J.; Lund, J.W.; Rafferty, K.; Culver, G.

    1994-08-01

    This report presents the direct uses of geothermal energy in the United States. Topics discussed include: low-temperature geothermal energy resources; energy reserves; geothermal heat pumps; geothermal energy for residential buildings; and geothermal energy for industrial usage.

  17. The effect of physician experience on the measurement reliability of the Reimers’ hip migration percentage in children with cerebral palsy

    PubMed Central

    Analan, Pınar Doruk; Yilmaz, Emine Ece; Adam, Mehmet; Leblebici, Berrin

    2015-01-01

    [Purpose] Reimers’ hip migration percentage (MP) is commonly used to document the extent of hip displacement in children with cerebral palsy (CP). However, factors such as poor administration of pelvic radiographs, a lack of concentration, inexperience, or a busy clinical environment may result in variations in the MP measurements. The aim of this study was to compare the differences in the MP results of two physiatrists with varying levels of experience to determine the role of experience in the measurement’s accuracy. [Subjects and Methods] This retrospective study included 62 hip radiographs of 31 children with spastic CP. Two physiatrists with different experience levels calculated the baseline MP on two occasions six weeks apart. Correlations, intra- and inter-rater reliabilities, and differences in the MPs were compared. [Results] Correlations and inter- and intra-rater reliabilities of the measurements were excellent. There were no statistically significant intra- or inter-rater differences for either of the two measurement points. Inter-rater correlations for each session were 0.94. [Conclusion] Experience does not appear to be a factor in the evaluation of MP, and inter-rater differences do not cause problems regarding patient follow-up. Therefore, repeated pelvic radiographs are not necessary in the evaluation of MP in children with CP unless indicated. PMID:26644686

  18. The geothermal power organization

    SciTech Connect

    Scholl, K.L.

    1997-12-31

    The Geothermal Power Organization is an industry-led advisory group organized to advance the state-of-the-art in geothermal energy conversion technologies. Its goal is to generate electricity from geothermal fluids in the most cost-effective, safe, and environmentally benign manner possible. The group achieves this goal by determining the Member`s interest in potential solutions to technological problems, advising the research and development community of the needs of the geothermal energy conversion industry, and communicating research and development results among its Members. With the creation and adoption of a new charter, the Geothermal Power Organization will now assist the industry in pursuing cost-shared research and development projects with the DOE`s Office of Geothermal Technologies.

  19. Estimation of static formation temperatures in geothermal wells by using an artificial neural network approach

    NASA Astrophysics Data System (ADS)

    Bassam, A.; Santoyo, E.; Andaverde, J.; Hernández, J. A.; Espinoza-Ojeda, O. M.

    2010-09-01

    An artificial neural network (ANN) approach was used to develop a new predictive model for the calculation of static formation temperature (SFT) in geothermal wells. A three-layer ANN architecture was successfully trained using a geothermal borehole database, which contains "statistically normalised" SFT estimates. These estimates were inferred from seven analytical methods commonly used in geothermal industry. Bottom-hole temperature (BHT) measurements and shut-in times were used as main input variables for the ANN training. Transient temperature gradients were used as secondary variables. The Levenberg-Marquardt (LM) learning algorithm, the hyperbolic tangent sigmoid transfer function and the linear transfer function were used for the ANN optimisation. The best training data set was obtained with an ANN architecture composed by five neurons in the hidden layer, which made possible to predict the SFT with a satisfactory efficiency ( R2>0.95). A suitable accuracy of the ANN model was achieved with a percentage error less than ±5%. The SFTs predicted by the ANN model were statistically analyzed and compared with "true" SFTs measured in synthetic experiments and actual BHT logs collected in geothermal boreholes during long shut-in times. These data sets were processed both to validate the new ANN model and to avoid bias. The SFT estimates inferred from the ANN validation process were in good agreement ( R2>0.95) with the "true" SFT data reported for synthetic and field experiments. The results suggest that the new ANN model could be used as a practical tool for the reliable prediction of SFT in geothermal wells using BHT and shut-in time as input data only.

  20. Geothermal Today - 2001

    SciTech Connect

    2001-08-01

    U.S. Department of Energy Geothermal Energy Program Highlights Partnering with Industry A New Power Source for Nevada Drilling Research Finding Geothermal Resources Small-Scale Geothermal Power Plants The Heat Beneath Your Feet R&D 100 Award Program in Review Milestones January 2000 The U.S. Department of Energy GeoPowering the West initiative was launched. February 2000 Grants totaling $4.8 million were awarded in six western states, primarily for development of reservoir exploration, character

  1. Geothermal Today - 1999

    SciTech Connect

    2000-05-01

    U.S. Department of Energy 1999 Geothermal Energy Program Highlights The Hot Facts Getting into Hot Water Turning Waste water into Clean Energy Producing Even Cleaner Power Drilling Faster and Cheaper Program in Review 1999: The Year in Review JanuaryCal Energy announced sale of Coso geothermal power plants at China Lake, California, to Caithness Energy, for $277 million. U.S. Export-Import Bank completed a $50 million refinancing of the Leyte Geothermal Optimization Project in the Philippines. F

  2. Operating Experience and Reliability Improvements on the 5 kW CW Klystron at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Nelson, R.; Holben, S.

    1997-05-01

    With substantial operating hours on the RF system, considerable information on reliability of the 5 kW CW klystrons has been obtained. High early failure rates led to examination of the operating conditions and failure modes. Internal ceramic contamination caused premature failure of gun potting material and ultimate tube demise through arcing or ceramic fracture. A planned course of repotting and reconditioning of approximately 300 klystrons, plus careful attention to operating conditions and periodic analysis of operational data, has substantially reduced the failure rate. It is anticipated that implementation of planned supplemental monitoring systems for the klystrons will allow most catastrophic failures to be avoided. By predicting end of life, tubes can be changed out before they fail, thus minimizing unplanned downtime. Initial tests have also been conducted on this same klystron operated at higher voltages with resultant higher output power. The outcome of these tests will provide information to be considered for future upgrades to the accelerator.

  3. Operating experience and reliability improvements on the 5 kW CW klystron at Jefferson Lab

    SciTech Connect

    Nelson, R.; Holben, S.

    1997-06-01

    With substantial operating hours on the RF system, considerable information on reliability of the 5 kW CW klystrons has been obtained. High early failure rates led to examination of the operating conditions and failure modes. Internal ceramic contamination caused premature failure of gun potting material and ultimate tube demise through arcing or ceramic fracture. A planned course of reporting and reconditioning of approximately 300 klystrons, plus careful attention to operating conditions and periodic analysis of operational data, has substantially reduced the failure rate. It is anticipated that implementation of planned supplemental monitoring systems for the klystrons will allow most catastrophic failures to be avoided. By predicting end of life, tubes can be changed out before they fail, thus minimizing unplanned downtime. Initial tests have also been conducted on this same klystron operated at higher voltages with resultant higher output power. The outcome of these tests will provide information to be considered for future upgrades to the accelerator.

  4. A study of pumps for the Hot Dry Rock Geothermal Energy extraction experiment (LTFT (Long Term Flow Test))

    SciTech Connect

    Tatro, C.A.

    1986-10-01

    A set of specifications for the hot dry rock (HDR) Phase II circulation pumping system is developed from a review of basic fluid pumping mechanics, a technical history of the HDR Phase I and Phase II pumping systems, a presentation of the results from experiment 2067 (the Initial Closed-Loop Flow Test or ICFT), and consideration of available on-site electrical power limitations at the experiment site. For the Phase II energy extraction experiment (the Long Term Flow Test or LTFT) it is necessary to provide a continuous, low maintenance, and highly efficient pumping capability for a period of twelve months at variable flowrates up to 420 gpm and at surface injection pressures up to 5000 psi. The pumping system must successfully withstand attacks by corrosive and embrittling gases, erosive chemicals and suspended solids, and fluid pressure and temperature fluctuations. In light of presently available pumping hardware and electric power supply limitations, it is recommended that positive displacement multiplex plunger pumps, driven by variable speed control electric motors, be used to provide the necessary continuous surface injection pressures and flowrates for LTFT. The decision of whether to purchase the required circulation pumping hardware or to obtain contractor provided pumping services has not been made.

  5. Geothermal Life Cycle Calculator

    DOE Data Explorer

    Sullivan, John

    2014-03-11

    This calculator is a handy tool for interested parties to estimate two key life cycle metrics, fossil energy consumption (Etot) and greenhouse gas emission (ghgtot) ratios, for geothermal electric power production. It is based solely on data developed by Argonne National Laboratory for DOE’s Geothermal Technologies office. The calculator permits the user to explore the impact of a range of key geothermal power production parameters, including plant capacity, lifetime, capacity factor, geothermal technology, well numbers and depths, field exploration, and others on the two metrics just mentioned. Estimates of variations in the results are also available to the user.

  6. Geothermal development attitudes surveyed

    SciTech Connect

    Not Available

    1986-01-01

    The State of Hawaii has conducted several surveys on public opinion towards the development of geothermal energy. The latest poll was designed to: measure public opinion in the County of Hawaii relevant to geothermal development for electrical power supplied to Island of Hawaii residents only; measure public opinion in the County of Hawaii relevant to geothermal development of electricity to be exported for use on Oahu; and identify barriers to, and opportunities for energy conservation programs, including geothermal development. In general, the residents of the County of Hawaii favor some form of geothermal development. Issues on geothermal development of concern to the public were similar to those mentioned in the 1982 study. Basically, the issues amount to a trade-off between the economic advantages and the environmental problems of geothermal development. The strong points in favor of development include a perceived need for more energy, a strong preference for alternate energy forms over petroleum, perceived benefits for the local economy and the employment rates, and the possibility that development may reduce or contain utility bills. On the other hand, it appears that geothermal development will cause health problems for those who live near the wells, be hazardous to flora and fauna in the Puna area, and create noise and odor above tolerable levels. These are oversimplified statements of the reasons behind both support and opposition for geothermal development.

  7. Geothermal policy development program: expediting the local geothermal permitting process

    SciTech Connect

    Not Available

    1981-07-01

    For a number of years, concerns have been raised about the length of time and the complexity involved in obtaining required permits in order to develop the geothermal resource at the Geysers. Perhaps the most important factor is jurisdiction. At the Geysers, all three levels of government - local, state, and federal - exercise significant authority over various aspects of geothermal development. In addition, several agencies within each governmental level play an active role in the permitting process. The present study is concerned primarily with the local permitting process, and the ways in which this process could be expedited. This report begins by looking at the local role in the overall permitting process, and then reviews the findings and conclusions that have been reached in other studies of the problem. This is followed by a case study evaluation of recent permitting experience in the four Geysers-Calistoga KGRA counties, and the report concludes by outlining several approaches to expediting the local permitting process.

  8. Fault-free behavior of reliable multiprocessor systems: FTMP experiments in AIRLAB

    NASA Technical Reports Server (NTRS)

    Clune, E.; Segall, Z.; Siewiorek, D.

    1985-01-01

    This report describes a set of experiments which were implemented on the Fault tolerant Multi-Processor (FTMP) at NASA/Langley's AIRLAB facility. These experiments are part of an effort to formulate and evaluate validation methodologies for fault-tolerant computers. This report deals with the measurement of single parameters (baselines) of a fault free system. The initial set of baseline experiments lead to the following conclusions: (1) The system clock is constant and independent of workload in the tested cases; (2) the instruction execution times are constant; (3) the R4 frame size is 40mS with some variation; (4) the frame stretching mechanism has some flaws in its implementation that allow the possibility of an infinite stretching of frame duration. Future experiments are planned. Some will broaden the results of these initial experiments. Others will measure the system more dynamically. The implementation of a synthetic workload generation mechanism for FTMP is planned to enhance the experimental environment of the system.

  9. Geothermal research at the Puna Facility. Technical report

    SciTech Connect

    Chen, B.

    1986-04-01

    This report consists of a summary of the experiments performed to date at the Puna Geothermal Research Facility on silica in the geothermal fluid from the HGP-A well. Also presented are some results of investigations in commercial applications of the precipitated silica. (ACR)

  10. Geothermal heating demonstration project at Mammoth Lakes Village. Final report

    SciTech Connect

    Sims, A.V.; Campbell, R.G.

    1980-03-01

    A pilot project is described which demonstrated the feasibility of using geothermal energy for space heating and snow-melting at the Casa Diablo geothermal reservoir near Mammoth Lakes Village, California. The geothermal heating system employed was modeled after the geothermal district heating system used extensively in Iceland. The geothermal heating system incorporated a closed secondary heating loop (Iceland's system uses the geothermal fluids directly) to provide heat to a lumber store, warehouse and display area, and to melt snow on a connecting walkway between the buildings. The secondary loop, containing a mixture of fresh water and ethylene glycol, was heated by geothermal fluids produced from a nearby well. After passing through a heat exchanger, the cooled geothermal fluids were reinjected down another well. The heating system operated for three different periods, and the project concluded after a successful, long-term demonstration of well pump and heating system operation. Pump problems encountered early in the project were solved, and information gained in the final operation period indicated that reliable, extended periods of well pump operation can be achieved. The hydronic heaters effectively heated buildings, and the snow-melting walkway performed very well during winter operation.

  11. A reliable pipelining protocol for the message service of the Mobile Satellite Experiment

    NASA Technical Reports Server (NTRS)

    Li, V. O. K.; Yan, T.-Y.

    1986-01-01

    This paper describes and analyzes a pipelining protocol for the data message communications of MSAT-X, a proposed experimental satellite-based mobile communications network. A demand assigned multiple access protocol using pure ALOHA for making reservation requests has been developed for MSAT-X under error-free assumptions. Preliminary propagation studies indicate that the short term bit error rate of satellite channels in a mobile environment can be as high as 0.001. Therefore, error-control schemes must be developed to ensure reliable transmissions. A retransmission scheme using selective repeat to minimize the end-to-end delay is proposed. Slotted ALOHA for making reservation requests is used to increase the overall system throughput. Since the number of channels available for reservation and data channels is essentially fixed for a given voice call blocking probability and a fixed call arrival rate, the analysis presented in this paper is also applicable to the integrated voice and data services of MSAT-X. Various operational scenarios have been investigated.

  12. Models of Geothermal Brine Chemistry

    SciTech Connect

    Nancy Moller Weare; John H. Weare

    2002-03-29

    Many significant expenses encountered by the geothermal energy industry are related to chemical effects. When the composition, temperature of pressure of the fluids in the geological formation are changed, during reservoir evolution, well production, energy extraction or injection processes, the fluids that were originally at equilibrium with the formation minerals come to a new equilibrium composition, temperature and pressure. As a result, solid material can be precipitated, dissolved gases released and/or heat lost. Most geothermal energy operations experience these phenomena. For some resources, they create only minor problems. For others, they can have serious results, such as major scaling or corrosion of wells and plant equipment, reservoir permeability losses and toxic gas emission, that can significantly increase the costs of energy production and sometimes lead to site abandonment. In future operations that exploit deep heat sources and low permeability reservoirs, new chemical problems involving very high T, P rock/water interactions and unknown injection effects will arise.

  13. Geothermal Heat Pump Benchmarking Report

    SciTech Connect

    1997-01-17

    A benchmarking study was conducted on behalf of the Department of Energy to determine the critical factors in successful utility geothermal heat pump programs. A Successful program is one that has achieved significant market penetration. Successfully marketing geothermal heat pumps has presented some major challenges to the utility industry. However, select utilities have developed programs that generate significant GHP sales. This benchmarking study concludes that there are three factors critical to the success of utility GHP marking programs: (1) Top management marketing commitment; (2) An understanding of the fundamentals of marketing and business development; and (3) An aggressive competitive posture. To generate significant GHP sales, competitive market forces must by used. However, because utilities have functioned only in a regulated arena, these companies and their leaders are unschooled in competitive business practices. Therefore, a lack of experience coupled with an intrinsically non-competitive culture yields an industry environment that impedes the generation of significant GHP sales in many, but not all, utilities.

  14. Hawaiian direct-heat grants encourage geothermal creativity

    SciTech Connect

    Beck, A.G. )

    1988-12-01

    The Hawaiian Community Geothermal Technology Program is unique. Under its auspices, heat and other by-products of Hawaii's high-temperature HGP-A geothermal well and power plant are not wasted. Instead, they form the backbone of a direct-heat grant program that reaches into the local community and encourages community members to develop creative uses for geothermal energy. A by-product of this approach is a broadened local base of support for geothermal energy development. With the experimental and precommercial work completed, most of the original grantees are looking for ways to continue their projects on a commercial scale by studying the economics of using geothermal heat in a full-scale business and researching potential markets. A geothermal mini-park may be built near the research center. In 1988, a second round of projects was funded under the program. The five new projects are: Geothermal Aquaculture Project - an experiment with low-cost propagation of catfish species in geothermally heated tanks with a biofilter; Media Steam Sterilization and Drying - an application of raw geothermal steam to shredded, locally-available materials such as coconut husks, which would be used as certified nursery growing media; Bottom-Heating System Using Geothermal Power for Propagation - a continuation of Leilani Foliage's project from the first round of grants, focusing on new species of ornamental palms; Silica Bronze - the use of geothermal silica as a refractory material in casting bronze artwork; and Electro-deposition of Minerals in Geothermal Brine - the nature and possible utility of minerals deposited from the hot fluid.

  15. Geothermal Financing Workbook

    SciTech Connect

    Battocletti, E.C.

    1998-02-01

    This report was prepared to help small firm search for financing for geothermal energy projects. There are various financial and economics formulas. Costs of some small overseas geothermal power projects are shown. There is much discussion of possible sources of financing, especially for overseas projects. (DJE-2005)

  16. Benefits of Geothermal Energy

    SciTech Connect

    2004-07-01

    One of the principal benefits of geothermal power plants is that they provide baseload power. Baseload power plants provide power all or most of the time and contrast with peaker plants which turn on or off as demand rises, or peaks, throughout the day. Geothermal plants contrast with other renewable energy resources like wind and solar energy that generate power intermittently.

  17. Geothermal energy program summary

    SciTech Connect

    Not Available

    1990-01-01

    This document reviews Geothermal Energy Technology and the steps necessary to place it into service. Specific topics covered are: four types of geothermal resources; putting the resource to work; power generation; FY 1989 accomplishments; hard rock penetration; conversion technology; and geopressured brine research. 16 figs. (FSD)

  18. Geothermal energy: a brief assessment

    SciTech Connect

    Lunis, B.C.; Blackett, R.; Foley, D.

    1982-07-01

    This document includes discussions about geothermal energy, its applications, and how it is found and developed. It identifies known geothermal resources located in Western's power marketing area, and covers the use of geothermal energy for both electric power generation and direct applications. Economic, institutional, environmental, and other factors are discussed, and the benefits of the geothermal energy resource are described.

  19. Geothermal energy in Iceland

    SciTech Connect

    Ragnarsson, A.

    1996-11-01

    The annual primary energy supply in Iceland, which has a population of 268,000, is 98,000 TJ (T = 10{sup 12}) or 366 GJ per capita, which is among the highest in the world. Geothermal energy provides about 48.8% of the total, hydropower 17.2%, oil 31.5% and coal 2.5%. The main use of geothermal energy is for space heating. About 85% of all houses are heated with geothermal energy; the rest are heated mainly by electricity. So far, geothermal resources have only, to a limited extent, been used for electric power generation, because of the availability of relatively cheap hydropower resources. Of the total electricity production of 5,000 GWh in 1995, only 288 GWh or 5.8% came from geothermal energy, 94% from hydro and 0.2% from fuels.

  20. Advanced Geothermal Turbodrill

    SciTech Connect

    W. C. Maurer

    2000-05-01

    Approximately 50% of the cost of a new geothermal power plant is in the wells that must be drilled. Compared to the majority of oil and gas wells, geothermal wells are more difficult and costly to drill for several reasons. First, most U.S. geothermal resources consist of hot, hard crystalline rock formations which drill much slower than the relatively soft sedimentary formations associated with most oil and gas production. Second, high downhole temperatures can greatly shorten equipment life or preclude the use of some technologies altogether. Third, producing viable levels of electricity from geothermal fields requires the use of large diameter bores and a high degree of fluid communication, both of which increase drilling and completion costs. Optimizing fluid communication often requires creation of a directional well to intersect the best and largest number of fracture capable of producing hot geothermal fluids. Moineau motor stators made with elastomers cannot operate at geothermal temperatures, so they are limited to the upper portion of the hole. To overcome these limitations, Maurer Engineering Inc. (MEI) has developed a turbodrill that does not use elastomers and therefore can operate at geothermal temperatures. This new turbodrill uses a special gear assembly to reduce the output speed, thus allowing a larger range of bit types, especially tri-cone roller bits, which are the bits of choice for drilling hard crystalline formations. The Advanced Geothermal Turbodrill (AGT) represents a significant improvement for drilling geothermal wells and has the potential to significantly reduce drilling costs while increasing production, thereby making geothermal energy less expensive and better able to compete with fossil fuels. The final field test of the AGT will prepare the tool for successful commercialization.

  1. Geothermal energy in the western United States and Hawaii: Resources and projected electricity generation supplies. [Contains glossary and address list of geothermal project developers and owners

    SciTech Connect

    Not Available

    1991-09-01

    Geothermal energy comes from the internal heat of the Earth, and has been continuously exploited for the production of electricity in the United States since 1960. Currently, geothermal power is one of the ready-to-use baseload electricity generating technologies that is competing in the western United States with fossil fuel, nuclear and hydroelectric generation technologies to provide utilities and their customers with a reliable and economic source of electric power. Furthermore, the development of domestic geothermal resources, as an alternative to fossil fuel combustion technologies, has a number of associated environmental benefits. This report serves two functions. First, it provides a description of geothermal technology and a progress report on the commercial status of geothermal electric power generation. Second, it addresses the question of how much electricity might be competitively produced from the geothermal resource base. 19 figs., 15 tabs.

  2. Sexual victimization among African American adolescent females: examination of the reliability and validity of the Sexual Experiences Survey.

    PubMed

    Cecil, Heather; Matson, Steven C

    2006-01-01

    Adolescent females are disproportionately represented among reported cases of sexual victimization. Because sexual victimization is associated with an array of negative sequelae (e.g., depression, alcohol abuse), psychometrically sound instruments are urgently needed to assess sexual victimization or coercion. The investigation conducts a preliminary analysis of the reliability and validity of the Sexual Experiences Survey (SES) for a sample drawn from a high-risk population-African American adolescent females. Our analyses indicate good internal consistency for the SES with this sample. Convergent validity is demonstrated. Specifically, scores on the SES are associated with significantly lower levels of self-esteem and mastery, higher levels of depression, lower levels of family cohesion, higher levels of family conflict, and higher levels of using alcohol and being a smoker. Preliminary support for discriminant validity is also obtained. This study is a stepping stone for future investigations into the psychometric evaluation of the SES.

  3. Navy Geothermal Plan

    SciTech Connect

    Not Available

    1984-12-01

    Domestic geothermal resources with the potential for decreasing fossil fuel use and energy cost exist at a significant number of Navy facilities. The Geothermal Plan is part of the Navy Energy R and D Program that will evaluate Navy sites and provide a technical, economic, and environmental base for subsequent resource use. One purpose of the program will be to provide for the transition of R and D funded exploratory efforts into the resource development phase. Individual Navy geothermal site projects are described as well as the organizational structure and Navy decision network. 2 figs.

  4. Geothermal aquaculture in Nevada

    SciTech Connect

    Birk, S.

    1987-06-01

    Work in geothermal aquaculture and vertically integrated agriculture is undertaken by Washoe Aquaculture Limited, Gourmet Prawnz Inc., General Managing Partners. This approach to agriculture is researched at the integrated Prototype Aquaculture Facility (IPAF) at Hobo Hot Springs, Nevada. The principal objective at the IPAF is to use geothermal aquifers to commercially raise food, plants, and ornamental fish. At the IPAF, the feasibility of geothermal aquaculture has been demonstrated. The company has implemented many demonstration projects, including the cultivation of freshwater prawns, native baitfish, exotic tropical species, and commercially important aquatic plants.

  5. Novel approaches for an enhanced geothermal development of residential sites

    NASA Astrophysics Data System (ADS)

    Schelenz, Sophie; Firmbach, Linda; Shao, Haibing; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    An ongoing technological enhancement drives an increasing use of shallow geothermal systems for heating and cooling applications. However, even in areas with intensive shallow geothermal use, planning of geothermal systems is in many cases solely based on geological maps, drilling databases, and literature references. Thus, relevant heat transport parameters are rather approximated than measured for the specific site. To increase the planning safety and promote the use of renewable energies in the domestic sector, this study investigates a novel concept for an enhanced geothermal development of residential neighbourhoods. This concept is based on a site-specific characterization of subsurface conditions and the implementation of demand-oriented geothermal usage options. Therefore, an investigation approach has been tested that combines non-invasive with minimum-invasive exploration methods. While electrical resistivity tomography has been applied to characterize the geological subsurface structure, Direct Push soundings enable a detailed, vertical high-resolution characterization of the subsurface surrounding the borehole heat exchangers. The benefit of this site-specific subsurface investigation is highlighted for 1) a more precise design of shallow geothermal systems and 2) a reliable prediction of induced long-term changes in groundwater temperatures. To guarantee the financial feasibility and practicability of the novel geothermal development, three different options for its implementation in residential neighbourhoods were consequently deduced.

  6. Geothermal Energy: Current abstracts

    SciTech Connect

    Ringe, A.C.

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  7. Geothermal Orientation Handbook

    SciTech Connect

    1984-07-01

    This is a useful overview of the Department of Energy's outlook on geothermal energy development in the U.S. as of late 1983. For example, Exhibit 4 shows how electric utility planners' estimates of likely amounts of geothermal power on line for 1990 and 2000 first increased and then declined over time as they were surveyed in 1977 through 1983 (date are from the EPRI Survey). Additions to direct heat uses in 1979 through 1981 are in Exhibit 7. A Table (not numbered) at the back of the report "Historical Development of Geothermal Power ..." shows world installed geothermal capacity by nation at decadal intervals from 1950 to 1980, and the first year of power production for each country. (DJE 2005)

  8. Geothermal training in Iceland 1979-1996

    SciTech Connect

    Fridleifsson, I.B.

    1996-11-01

    The Geothermal Training Programme of the United Nations University (UNU) was established in Iceland in 1979. Since then, a group of scientists and engineers from energy agencies and research organizations, and in a few instances, universities in the developing countries, have come to Iceland every spring to spend six months in high-specialized studies and on-the-job training in geothermal science and engineering. All of them are university graduates with practical experience in geothermal work in their home countries. The training is tailor-made to the individual and the needs of his institution/country. In all, 181 participants from 33 countries completed the six-month course during 1979-1996.

  9. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  10. Geothermal irrigation pump

    SciTech Connect

    Matthews, H.B.

    1982-04-20

    A deep well pumping apparatus utilizing a geothermal source of energy is disposed within or above a stratum having a cool irrigating fluid, and an associated heat exchange unit is disposed within a stratum having the geothermal source. An organic working fluid is conveyed under pressure through the heat exchange unit and applied as a gas to a turbine assembly operatively coupled to the pump. The spent working fluid and cool irrigation fluid are then conveyed to the surface.

  11. Geothermal Energy Retrofit

    SciTech Connect

    Bachman, Gary

    2015-07-28

    The Cleary University Geothermal Energy Retrofit project involved: 1. A thermal conductivity test; 2. Assessment of alternative horizontal and vertical ground heat exchanger options; 3. System design; 4. Asphalt was stripped from adjacent parking areas and a vertical geothermal ground heat exchanger system installed; 5. the ground heat exchanger was connected to building; 6. a system including 18 heat pumps, control systems, a manifold and pumps, piping for fluid transfer and ductwork for conditioned air were installed throughout the building.

  12. Geothermal Frontier: Penetrate a boundary between hydrothermal convection and heat conduction zones to create 'Beyond Brittle Geothermal Reservoir'

    NASA Astrophysics Data System (ADS)

    Tsuchiya, N.; Asanuma, H.; Sakaguchi, K.; Okamoto, A.; Hirano, N.; Watanabe, N.; Kizaki, A.

    2013-12-01

    EGS has been highlightened as a most promising method of geothermal development recently because of applicability to sites which have been considered to be unsuitable for geothermal development. Meanwhile, some critical problems have been experimentally identified, such as low recovery of injected water, difficulties to establish universal design/development methodology, and occurrence of large induced seismicity. Future geothermal target is supercritical and superheated geothermal fluids in and around ductile rock bodies under high temperatures. Ductile regime which is estimated beyond brittle zone is target region for future geothermal development due to high enthalpy fluids and relatively weak water-rock interaction. It is very difficult to determine exact depth of Brittle-Ductile boundary due to strong dependence of temperature (geotherm) and strain rate, however, ductile zone is considered to be developed above 400C and below 3 km in geothermal fields in Tohoku District. Hydrothermal experiments associated with additional advanced technology will be conducting to understand ';Beyond brittle World' and to develop deeper and hotter geothermal reservoir. We propose a new concept of the engineered geothermal development where reservoirs are created in ductile basement, expecting the following advantages: (a)simpler design and control the reservoir, (b)nearly full recovery of injected water, (c)sustainable production, (d)cost reduction by development of relatively shallower ductile zone in compression tectonic zones, (e)large quantity of energy extraction from widely distributed ductile zones, (f)establishment of universal and conceptual design/development methodology, and (g) suppression of felt earthquakes from/around the reservoirs. In ductile regime, Mesh-like fracture cloud has great potential for heat extraction between injection and production wells in spite of single and simple mega-fracture. Based on field observation and high performance hydrothermal

  13. Validity and Reliability of a New Measure of Nursing Experience With Unintended Consequences of Electronic Health Records.

    PubMed

    Gephart, Sheila M; Bristol, Alycia A; Dye, Judy L; Finley, Brooke A; Carrington, Jane M

    2016-10-01

    Unintended consequences of electronic health records represent undesired effects on individuals or systems, which may contradict initial goals and impact patient care. The purpose of this study was to determine the extent to which a new quantitative measure called the Carrington-Gephart Unintended Consequences of Electronic Health Record Questionnaire (CG-UCE-Q) was valid and reliable. Then, it was used to describe acute care nurses' experience with unintended consequences of electronic health records and relate them to the professional practice environment. Acceptable content validity was achieved for two rounds of surveys with nursing informatics experts (n = 5). Then, acute care nurses (n = 144) were recruited locally and nationally to complete the survey and describe the frequency with which they encounter unintended consequences in daily work. Principal component analysis with oblique rotation was applied to evaluate construct validity. Correlational analysis with measures of the professional practice environment and workarounds was used to evaluate convergent validity. Test-retest reliability was measured in the local sample (N = 68). Explanation for 63% of the variance across six subscales (patient safety, system design, workload issues, workarounds, technology barriers, and sociotechnical impact) supported construct validity. Relationships were significant between subscales for electronic health record-related threats to patient safety and low autonomy/leadership (P < .01), poor communication about patients (P < .01), and low control over practice (P < .01). The most frequent sources of unintended consequences were increased workload, interruptions that shifted tasks from the computer, altered workflow, and the need to duplicate data entry. Convergent validity of the CG-UCE-Q was moderately supported with both the context and processes of workarounds with strong relationships identified for when nurses perceived a block and altered process to work around it

  14. The National Geothermal Collaborative, EERE-Geothermal Program, Final Report

    SciTech Connect

    Jody Erikson

    2006-05-26

    Summary of the work conducted by the National Geothermal Collaborative (a consensus organization) to identify impediments to geothermal development and catalyze events and dialogues among stakeholders to over those impediments.

  15. Geothermal Program Review X: proceedings. Geothermal Energy and the Utility Market -- the Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market

    SciTech Connect

    Not Available

    1992-01-01

    Each year the Geothermal Division of the US Department of Energy conducts an in-depth review of its entire geothermal R&D program. The conference serves several purposes: a status report on current R&D activities, an assessment of progress and problems, a review of management issues, and a technology transfer opportunity between DOE and the US geothermal city. This year`s conference, Program Review X, was held in San Francisco on March 24--26, 1992. The theme of the review, ``Geothermal Energy and the Utility Market -- The Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market,`` focused on the needs of the electric utility sector. Geothermal energy, with its power capacity potential of 10 GWe by the year 2010, can provide reliable, enviromentally clean electricity which can help offset the projected increase in demand. Program Review X consisted of seven sessions including an opening session with presentations by Mr. Vikram Budhraja, Vice President of System Planning and Operations, Southern California Edison Company, and Mr. Richard Jaros, President and Chief Operating Officer, California Energy Company. The six technical sessions included presentations by the relevant field researchers covering DOE-sponsored R&D in hydrothermal, hot dry rock, and geopressured energy. Individual projects are processed separately for the data bases.

  16. Geothermal energy: 1992 program overview

    SciTech Connect

    Not Available

    1993-04-01

    Geothermal energy is described in general terms with drawings illustrating the technology. A map of known and potential geothermal resources in the US is included. The 1992 program activities are described briefly. (MHR)

  17. Geothermal resources of Utah, 1980

    SciTech Connect

    Not Available

    1980-01-01

    This map shows heat flow, Known Geothermal Resources Areas, thermal springs and wells, and areas of low-temperature geothermal waters. Also shown are Indian reservations, military reservation, national or state forests, and parks, wildlife refuges, wilderness areas, etc. (MHR)

  18. South Dakota Geothermal Energy Handbook

    SciTech Connect

    Not Available

    1980-06-01

    The sources of geothermal fluids in South Dakota are described and some of the problems that exist in utilization and materials selection are detailed. Methods of heat extraction and the environmental concerns that accompany geothermal fluid development are briefly described. Governmental rules, regulations and legislation are explained. The time and steps necessary to bring about the development of the geothermal resources are explained in detail. Some of the federal incentives that encourage the use of geothermal energy are summarized.

  19. Accelerating Geothermal Research (Fact Sheet)

    SciTech Connect

    Not Available

    2014-05-01

    Geothermal research at the National Renewable Energy Laboratory (NREL) is advancing geothermal technologies to increase renewable power production. Continuous and not dependent on weather, the geothermal resource has the potential to jump to more than 500 gigawatts in electricity production, which is equivalent to roughly half of the current U.S. capacity. Enhanced geothermal systems have a broad regional distribution in the United States, allowing the potential for development in many locations across the country.

  20. Effects of irrigation on crops and soils with Raft River geothermal water

    SciTech Connect

    Stanley, N.E.; Schmitt, R.C.

    1980-01-01

    The Raft River Irrigation Experiment investigated the suitability of using energy-expended geothermal water for irrigation of selected field-grown crops. Crop and soil behavior on plots sprinkled or surface irrigated with geothermal water was compared to crop and soil behavior on plots receiving water from shallow irrigation wells and the Raft River. In addition, selected crops were produced, using both geothermal irrigation water and special management techniques. Crops irrigated with geothermal water exhibited growth rates, yields, and nutritional values similar to comparison crops. Cereal grains and surface-irrigated forage crops did not exhibit elevated fluoride levels or accumulations of heavy metals. However, forage crops sprinkled with geothermal water did accumulate fluorides, and leaching experiments indicate that new soils receiving geothermal water may experience increased salinity, exchangeable sodium, and decreased permeability. Soil productivity may be maintained by leaching irrigations.

  1. Evaluation of Geothermal Heat Pump Systems under Various Conditions

    NASA Astrophysics Data System (ADS)

    Lee, S.; Bae, G.; Lee, K.

    2006-12-01

    Experimental and numerical test were accomplished to evaluate the relations between the geothermal system and the hydrogeological condition. Sand tank experiment was designed. Combinations of different gradients and temperature gradients were applied for testing the real-time monitoring performance. Numerical modeling results were compared with the experimental data. Water injection-system imitating open- and closed-loop geothermal heat pumps were applied to estimate the change of the distribution of ambient groundwater temperature. The experimental results of different settings were used to estimate the effects of shallow depth geothermal energy utilization on the groundwater system.

  2. Geothermal Energy - An Emerging Resource

    SciTech Connect

    Berg, John R.

    1987-01-20

    Address on the Department of Energy's overall energy policy, the role of alternative energy sources within the policy framework, and expectations for geothermal energy. Commendation of the industry's decision to pursue the longer-term field effort while demand for geothermal energy is low, and thus prepare for a substantial geothermal contribution to the nation's energy security.

  3. Advanced geothermal technologies

    NASA Astrophysics Data System (ADS)

    Whetten, J. T.; Murphy, H. D.; Hanold, R. J.; Myers, C. W.; Dunn, J. C.

    Research and development in advanced technologies for geothermal energy production continue to increase the energy production options for the Nation. The high-risk investment over the past few years by the U.S. Department of Energy in geopressured, hot dry rock, and magma energy resources is producing new means to lower production costs and to take advantage of these resources. The Nation has far larger and more regionally extensive geothermal resources than heretofore realized. At the end of a short 30-day closed-loop flow test, the manmade hot dry rock reservoir at Fenton Hill, New Mexico was producing 10 MW thermal, and still climbing, proving the technical feasibility of this new technology. The scientific feasibility of magma energy extraction was demonstrated, and new field tests to evaluate this technology are planned. Analysis and field tests confirm the viability of geopressured-geothermal energy and the prospect that many dry-hole or depleted petroleum wells can be turned into producing geopressured-geothermal wells. Technological advances achieved through hot dry rock, magma, geopressured, and other geothermal research are making these resources and conventional hydrothermal resources more competitive.

  4. Enhanced geothermal systems

    SciTech Connect

    McLarty, L.; Grabowski, P.

    1998-07-01

    A vast amount of geothermal energy is stored in the upper portion of the earth's crust; this energy is accessible with current drilling technology. The US Geological Survey has estimated that in the US, the heat energy stored in the upper 10 kilometers of the earth's crust is over 33 {times} 10{sup 24} Joules. Only a small fraction of this energy could conceivably be extracted. However, just one tenth of one percent of this energy is sufficient to provide the US with all its current level of non-transportation energy needs for over 500 years. Current technology is being used widely to extract geothermal energy in areas where subterranean water contacted hot rock formations, became heated, and was trapped by an impermeable layer in the earth's crust, forming a geothermal hydrothermal reservoir. The water serves as a medium to transport the heat to the surface through a conventional well similar to an oil well. Unfortunately, hydrothermal reservoirs are not widespread and represent only a minuscule portion of the geothermal energy that is accessible with current technology. Scientists and engineers in the US, Europe, Japan, and Australia, are developing systems that extract heat from the earth where there is insufficient permeability or water in the rock formation to transport the heat to the surface. Such systems are referred to as Enhanced Geothermal Systems.

  5. The status and future of geothermal power

    SciTech Connect

    Kutscher, Charles F.

    2000-08-01

    Geothermal electricity production in the United States began in 1960. Today there are over 20 plants in the western United States providing a total of about 2,200 MW of clean and reliable electricity. Currently identified resources could provide over 20,000 MW of power in the U.S., and undiscovered resources might provide 5 times that amount. In the 1990s industry growth slowed due to the loss of market incentives and competition from natural gas. However, increased interest in clean energy sources, ongoing technological improvements, and renewed opportunities abroad hold promise for a resurgence in the industry. This review paper covers the status of the technology, the issues faced, and the latest research. While the focus is on geothermal in the U.S., a brief description of the large international market is included.

  6. The influence of resistance training experience on the between-day reliability of commonly used strength measures in male youth athletes.

    PubMed

    Weakley, Jonathon; Till, Kevin; Darrall-Jones, Joshua; Roe, Gregory; Phibbs, Padraic; Read, Dale; Jones, Ben

    2017-03-08

    The purpose of this study was to determine the between-day reliability of commonly used strength measures in male youth athletes, while considering resistance training experience. Data were collected on 25 male athletes over two testing sessions, with 72 hours rest between, for the 3RM front squat, chin up and bench press. Subjects were initially categorized by resistance training experience (inexperienced; 6-12 months, experienced; >2 years). The assessment of the between-day reliability (coefficient of variation [CV%]) showed the front squat (experienced: 2.90%; inexperienced: 1.90%), chin up (experienced: 1.70%; inexperienced: 1.90%), and bench press (experienced: 4.50%; inexperienced: 2.40%) were all reliable measures of strength in both groups. Comparison between groups for the error of measurement for each exercise showed trivial differences. When both groups were combined, the CV% for the front squat, bench press, and chin up were 2.50%, 1.80%, and 3.70%, respectively. This study provides scientists and practitioners with the between-day reliability reference data to determine real and practical changes for strength in male youth athletes with different resistance training experience. Furthermore, this study demonstrates that 3RM front squat, chin up and bench press are reliable exercises to quantify strength in male youth athletes.

  7. Geothermal steam condensate reinjection

    NASA Technical Reports Server (NTRS)

    Chasteen, A. J.

    1974-01-01

    Geothermal electric generating plants which use condensing turbines and generate and excess of condensed steam which must be disposed of are discussed. At the Geysers, California, the largest geothermal development in the world, this steam condensate has been reinjected into the steam reservoir since 1968. A total of 3,150,000,000 gallons of steam condensate has been reinjected since that time with no noticeable effect on the adjacent producing wells. Currently, 3,700,000 gallons/day from 412 MW of installed capacity are being injected into 5 wells. Reinjection has also proven to be a satisfactory method of disposing of geothermal condensate a Imperial Valley, California, and at the Valles Caldera, New Mexico.

  8. Geothermal reservoir engineering research

    NASA Technical Reports Server (NTRS)

    Ramey, H. J., Jr.; Kruger, P.; Brigham, W. E.; London, A. L.

    1974-01-01

    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs.

  9. Geothermal hydrogen sulfide removal

    SciTech Connect

    Urban, P.

    1981-04-01

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  10. Geothermal Plant Capacity Factors

    SciTech Connect

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  11. Geothermal energy program summary

    SciTech Connect

    Not Available

    1990-01-01

    The Geothermal Technology Division (GTD) of the US Department of Energy (DOE) is charged with the lead federal role in the research and development (R D) of technologies that will assist industry in economically exploiting the nation's vast geothermal resources. The GTD R D Program represents a comprehensive, balanced approach to establishing all forms of geothermal energy as significant contributors to the nation's energy supply. It is structured both to maintain momentum in the growth of the existing hydrothermal industry and to develop long-term options offering the greatest promise for practical applications. This volume, Volume 2, contains a detailed compilation of each GTD-funded R D activity performed by national laboratories or under contract to industrial, academic, and nonprofit research institutions.

  12. Honey Lake hybrid geothermal wood residue power project

    SciTech Connect

    Toland, J.

    1981-05-01

    The Honey Lake Hybrid Geothermal Wood Residue Power Project with a planned output of 50 MW is undergoing feasibility studies funded by GeoProducts Corporation, Department of Water Resources, State of California, US Department of Energy and the Forest Service, USDA. The outlook is optimistic. It is reliably estimated that the required volume of woody biomass can be made available without environmental degradation.

  13. Advanced geothermal technologies

    SciTech Connect

    Whetten, J.T.; Murphy, H.D.; Hanold, R.J.; Myers, C.W.; Dunn, J.C.

    1988-01-01

    Research and development in advanced technologies for geothermal energy production continue to increase the energy production options for the Nation. The high-risk investment over the past few years by the US Department of Energy in geopressured, hot dry rock, and magma energy resources is producing new means to lower production costs and to take advantage of these resources. The Nation has far larger and more regionally extensive geothermal resources than heretofore realized. At the end of a short 30-day closed-loop flow test, the manmade hot dry rock reservoir at Fenton Hill, New Mexico, was producing 10 MW thermal - and still climbing - proving the technical feasibility of this new technology. The scientific feasibility of magma energy extraction has been demonstrated, and new field tests to evaluate this technology are planned. Analysis and field tests confirm the viability of geopressured-geothermal energy and the prospect that many dry-hole or depleted petroleum wells can be turned into producing geopressured-geothermal wells. Technological advances achieved through hot dry rock, magma, geopressured, and other geothermal research are making these resources and conventional hydrothermal resources more competitive. Noteworthy among these technological advances are techniques in computer simulation of geothermal reservoirs, new means for well stimulation, new high-temperature logging tools and packers, new hard-rock penetration techniques, and new methods for mapping fracture flow paths across large underground areas in reservoirs. In addition, many of these same technological advances can be applied by the petroleum industry to help lower production costs in domestic oil and gas fields. 5 refs., 4 figs.

  14. Overview of Geopressured-Geothermal

    SciTech Connect

    Jelacic, Allan

    1992-03-24

    Company, concentrated on the operating history of Gladys McCall and Pleasant Bayou Wells. Ben Eaton noted that early problems with scaling and acidification required frequent shutdown--driving costs up. He stated that once these problems found solutions and proper injection techniques were adopted, the wells demonstrated reliable, long-term flow. Michael Shook of INEL spoke next about the numerical modeling of the Pleasant Bayou well. The object of this INEL research was to check the accuracy of a currently used model for geopressured reservoirs referred to as ''the leaky fault model''. Data from transient pressure tests covering ten years of production from the Pleasant Bayou well should provide the corroboration. Mr. Shook noted that preliminary analysis strongly suggests the model to be accurate. Michael Kramer of the California Energy Commission then analyzed the Geopressured resource in the State of California and pointed out a number of suspected geopressured basins throughout the State. Mr. Kramer noted that the Commission was proposing that GeothermEx identify the geopressured basins through an explicit exploration program with the goal of possible economic development of the resource. Jane Negusde Wys closed the session with a review of the organizations and mechanisms available for technology transfer--organizations such as the American Association of Petroleum Geologists, the Industrial Consortium for the Utilization of the Geopressured Geothermal Resource, and the GRC, and mechanisms such as CRADAs and research consortia. Jane Negusde Wys exhorted the attendees to give serious thought to ''the best way to reach the market''. She closed by acknowledging her debt to the leadership of Dr. Myron Dorfman.

  15. Geothermal Energy; (USA)

    SciTech Connect

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

    1991-01-01

    Geothermal Energy (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. This publication contains the abstracts of DOE reports, journal article, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past two months. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements.

  16. California's geothermal resource potential

    NASA Technical Reports Server (NTRS)

    Leibowitz, L. P.

    1978-01-01

    According to a U.S. Geological Survey estimate, recoverable hydrothermal energy in California may amount to 19,000 MW of electric power for a 30-year period. At present, a geothermal installation in the Geysers region of the state provides 502 MWe of capacity; an additional 1500 MWe of electric generating capacity is scheduled to be in operation in geothermal fields by 1985. In addition to hydrothermal energy sources, hot-igneous and conduction-dominated resources are under investigation for possible development. Land-use conflicts, environmental concerns and lack of risk capital may limit this development.

  17. Geothermal hazards - Mercury emission

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Siegel, B. Z.

    1975-01-01

    Enthusiasm for intensified geothermal exploration may induce many participants to overlook a long-term potential toxicity hazard possibly associated with the tapping of magmatic steam. The association of high atmospheric Hg levels with geothermal activity has been established both in Hawaii and Iceland, and it has been shown that mercury can be introduced into the atmosphere from fumaroles, hot springs, and magmatic sources. These arguments, extended to thallium, selenium, and other hazardous elements, underscore the need for environmental monitoring in conjunction with the delivery of magmatic steam to the surface.

  18. Geothermal energy program summary: Volume 1: Overview Fiscal Year 1988

    NASA Astrophysics Data System (ADS)

    1989-02-01

    Geothermal energy is a here-and-now technology for use with dry steam resources and high-quality hydrothermal liquids. These resources are supplying about 6 percent of all electricity used in California. However, the competitiveness of power generation using lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma still depends on the technology improvements sought by the DOE Geothermal Energy R and D Program. The successful outcome of the R and D initiatives will serve to benefit the U.S. public in a number of ways. First, if a substantial portion of our geothermal resources can be used economically, they will add a very large source of secure, indigenous energy to the nation's energy supply. In addition, geothermal plants can be brought on line quickly in case of a national energy emergency. Geothermal energy is also a highly reliable resource, with very high plant availability. For example, new dry steam plants at The Geysers are operable over 99 percent of the time, and the small flash plant in Hawaii, only the second in the United States, has an availability factor of 98 percent. Geothermal plants also offer a viable baseload alternative to fossil and nuclear plants -- they are on line 24 hours a day, unaffected by diurnal or seasonal variations. The hydrothermal power plants with modern emission control technology have proved to have minimal environmental impact. The results to date with geopressured and hot dry rock resources suggest that they, too, can be operated so as to reduce environmental effects to well within the limits of acceptability. Preliminary studies on magma are also encouraging. In summary, the character and potential of geothermal energy, together with the accomplishments of DOE's Geothermal R and D Program, ensure that this huge energy resource will play a major role in future U.S. energy markets.

  19. Geothermal energy and the utility market -- the opportunities and challenges for expanding geothermal energy in a competitive supply market: Proceedings

    SciTech Connect

    Not Available

    1992-01-01

    Each year the Geothermal Division of the US Department of Energy conducts an in-depth review of its entire geothermal R D program. The conference serves several purposes: a status report on current R D activities, an assessment of progress and problems, a review of management issues, and a technology transfer opportunity between DOE and the US geothermal city. This year's conference, Program Review X, was held in San Francisco on March 24--26, 1992. The theme of the review, Geothermal Energy and the Utility Market -- The Opportunities and Challenges for Expanding Geothermal Energy in a Competitive Supply Market,'' focused on the needs of the electric utility sector. Geothermal energy, with its power capacity potential of 10 GWe by the year 2010, can provide reliable, enviromentally clean electricity which can help offset the projected increase in demand. Program Review X consisted of seven sessions including an opening session with presentations by Mr. Vikram Budhraja, Vice President of System Planning and Operations, Southern California Edison Company, and Mr. Richard Jaros, President and Chief Operating Officer, California Energy Company. The six technical sessions included presentations by the relevant field researchers covering DOE-sponsored R D in hydrothermal, hot dry rock, and geopressured energy. Individual projects are processed separately for the data bases.

  20. Comparing a FACE experiment with mechanistic ecohydrological modeling: which processes are reliably simulated under elevated CO2?

    NASA Astrophysics Data System (ADS)

    Fatichi, S.; Leuzinger, S.

    2013-12-01

    Scenarios for the future terrestrial carbon and water cycle rely on numerical tools that simulate the dynamics of vegetation from assimilation of carbon through stomata to long-term forest development at the global scale. However, these tools are rarely tested to perform well in conditions different from the historical climate and comparisons are mostly limited to carbon and energy fluxes. A combination of numerical modeling and observations is used here to investigate the capability of a mechanistic approach to simulate the hydrology and the vegetation behavior of a forest exposed to elevated CO2 concentrations. Specifically, we thoroughly compare data from a free air CO2 enrichment (FACE) experiment in a mature deciduous forest in Switzerland with realizations from a state-of-the-art ecohydrological model (Tethys-Chloris). Model realizations compare favorably with field observations of photosynthesis, stomatal conductance, sap flow, leaf and fruit litter, as well as qualitative changes in soil moisture. The simulated differences between CO2 scenarios for both the carbon and water balance are generally very small (less than 10%) and fall within the uncertainty of experimental observations. More problematic is the simulation of stem growth which is significantly higher in the modeled scenario with elevated CO2 but not in the observations even though current accuracy of field measurements precludes robust conclusions. These results demonstrate that while ecohydrological models can be used to reliably simulate multi-year energy, water, and carbon fluxes, evaluating the modeled carbon allocation remains critical. However, experimental evidence suggests that the structure of current vegetation models which use the photosynthesized carbon to directly drive plant growth should be revised because plant tissue growth is very sensitive to direct controls of environmental variables, independently of the amount of assimilated carbon.

  1. Multidisciplinary research of geothermal modeling

    NASA Astrophysics Data System (ADS)

    -Ing. Ulvi Arslan, Univ., ., Dr. _., Prof.; Heiko Huber, Dipl.-Ing.

    2010-05-01

    KEYWORDS Geothermal sciences, geothermics, research, theory and application, numerical calculation, geothermal modeling, Technical University Darmstadt, Ministry of Economics and Technology (BMWi) INTRODUCTION In times of global warming renewable, green energies are getting more and more important. The development of application of geothermal energy as a part of renewable energies in Germany is a multidisciplinary process of fast growing research and improvements. Geothermal energy is the energy, which is stored below earth's surface. The word geothermal derives from the Greek words geo (earth) and thermos (heat), so geothermal is a synonym to earth heat. Geothermal energy is one of the auspicious renewable energies. In average the temperature increases 3°C every 100 m of depth, which is termed as geothermal gradient. Therefore 99 percent of our planet is hotter than 1.000°C, while 99 percent of that last percent is even hotter than 100°C. Already in a depth of about 1 kilometer temperatures of 35 - 40°C can be achieved. While other renewable energies arise less or more from the sun, geothermal energy sources its heat from the earth's interior, which is caused mostly by radioactive decay of persistent isotopes. This means a possibility of a base-loadable form of energy supply. Especially efficient is the use of deep geothermal energy of high-enthalpie reservoirs, which means a high energy potential in low depths. In Germany no high-enthalpie reservoirs are given. To use the given low-enthalpie potential and to generate geothermal power efficiently inventions and improvements need to be performed. An important part of geothermal progresses is performed by universities with multidisciplinary research of geothermal modeling. Especially in deep geothermal systems numerical calculations are essential for a correct dimensioning of the geothermal system. Therefore German universities and state aided organizations are developing numerical programs for a detailed use of

  2. Human Resources in Geothermal Development

    SciTech Connect

    Fridleifsson, I.B.

    1995-01-01

    Some 80 countries are potentially interested in geothermal energy development, and about 50 have quantifiable geothermal utilization at present. Electricity is produced from geothermal in 21 countries (total 38 TWh/a) and direct application is recorded in 35 countries (34 TWh/a). Geothermal electricity production is equally common in industrialized and developing countries, but plays a more important role in the developing countries. Apart from China, direct use is mainly in the industrialized countries and Central and East Europe. There is a surplus of trained geothermal manpower in many industrialized countries. Most of the developing countries as well as Central and East Europe countries still lack trained manpower. The Philippines (PNOC) have demonstrated how a nation can build up a strong geothermal workforce in an exemplary way. Data from Iceland shows how the geothermal manpower needs of a country gradually change from the exploration and field development to monitoring and operations.

  3. Geothermal energy survey and technology

    NASA Astrophysics Data System (ADS)

    This is an FY-1990 Annual Report on 'geothermal energy survey and technology' by New Energy and Industrial Technology Development Organization (NEDO). First, concerning geothermal resources exploration project in which surveys have been executed throughout Japan since 1980, outlines of surveys in 1990 and objectives for FY-1992 are summarized. As for surveys for promoting development of geothermal energy, surveys in 8 areas conducted for three years from 1988 to 1990 as well as future plans are also described. Then, the verification investigation for geothermal survey technologies, which has been executed since 1980 for the purpose of establishing geothermal survey technologies to promote the development of geothermal resources in Japan, is introduced with outlines of surveys in 1990 and objectives for FY-1992. Furthermore, development conditions of power generation technologies utilizing geothermal energy such as binary-cycle power generation and hot dry rock power generation are described.

  4. 2008 Geothermal Technologies Market Report

    SciTech Connect

    Cross, J.; Freeman, J.

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the U.S. DOE's Geothermal Technology Program's (GTP's) involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including geothermal heat pumps (GHPs). The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  5. Geothermal materials survey: Baca Geothermal Demonstration Power Plant, Baca, New Mexico

    SciTech Connect

    Ellis, P.F. II

    1980-10-07

    The results of a materials survey for the Baca 50 MW(e) single flash geothermal plant in the Valles Caldera of New Mexico are presented. From the design documents provided, materials proposed for use in contact with the plant atmosphere, the two-phase geofluid, the separated steam, and the recirculating condensate cooling water were assessed for suitability. Special emphasis was given to records of performance of the materials in other geothermal plants. Based upon these considerations of chemical reactivity and plant operating experience, a number of recommendations were made.

  6. National Geothermal Data System: Transforming the Discovery, Access, and Analytics of Data for Geothermal Exploration

    SciTech Connect

    Patten, Kim

    2013-05-01

    Compendium of Papers from the 38th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California February 11-13, 2013 The National Geothermal Data System (NGDS) is a distributed, interoperable network of data collected from state geological surveys across all fifty states and the nation’s leading academic geothermal centers. The system serves as a platform for sharing consistent, reliable, geothermal-relevant technical data with users of all types, while supplying tools relevant for their work. As aggregated data supports new scientific findings, this content-rich linked data ultimately broadens the pool of knowledge available to promote discovery and development of commercial-scale geothermal energy production. Most of the up-front risks associated with geothermal development stem from exploration and characterization of subsurface resources. Wider access to distributed data will, therefore, result in lower costs for geothermal development. NGDS is on track to become fully operational by 2014 and will provide a platform for custom applications for accessing geothermal relevant data in the U.S. and abroad. It is being built on the U.S. Geoscience Information Network (USGIN) data integration framework to promote interoperability across the Earth sciences community. The basic structure of the NGDS employs state-of-the art informatics to advance geothermal knowledge. The following four papers comprising this Open-File Report are a compendium of presentations, from the 38th Annual Workshop on Geothermal Reservoir Engineering, taking place February 11-13, 2013 at Stanford University, Stanford, California. “NGDS Geothermal Data Domain: Assessment of Geothermal Community Data Needs,” outlines the efforts of a set of nationwide data providers to supply data for the NGDS. In particular, data acquisition, delivery, and methodology are discussed. The paper addresses the various types of data and metadata required and why simple links to existing

  7. Geothermal development plan: northern Arizona counties

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1982-08-01

    The Northern Counties Area Development Plan evaluated the regional market potential for utilizing geothermal energy. This study identified five potential geothermal resource areas, four of which have low temperature (<90{sup 0}C, 194{sup 0}F) potential and one possible igneous system. The average population growth rate in the Northern Counties is expected to be five percent per year over the next 40 years, with Mohave and Yavapai Counties growing the fastest. Rapid growth is anticipated in all major employment sectors, including trade, service, manufacturing, mining and utilities. A regional energy use analysis is included, containing information on current energy use patterns for all user classes. Water supplies are expected to be adequate for expected growth generally, though Yavapai and Gila Counties will experience water deficiencies. A preliminary district heating analysis is included for the towns of Alpine and Springerville. Both communities are believed located on geothermal resource sites. The study also contains a section identifying potential geothermal resource users in northern Arizona.

  8. Modern geothermal power: GeoPP with geothermal steam turbines

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  9. Silica recovery and control in Hawaiian geothermal fluids

    SciTech Connect

    Thomas, D.M.

    1992-06-01

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  10. Silica recovery and control in Hawaiian geothermal fluids. Final report

    SciTech Connect

    Thomas, D.M.

    1992-06-01

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  11. Geothermal industry assessment

    SciTech Connect

    Not Available

    1980-07-01

    An assessment of the geothermal industry is presented, focusing on industry structure, corporate activities and strategies, and detailed analysis of the technological, economic, financial, and institutional issues important to government policy formulation. The study is based principally on confidential interviews with executives of 75 companies active in the field. (MHR)

  12. OIT geothermal system improvements

    SciTech Connect

    Lienau, P.J.

    1996-08-01

    Three geothermal wells drilled during the original campus construction vary from 396 m (1,300 ft) to 550 m (1,800 ft). These wells supply all of the heating and part of the cooling needs of the 11-building, 62,200 m{sup 2} (670,000 ft{sup 2}) campus. The combined capacity of the well pumps is 62 L/s(980 gpm) of 89{degrees}C (192{degrees}F) geothermal fluids. Swimming pool and domestic hot water heating impose a small but nearly constant year-round flow requirement. In addition to heating, a portion of the campus is also cooled using the geothermal resource. This is accomplished through the use of an absorption chiller. The chiller, which operates on the same principle as a gas refrigerator, requires a flow of 38 L/s (600 gpm) of geothermal fluid and produces 541 kW (154 tons) of cooling capacity (Rafferty, 1989). The annual operating costs for the system is about $35,000 including maintenance salary, equipment replacement and cost of pumping. This amounts to about $0.05 per square foot per year.

  13. Energy 101: Geothermal Energy

    SciTech Connect

    2014-05-27

    See how we can generate clean, renewable energy from hot water sources deep beneath the Earth's surface. The video highlights the basic principles at work in geothermal energy production, and illustrates three different ways the Earth's heat can be converted into electricity.

  14. Geothermal energy conversion facility

    SciTech Connect

    Kutscher, C.F.

    1997-12-31

    With the termination of favorable electricity generation pricing policies, the geothermal industry is exploring ways to improve the efficiency of existing plants and make them more cost-competitive with natural gas. The Geothermal Energy Conversion Facility (GECF) at NREL will allow researchers to study various means for increasing the thermodynamic efficiency of binary cycle geothermal plants. This work has received considerable support from the US geothermal industry and will be done in collaboration with industry members and utilities. The GECF is being constructed on NREL property at the top of South Table Mountain in Golden, Colorado. As shown in Figure 1, it consists of an electrically heated hot water loop that provides heating to a heater/vaporizer in which the working fluid vaporizes at supercritical or subcritical pressures as high as 700 psia. Both an air-cooled and water-cooled condenser will be available for condensing the working fluid. In order to minimize construction costs, available equipment from the similar INEL Heat Cycle Research Facility is being utilized.

  15. Geothermal Systems for School.

    ERIC Educational Resources Information Center

    Dinse, David H.

    1998-01-01

    Describes an award-winning school heating and cooling system in which two energy-efficient technologies, variable-flow pumping and geothermal heat pumps, were combined. The basic system schematic and annual energy use and cost savings statistics are provided. (GR)

  16. Geothermal Grows Up

    ERIC Educational Resources Information Center

    Johnson, William C.; Kraemer, Steven; Ormond, Paul

    2011-01-01

    Self-declared energy and carbon reduction goals on the part of progressive colleges and universities have driven ground source geothermal space heating and cooling systems into rapid evolution, as part of long-term climate action planning efforts. The period of single-building or single-well solutions is quickly being eclipsed by highly engineered…

  17. Reinjection into geothermal reservoirs

    SciTech Connect

    Bodvarsson, G.S.; Stefansson, V.

    1987-08-01

    Reinjection of geothermal wastewater is practiced as a means of disposal and for reservoir pressure support. Various aspects of reinjection are discussed, both in terms of theoretical studies as well as specific field examples. The discussion focuses on the major effects of reinjection, including pressure maintenance and chemical and thermal effects. (ACR)

  18. Energy 101: Geothermal Energy

    ScienceCinema

    None

    2016-07-12

    See how we can generate clean, renewable energy from hot water sources deep beneath the Earth's surface. The video highlights the basic principles at work in geothermal energy production, and illustrates three different ways the Earth's heat can be converted into electricity.

  19. National Geothermal Data System (NGDS)

    DOE Data Explorer

    The National Geothermal Data System (NGDS) is a DOE-funded distributed network of databases and data sites. Much of the risk of geothermal energy development is associated with exploring for, confirming and characterizing the available geothermal resources. The overriding purpose of the NGDS is to help mitigate this up-front risk by serving as a central gateway for geothermal and relevant related data as well as a link to distributed data sources. Assessing and categorizing the nation's geothermal resources and consolidating all geothermal data through a publicly accessible data system will support research, stimulate public interest, promote market acceptance and investment, and, in turn, the growth of the geothermal industry. Major participants in the NGDS to date include universities, laboratories, the Arizona Geological Survey and Association of American State Geologists (Arizona Geological Survey, lead), the Geothermal Resources Council, and the U.S. Geological Survey. The Geothermal Energy Association is collaborating with the NGDS to insure that it meets the needs of the geothermal industry.

  20. Advanced Electric Submersible Pump Design Tool for Geothermal Applications

    SciTech Connect

    Xuele Qi; Norman Turnquist; Farshad Ghasripoor

    2012-05-31

    Electrical Submersible Pumps (ESPs) present higher efficiency, larger production rate, and can be operated in deeper wells than the other geothermal artificial lifting systems. Enhanced Geothermal Systems (EGS) applications recommend lifting 300 C geothermal water at 80kg/s flow rate in a maximum 10-5/8-inch diameter wellbore to improve the cost-effectiveness. In this paper, an advanced ESP design tool comprising a 1D theoretical model and a 3D CFD analysis has been developed to design ESPs for geothermal applications. Design of Experiments was also performed to optimize the geometry and performance. The designed mixed-flow type centrifugal impeller and diffuser exhibit high efficiency and head rise under simulated EGS conditions. The design tool has been validated by comparing the prediction to experimental data of an existing ESP product.

  1. Geothermal energy in Nevada: development and utilization

    SciTech Connect

    Not Available

    1982-01-01

    The nature of geothermal resources in Nevada and resource applications are discussed. The social and economic advantages of using geothermal energy are outlined. Federal and state programs established to foster the development of geothermal energy are discussed. (MHR)

  2. Thirteenth workshop on geothermal reservoir engineering: Proceedings

    SciTech Connect

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.; Cook, J.W.

    1988-01-21

    PREFACE The Thirteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 19-21, 1988. Although 1987 continued to be difficult for the domestic geothermal industry, world-wide activities continued to expand. Two invited presentations on mature geothermal systems were a keynote of the meeting. Malcolm Grant presented a detailed review of Wairakei, New Zealand and highlighted plans for new development. G. Neri summarized experience on flow rate decline and well test analysis in Larderello, Italy. Attendance continued to be high with 128 registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, New Zealand, Japan, Mexico and The Philippines. A discussion of future workshops produced a strong recommendation that the Stanford Workshop program continue for the future. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Four technical papers not presented at the Workshop are also published. In addition to these forty five technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was Gustavo Calderon from the Inter-American Development Bank. We thank him for sharing with the Workshop participants a description of the Bank???s operations in Costa Rica developing alternative energy resources, specifically Geothermal, to improve the country???s economic basis. His talk appears as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: J. Combs, G. T. Cole, J. Counsil, A. Drenick, H. Dykstra, K. Goyal, P. Muffler, K. Pruess, and S. K. Sanyal. The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Marilyn King, Pat Oto, Terri Ramey, Bronwyn Jones

  3. Geothermal research and development program of the US Atomic Energy Commission

    NASA Technical Reports Server (NTRS)

    Werner, L. B.

    1974-01-01

    Within the overall federal geothermal program, the Atomic Energy Commission has chosen to concentrate on development of resource utilization and advanced research and technology as the areas most suitable to the expertise of its staff and that of the National Laboratories. The Commission's work in geothermal energy is coordinated with that of other agencies by the National Science Foundation, which has been assigned lead agency by the Office of Management and Budget. The objective of the Commission's program, consistent with the goals of the total federal program is to facilitate, through technological advancement and pilot plant operations, achievement of substantial commercial production of electrical power and utilization of geothermal heat by the year 1985. This will hopefully be accomplished by providing, in conjunction with industry, credible information on the economic operation and technological reliability of geothermal power and use of geothermal heat.

  4. Agriculture, greenhouse, wetland and other beneficial uses of geothermal fluids and heat

    SciTech Connect

    Schmitt, R.C.

    1981-04-05

    The status for related beneficial uses including agriculture, greenhousing, and geothermal wetlands is presented. Data published for the geothermal fluids found in areas of China have been examined and compared with the geothermal fluids used in the agriculture evaluations in the United States. This comparison indicates that the geothermal fluids found in parts of China are similar to those used in the US agriculture experiments. Greenhousing is addressed largely from the standpoint of hardware systems and technology being employed or being proposed in the United States.

  5. Chemical logging of geothermal wells

    DOEpatents

    Allen, Charles A.; McAtee, Richard E.

    1981-01-01

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  6. Chemical logging of geothermal wells

    DOEpatents

    Allen, C.A.; McAtee, R.E.

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  7. Geothermal development plan: Yuma county

    SciTech Connect

    White, D.H.

    1981-01-01

    One hot spring and 33 wells drilled in the county discharge water at temperatures sufficient for direct-use geothermal applications such as process heat and space heating and cooling. Currently, one industry within the county has been identified which may be able to use geothermal energy for its process heat requirements. Also, a computer simulation model was used to predict geothermal energy on line as a function of time under both private and city-owned utility development of the resource.

  8. Temperature distribution in the Cerro Prieto geothermal field

    SciTech Connect

    Castillo B, F.; Bermejo M, F.J.; Domiguez A, B.; Esquer P, C.A.; Navarro O, F.J.

    1981-01-01

    A series of temperature and pressure logs and flow rate measurements was compiled for each of the geothermal wells drilled to different reservoir depths between October 1979 and December 1980. Based on the valuable information obtained, a series of graphs showing the thermal characteristics of the reservoir were prepared. These graphs clearly show the temperature distribution resulting from the movement of fluids from the deep regions toward the higher zones of the reservoir, thus establishing more reliable parameters for locating new wells with better production zones. Updated information based on data from new deep wells drilled in the geothermal field is presented here. This new information does not differ much from earlier estimates and theories. However, the influence of faulting and fracturing on the hydrothermal recharge of the geothermal reservoir is seen more clearly.

  9. Shallow open-loop geothermal systems: simulation of heat transfer in groundwater and experimental tests for improving parameterization

    NASA Astrophysics Data System (ADS)

    Fossoul, F.; Orban, P.; Dassargues, A.; Hydrogeology; Environmental Geology

    2011-12-01

    Innovative and efficient strategies for energy use become a priority, especially in civil engineering. Geothermal open-loop systems (geothermal wells) are not so developed in Belgium contrary to close-loop systems. This is generally due to the lack of relevant dimensioning and impact study that must be foreseen during the planning phases of the building. However, as shallow groundwater is widely available, geothermal wells potential is significant. Using both experimental and numerical tools, our aim is to develop a rigorous methodology to design heating and cooling shallow geothermal wells (pumping/reinjection), with a detailed hydrogeological characterization coupled to feasibility, environmental impact assessment, dimensioning, and system sustainability. Concerning numerical modeling, Groundwater flow and heat transfer is computed using different codes (HydroGeoSphere, MT3DMS and SHEMAT) for a comparative sensitivity analysis on a typical case. Coupling and temperature non linearities of hydro-thermal parameters values are checked accurately. As shown previously, small temperature variations (temperatures ranging from 12 to 25 °C) allow to use conventional solute transport codes for modeling heat transfer in groundwater taking benefits of the similarities between solute transport and heat transfer equations. When numerical codes are used as dimensioning tools for long-term simulations, reliable values for hydro-thermal properties of the aquifer are essential. As very few experimental values are available in the literature, field experiments are needed to determine more accurately the local values in different geological/hydrogeological conditions. Apart from thermal response tests (TRT) usually performed for designing a close-loop system within a borehole considered in static groundwater conditions, there is no standard procedure for geothermal wells systems. In an open-loop system, groundwater movement induced by the pumping is responsible for a major heat

  10. Direct application of geothermal energy

    SciTech Connect

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  11. The Philippines geothermal success story

    NASA Astrophysics Data System (ADS)

    Birsic, R. J.

    1980-09-01

    Geothermal electrical plants currently in operation in the Philippines are presented. Following a brief review of the geographical and energy situation of the nation, attention is given to the first 55,000-kW unit of the Tiwi Geothermal Electric Plant, which commenced operation in January 1979, the portable 3,000-kE Leyte Geothermal Pilot Plant, which commenced operation in July, 1977 as the first geothermal power plant in the country, the Makiling-Banahaw (Mak-Ban) Geothermal Power Plant, the first 55,000-kW unit of which began operation in May, 1979 and the second 55,000-kW unit of the Tiwi plant, which came into service in June, 1979, thus making the Philippines the fourth largest producer of geothermal electricity in the world. Factors favoring the use of geothermal plants in developing nations are pointed out, including low capital costs, no foreign exchange costs for fuel, small units, and little environmental impact, and the start-up of two more plants, the second 55,000-kW unit at Mak-Ban in September 1979 and the third Tiwi unit in January 1980, are noted. It is predicted that in 1981, when the Philippines is expected to become the largest user of geothermal energy from hot-water fields, it will have a total capacity of 552 MW from the Mak-Ban, Tiwi and Leyte sites. Further areas with geothermal potential are also pointed out.

  12. NATIONAL GEOTHERMAL DATA SYSTEM (NGDS) GEOTHERMAL DATA DOMAIN: ASSESSMENT OF GEOTHERMAL COMMUNITY DATA NEEDS

    SciTech Connect

    Anderson, Arlene; Blackwell, David; Chickering, Cathy; Boyd, Toni; Horne, Roland; MacKenzie, Matthew; Moore, Joseph; Nickull, Duane; Richard, Stephen; Shevenell, Lisa A.

    2013-01-01

    To satisfy the critical need for geothermal data to ad- vance geothermal energy as a viable renewable ener- gy contender, the U.S. Department of Energy is in- vesting in the development of the National Geother- mal Data System (NGDS). This paper outlines efforts among geothermal data providers nationwide to sup- ply cutting edge geo-informatics. NGDS geothermal data acquisition, delivery, and methodology are dis- cussed. In particular, this paper addresses the various types of data required to effectively assess geother- mal energy potential and why simple links to existing data are insufficient. To create a platform for ready access by all geothermal stakeholders, the NGDS in- cludes a work plan that addresses data assets and re- sources of interest to users, a survey of data provid- ers, data content models, and how data will be ex- changed and promoted, as well as lessons learned within the geothermal community.

  13. Geothermal Ultrasonic Fracture Imager

    SciTech Connect

    Patterson, Doug; Leggett, Jim

    2013-07-29

    The Geothermal Ultrasonic Fracture Imager project has a goal to develop a wireline ultrasonic imager that is capable of operating in temperatures up to 300°C (572°F) and depths up to 10 km (32,808 ft). This will address one of the critical needs in any EGS development of understanding the hydraulic flow paths in the reservoir. The ultrasonic imaging is well known in the oil and gas industry as one of the best methods for fracture evaluation; providing both high resolution and complete azimuthal coverage of the borehole. This enables fracture detection and characterization, both natural and induced, providing information as to their location, dip direction and dip magnitude. All of these factors are critical to fully understand the fracture system to enable the optimization of the thermal drainage through injectors and producers in a geothermal resource.

  14. Hawaii's geothermal program

    SciTech Connect

    Zorpette, G.

    1992-02-01

    This paper reports that in a forest on the island of Hawaii, legal and regulatory activity has postponed the start-up of a small new power plant and imperilled the design and construction of several facilities like it. The same old story Hardly. The power plants at stake are not nuclear or coal- or even oil-fired, but geothermal, widely considered one of the more environmentally benign ways of generating electricity. In a further twist, the opposition is coming not only from the usual citizens; and environmental groups, but also from worshippers of a native good and, it has been alleged, growers of marijuana, a lucrative local crop. The clash occurs just as geothermal power sources have finally proven commercially viable, experts say, adding that technological advances and industry trends in the United States and elsewhere seem to factor great expansion in its use.

  15. Geothermal materials development

    SciTech Connect

    Kukacka, L.E.

    1991-02-01

    Advances in the development of new materials, the commercial availabilities of which are essential for the attainment of Hydrothermal Category Level 1 and 2 Objectives, continue to be made in the Geothermal Materials Development Project. Many successes have already been accrued and the results transferred to industry. In FY 1990, the R D efforts were focused on reducing well drilling and completion costs and on mitigating corrosion in well casing. Activities on lost circulation control materials, CO{sub 2}- resistant lightweight cements, and thermally conductive corrosion and scale-resistant protective liner systems have reached the final development stages, and cost-shared field tests are planned for the FY 1991--1992 time frame. Technology transfer efforts on high temperature elastomers for use in drilling tools are continuing under Geothermal Drilling Organization (GDO) sponsorship.

  16. Amedee geothermal power plant

    SciTech Connect

    Hodgson, S.F.

    1988-12-01

    In September 1988, the power plant began generating electricity in Northern California, near Honey Lake. The plant generates 2 megawatts, net, of electricity in the winter, and from 20 to 30% less in the summer, depending on the temperature. Geothermal fluids from two wells are used to operate the plant, and surface discharge is used to dispose of the spent fluids. This is possible because the geothermal fluids have a very low salinity and a composition the same as area hot spring waters. The binary power plant has a Standard Offer No. 4 contract for 5 megawatts with pacific Gas and Electric Company. Sometime in the near future, they will expand the project to add another 3 megawatts of electrical generation.

  17. Economic Impacts of Geothermal Development in Malheur County, Oregon.

    SciTech Connect

    Sifford, Alex; Beale, Kasi

    1993-01-01

    This study provides local economic impact estimates for a 100 megawatt (MW) geothermal power project in Oregon. The hypothetical project would be in Malheur County, shown in Figure 1. Bonneville Power Administration commissioned this study to quantify such impacts as part of regional confirmation work recommended by the Northwest Power Planning Council and its advisors. Malheur County was chosen as it has both identified resources and industry interest. Local economic impacts include direct, indirect, and induced changes in the local economy. Direct economic impacts result from the costs of plant development, construction, and operation. Indirect impacts result from household and local government purchases. Induced impacts result from continued responding as goods and services to support the households and local governments are purchased. Employment impacts of geothermal development follow a pattern similar to the economic impacts. Public service impacts include costs such as education, fire protection, roads, waste disposal, and water supply. The project assumption discussion notes experiences at other geothermal areas. The background section compares geothermal with conventional power plants. Power plant fuel distinguishes geothermal from other power sources. Other aspects of development are similar to small scale conventional thermal sources. The process of geothermal development is then explained. Development consists of well drilling, gathering system construction, power plant construction, plant operation and maintenance, and wellfield maintenance.

  18. Colorado Geothermal Commercialization Program

    SciTech Connect

    Healy, F.C.

    1980-04-01

    Chaffee County, located in central Colorado, has immense potential for geothermal development. This report has been prepared to assist residents and developers in and outside the area to develop the hydrothermal resources of the county. Data has been collected and interpreted from numerous sources in order to introduce a general description of the area, estimate energy requirements, describe the resources and postulate a development plan. Electric power generation and direct heat application potential for the region are described.

  19. Federal Interagency Geothermal Activities

    SciTech Connect

    Anderson, Arlene; Prencipe, Loretta; Todaro, Richard M.; Cuyler, David; Eide, Elizabeth

    2011-06-01

    This collaborative document describes the roles and responsibilities of key Federal agencies in the development of geothermal technologies including the U.S. Department of Energy (DOE); the U.S. Department of Agriculture (USDA), including the U.S. Forest Service; the U.S. Department of Interior (DOI), including the United States Geological Survey (USGS) and Bureau of Land Management (BLM); the Environmental Protection Agency (EPA); and the Department of Defense (DOD).

  20. Geothermal resources of Montana

    SciTech Connect

    Metesh, J.

    1994-06-01

    The Montana Bureau of Mines and Geology has updated its inventory of low and moderate temperature resources for the state and has assisted the Oregon Institute of Technology - GeoHeat Center and the University of Utah Research Institute in prioritizing and collocating important geothermal resource areas. The database compiled for this assessment contains information on location, flow, water chemistry, and estimated reservoir temperatures for 267 geothermal well and springs in Montana. For this assessment, the minimum temperature for low-temperature resource is defined as 10{degree} C above the mean annual air temperature at the surface. The maximum temperature for a moderate-temperature resource is defined as greater than 50{degree} C. Approximately 12% of the wells and springs in the database have temperatures above 50{degree} C, 17% are between 30{degree} and 50{degree} C, 29% are between 20{degree} and 30{degree}C, and 42% are between 10{degree} and 20{degree} C. Low and moderate temperature wells and springs can be found in nearly all areas of Montana, but most are in the western third of the state. Information sources for the current database include the MBMG Ground Water Information Center, the USGS statewide database, the USGS GEOTHERM database, and new information collected as part of this program. Five areas of Montana were identified for consideration in future investigations of geothermal development. The areas identified are those near Bozeman, Ennis, Butte, Boulder, and Camas Prairie. These areas were chosen based on the potential of the resource and its proximity to population centers.

  1. Navy Geothermal Plan

    DTIC Science & Technology

    1984-12-01

    the geothermal portion of the R&D program are those that require attention because of operational expansion and mission-related problems such as...RESOURCE/ PROBLEM MAJOR CLAIMA.. ’ ASSESSMENT - ACTIVITY, CONSULTED , I"" C NI E U R&D J EGTORD OA RECOMMENDSI I NNO FURTHER CONSIDERATION zz7 MILITARY...disposal problems and environmental concerns. Resource Confirmation The exploration methods discussed under the sections titled "Preliminary Site Survey

  2. UWC geothermal resource exploration

    SciTech Connect

    1996-04-01

    A program was developed to explore the strength of the geothermal and hot dry rock (HDR) resource at the Montezuma Hot Springs at the United World College (UWC). The purpose of the UWC {number_sign}1 well is to obtain hydrologic, geologic, and temperature information for ongoing geothermal evaluation of the Montezuma Hot Springs area. If sufficient fluids are encountered, the hole will be cased with a 4 1/2 inch production casing and re-permitted as a geothermal low-temperature well. If no fluid is encountered, the well will be abandoned per Oil Conservation Division regulation. The objectives of the exploration are to evaluate the resource potential to provide space heating for the entire campus of the United World College, determine the effect of a well on the Hot Springs outflow, accurately measure the UWC heating loads versus time, evaluate the potential to support local thermal industry development, assess the feasibility of HDR development, and create an educational program from the collection of data derived from the research effort.

  3. Geothermal Power Generation Plant

    SciTech Connect

    Boyd, Tonya

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196°F resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  4. Geotherm: the U.S. geological survey geothermal information system

    USGS Publications Warehouse

    Bliss, J.D.; Rapport, A.

    1983-01-01

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey. Information in the system is available to the public on request. ?? 1983.

  5. Geotherm: the U.S. geological survey geothermal information system

    NASA Astrophysics Data System (ADS)

    Bliss, J. D.; Rapport, A.

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey. Information in the system is available to the public on request.

  6. Numerical and experimental design of coaxial shallow geothermal energy systems

    NASA Astrophysics Data System (ADS)

    Raghavan, Niranjan

    geothermal piping systems. Based on the simulations and experiments, the effect of parameters on the overall operating costs is studied. Finally, with the results obtained, the economics and return on investment behind coaxial geothermal energy systems are discussed. Government policies on renewable energy are explained, highlighting the energy incentives associated with geothermal energy in the United States. The findings of this research provides a platform for further shallow geothermal energy system studies with an immense potential to revolutionize the energy industry in the future.

  7. Deep geothermal processes acting on faults and solid tides in coastal Xinzhou geothermal field, Guangdong, China

    NASA Astrophysics Data System (ADS)

    Lu, Guoping; Wang, Xiao; Li, Fusi; Xu, Fangyiming; Wang, Yanxin; Qi, Shihua; Yuen, David

    2017-03-01

    This paper investigated the deep fault thermal flow processes in the Xinzhou geothermal field in the Yangjiang region of Guangdong Province. Deep faults channel geothermal energy to the shallow ground, which makes it difficult to study due to the hidden nature. We conducted numerical experiments in order to investigate the physical states of the geothermal water inside the fault zone. We view the deep fault as a fast flow path for the thermal water from the deep crust driven up by the buoyancy. Temperature measurements at the springs or wells constrain the upper boundary, and the temperature inferred from the Currie temperature interface bounds the bottom. The deepened boundary allows the thermal reservoir to revolve rather than to be at a fixed temperature. The results detail the concept of a thermal reservoir in terms of its formation and heat distribution. The concept also reconciles the discrepancy in reservoir temperatures predicted from both quartz and Na-K-Mg. The downward displacement of the crust increases the pressure at the deep ground and leads to an elevated temperature and a lighter water density. Ultimately, our results are a first step in implementing numerical studies of deep faults through geothermal water flows; future works need to extend to cases of supercritical states. This approach is applicable to general deep-fault thermal flows and dissipation paths for the seismic energy from the deep crust.

  8. Energy 101: Geothermal Heat Pumps

    ScienceCinema

    None

    2016-07-12

    An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

  9. Geothermal Energy: Prospects and Problems

    ERIC Educational Resources Information Center

    Ritter, William W.

    1973-01-01

    An examination of geothermal energy as a means of increasing the United States power resources with minimal pollution problems. Developed and planned geothermal-electric power installations around the world, capacities, installation dates, etc., are reviewed. Environmental impact, problems, etc. are discussed. (LK)

  10. Energy 101: Geothermal Heat Pumps

    SciTech Connect

    2011-01-01

    An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

  11. The Future of Geothermal Energy

    SciTech Connect

    Kubik, Michelle

    2006-01-01

    A comprehensive assessment of enhanced, or engineered, geothermal systems was carried out by an 18-member panel assembled by the Massachusetts Institute of Technology (MIT) to evaluate the potential of geothermal energy becoming a major energy source for the United States.

  12. Silica extraction from geothermal water

    DOEpatents

    Bourcier, William L; Bruton, Carol J

    2014-09-23

    A method of producing silica from geothermal fluid containing low concentration of the silica of less than 275 ppm includes the steps of treating the geothermal fluid containing the silica by reverse osmosis treatment thereby producing a concentrated fluid containing the silica, seasoning the concentrated fluid thereby producing a slurry having precipitated colloids containing the silica, and separating the silica from the slurry.

  13. Empirical equation estimates geothermal gradients

    SciTech Connect

    Kutasov, I.M. )

    1995-01-02

    An empirical equation can estimate geothermal (natural) temperature profiles in new exploration areas. These gradients are useful for cement slurry and mud design and for improving electrical and temperature log interpretation. Downhole circulating temperature logs and surface outlet temperatures are used for predicting the geothermal gradients.

  14. Geothermal Energy: Tapping the Potential

    ERIC Educational Resources Information Center

    Johnson, Bill

    2008-01-01

    Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…

  15. Middlesex Community College Geothermal Project

    SciTech Connect

    Klein, Jessie; Spaziani, Gina

    2013-03-29

    The purpose of the project was to install a geothermal system in the trustees house on the Bedford campus of Middlesex Community College. In partnership with the environmental science faculty, learning activities for environmental science courses were developed to explain geothermal energy and more specifically the newly installed system to Middlesex students. A real-time monitoring system highlights the energy use and generation.

  16. World Geothermal Congress WGC-2015

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.

    2016-08-01

    This article discusses materials and results of the World Geothermal Congress that was held in Melbourne (Australia) from April 19 to April 25, 2015. Information on the extent and technological features of utilization of geothermal resources for heat supply and power production, as well as in other economic areas, is given. A stable growth in the capacity and number of geothermal power systems that is determined by ecological cleanliness, economic efficiency, and the highest (among renewable energy sources) indicators of installed capacity utilization is shown. It was noted that combined schemes of geothermal power plants (GPPs), such as turbine units of different type (binary units, units with one or two separation pressures, etc.), have become more frequently used to increase the efficiency of utilization of geothermal heat carrier. Actual data determining room heating systems with the total worldwide capacity of nearly 50000 MW thermal (MWt) as the most currently significant segment of consumption of geothermal waters are given. In addition, geothermal resources are also utilized in soil pumps, balneological and sports basins, greenhouse complexes, and other manufactures. It was noted that geological studies were carried out in more than 40 countries, with the development of methods of simulation of tanks for the existing and new geothermal fields. Trends of development and the role of geothermal power engineering in the energy supply of many countries are shown. It was shown that prospects for the development of geothermal power generation are significantly associated with utilization of low-temperature geothermal sources in binary power generating units, as well as with the increase in installed capacity of operating geothermal power plants (GPPs) without drilling additional wells, i.e., by using waste geothermal heat carrier in binary-cycle or combined-cycle power plants. The article provides data on a pilot binary power unit at Pauzhetka GPP and on a

  17. Geothermal resource evaluation of the Yuma area

    SciTech Connect

    Poluianov, E.W.; Mancini, F.P.

    1985-11-29

    This report presents an evaluation of the geothermal potential of the Yuma, Arizona area. A description of the study area and the Salton Trough area is followed by a geothermal analysis of the area, a discussion of the economics of geothermal exploration and exploitation, and recommendations for further testing. It was concluded economic considerations do not favor geothermal development at this time. (ACR)

  18. Geothermal reconnaissance of northeastern Venezuela

    SciTech Connect

    Urbani, F. )

    1989-01-01

    About 60% of Venezuela has been covered by a reconnaissance geothermal survey that includes geologic and water geochemical studies. The information is stored in a computerized data bank that holds data from 361 geothermal localities. The subsurface reservoir temperatures of the geothermal systems have been estimated using chemical geothermometry and mixing models and in many cases conceptual geothermal modes have been postulated. Preliminary assessments of the northeastern Venezuelan geothermal systems indicate that the most promising system is Las Minas near El Pilar in the state of Sucre, with an estimated deep reservoir temperature of 200-220{sup 0}C. Further studies are intended to evaluate its potential for electricity generation. Based on present data, other medium and low temperature systems in Venezuela appear useful for direct applications.

  19. Geopressured geothermal bibliography (Geopressure Thesaurus)

    SciTech Connect

    Hill, T.R.; Sepehrnoori, K.

    1981-08-01

    This thesaurus of terminology associated with the geopressured geothermal energy field has been developed as a part of the Geopressured Geothermal Information System data base. A thesaurus is a compilation of terms displaying synonymous, hierarchical, and other relationships between terms. These terms, which are called descriptors, constitute the special language of the information retrieval system, the system vocabulary. The Thesaurus' role in the Geopressured Geothermal Information System is to provide a controlled vocabulary of sufficient specificity for subject indexing and retrieval of documents in the geopressured geothermal energy field. The thesauri most closely related to the Geopressure Thesaurus in coverage are the DOE Energy Information Data Base Subject Thesaurus and the Geothermal Thesaurus being developed at the Lawrence Berkeley Laboratory (LBL). The Geopressure Thesaurus differs from these thesauri in two respects: (1) specificity of the vocabulary or subject scope and (2) display format.

  20. 2008 Geothermal Technologies Market Report

    SciTech Connect

    Jonathan Cross

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the GTP’s involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including GHPs.† The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  1. Geothermal resource data base: Arizona

    SciTech Connect

    Witcher, J.C.

    1995-09-01

    This report provides a compilation of geothermal well and spring information in Arizona up to 1993. This report and data base are a part of a larger congressionally-funded national effort to encourage and assist geothermal direct-use. In 1991, the US Department of Energy, Geothermal Division (DOE/GD) began a Low-Temperature Geothermal Resources and Technology Transfer Program. Phase 1 of this program includes updating the inventory of wells and springs of ten western states and placing these data into a digital format that is universally accessible to the PC. The Oregon Institute of Technology GeoHeat Center (OIT) administers the program and the University of Utah Earth Sciences and Resources Institute (ESRI) provides technical direction. In recent years, the primary growth in geothermal use in Arizona has occurred in aquaculture. Other uses include minor space heating and supply of warm mineral waters for health spas.

  2. Environmental Assessment Lakeview Geothermal Project

    SciTech Connect

    Treis, Tania

    2012-04-30

    The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

  3. Geothermal Small Business Workbook [Geothermal Outreach and Project Financing

    SciTech Connect

    Elizabeth Battocletti

    2003-05-01

    Small businesses are the cornerstone of the American economy. Over 22 million small businesses account for approximately 99% of employers, employ about half of the private sector workforce, and are responsible for about two-thirds of net new jobs. Many small businesses fared better than the Fortune 500 in 2001. Non-farm proprietors income rose 2.4% in 2001 while corporate profits declined 7.2%. Yet not all is rosy for small businesses, particularly new ones. One-third close within two years of opening. From 1989 to 1992, almost half closed within four years; only 39.5% were still open after six years. Why do some new businesses thrive and some fail? What helps a new business succeed? Industry knowledge, business and financial planning, and good management. Small geothermal businesses are no different. Low- and medium-temperature geothermal resources exist throughout the western United States, the majority not yet tapped. A recent survey of ten western states identified more than 9,000 thermal wells and springs, over 900 low- to moderate-temperature geothermal resource areas, and hundreds of direct-use sites. Many opportunities exist for geothermal entrepreneurs to develop many of these sites into thriving small businesses. The ''Geothermal Small Business Workbook'' (''Workbook'') was written to give geothermal entrepreneurs, small businesses, and developers the tools they need to understand geothermal applications--both direct use and small-scale power generation--and to write a business and financing plan. The Workbook will: Provide background, market, and regulatory data for direct use and small-scale (< 1 megawatt) power generation geothermal projects; Refer you to several sources of useful information including owners of existing geothermal businesses, trade associations, and other organizations; Break down the complicated and sometimes tedious process of writing a business plan into five easy steps; Lead you--the geothermal entrepreneur, small company, or

  4. Rational Hydrogenation for Enhanced Mobility and High Reliability on ZnO-based Thin Film Transistors: From Simulation to Experiment.

    PubMed

    Xu, Lei; Chen, Qian; Liao, Lei; Liu, Xingqiang; Chang, Ting-Chang; Chang, Kuan-Chang; Tsai, Tsung-Ming; Jiang, Changzhong; Wang, Jinlan; Li, Jinchai

    2016-03-02

    Hydrogenation is one of the effective methods for improving the performance of ZnO thin film transistors (TFTs), which originate from the fact that hydrogen (H) acts as a defect passivator and a shallow n-type dopant in ZnO materials. However, passivation accompanied by an excessive H doping of the channel region of a ZnO TFT is undesirable because high carrier density leads to negative threshold voltages. Herein, we report that Mg/H codoping could overcome the trade-off between performance and reliability in the ZnO TFTs. The theoretical calculation suggests that the incorporation of Mg in hydrogenated ZnO decrease the formation energy of interstitial H and increase formation energy of O-vacancy (VO). The experimental results demonstrate that the existence of the diluted Mg in hydrogenated ZnO TFTs could be sufficient to boost up mobility from 10 to 32.2 cm(2)/(V s) at a low carrier density (∼2.0 × 10(18) cm(-3)), which can be attributed to the decreased electron effective mass by surface band bending. The all results verified that the Mg/H codoping can significantly passivate the VO to improve device reliability and enhance mobility. Thus, this finding clearly points the way to realize high-performance metal oxide TFTs for low-cost, large-volume, flexible electronics.

  5. Vertical flow array chips reliably identify cell types from single-cell mRNA sequencing experiments

    PubMed Central

    Shirai, Masataka; Arikawa, Koji; Taniguchi, Kiyomi; Tanabe, Maiko; Sakai, Tomoyuki

    2016-01-01

    Single-cell mRNA sequencing offers an unbiased approach to dissecting cell types as functional units in multicellular tissues. However, highly reliable cell typing based on single-cell gene expression analysis remains challenging because of the lack of methods for efficient sample preparation for high-throughput sequencing and evaluating the statistical reliability of the acquired cell types. Here, we present a highly efficient nucleic reaction chip (a vertical flow array chip (VFAC)) that uses porous materials to reduce measurement noise and improve throughput without a substantial increase in reagent. We also present a probabilistic evaluation method for cell typing depending on the amount of measurement noise. Applying the VFACs to 2580 monocytes provides 1967 single-cell expressions for 47 genes, including low-expression genes such as transcription factors. The statistical method can distinguish two cell types with probabilistic quality values, with the measurement noise level being considered for the first time. This approach enables the identification of various sub-types of cells in tissues and provides a foundation for subsequent analyses. PMID:27876759

  6. Hydraulic Fracture Stimulation and Acid Treatment of Well Baca 20; Geothermal Reservoir Well Stimulation Program

    SciTech Connect

    1983-07-01

    The U.S. Department of Energy-sponsored Geothermal Reservoir Well Stimulation Program was initiated in February 1979 to pursue industry interest in geothermal well stimulation work and to develop technical expertise in areas directly related to geothermal well stimulation activities. This report provides an overview of the two experiments conducted in the high-temperature reservoir in Baca, New Mexico. The report discusses resource and reservoir properties, and provides a description of the stimulation experiment, a description of the treatment evaluation, and a summary of the experiment costs. (DJE-2005)

  7. Mushroom growing project at the Los Humeros, Mexico geothermal field

    SciTech Connect

    Rangel, M.E.R.

    1998-12-01

    There are several projects of direct (non-electrical) use of geothermal energy in Mexico. Personnel of the Comision Federal de Electricidad (CFE) have experience in various of these projects, like drying of timber and fruits, space heating, food processing, etc. Taking this in consideration, CFE built the Los Humeros mushroom plant using for heat source the geothermal steam from Well H-1. The main purpose of the project was to take advantage of residual geothermal energy in a food production operation and to develop the appropriate technology. In 1992, existing installations were renovated, preparing appropriate areas for pasteurization, inoculation and production. The mushroom Pleurotus ostreatus var. florida and columbinus was used. A year later, CFE proposed the construction of improved facilities for growing edible mushrooms. New materials and equipment, as well as different operation conditions, were proposed on the basis of the experience gained in the initial project. The construction and renovation activities were completed in 1994.

  8. Geothermal Heat Pumps are Scoring High Marks

    SciTech Connect

    2000-08-01

    Geothermal Energy Program Office of Geothermal and Wind Technologies Geothermal Heat Pumps are Scoring High Marks Geothermal heat pumps, one of the clean energy technology stars Geothermal heat pumps (GHPs) are one of the most cost-effective heating, cooling, and water heating systems available for both residential and commercial buildings. GHPs extract heat from the ground during the heating season and discharge waste heat to the ground during the cooling season. The U.S. Environmental Protecti

  9. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    SciTech Connect

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  10. Geothermal Direct Heat Applications Program Summary

    SciTech Connect

    1981-09-25

    Because of the undefined risk in the development and use of geothermal energy as a thermal energy source, the Department of Energy Division of Geothermal Energy solicited competitive proposals for field experiments in the direct use of geothermal energy. Twenty-two proposals were selected for cost-shared funding with one additional project co-funded by the State of New Mexico. As expected, the critical parameter was developing a viable resource. So far, of the twenty resources drilled, fourteen have proved to be useful resources. These are: Boise, Idaho; Elko heating Company in Nevada; Pagosa Springs, Colorado; Philip School, Philip, South Dakota; St. Mary's Hospital, Pierre, South Dakota; Utah Roses near Salt Lake City; Utah State Prison, Utah; Warm Springs State Hospital, Montana; T-H-S Hospital, Marlin, Texas; Aquafarms International in the Cochella Valley, California; Klamath County YMCA and Klamath Falls in Oregon; Susanville, California and Monroe, utah. Monroe's 164 F and 600 gpm peak flow was inadequate for the planned project, but is expected to be used in a private development. Three wells encountered a resource insufficient for an economical project. These were Madison County at Rexburg, Idaho; Ore-Ida Foods at Ontario, Oregon and Holly Sugar at Brawley, California. Three projects have yet to confirm their resource. The Navarro College well in Corsicana, Texas is being tested; the Reno, Moana, Nevada well is being drilled and the El Centro, California well is scheduled to be drilled in January 1982. The agribusiness project at Kelly Hot Springs was terminated because a significant archeological find was encountered at the proposed site. The Diamond Ring Ranch in South Dakota, and the additional project, Carrie Tingley Hospital in Truth or Consequences, New Mexico both used existing wells. The projects that encountered viable resources have proceeded to design, construct, and in the most advanced projects, to operate geothermal systems for district

  11. NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.

    SciTech Connect

    BERNDT,M.L.

    2001-03-23

    Non-destructive testing is a key component of optimized plant inspection and maintenance programs. Risk based inspection, condition based maintenance and reliability centered maintenance systems all require detection, location and sizing of defects or flaws by non-destructive methods. Internal damage of geothermal piping by corrosion and erosion-corrosion is an ongoing problem requiring inspection and subsequent maintenance decisions to ensure safe and reliable performance. Conventional manual ultrasonic testing to determine remaining wall thickness has major limitations, particularly when damage is of a random and localized nature. Therefore, it is necessary to explore alternative non-destructive methods that offer potential benefits in terms of accurate quantification of size, shape and location of damage, probability of detection, ability to use on-line over long ranges, and economics. A review of non-destructive methods and their applicability to geothermal piping was performed. Based on this, ongoing research will concentrate on long range guided wave and dynamic methods.

  12. Geothermal development plan: Yuma County

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1982-08-01

    The Yuma County Area Development Plan evaluated the county-wide market potential for utilizing geothermal energy. The study identified four potential geothermal resource areas with temperatures less than 90/sup 0/C (194/sup 0/F), and in addition, two areas are inferred to contain geothermal resources with intermediate (90/sup 0/C to 150/sup 0/C, 194/sup 0/F to 300/sup 0/F) temperature potential. The resource areas are isolated, although one resource area is located near Yuma, Arizona. One resource site is inferred to contain a hot dry rock resource. Anticipated population growth in the county is expected to be 2 percent per year over the next 40 years. The primary employment sector is agriculture, though some light industry is located in the county. Water supplies are found to be adequate to support future growth without advese affect on agriculture. Six firms were found in Yuma County which may be able to utilize geothermal energy for process heat needs. In addition, several agricultural processors were found, concentrated in citrus processing and livestock raising. Geothermal energy utilization projections suggest that by the year 2000, geothermal energy may economically provide the energy equivalent of 53,000 barrels of oil per year to the industrial sector if developed privately. Geothermal utilization projections increase to 132,000 barrels of oil per year by 2000 if a municipal utility developed the resource.

  13. Geothermal heating for Caliente, Nevada

    SciTech Connect

    Wallis, F.; Schaper, J.

    1981-02-01

    Utilization of geothermal resources in the town of Caliente, Nevada (population 600) has been the objective of two grants. The first grant was awarded to Ferg Wallis, part-owner and operator of the Agua Caliente Trailer Park, to assess the potential of hot geothermal water for heating the 53 trailers in his park. The results from test wells indicate sustainable temperatures of 140/sup 0/ to 160/sup 0/F. Three wells were drilled to supply all 53 trailers with domestic hot water heating, 11 trailers with space heating and hot water for the laundry from the geothermal resource. System payback in terms of energy cost-savings is estimated at less than two years. The second grant was awarded to Grover C. Dils Medical Center in Caliente to drill a geothermal well and pipe the hot water through a heat exchanger to preheat air for space heating. This geothermal preheater served to convert the existing forced air electric furnace to a booster system. It is estimated that the hospital will save an average of $5300 in electric bills per year, at the current rate of $.0275/KWH. This represents a payback of approximately two years. Subsequent studies on the geothermal resource base in Caliente and on the economics of district heating indicate that geothermal may represent the most effective supply of energy for Caliente. Two of these studies are included as appendices.

  14. Geothermal development plan: Pima County

    NASA Astrophysics Data System (ADS)

    White, D. H.; Goldstone, L. A.

    1982-08-01

    The Pima County Area Development evaluated the county-wide market potential for utilizing geothermal energy. Four potential geothermal resource areas with temperatures less than 1000 C (2120 F) were identified. In addition, one area is identified as having a temperature of 1470 F (2970 F). Geothermal resources are found to occur in Tecson where average population growth rates of two to three percent per year are expected over the next 40 years. Rapid growth in the manufacturing sector and the existence of major copper mines provide opportunities for the direct utilization of geothermal energy. However, available water supplies are identified as a major constraing to projected growth. A regional energy analysis, future predictions for energy consumption, and energy prices are given. Potential geothermal users in Pima County are identified and projections of maximum economic geothermal utilization are given. One hundred fifteen firms in 32 industrial classes have some potential for geothermal use are identified. In addition, 26 agribusiness firms were found in the county.

  15. Tracing Geothermal Fluids

    SciTech Connect

    Michael C. Adams; Greg Nash

    2004-03-01

    Geothermal water must be injected back into the reservoir after it has been used for power production. Injection is critical in maximizing the power production and lifetime of the reservoir. To use injectate effectively the direction and velocity of the injected water must be known or inferred. This information can be obtained by using chemical tracers to track the subsurface flow paths of the injected fluid. Tracers are chemical compounds that are added to the water as it is injected back into the reservoir. The hot production water is monitored for the presence of this tracer using the most sensitive analytic methods that are economically feasible. The amount and concentration pattern of the tracer revealed by this monitoring can be used to evaluate how effective the injection strategy is. However, the tracers must have properties that suite the environment that they will be used in. This requires careful consideration and testing of the tracer properties. In previous and parallel investigations we have developed tracers that are suitable from tracing liquid water. In this investigation, we developed tracers that can be used for steam and mixed water/steam environments. This work will improve the efficiency of injection management in geothermal fields, lowering the cost of energy production and increasing the power output of these systems.

  16. What is an Enhanced Geothermal System (EGS)? Fact Sheet

    SciTech Connect

    U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy

    2012-09-14

    This Geothermal Technologies Office fact sheet explains how engineered geothermal reservoirs called Enhanced Geothermal Systems are used to produce energy from geothermal resources that are otherwise not economical due to a lack of fluid and/or permeability.

  17. NREL Geothermal Policymakers' Guidebooks Web site (Fact Sheet)

    SciTech Connect

    Not Available

    2010-10-01

    This document highlights the NREL Geothermal Policymakers' Guidebooks Web site, including the five steps to effective geothermal policy development for geothermal electricity generation and geothermal heating and cooling technologies.

  18. Geothermal development plan: northern Arizona

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1981-01-01

    Much of the northern counties (Apache, Coconino, Gila, Mohave, Navajo and Yavapai) is located in the Colorado Plateau province, a region of low geothermal potential. Two areas that do show some potential are the Flagstaff - San Francisco Peaks area and the Springerville area. Flagstaff is rapidly becoming the manufacturing center of Arizona and will have many opportunities to use geothermal energy to satisfy part of its increasing need for energy. Using a computer simulation model, projections of geothermal energy on line as a function of time are made for both private and city-owned utility development of a resource.

  19. Direct utilization of geothermal energy for Pagosa Springs, Colorado. Final report, June 1979-June 1984

    SciTech Connect

    Goering, S.W.; Garing, K.L.; Coury, G.

    1984-08-01

    The Pagosa Springs Geothermal District Heating System was conceptualized, designed, and constructed between 1979 to 1984 under the US Department of Energy Program Opportunity Notice (PON) program to demonstrate the feasibility for utilizing moderate temperature geothermal resources for direct-use applications. The Pagosa Springs system successfully provides space heating to public buildings, school facilities, residences, and commercial establishments at costs significantly lower than costs of available conventional fuels. The Pagosa Springs project encompassed a full range of technical, institutional, and economic activities. Geothermal reservoir evaluations and testing were performed, and two productive approx.140/sup 0/F geothermal supply wells were successfully drilled and completed. Transmission and distribution system design, construction, startup, and operation were achieved with minimum difficulty. The geothermal system operation during the first two heating seasons has been fully reliable and well respected in the community. The project has proven that low to moderate-temperature waters can effectively meet required heating loads, even for harsh winter-mountain environments. The principal difficulty encountered has been institutional in nature and centers on the obtaining of the geothermal production well permits and the adjudicated water rights necessary to supply the geothermal hot water fluids for the full operating life of the system. 28 figs., 15 tabs.

  20. Geothermal Energy Production With Innovative Methods Of Geothermal Heat Recovery

    SciTech Connect

    Swenson, Allen; Darlow, Rick; Sanchez, Angel; Pierce, Michael; Sellers, Blake

    2014-12-19

    The ThermalDrive™ Power System (“TDPS”) offers one of the most exciting technological advances in the geothermal power generation industry in the last 30 years. Using innovations in subsurface heat recovery methods, revolutionary advances in downhole pumping technology and a distributed approach to surface power production, GeoTek Energy, LLC’s TDPS offers an opportunity to change the geothermal power industry dynamics.

  1. The minimum information required for a glycomics experiment (MIRAGE) project: sample preparation guidelines for reliable reporting of glycomics datasets.

    PubMed

    Struwe, Weston B; Agravat, Sanjay; Aoki-Kinoshita, Kiyoko F; Campbell, Matthew P; Costello, Catherine E; Dell, Anne; Ten Feizi; Haslam, Stuart M; Karlsson, Niclas G; Khoo, Kay-Hooi; Kolarich, Daniel; Liu, Yan; McBride, Ryan; Novotny, Milos V; Packer, Nicolle H; Paulson, James C; Rapp, Erdmann; Ranzinger, Rene; Rudd, Pauline M; Smith, David F; Tiemeyer, Michael; Wells, Lance; York, William S; Zaia, Joseph; Kettner, Carsten

    2016-09-01

    The minimum information required for a glycomics experiment (MIRAGE) project was established in 2011 to provide guidelines to aid in data reporting from all types of experiments in glycomics research including mass spectrometry (MS), liquid chromatography, glycan arrays, data handling and sample preparation. MIRAGE is a concerted effort of the wider glycomics community that considers the adaptation of reporting guidelines as an important step towards critical evaluation and dissemination of datasets as well as broadening of experimental techniques worldwide. The MIRAGE Commission published reporting guidelines for MS data and here we outline guidelines for sample preparation. The sample preparation guidelines include all aspects of sample generation, purification and modification from biological and/or synthetic carbohydrate material. The application of MIRAGE sample preparation guidelines will lead to improved recording of experimental protocols and reporting of understandable and reproducible glycomics datasets.

  2. Geothermal Data from the National Geothermal Data System (NGDS)

    DOE Data Explorer

    The National Geothermal Data System (NGDS) is a distributed data system providing access to information resources related to geothermal energy from a network of data providers. Data are contributed by academic researchers, private industry, and state and federal agencies. Built on a scalable and open platform through the U.S. Geoscience Information Network (USGIN), NGDS respects data provenance while promoting shared resources.Since NGDS is built using a set of open protocols and standards, relying on the Open Geospatial Consortium (OGC) and International Organization for Standardization (ISO), members of the community may access the data in a variety of proprietary and open-source applications and software. In addition, developers can add functionality to the system by creating new applications based on the open protocols and standards of the NGDS. The NGDS, supported by the U.S. Department of Energy’s Geothermal Technology Program, is intended to provide access to all types of geothermal data to enable geothermal analysis and widespread public use in an effort to reduce the risk of geothermal energy development [copied from http://www.geothermaldata.org/page/about]. See the long list of data contributors at http://geothermaldata.org/page/data-types-and-contributors#data-contributors.

  3. Time frames for geothermal project development

    SciTech Connect

    McClain, David W.

    2001-04-17

    Geothermal development can generally be broken down into distinct phases: Exploration and Leasing; Project Development And Feasibility Studies; Well Field Development; Project Finance, Construction and Start-up Operations; and Commercial Operations. Each phase represents different levels of cost and risk and different types of management teams that are needed to assess and manage the project and associated risk. Orderly transitions of management at each major phase are needed. Exploration programs are largely science based, the primary focus of the science based investigations should be to: secure the lease position, and develop sufficient information to identify and characterize an economical geothermal resource. Project development specialists build on the exploration data to: pull together a project design, develop a detailed cost estimate; prepare an environmental assessment; and collect all data needed for project financing. Construction specialist build from the development phase to: develop detailed engineering, procure equipment and materials, schedule and manage the facilities construction programs, and start and test the power plant. Operations specialists take over from construction during start-up and are responsible for sustainable and reliable operations of the resource and power generation equipment over the life of the project.

  4. Geothermal energy abstract sets. Special report No. 14

    SciTech Connect

    Stone, C.

    1985-01-01

    This bibliography contains annotated citations in the following areas: (1) case histories; (2) drilling; (3) reservoir engineering; (4) injection; (5) geothermal well logging; (6) environmental considerations in geothermal development; (7) geothermal well production; (8) geothermal materials; (9) electric power production; (10) direct utilization of geothermal energy; (11) economics of geothermal energy; and (12) legal, regulatory and institutional aspects. (ACR)

  5. Geothermal energy for American Samoa

    SciTech Connect

    Not Available

    1980-03-01

    The geothermal commercialization potential in American Samoa was investigated. With geothermal energy harnessed in American Samoa, a myriad of possibilities would arise. Existing residential and business consumers would benefit from reduced electricity costs. The tuna canneries, demanding about 76% of the island's process heat requirements, may be able to use process heat from a geothermal source. Potential new industries include health spas, aquaculture, wood products, large domestic and transhipment refrigerated warehouses, electric cars, ocean nodule processing, and a hydrogen economy. There are no territorial statutory laws of American Samoa claiming or reserving any special rights (including mineral rights) to the territorial government, or other interests adverse to a land owner, for subsurface content of real property. Technically, an investigation has revealed that American Samoa does possess a geological environment conducive to geothermal energy development. Further studies and test holes are warranted.

  6. Advances in geothermal energy use

    SciTech Connect

    Kilkis, I.B.; Eltez, M.

    1996-10-01

    One of the earliest examples of large scale use of the geothermal energy is the district heating system in Boise, Idaho. Established in 1892, this system now serves 266 customers--mostly residential. Today, excluding heat pumps, there are about 300 sites in America where geothermal energy is currently used in various applications; including district heating, absorption cooling and refrigeration, industrial processes, aquaculture, horticulture, and snow melting/freeze protection. Among these, 18 geothermal district heating systems are operating with 677 GBtu (714 TJ) total annual heat output. Geothermal activity was first generated in Italy, in 1904, with a 10 kWe capacity. Now, commercial power plants are in service using vapor-dominated and liquid-dominated plants with a world-wide installed capacity of 6 GWe. This paper looks at a hybrid cycle/integrated district HVAC system.

  7. Geothermal resources assessed in Honduras

    SciTech Connect

    Not Available

    1986-01-01

    The investigation of the Platanares geothermal site is part of a joint Honduras (Empresa Nacional de Energia Electrica)/US (Los Alamos National Laboratory and US Geological Survey) assessment of the nationwide geothermal resource potential of Honduras. Platanares was selected as one of the initial sites for detailed study on the basis of previous geothermal reconnaissance work. The results of the geologic studies indicate that Platarnares' potential for development as an electrical power source is extremely good. This preliminary conclusion must be substantiated and refined through additional studies. Geophysical investigations are needed to further define the subsurface geology and fracture system. Several wells should be drilled to a depth of several hundred meters to measure thermal gradients. This will allow the calculation of the geothermal potential of the Platanares site and will indicate whether further development of the site is warranted.

  8. Hawaii geothermal resource assessment: 1982

    SciTech Connect

    Thomas, D.M.; Cox, M.; Kavahikaua, J.P.; Lienert, B.R.; Mattice, M.

    1982-10-01

    The Geothermal Resource Assessment Program of the Hawaii Institute of Geophysics has conducted a series of geochemical and geophysical surveys throughout the State of Hawaii since February 1978. The results compiled during this study have been used to prepare a map of potential geothermal resource areas throughout the state. Approximately thirteen separate locations on three islands have been studied in detail. Of these, four areas are known to have direct evidence of a geothermal anomaly (Kilauea East Rift Zone, Kilauea Southwest Rift Zone, Kawaihae, and Olowalu-Ukumehame) and three others are strongly suspected of having at least a low-temperature resource (Hualalai west flank, Haleakala Southwest Rift, and Lualualei Valley). In the remainder of the areas surveyed, the data obtained either were contradictory or gave no evidence of a geothermal resource.

  9. Geothermal Program Review IV: proceedings

    SciTech Connect

    Not Available

    1985-01-01

    The research and development program of DOE's Geothermal Technology Division is reviewed in separate presentations according to program area. Separate abstracts have been prepared for the individual papers. (ACR)

  10. Geothermal Permeability Enhancement - Final Report

    SciTech Connect

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  11. Process for cementing geothermal wells

    SciTech Connect

    Eilers, L. H.

    1985-12-03

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight monoor copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  12. Engineered Geothermal System Demonstration Project

    SciTech Connect

    Petty, Susan

    2014-06-19

    In June 2009, AltaRock Energy began field work on a project supported by the U.S. Department of Energy entitled “Use of Multiple Stimulations to Improve Economics of Engineered Geothermal Systems in Shallow High Temperature Intrusives.” The goal of the project was to develop an Engineered Geothermal System (EGS) in the portion of The Geysers geothermal field operated by the Northern California Power Agency (NCPA). The project encountered several problems while deepening Well E-7 which culminated in the suspension of field activities in September 2009. Some of the problems encountered are particular to The Geysers area, while others might be encountered in any geothermal field, and they might be avoided in future operations.

  13. Tailored Working Fluids for Enhanced Binary Geothermal Power Plants

    SciTech Connect

    Mahmoud, Ahmad

    2013-01-29

    United Technologies Research Center (UTRC), in collaboration with the Georgia Institute of Technology and the National Institute of Standards and Technology will evaluate and develop fundamental and component level models, conduct experiments and generate data to support the use of mixed or enhanced working fluids for geothermal power generation applications.

  14. Development and evaluation of elastomeric materials for geothermal applications

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Kalfayan, S. H.; Reilly, W. W.; Ingham, J. D.

    1978-01-01

    A material for a casing packer for service for 24 hours in a geothermal environment was developed by synthesis of new elastomers and formulation of available materials. Formulation included use of commercial elastomer gumstocks and also crosslinking of plastic (high Tg) materials. Fibrous reinforcement of fluorocarbon rubbers was emphasized. Organic fiber reinforcement did not increase hot properties significantly. Glass fiber reinforcement gave significant increase in tensile properties. Elongation was reduced, and the glass-reinforced composition examined so far did not hold up well in the geothermal environment. Colloidal asbestos fibers were also investigated. A few experiments with polyphenyl ether gave material with low tensile and high compression set. Available high styrene SBR compositions were studied. Work to date suggests that new synthetic polymers will be required for service in geothermal environments.

  15. Computerized international geothermal information systems

    SciTech Connect

    Phillips, S.L.; Lawrence, J.D.; Lepman, S.R.

    1980-03-01

    The computerized international geothermal energy information system is reviewed. The review covers establishment of the Italy - United States linked data centers by the NATO Committee on Challenges of Modern Society, through a bilateral agreement, and up to the present time. The result of the information exchange project is given as the bibliographic and numerical data available from the data centers. Recommendations for the exchange of computerized geothermal information at the international level are discussed.

  16. The Marysville, Montana Geothermal Project

    NASA Technical Reports Server (NTRS)

    Mcspadden, W. R.; Stewart, D. H.; Kuwada, J. T.

    1974-01-01

    Drilling the first geothermal well in Montana presented many challenges, not only in securing materials and planning strategies for drilling the wildcat well but also in addressing the environmental, legal, and institutional issues raised by the request for permission to explore a resource which lacked legal definition. The Marysville Geothermal Project was to investigate a dry hot rock heat anomaly. The well was drilled to a total depth of 6790 feet and many fractured water bearing zones were encountered below 1800 feet.

  17. Geothermal resource assessment in Oklahoma

    SciTech Connect

    Harrison, W.E.; Luza, K.V.; Prater, M.L.; Cheung, P.K.; Ruscetta, C.A.

    1982-07-01

    The procedures and methods used to develop a geothermal gradient map of Oklahoma are discussed. Two areas, Haskell and Pittsburg Counties, in the Arkoma Basin, are discussed in detail. Three sandstone units, the Spiro, Cromwell, and Hartshorne were selected as potential low-temperature geothermal water sources. The average temperature ranged from 103/sup 0/F at Hartshorne to 158/sup 0/F at Cromwell. (MJF)

  18. Optimizing Sustainable Geothermal Heat Extraction

    NASA Astrophysics Data System (ADS)

    Patel, Iti; Bielicki, Jeffrey; Buscheck, Thomas

    2016-04-01

    Geothermal heat, though renewable, can be depleted over time if the rate of heat extraction exceeds the natural rate of renewal. As such, the sustainability of a geothermal resource is typically viewed as preserving the energy of the reservoir by weighing heat extraction against renewability. But heat that is extracted from a geothermal reservoir is used to provide a service to society and an economic gain to the provider of that service. For heat extraction used for market commodities, sustainability entails balancing the rate at which the reservoir temperature renews with the rate at which heat is extracted and converted into economic profit. We present a model for managing geothermal resources that combines simulations of geothermal reservoir performance with natural resource economics in order to develop optimal heat mining strategies. Similar optimal control approaches have been developed for managing other renewable resources, like fisheries and forests. We used the Non-isothermal Unsaturated-saturated Flow and Transport (NUFT) model to simulate the performance of a sedimentary geothermal reservoir under a variety of geologic and operational situations. The results of NUFT are integrated into the optimization model to determine the extraction path over time that maximizes the net present profit given the performance of the geothermal resource. Results suggest that the discount rate that is used to calculate the net present value of economic gain is a major determinant of the optimal extraction path, particularly for shallower and cooler reservoirs, where the regeneration of energy due to the natural geothermal heat flux is a smaller percentage of the amount of energy that is extracted from the reservoir.

  19. The Oregon Geothermal Planning Conference

    SciTech Connect

    1980-10-02

    Oregon's geothermal resources represent a large portion of the nation's total geothermal potential. The State's resources are substantial in size, widespread in location, and presently in various stages of discovery and utilization. The exploration for, and development of, geothermal is presently dependent upon a mixture of engineering, economic, environmental, and legal factors. In response to the State's significant geothermal energy potential, and the emerging impediments and incentives for its development, the State of Oregon has begun a planning program intended to accelerate the environmentally prudent utilization of geothermal, while conserving the resource's long-term productivity. The program, which is based upon preliminary work performed by the Oregon Institute of Technology's Geo-Heat Center, will be managed by the Oregon Department of Energy, with the assistance of the Departments of Economic Development, Geology and Mineral Industries, and Water Resources. Funding support for the program is being provided by the US Department of Energy. The first six-month phase of the program, beginning in July 1980, will include the following five primary tasks: (1) coordination of state and local agency projects and information, in order to keep geothermal personnel abreast of the rapidly expanding resource literature, resource discoveries, technological advances, and each agency's projects. (2) Analysis of resource commercialization impediments and recommendations of incentives for accelerating resource utilization. (3) Compilation and dissemination of Oregon geothermal information, in order to create public and potential user awareness, and to publicize technical assistance programs and financial incentives. (4) Resource planning assistance for local governments in order to create local expertise and action; including a statewide workshop for local officials, and the formulation of two specific community resource development plans. (5) Formulation and

  20. Laboratory simulation of the geothermal heating effects on ocean overturning circulation

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Huang, Shi-Di; Zhou, Sheng-Qi; Xia, Ke-Qing

    2016-10-01

    Motivated by a desire to understand the geothermal heating effects on ocean circulation, a large-scale circulation generated and sustained by thermal forcing at the surface subject to a small amount of heating from the bottom boundary is investigated through laboratory experiments. Despite its idealization, our experiments demonstrate that the leading order effect of geothermal heating is to significantly enhance the abyssal overturning, in agreement with the findings in ocean circulation models. Our experiments also demonstrate that geothermal heating cannot influence the poleward heat transport due to the strong stratification in the thermocline. Our study further reveals that the ratio of geothermal-flux-induced turbulent dissipation to the dissipation due to other energies is the key parameter determining the dynamical importance of geothermal heating. This quantity explains why the impact of geothermal heating is sensitive to the deep stratification, the diapycnal mixing, and the amount of geothermal flux. Moreover, it is found that this dissipation ratio may be used to understand results from different studies in a consistent way.

  1. Hydraulic fracture stimulation treatment of Well Baca 23. Geothermal Reservoir Well-Stimulation Program

    SciTech Connect

    Not Available

    1981-06-01

    Well Stimulation Experiment No. 5 of the Geothermal Reservoir Well Stimulation Program (GRWSP) was performed on March 22, 1981 in Baca 23, located in Union's Redondo Creek Project Area in Sandoval County, New Mexico. The treatment selected was a large hydraulic fracture job designed specifically for, and utilizing frac materials chosen for, the high temperature geothermal environment. The well selection, fracture treatment, experiment evaluation, and summary of the job costs are presented herein.

  2. Geothermal Money Book [Geothermal Outreach and Project Financing

    SciTech Connect

    Elizabeth Battocletti

    2004-02-01

    Small business lending is big business and growing. Loans under $1 million totaled $460 billion in June 2001, up $23 billion from 2000. The number of loans under $100,000 continued to grow at a rapid rate, growing by 10.1%. The dollar value of loans under $100,000 increased 4.4%; those of $100,000-$250,000 by 4.1%; and those between $250,000 and $1 million by 6.4%. But getting a loan can be difficult if a business owner does not know how to find small business-friendly lenders, how to best approach them, and the specific criteria they use to evaluate a loan application. This is where the Geothermal Money Book comes in. Once a business and financing plan and financial proposal are written, the Geothermal Money Book takes the next step, helping small geothermal businesses locate and obtain financing. The Geothermal Money Book will: Explain the specific criteria potential financing sources use to evaluate a proposal for debt financing; Describe the Small Business Administration's (SBA) programs to promote lending to small businesses; List specific small-business friendly lenders for small geothermal businesses, including those which participate in SBA programs; Identify federal and state incentives which are relevant to direct use and small-scale (< 1 megawatt) power generation geothermal projects; and Provide an extensive state directory of financing sources and state financial incentives for the 19 states involved in the GeoPowering the West (GPW). GPW is a U.S. Department of Energy-sponsored activity to dramatically increase the use of geothermal energy in the western United States by promoting environmentally compatible heat and power, along with industrial growth and economic development. The Geothermal Money Book will not: Substitute for financial advice; Overcome the high exploration, development, and financing costs associated with smaller geothermal projects; Remedy the lack of financing for the exploration stage of a geothermal project; or Solve financing

  3. Geothermal development in Australia

    NASA Astrophysics Data System (ADS)

    Burns, K. L.; Creelman, R. A.; Buckingham, N. W.; Harrington, H. J.

    In Australia, natural hot springs and hot artesian bores have been developed for recreational and therapeutic purposes. A district heating system at Portland, in the Otway Basin of western Victoria, has provided uninterrupted service for 12 Sears without significant problems, is servicing a building area of 18 990 sq m, and has prospects of expansion to manufacturing uses. A geothermal well has provided hot water for paper manufacture at Traralgon, in the Gippsland Basin of eastern Victoria. Power production from hot water aquifers was tested at Mulka in South Australia, and is undergoing a four-year production trial at Birdsville in Queensland. An important Hot Dry Rock resource has been confirmed in the Cooper Basin. It has been proposed to build an HDR experimental facility to test power production from deep conductive resources in the Sydney Basin near Muswellbrook.

  4. Geothermal development in Australia

    SciTech Connect

    Burns, K.L.; Creelman, R.A.; Buckingham, N.W.; Harrington, H.J. |

    1995-03-01

    In Australia, natural hot springs and hot artesian bores have been developed for recreational and therapeutic purposes. A district heating system at Portland, in the Otway Basin of western Victoria, has provided uninterrupted service for 12 Sears without significant problems, is servicing a building area of 18 990 m{sup 2}, and has prospects of expansion to manufacturing uses. A geothermal well has provided hot water for paper manufacture at Traralgon, in the Gippsland Basin of eastern Victoria. Power production from hot water aquifers was tested at Mulka in South Australia, and is undergoing a four-year production trial at Birdsville in Queensland. An important Hot Dry Rock resource has been confirmed in the Cooper Basin. It has been proposed to build an HDR experimental facility to test power production from deep conductive resources in the Sydney Basin near Muswellbrook.

  5. Enhanced Geothermal Systems

    SciTech Connect

    Jeanloz, R.; Stone, H.

    2013-12-31

    DOE, through the Geothermal Technologies Office (GTO) within the Office of Energy Efficiency and Renewable Energy, requested this study, identifying a focus on: i) assessment of technologies and approaches for subsurface imaging and characterization so as to be able to validate EGS opportunities, and ii) assessment of approaches toward creating sites for EGS, including science and engineering to enhance permeability and increase the recovery factor. Two days of briefings provided in-depth discussion of a wide range of themes and challenges in EGS, and represented perspectives from industry, government laboratories and university researchers. JASON also contacted colleagues from universities, government labs and industry in further conversations to learn the state of the field and potential technologies relevant to EGS.

  6. Geothermal energy geopressure subprogram

    SciTech Connect

    Not Available

    1981-02-01

    The proposed action will consist of drilling one geopressured-geothermal resource fluid well for intermittent production testing over the first year of the test. During the next two years, long-term testing of 40,000 BPD will be flowed. A number of scenarios may be implemented, but it is felt that the total fluid production will approximate 50 million barrels. The test well will be drilled with a 22 cm (8.75 in.) borehole to a total depth of approximately 5185 m (17,000 ft). Up to four disposal wells will provide disposal of the fluid from the designated 40,000 BPD test rate. The following are included in this assessment: the existing environment; probable environmental impacts-direct and indirect; probable cumulative and long-term environmental impacts; accidents; coordination with federal, state, regional, and local agencies; and alternative actions. (MHR)

  7. Geothermal innovative technologies catalog

    SciTech Connect

    Kenkeremath, D.

    1988-09-01

    The technology items in this report were selected on the basis of technological readiness and applicability to current technology transfer thrusts. The items include technologies that are considered to be within 2 to 3 years of being transferred. While the catalog does not profess to be entirely complete, it does represent an initial attempt at archiving innovative geothermal technologies with ample room for additions as they occur. The catalog itself is divided into five major functional areas: Exploration; Drilling, Well Completion, and Reservoir Production; Materials and Brine Chemistry; Direct Use; and Economics. Within these major divisions are sub-categories identifying specific types of technological advances: Hardware; Software; Data Base; Process/Procedure; Test Facility; and Handbook.

  8. Geothermal systems: Principles and case histories

    NASA Astrophysics Data System (ADS)

    Rybach, L.; Muffler, L. J. P.

    The classification of geothermal systems is considered along with the geophysical and geochemical signatures of geothermal systems, aspects of conductive heat transfer and regional heat flow, and geothermal anomalies and their plate tectonic framework. An investigation of convective heat and mass transfer in hydrothermal systems is conducted, taking into account the mathematical modelling of hydrothermal systems, aspects of idealized convective heat and mass transport, plausible models of geothermal reservoirs, and preproduction models of hydrothermal systems. Attention is given to the prospecting for geothermal resources, the application of water geochemistry to geothermal exploration and reservoir engineering, heat extraction from geothermal reservoirs, questions of geothermal resource assessment, and environmental aspects of geothermal energy development. A description is presented of a number of case histories, taking into account the low enthalpy geothermal resource of the Pannonian Basin in Hungary, the Krafla geothermal field in Northeast Iceland, the geothermal system of the Jemez Mountains in New Mexico, and extraction-reinjection at the Ahuachapan geothermal field in El Salvador.

  9. Health Services OutPatient Experience questionnaire: factorial validity and reliability of a patient-centered outcome measure for outpatient settings in Italy

    PubMed Central

    Coluccia, Anna; Ferretti, Fabio; Pozza, Andrea

    2014-01-01

    Purpose The patient-centered approach to health care does not seem to be sufficiently developed in the Italian context, and is still characterized by the biomedical model. In addition, there is a lack of validated outcome measures to assess outpatient experience as an aspect common to a variety of settings. The current study aimed to evaluate the factorial validity, reliability, and invariance across sex of the Health Services OutPatient Experience (HSOPE) questionnaire, a short ten-item measure of patient-centeredness for Italian adult outpatients. The rationale for unidimensionality of the measure was that it could cover global patient experience as a process common to patients with a variety of diseases and irrespective of the phase of treatment course. Patients and methods The HSOPE was compiled by 1,532 adult outpatients (51% females, mean age 59.22 years, standard deviation 16.26) receiving care in ten facilities at the Santa Maria alle Scotte University Hospital of Siena, Italy. The sample represented all the age cohorts. Twelve percent were young adults, 57% were adults, and 32% were older adults. Exploratory and confirmatory factor analyses were conducted to evaluate factor structure. Reliability was evaluated as internal consistency using Cronbach’s α. Factor invariance was assessed through multigroup analyses. Results Both exploratory and confirmatory analyses suggested a clearly defined unidimensional structure of the measure, with all the ten items having salient loadings on a single factor. Internal consistency was excellent (α=0.95). Indices of model fit supported a single-factor structure for both male and female outpatient groups. Young adult outpatients had significantly lower scores on perceived patient-centeredness relative to older adults. No significant difference emerged on patient-centeredness between male and female outpatients. Conclusion The HSOPE questionnaire seemed to be a tool with high acceptability and excellent psychometric

  10. Research on geothermal chemistry and advanced instrumentation

    NASA Astrophysics Data System (ADS)

    Robertus, R. J.; Shannon, D. W.; Sullivan, R. G.; Kindle, C. H.; Pool, K. H.

    1985-09-01

    Research at the Pacific Northwest Laboratory (PNL) focuses on long-term geothermal power plant reliability. Past work concentrated on development of continuous high-temperature probes for monitoring process variables. PNL also completed a comprehensive handbook of brine treatment processes as they relate to injection well longevity. A recently completed study analyzed corrosion in the hydrocarbon system of a binary cycle plant. Over the two-year monitoring period, corrosion rates were less than 1 MPY in any part of the hydrocarbon system. The system was kept completely dry so the rates seem reasonable. Present projects include: (1) determination of gas breakout conditions at the Herber Binary Demonstration Plant operated by San Diego Gas and Electric Company; (2) generation of water mixing solubility data; (3) installation of prototype leak detectors at the Herber Plant; and (4) evaluation of state-of-the-art particle counters.

  11. Geothermal -- The Energy Under Our Feet: Geothermal Resource Estimates for the United States

    SciTech Connect

    Green, B. D.; Nix, R. G.

    2006-11-01

    On May 16, 2006, the National Renewable Energy Laboratory (NREL) in Golden, Colorado hosted a geothermal resources workshop with experts from the geothermal community. The purpose of the workshop was to re-examine domestic geothermal resource estimates. The participating experts were organized into five working groups based on their primary area of expertise in the following types of geothermal resource or application: (1) Hydrothermal, (2) Deep Geothermal Systems, (3) Direct Use, (4) Geothermal Heat Pumps (GHPs), and (5) Co-Produced and Geopressured. The workshop found that the domestic geothermal resource is very large, with significant benefits.

  12. Reliability training

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

    1992-01-01

    Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

  13. Outstanding issues for new geothermal resource assessments

    USGS Publications Warehouse

    Williams, C.F.; Reed, M.J.

    2005-01-01

    A critical question for the future energy policy of the United States is the extent to which geothermal resources can contribute to an ever-increasing demand for electricity. Electric power production from geothermal sources exceeds that from wind and solar combined, yet the installed capacity falls far short of the geothermal resource base characterized in past assessments, even though the estimated size of the resource in six assessments completed in the past 35 years varies by thousands of Megawatts-electrical (MWe). The U. S. Geological Survey (USGS) is working closely with the Department of Energy's (DOE) Geothermal Research Program and other geothermal organizations on a three-year effort to produce an updated assessment of available geothermal resources. The new assessment will introduce significant changes in the models for geothermal energy recovery factors, estimates of reservoir permeability, limits to temperatures and depths for electric power production, and include the potential impact of evolving Enhanced (or Engineered) Geothermal Systems (EGS) technology.

  14. Fifteenth workshop on geothermal reservoir engineering: Proceedings

    SciTech Connect

    Not Available

    1990-01-01

    The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

  15. An Evaluation of Enhanced Geothermal Systems Technology

    SciTech Connect

    Jelacic, Allan; Fortuna, Raymond; LaSala, Raymond; Nathwani, Jay; Nix, Gerald; Visser, Charles; Green, Bruce; Renner, Joel; Blankenship, Douglas; Kennedy, Mack; Bruton, Carol

    2008-04-01

    This 2008 document presents the results of an eight-month study by the Department of Energy (DOE) and its support staff at the national laboratories concerning the technological requirements to commercialize a new geothermal technology, Enhanced Geothermal Systems (EGS).

  16. Geothermal Energy: Evaluation of a Resource

    ERIC Educational Resources Information Center

    Bockemuehl, H. W.

    1976-01-01

    This article suggests the use of geothermal energy for producing electricity, using as an example the development at Wairakei, New Zealand. Other geothermal areas are identified, and economic and environmental co sts of additional development are explored. (Author/AV)

  17. Imperial County geothermal development annual meeting: summary

    SciTech Connect

    Not Available

    1983-01-01

    All phases of current geothermal development in Imperial County are discussed and future plans for development are reviewed. Topics covered include: Heber status update, Heber binary project, direct geothermal use for high-fructose corn sweetener production, update on county planning activities, Brawley and Salton Sea facility status, status of Imperial County projects, status of South Brawley Prospect 1983, Niland geothermal energy program, recent and pending changes in federal procedures/organizations, plant indicators of geothermal fluid on East Mesa, state lands activities in Imperial County, environmental interests in Imperial County, offshore exploration, strategic metals in geothermal fluids rebuilding of East Mesa Power Plant, direct use geothermal potential for Calipatria industrial Park, the Audubon Society case, status report of the Cerro Prieto geothermal field, East Brawley Prospect, and precision gravity survey at Heber and Cerro Prieto geothermal fields. (MHR)

  18. Choosing a Geothermal as an HVAC System.

    ERIC Educational Resources Information Center

    Lensenbigler, John D.

    2002-01-01

    Describes the process of selecting and installing geothermal water source heat pumps for new residence halls at Johnson Bible College in Knoxville, Tennessee, including choosing the type of geothermal design, contractors, and interior equipment, and cost and payback. (EV)

  19. Exploring for Geothermal Resources with Electromagnetic Methods

    NASA Astrophysics Data System (ADS)

    Muñoz, Gerard

    2014-01-01

    Electrical conductivity of the subsurface is known to be a crucial parameter for the characterization of geothermal settings. Geothermal systems, composed by a system of faults and/or fractures filled with conducting geothermal fluids and altered rocks, are ideal targets for electromagnetic (EM) methods, which have become the industry standard for exploration of geothermal systems. This review paper presents an update of the state-of-the-art geothermal exploration using EM methods. Several examples of high-enthalpy geothermal systems as well as non-volcanic systems are presented showing the successful application of EM for geothermal exploration but at the same time highlighting the importance of the development of conceptual models in order to avoid falling into interpretation pitfalls. The integration of independent data is key in order to obtain a better understanding of the geothermal system as a whole, which is the ultimate goal of exploration.

  20. Person Reliability

    ERIC Educational Resources Information Center

    Lumsden, James

    1977-01-01

    Person changes can be of three kinds: developmental trends, swells, and tremors. Person unreliability in the tremor sense (momentary fluctuations) can be estimated from person characteristic curves. Average person reliability for groups can be compared from item characteristic curves. (Author)

  1. An Integrated Chemical Geothermometry System for Geothermal Exploration

    NASA Astrophysics Data System (ADS)

    Spycher, N. F.; Sonnenthal, E. L.; Kennedy, B. M.

    2010-12-01

    The objective of this project is to develop a reliable and improved methodology to predict geothermal reservoir temperatures from full and integrated chemical analyses of spring and shallow well water samples, to see through near surface processes, such as dilution, gas loss, etc., that mask or hide the chemical signatures of deep reservoir fluids in near surface waters. The system builds on a multicomponent chemical geothermometry method developed previously for single point sources relying on computed saturation indices of multiple minerals. Taking advantage of recent advances in optimization and geochemical/reactive transport modeling, the system integrates the multicomponent geothermometry method into an optimization system that allows simultaneous processing of multiple water analyses to estimate reservoir temperatures. In doing so, the system will also be able to solve for amounts and compositions of potential mixing end-members diluting the reservoir fluids and/or composition and amounts of gas phase lost as deep geothermal fluids ascend to ground surface. This integrated approach is expected to allow estimations of reservoir temperatures with better reliability and consistency than currently possible using standard chemical geothermometers. The proposed approach is being implemented and tested using an extensive set of water and gas compositions from springs and wells at the geothermal system in Dixie Valley, Nevada, where standard chemical geothermometers yield temperatures inconsistent with measured reservoir temperatures.

  2. Geothermal Heat Pumps for Federal Buildings

    SciTech Connect

    1999-08-01

    OFFICE OF GEOTHERMAL TECHNOLOGIES Geothermal Heat Pumps for Federal Buildings The U.S. Government spends approximately $8 billion annually on its energy needs. To reduce energy use in Federal buildings, President Bill Clinton issued Executive Order 13123 in June 1999, which calls for a 35% reduction in Federal energy use from 1985 levels by 2010. Geothermal heat pumps--when installed in virtually any type of building--can help accomplish this goal with energy savings of up to 40%. Geothermal he.

  3. Use of a Reliable Homemade Dilatometer To Study the Kinetics of the Radical Chain Polymerization of PMMA: An Undergraduate Polymer Chemistry Laboratory Kinetics Experiment

    NASA Astrophysics Data System (ADS)

    Mendicuti, Francisco; Martín, Olga; Tarazona, Maria Pilar

    1998-11-01

    In this laboratory experiment, a simple, reliable homemade dilatometer was used to study the kinetics of the radical chain polymerization of PMMA. The reaction was carried out in toluene with benzoyl peroxide as the initiator at a temperature of 80 °C. Each student studied the kinetics at a different initiator concentration constant. Pseudo-first-order plots permit students to obtain kapp and to demonstrate order 1 with respect to the monomer concentration. Finally, a log-log plot of kapp versus the initiator concentration from the data collected by each student demonstrates order 0.5 with respect to the initiator concentration. Results also agree with the rate constants of the process implicated in this type of polymerization.

  4. Microbiological monitoring in geothermal plants and a cold storage

    NASA Astrophysics Data System (ADS)

    Alawi, Mashal; Lerm, Stephanie; Vieth, Andrea; Vetter, Alexandra; Miethling-Graff, Rona; Seibt, Andrea; Wolfgramm, Markus; Würdemann, Hilke

    2010-05-01

    Enhanced process understanding of engineered geothermal systems is mandatory to optimize plant reliability and economy. In the scope of the research project 'AquiScreen' we investigated geothermally used groundwater systems under microbial, geochemical, mineralogical and petrological aspects. Geothermal systems located in the North German Basin and the Molasse Basin were analyzed by sampling of fluids and solid phases. The investigated sites were characterized by different temperatures, salinities and potential microbial substrates. The microbial population was analyzed by the use of genetic fingerprinting techniques based on PCR-amplified 16S rRNA genes. Sequencing of dominant bands of fingerprints from different sites and the subsequent comparison on public databases enables a correlation to metabolic classes and provides information about the biochemical processes. In all investigated geothermal plants covering a temperature range from 45° to 120° C microorganisms were found. Phylogenetic gene analyses indicate a broad diversity of microorganisms adapted to the specific conditions in the engineered system. Beside characterized bacteria like Thermus scotoductus, Siderooxidans lithoautotrophicus and the archaeon Methanothermobacter thermoautotrophicus a high number of so far uncultivated microorganisms was detected. As it is known that -in addition to abiotic factors- microbes like sulfate-reducing bacteria (SRB) are involved in the processes of corrosion and scaling in plant components we identified SRB by specific analyses of dissimilatoric sulfite reductase genes. The SRB detected are closely related to thermotolerant and thermophilic species of Desulfotomaculum, Thermodesulfovibrio and Thermodesulfobacterium, respectively. Overall, the detection of microbes known to be involved in biocorrosion and examined precipitation products like iron sulfides are indicating that microorganisms play an important role for the understanding of processes in engineered

  5. Strategic plan for the geothermal energy program

    SciTech Connect

    1998-06-01

    Geothermal energy (natural heat in the Earth`s crust) represents a truly enormous amount of energy. The heat content of domestic geothermal resources is estimated to be 70,000,000 quads, equivalent to a 750,000-year supply of energy for the entire Nation at current rates of consumption. World geothermal resources (exclusive of resources under the oceans) may be as much as 20 times larger than those of the US. While industry has focused on hydrothermal resources (those containing hot water and/or steam), the long-term future of geothermal energy lies in developing technology to enable use of the full range of geothermal resources. In the foreseeable future, heat may be extracted directly from very hot rocks or from molten rocks, if suitable technology can be developed. The US Department of Energy`s Office of Geothermal Technologies (OGT) endorses a vision of the future in which geothermal energy will be the preferred alternative to polluting energy sources. The mission of the Program is to work in partnership with US industry to establish geothermal energy as a sustainable, environmentally sound, economically competitive contributor to the US and world energy supply. In executing its mission and achieving its long-term vision for geothermal energy, the Program has identified five strategic goals: electric power generation; direct use applications and geothermal heat pumps; international geothermal development; science and technology; and future geothermal resources. This report discusses the objectives of these five goals.

  6. Geothermal Energy Development annual report 1979

    SciTech Connect

    Not Available

    1980-08-01

    This report is an exerpt from Earth Sciences Division Annual Report 1979 (LBL-10686). Progress in thirty-four research projects is reported including the following area: geothermal exploration technology, geothermal energy conversion technology, reservoir engineering, and geothermal environmental research. Separate entries were prepared for each project. (MHR)

  7. Geothermal progress monitor. Progress report No. 7

    SciTech Connect

    Not Available

    1983-04-01

    A state-by-state review of major geothermal-development activities during 1982 is presented. It also inlcudes a summary of recent drilling and exploration efforts and the results of the 1982 leasing program. Two complementary sections feature an update of geothermal direct-use applications and a site-by-site summary of US geothermal electric-power development.

  8. Advanced seismic imaging for geothermal development

    SciTech Connect

    Louie, John; Pullammanappallil, Satish; Honjas, Bill

    2016-08-01

    J. N. Louie, Pullammanappallil, S., and Honjas, W., 2011, Advanced seismic imaging for geothermal development: Proceedings of the New Zealand Geothermal Workshop 2011, Nov. 21-23, Auckland, paper 32, 7 pp. Preprint available at http://crack.seismo.unr.edu/geothermal/Louie-NZGW11.pdf

  9. Geothermal energy for Hawaii: a prospectus

    SciTech Connect

    Yen, W.W.S.; Iacofano, D.S.

    1981-01-01

    An overview of geothermal development is provided for contributors and participants in the process: developers, the financial community, consultants, government officials, and the people of Hawaii. Geothermal energy is described along with the issues, programs, and initiatives examined to date. Hawaii's future options are explored. Included in appendices are: a technical glossary, legislation and regulations, a geothermal directory, and an annotated bibliography. (MHR)

  10. Hydraulic fracturing in granite under geothermal conditions

    USGS Publications Warehouse

    Solberg, P.; Lockner, D.; Byerlee, J.D.

    1980-01-01

    The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

  11. Geothermal Well Stimulated Using High Energy Gas Fracturing

    SciTech Connect

    Chu, T.Y.; Jacobson, R.D.; Warpinski, N.; Mohaupt, Henry

    1987-01-20

    This paper reports the result of an experimental study of the High Energy Gas Fracturing (HEGF) technique for geothermal well stimulation. These experiments demonstrated that multiple fractures could be created to link a water-filled borehole with other fractures. The resulting fracture network and fracture interconnections were characterized by flow tests as well as mine back. Commercial oil field fracturing tools were used successfully in these experiments. 5 refs., 2 tabs., 5 figs.

  12. Models for geothermal wells

    SciTech Connect

    Michaelides, E.E.

    1980-06-01

    The problem of two-phase flow pressure loss is examined in order to give an answer to the problem of determination of the wellhead conditions. For this purpose two models have been developed, the first based on the pattern structure of the flow and the second on the mixing length theory. The void fraction correlations and the transition conditions are presented in the first model as a means of estimating the pressure loss. Heat losses, and the effect of impurities are examined in detail. An expression for the critical flow conditions is also derived. The model is used to predict the available power at the wellhead under various conditions and an answer to the problem of well pumping is given. For the second model an outline of the mixing length theory and the boundary layer coordinates is given; a density distribution in the geothermal well is assumed and the equations for the pressure loss are derived by means of the entropy production function. Finally a comparison of the two models is made and their predictive power is tested against known well data. A brief comparison with the Denver Research Institute is also made.

  13. Thermodynamics of geothermal fluids

    SciTech Connect

    Rogers, P.S.Z.

    1981-03-01

    A model to predict the thermodynamic properties of geothermal brines, based on a minimum amount of experimental data on a few key systems, is tested. Volumetric properties of aqueous sodium chloride, taken from the literature, are represented by a parametric equation over the range 0 to 300{sup 0}C and 1 bar to 1 kbar. Density measurements at 20 bar needed to complete the volumetric description also are presented. The pressure dependence of activity and thermal properties, derived from the volumetric equation, can be used to complete an equation of state for sodium chloride solutions. A flow calorimeter, used to obtain heat capacity data at high temperatures and pressures, is described. Heat capacity measurements, from 30 to 200{sup 0}C and 1 bar to 200 bar, are used to derive values for the activity coefficient and other thermodynamic properties of sodium sulfate solutions as a function of temperature. Literature data on the solubility of gypsum in mixed electrolyte solutions have been used to evaluate model parameters for calculating gypsum solubility in seawater and natural brines. Predictions of strontium and barium sulfate solubility in seawater also are given.

  14. Colorado Potential Geothermal Pathways

    DOE Data Explorer

    Zehner, Richard E.

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Publication Date: 2012 Title: Colorado PRS Cool Fairways Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science (CIRES), University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the weakened basement rocks. Isostatic gravity was utilized to identify structural basin areas, characterized by gravity low values reflecting weakened basement rocks. Together interpreted regional fault zones and basin outlines define geothermal "exploration fairways", where the potential exists for deep, superheated fluid flow in the absence of Pliocene or younger volcanic units Spatial Domain: Extent: Top: 4544698.569273 m Left: 144918.141004 m Right: 763728.391299 m Bottom: 4094070.397932 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System ’1984 (WGS ’1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  15. Geothermal resource of Sumatra

    SciTech Connect

    Hochstein, M.P. . Geothermal Inst.); Sudarman, Sayogi . Geothermal Section)

    1993-06-01

    There are at least 30 high temperatures systems (with inferred reservoir temperatures > 200 C) along the active Sumatra Arc that transfer heat from crustal intrusions to the surface. These systems, together with eleven active volcanoes, five degassing volcanoes and one caldera volcano (Lake Toba), are controlled by the Sumatra Fault Zone, an active mega shear zone that follows the median axis of the arc. At least half of the active and degassing volcanoes are associated with volcanic geothermal reservoirs containing magmatic gases and acid fluids. Large, low temperature resources exist in the Tertiary sedimentary basins of east Sumatra (back-arc region), where anomalously higher thermal gradients (up to 8 C/100 m) have been measured. Volcanic activity was not continuous during the Cenozoic; subduction and arc volcanism probably decreased after the Eocene as a result of a clockwise rotation of Sumatra. In the Late Miocene, subduction started again, and andesitic volcanism reached a new peak of intensity in the Pliocene and has been continuous ever since. Rhyolitic volcanism, which has produced voluminous ignimbrite flows, began later (Pliocene/Pleistocene). All known rhyolitic centers associated with ignimbrite flows appear to lie along the Sumatra Fault Zone.

  16. Geothermal reservoir engineering research at Stanford University. First annual report, October 1, 1980-September 30, 1981

    SciTech Connect

    Brigham, W.E.; Horne, R.N.; Kruger, P.; Miller, F.G.; Ramey, H.J. Jr.

    1981-09-01

    The work on energy extraction experiments concerns the efficiency with which the in-place heat and fluids can be produced. The work on noncondensable gas reservoir engineering covers both the completed and continuing work in these two interrelated research areas: radon emanation from the rock matrix of geothermal reservoirs, and radon and ammonia variations with time and space over geothermal reservoirs. Cooperative research programs with Italy and Mexico are described. The bench-scale experiments and well test analysis section covers both experimental and theoretical studies. The small core model continues to be used for the study of temperature effects on absolute permeability. The unconsolidated sand study was completed at the beginning of this contract period. The Appendices describe some of the Stanford Geothermal program activities that results in interactions with the geothermal community. These occur in the form of SGP Technical Reports, presentations at technical meetings and publications in the open literature.

  17. Small-scale Geothermal Power Plants Using Hot Spring Water

    NASA Astrophysics Data System (ADS)

    Tosha, T.; Osato, K.; Kiuchi, T.; Miida, H.; Okumura, T.; Nakashima, H.

    2013-12-01

    The installed capacity of the geothermal power plants has been summed up to be about 515MW in Japan. However, the electricity generated by the geothermal resources only contributes to 0.2% of the whole electricity supply. After the catastrophic earthquake and tsunami devastated the Pacific coast of north-eastern Japan on Friday, March 11, 2011, the Japanese government is encouraging the increase of the renewable energy supply including the geothermal. It needs, however, more than 10 years to construct the geothermal power plant with more than 10MW capacity since the commencement of the development. Adding the problem of the long lead time, high temperature fluid is mainly observed in the national parks and the high quality of the geothermal resources is limited. On the other hand hot springs are often found. The utilisation of the low temperature hot water becomes worthy of notice. The low temperature hot water is traditionally used for bathing and there are many hot springs in Japan. Some of the springs have enough temperature and enthalpy to turn the geothermal turbine but a new technology of the binary power generation makes the lower temp fluid to generate electricity. Large power generators with the binary technology are already installed in many geothermal fields in the world. In the recent days small-scale geothermal binary generators with several tens to hundreds kW capacity are developed, which are originally used by the waste heat energy in an iron factory and so on. The newly developed binary unit is compact suitable for the installation in a Japanese inn but there are the restrictions for the temperature of the hot water and the working fluid. The binary power unit using alternatives for chlorofluorocarbon as the working fluid is relatively free from the restriction. KOBELCO, a company of the Kobe Steel Group, designed and developed the binary power unit with an alternative for chlorofluorocarbon. The unit has a 70 MW class electric generator. Three

  18. Geothermal district piping - A primer

    SciTech Connect

    Rafferty, K.

    1989-11-01

    Transmission and distribution piping constitutes approximately 40 -60% of the capital costs of typical geothermal district heating systems. Selections of economical piping suitable for the fluid chemistry is critical. Presently, most piping (56%) in geothermal systems is of asbestos cement construction. Some fiberglass (19%) and steel (19%) is also in use. Identification of an economical material to replace asbestos cement is important to future project development. By providing information on relative costs, purchase considerations, existing material performance and new products, this report seeks to provide a background of information to the potential pipe purchaser. A brief discussion of the use of uninsulated piping in geothermal district heating systems is also provided. 5 refs., 19 figs., 1 tab.

  19. Alternative Geothermal Power Production Scenarios

    DOE Data Explorer

    Sullivan, John

    2014-03-14

    The information given in this file pertains to Argonne LCAs of the plant cycle stage for a set of ten new geothermal scenario pairs, each comprised of a reference and improved case. These analyses were conducted to compare environmental performances among the scenarios and cases. The types of plants evaluated are hydrothermal binary and flash and Enhanced Geothermal Systems (EGS) binary and flash plants. Each scenario pair was developed by the LCOE group using GETEM as a way to identify plant operational and resource combinations that could reduce geothermal power plant LCOE values. Based on the specified plant and well field characteristics (plant type, capacity, capacity factor and lifetime, and well numbers and depths) for each case of each pair, Argonne generated a corresponding set of material to power ratios (MPRs) and greenhouse gas and fossil energy ratios.

  20. Environmental problems and geothermal permitting

    SciTech Connect

    Windrem, P.F.; Marr, G.L.

    1982-01-01

    This paper describes the stages of geothermal development, the attendant environmental hazards, and the jurisdictions of the various government agencies. Most examples of environmental hazards are drawn from the electric-power production in the geysers of northern California. The major enviromental effects of geothermal development are observed on air quality (including noise), land (including soil erosion, seismic activity and subsidence, wildlife habitat, and visual quality), and water quality. Ownership determines which agencies have jurisdiction, with the preparation of an environmental impact statement at the heart of the federal regulatory process and an environmental-impact report required at the state level. Environmental rules also cover power-plant construction and geothermal field abandonment. 58 references.

  1. Geothermal progress monitor report No. 6

    SciTech Connect

    Not Available

    1982-06-01

    Geothermal Progress Monitor Report No. 6 presents a state-by-state summary of the status of geothermal leasing, exploration, and development in major physiographic regions where geothermal resource potential has been identified. Recent state-specific activities are reported at the end of each state status report, while recent activities of a more general nature are summarized briefly in Part II of the report. A list of recent publications of potential interest to the geothermal community and a directory of contributors to the geothermal progress monitoring system are also included.

  2. "Assistance to States on Geothermal Energy"

    SciTech Connect

    Linda Sikkema; Jennifer DeCesaro

    2006-07-10

    This final report summarizes work carried out under agreement with the U.S. Department of Energy, related to geothermal energy policy issues. This project has involved a combination of outreach and publications on geothermal energy—Contract Number DE-FG03-01SF22367—with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of geothermal energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of responses to information requests on geothermal energy and publications. The publications addressed: geothermal leasing, geothermal policy, constitutional and statutory authority for the development of geothermal district energy systems, and state regulation of geothermal district energy systems. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about geothermal energy for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt to develop their own policy proposals related to geothermal energy in the states. Coordination with the National Geothermal Collaborative: NCSL worked and coordinated with the National Geothermal Collaborative (NGC) to ensure that state legislatures were represented in all aspects of the NGC's efforts. NCSL participated in NGC steering committee conference calls, attended and participated in NGC business meetings and reviewed publications for the NGC. Additionally, NCSL and WSUEP staff drafted a series of eight issue briefs published by the NGC

  3. Geothermal Progress Monitor: Report No. 14

    SciTech Connect

    Not Available

    1992-12-01

    This issue of the Geothermal Progress Monitor, the 14th since its inception in 1980, highlights the anticipated rapid growth in the use of geothermal heat pumps and documents the continued growth in the use of geothermal energy for power generation, both in this country and abroad. In countries with a relatively large demand for new generation capacity, geothermal, if available, is being called on as a preferable alternative to the use of domestic or imported oil. On the other hand, in this country where current demand for new capacity is less, geothermal energy is commonly being put to use in small power generation units operating on the hot water resource.

  4. Measuring trauma and stressful events in childhood and adolescence among patients with first-episode psychosis: Initial factor structure, reliability, and validity of the Trauma Experiences Checklist

    PubMed Central

    Cristofaro, Sarah L.; Cleary, Sean D.; Wan, Claire Ramsay; Broussard, Beth; Chapman, Colby; Haggard, Patrick J.; Jananeh, Sara; Myers, Neely L.; Compton, Michael T.

    2013-01-01

    Past trauma and stressful events, especially in childhood and adolescence, are common among individuals with serious mental illnesses like schizophrenia. Traumatic experiences are thought to be a socio-environmental risk factor not only for poorer outcomes, but also potentially for the onset of these disorders. Because improved measurement tools are needed, we developed and studied, among 205 first-episode psychosis patients, the factor structure, internal consistency reliability, and initial validity of the Trauma Experiences Checklist (TEC), our measure of trauma and stressful events during childhood/adolescence. We assessed validity of subscales using correlations with Childhood Trauma Questionnaire-Short Form, Parental Harsh Discipline, Violence Exposure, and TEC-Informant Version scores. Exploratory factor analysis resulted in two internally consistent subscales (Cronbach’s =0.79 and 0.80, respectively), interpersonal abuse and family stress, and violence, death, and legal involvement. Scores from the former subscale were substantially associated with CTQ-SF physical, emotional, and sexual abuse (r=0.42–0.57, all p<0.001) and Violence Exposure (r=0.49, p<0.001). On the other hand, violence, death, and legal involvement scores were most highly correlated with Violence Exposure (r=0.49, p<0.001), and not with most CTQ-SF subscales. The TEC is a potentially useful tool in assessing diverse traumatic life events across various social contexts during childhood and adolescence. PMID:23850437

  5. Direct utilization of geothermal energy in western South Dakota agribusiness. Final report

    SciTech Connect

    Howard, S.M.

    1983-09-01

    This project involved the direct utilization of geothermal energy for (1) space heating of farm and ranch buildings, (2) drying grain, and (3) providing warm stock water during the winter. The site for this demonstration project was the Diamond Ring Ranch north of Midland, South Dakota. Geothermal water flowing from an existing well into the Madison Aquifer was used to heat four homes, a shop, a hospital barn for cattle, and air for a barn and grain dryer. This site is centrally located in the western region of South Dakota where geothermal water is available from the Madison Aquifer. The first year of the project involved the design of the heating systems and its construction while the following years were for operation, testing, demonstrating, and monitoring the system. Required modifications and improvements were made during this period. Operating modifications and improvements were made during this period. Operating experience showed that such application of geothermal resources is feasible and can result in substantial fuel savings. Economic analyses under a variety of assumptions generally gave payback periods of less than ten years. Numerous technical recommendations are made. The most significant being the necessity of passive protection from freezing of remote geothermal systems subject to winter shut downs caused by power or equipment failure. The primary institutional recommendation is to incorporate a use for the geothermal water such as irrigation or stock watering into agribusiness-related geothermal development.

  6. Geothermal resources of California sedimentary basins

    USGS Publications Warehouse

    Williams, C.F.; Grubb, F.V.; Galanis, S.P.

    2004-01-01

    The 2004 Department of Energy (DOE) Strategic Plan for geothermal energy calls for expanding the geothermal resource base of the United States to 40,000 MW of electric power generating potential. This will require advances in technologies for exploiting unconventional geothermal resources, including Enhanced Geothermal Systems (EGS) and geopressured geothermal. An investigation of thermal conditions in California sedimentary basins through new temperature and heat flow measurements reveals significant geothermal potential in some areas. In many of the basins, the combined cooling effects of recent tectonic and sedimentary processes result in relatively low (<60 mW/m2) heat flow and geothermal gradients. For example, temperatures in the upper 3 km of San Joaquin, Sacramento and Ventura basins are typically less than 125??C and do not reach 200??c by 5 km. By contrast, in the Cuyama, Santa Maria and western Los Angeles basins, heat flow exceeds 80 mW/m2 and temperatures near or above 200??C occur at 4 to 5 km depth, which represents thermal conditions equivalent to or hotter than those encountered at the Soultz EGS geothermal site in Europe. Although the extractable geothermal energy contained in these basins is not large relative to the major California producing geothermal fields at The Geysers or Salton Sea, the collocation in the Los Angeles basin of a substantial petroleum extraction infrastructure and a major metropolitan area may make it attractive for eventual geothermal development as EGS technology matures.

  7. Mexican geothermal development and the future

    SciTech Connect

    Serrano, J.M.E.V.

    1998-10-01

    Geothermics in Mexico started in 1954, by drilling the first geothermal well in Pathe, State of Hidalgo, which reached a depth of 237 meters. In 1959 electrical generation from geothermal origin began, with an installed capacity of 3.5 MW. From 1959 to 1994 Mexico increased its installed capacity to 753 MW, by developing three geothermal fields: Cerro Prieto, Los Azufres, and Los Humeros. Currently, 177 wells produce steam at a rate of 36 tons per hour (t/h) each. Comision Federal de Electricidad (CFE, Federal Commission of Electricity) has planned to increase the geothermal-electric installed capacity through construction and installation of several projects. Repowering of operating units and development of new geothermal zones will also allow Mexican geothermal growth.

  8. Reliability physics

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Ross, R. G., Jr.

    1984-01-01

    Speakers whose topics relate to the reliability physics of solar arrays are listed and their topics briefly reviewed. Nine reports are reviewed ranging in subjects from studies of photothermal degradation in encapsulants and polymerizable ultraviolet stabilizers to interface bonding stability to electrochemical degradation of photovoltaic modules.

  9. Geothermal Reservoirs: Products of Cooling Plutons

    SciTech Connect

    Denis L. Norton

    2002-09-24

    The goals of this project were to develop an in depth understanding of how geothermal reservoirs form and elucidate those features that could potentially be useful in exploration and development of additional energy reserves. Collaboration with Jeff Hulen, EGI helped closely coordinate theoretical concepts and computational experiments with geologic reality in fulfillment of the tasks for this project. Initial reconnaissance computations with Tom Brikowski, University of Texas were critical in realizing the final products of this project. The products of this work contribute basic understanding of the dynamical conditions attendant to the formation of reservoirs in general and the Geysers reservoir in particular. The most exciting of the discoveries were a combination of mineralogical, computational, and geothermometric data sets that revealed a chaotic-like behavior of the processes is critical in the formation of reservoirs near cooling plutions. This discovery provides a fundamental basis for improving resource assessment and exploration methods for geothermal energy associated with very young magmas. Some of the main results are documented in scientific publications, and DOE progress reports. An additional publication is in preparation on the overall significance of fracture propagation and microseismic activity around young magmas.

  10. Geothermal Program Review XII: proceedings. Geothermal Energy and the President's Climate Change Action Plan

    SciTech Connect

    Not Available

    1994-12-31

    Geothermal Program Review XII, sponsored by the Geothermal Division of US Department of Energy, was held April 25--28, 1994, in San Francisco, California. This annual conference is designed to promote effective technology transfer by bringing together DOE-sponsored researchers; utility representatives; geothermal energy developers; suppliers of geothermal goods and services; representatives from federal, state, and local agencies; and others with an interest in geothermal energy. In-depth reviews of the latest technological advancements and research results are presented during the conference with emphasis on those topics considered to have the greatest potential to impact the near-term commercial development of geothermal energy.

  11. Use of Geothermal Energy for Electric Power Generation

    SciTech Connect

    Mashaw, John M.; Prichett, III, Wilson

    1980-10-23

    The National Rural Electric Cooperative Association and its 1,000 member systems are involved in the research, development and utilization of many different types of supplemental and alternative energy resources. We share a strong commitment to the wise and efficient use of this country's energy resources as the ultimate answer to our national prosperity and economic growth. WRECA is indebted to the United States Department of Energy for funding the NRECA/DOE Geothermal Workshop which was held in San Diego, California in October, 1980. We would also like to express our gratitude to each of the workshop speakers who gave of their time, talent and experience so that rural electric systems in the Western U. S. might gain a clearer understanding of the geothermal potential in their individual service areas. The participants were also presented with practical, expert opinion regarding the financial and technical considerations of using geothermal energy for electric power production. The organizers of this conference and all of those involved in planning this forum are hopeful that it will serve as an impetus toward the full utilization of geothermal energy as an important ingredient in a more energy self-sufficient nation. The ultimate consumer of the rural electric system, the member-owner, expects the kind of leadership that solves the energy problems of tomorrow by fully utilizing the resources at our disposal today.

  12. Geothermal gradients in Mississippi embayment

    SciTech Connect

    Staub, W.P.; Treat, N.L.

    1983-09-01

    A statistical analysis of bottom-hole temperatures from oil and gas wells in the northern Mississippi embayment suggests that the geothermal gradient below a depth of 1 km is low (22.2/sup 0/C/km) and for the New Madrid seismic zone, it is even lower (15.7/sup 0/C/km). These data support the tentative conclusion of Swanberg et al that ground-water convection is the source of near-surface heat in shallow water wells of the region. Research by Mitchell et al had suggested a high geothermal gradient in the crust and upper mantel beneath the New Madrid seismic zone as a plausible explanation for the lower than average compressional wave velocities observed there. Warmer than normal wells in the northern Mississippi embayment are scattered at random and may be attributed to random error in the data. Deep wells in the southern Mississippi embayment are substantially hotter than wells at a comparable depth farther north. The regional geothermal gradient below a depth of 1 km from northern Louisiana to central Mississippi is 26.9/sup 0/C/km. From central Mississippi to central Alabama, the geothermal gradient (23.1/sup 0/C/km) is comparable to that of the northern Mississippi embayment.

  13. Process for cementing geothermal wells

    DOEpatents

    Eilers, Louis H.

    1985-01-01

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight mono- or copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  14. Guide to Geothermal Heat Pumps

    SciTech Connect

    2011-02-01

    Geothermal heat pumps, also known as ground source heat pumps, geoexchange, water-source, earth-coupled, and earth energy heat pumps, take advantage of this resource and represent one of the most efficient and durable options on the market to heat and cool your home.

  15. Leasing of federal geothermal resources

    NASA Technical Reports Server (NTRS)

    Stone, R. T.

    1974-01-01

    Pursuant to the Geothermal Steam Act of 1970 and the regulations published on December 21, 1973, the first Federal geothermal competitive lease sale was held on January 22, 1974, by the Department of the Interior, offering 33 tracts totalling over 50,000 acres in three Known Geothermal Resource Areas in California. On January 1, 1974, Federal lands outside Known Geothermal Resource Areas were opened to noncompetitive lease applications, of which, 3,763 had been received by June 1, 1974. During fiscal year 1974, a total of 22 competitive leases had been issued in California and Oregon. The principal components in the Department involved in the leasing program are the Geological Survey and the Bureau of Land Management. The former has jurisdiction over drilling and production operations and other activities in the immediate area of operations. The latter receives applications and issues leases and is responsible for managing leased lands under its jurisdiction outside the area of operations. The interrelationships of the above agencies and the procedures in the leasing program are discussed.

  16. Geothermal Exploration Cost and Time

    DOE Data Explorer

    Jenne, Scott

    2013-02-13

    The Department of Energy’s Geothermal Technology Office (GTO) provides RD&D funding for geothermal exploration technologies with the goal of lowering the risks and costs of geothermal development and exploration. The National Renewable Energy Laboratory (NREL) was tasked with developing a metric in 2012 to measure the impacts of this RD&D funding on the cost and time required for exploration activities. The development of this cost and time metric included collecting cost and time data for exploration techniques, creating a baseline suite of exploration techniques to which future exploration cost and time improvements can be compared, and developing an online tool for graphically showing potential project impacts (all available at http://en.openei.org/wiki/Gateway: Geothermal). This paper describes the methodology used to define the baseline exploration suite of techniques (baseline), as well as the approach that was used to create the cost and time data set that populates the baseline. The resulting product, an online tool for measuring impact, and the aggregated cost and time data are available on the Open Energy Information website (OpenEI, http://en.openei.org) for public access. - Published 01/01/2013 by US National Renewable Energy Laboratory NREL.

  17. Remote sensing application on geothermal exploration

    NASA Astrophysics Data System (ADS)

    Gaffar, Eddy Z.

    2013-09-01

    Geothermal energy is produced when water coming down from the surface of the earth and met with magma or hot rocks, which the heat comes from the very high levels of magma rises from the earth. This process produced a heated fluid supplied to a power generator system to finally use as energy. Geothermal field usually associated with volcanic area with a component from igneous rocks and a complex geological structures. The fracture and fault structure are important geological structures associated with geothermal. Furthermore, their geothermal manifestations also need to be evaluated associated their geological structures. The appearance of a geothermal surface manifestation is close to the structure of the fracture and the caldera volcanic areas. The relationship between the fault and geothermal manifestations can be seen in the form of a pattern of alignment between the manifestations of geothermal locations with other locations on the fault system. The use of remote sensing using electromagnetic radiation sensors to record images of the Earth's environment that can be interpreted to be a useful information. In this study, remote sensing was applied to determine the geological structure and mapping of the distribution of rocks and alteration rocks. It was found that remote sensing obtained a better localize areas of geothermal prospects, which in turn could cut the chain of geothermal exploration to reduce a cost of geothermal exploration.

  18. Geothermal reservoir characterization through active thermal testing

    NASA Astrophysics Data System (ADS)

    Jung, Martin; Klepikova, Maria; Jalali, Mohammadreza; Fisch, Hansruedi; Loew, Simon; Amann, Florian

    2016-04-01

    Development and deployment of Enhanced Geothermal Systems (EGS) as renewable energy resources are part of the Swiss Energy Strategy 2050. To pioneer further EGS projects in Switzerland, a decameter-scale in-situ hydraulic stimulation and circulation (ISC) experiment has been launched at the Grimsel Test Site (GTS). The experiments are hosted in a low fracture density volume of the Grimsel granodiorite, similar to those expected at the potential enhanced geothermal system sites in the deep basement rocks of Northern Switzerland. One of the key goals of this multi-disciplinary experiment is to provide a pre- and post-stimulation characterization of the hydraulic and thermal properties of the stimulated fracture network with high resolution and to determine natural structures controlling the fluid flow and heat transport. Active thermal tests including thermal dilution tests and heat tracer tests allow for investigation of groundwater fluid flow and heat transport. Moreover, the spatial and temporal integrity of distributed temperature sensing (DTS) monitoring upgrades the potential and applicability of thermal tests in boreholes (e.g. Read et al., 2013). Here, we present active thermal test results and discuss the advantages and limitations of this method compared to classical approaches (hydraulic packer tests, solute tracer tests, flowing fluid electrical conductivity logging). The experimental tests were conducted in two boreholes intersected by a few low to moderately transmissive fault zones (fracture transmissivity of about 1E-9 m2/s - 1E-7 m2/s). Our preliminary results show that even in low-permeable environments active thermal testing may provide valuable insights into groundwater and heat transport pathways. Read T., O. Bour, V. Bense, T. Le Borgne, P. Goderniaux, M.V. Klepikova, R. Hochreutener, N. Lavenant, and V. Boschero (2013), Characterizing groundwater flow and heat transport in fractured rock using Fiber-Optic Distributed Temperature Sensing

  19. Submarine geothermal resources

    USGS Publications Warehouse

    Williams, D.L.

    1976-01-01

    Approximately 20% of the earth's heat loss (or 2 ?? 1012 cal/s) is released through 1% of the earth's surface area and takes the form of hydrothermal discharge from young (Pleistocene or younger) rocks adjacent to active seafloor-spreading centers and submarine volcanic areas. This amount is roughly equivalent to man's present gross energy consumption rate. A sub-seafloor geothermal reservoir, to be exploitable under future economic conditions, will have to be hot, porous, permeable, large, shallow, and near an energy-deficient, populated land mass. Furthermore, the energy must be recoverable using technology achievable at a competitive cost and numerous environmental, legal and institutional problems will have to be overcome. The highest-temperature reservoirs should be found adjacent to the zones of the seafloor extension or volcanism that are subject to high sedimentation rates. The relatively impermeable sediments reduce hydrothermal-discharge flow rates, forcing the heat to be either conducted away or released by high-temperature fluids, both of which lead to reservoir temperatures that can exceed 300??C. There is evidence that the oceanic crust is quite permeable and porous and that it was amenable to deep (3-5 km) penetration by seawater at least some time in the early stages of its evolution. Most of the heat escapes far from land, but there are notable exceptions. For example, in parts of the Gulf of California, thermal gradients in the bottom sediments exceed 1??C/m. In the coastal areas of the Gulf of California, where electricity and fresh water are at a premium, this potential resource lies in shallow water (< 200 m) and within sight of land. Other interesting areas include the Sea of Japan, the Sea of Okhotsk and the Andaman Sea along the margins of the western Pacific, the Tyrrhenian Sea west of Italy, and the southern California borderland and west flank of the Juan de Fuca Ridge off the west coast of the United States. Many questions remain to be

  20. Sequential Reliability Tests.

    ERIC Educational Resources Information Center

    Eiting, Mindert H.

    1991-01-01

    A method is proposed for sequential evaluation of reliability of psychometric instruments. Sample size is unfixed; a test statistic is computed after each person is sampled and a decision is made in each stage of the sampling process. Results from a series of Monte-Carlo experiments establish the method's efficiency. (SLD)

  1. Reliable solar cookers

    SciTech Connect

    Magney, G.K.

    1992-12-31

    The author describes the activities of SERVE, a Christian relief and development agency, to introduce solar ovens to the Afghan refugees in Pakistan. It has provided 5,000 solar cookers since 1984. The experience has demonstrated the potential of the technology and the need for a durable and reliable product. Common complaints about the cookers are discussed and the ideal cooker is described.

  2. Semiannual progress report for the Idaho Geothermal Program, April 1-September 30, 1979

    SciTech Connect

    Ihrig, R.R.

    1980-03-01

    Progress made by the Idaho Geothermal Program between March 31 and September 30, 1979 is discussed. Geothermal well tests at the Raft River geothermal site, facility construction, and the first hydraulic fracture treatment of a geothermal well are summarized. The results of direct applications experiments are described briefly, including experiments in aquaculture, agriculture, fluidized bed space heating, fluidized bed food drying, essential oil extraction, and geothermal assisted conversion of biomass to ethanol. Improvements to the binary cycle prototype power plant at Raft River, construction progress on the 5-MW pilot plant, and experimental work on direct contact heat exchangers are discussed. Also outlined is progress on environmental studies at Raft River, including a brief discussion of socioeconomic impacts of geothermal development on Cassia County, Idaho. Results are presented of a 48-industry survey conducted to determine industry's views of the technology barriers to accelerating hydrothermal energy commercialization. A projection summarizes the capital and manpower needed through 1987 to place 6800 MW of direct applications development online. Progress reports are also included on DOE's Program Opportunity Notice (PON) Program demonstration projects and DOE's Program Research and Development Announcement (PRDA) Program study projects.

  3. Semiannual progress report for the Idaho Geothermal Program, April 1 to September 30, 1980

    SciTech Connect

    Ihrig, R.R.

    1981-03-01

    The completion of the 5-MW Pilot Power Plant at the Raft River Geothermal Test Site, modification of the similar, binary cycle Prototype Power Plant, and the water treatment program that studies environmentally safe ways to inhibit corrosion and scaling in geothermal power plants and investigates corrosion resistant materials are summarized. Studies of binary geothermal cycles using mixed hydrocarbon working fluids are described as part of the continuing search for ways to produce low-cost electricity from moderate-temperature geothermal fluids. Progress is reported on studies of direct contact heat exchanger concepts, heat rejection systems, and primary heat exchangers with augmentation. As part of the now-ended series of aquaculture experiments, an unsuccessful attempt to incubate common carp embryos in geothermal waters is reported. An experiment in revegetating disturbed land at Raft River is mentioned and progress on DOE's new User Coupled Confirmation Drilling Program is described. An estimate is presented of the amount of hydrothermal energy that could be produced by the year 2000, with and without Federal assistance, for electric generation and direct applications such as industrial process heat. Progress is reported on the Marketing Assistance Program, through which technical information and assistance is provided potential users and developers of geothermal resources. Also reported is progress in DOE's Program Opportunity Notice (PON) Program demonstration projects and Program Research and Development Announcement (PRDA) Program study projects.

  4. DOE Webinar - Residential Geothermal Heat Pump Retrofits (Presentation)

    SciTech Connect

    Anderson, E. R.

    2010-12-14

    This presentation was given December 14, 2010, as part of DOE's Webinar series. The presentation discusses geothermal heat pump retrofits, technology options, and an overview of geothermal energy and geothermal heat pumps.

  5. Seismic methods for resource exploration in enhanced geothermal systems

    SciTech Connect

    Gritto, Roland; Majer, Ernest L.

    2002-06-12

    A finite-difference modeling study of seismic wave propagation was conducted to determine how to best investigate subsurface faults and fracture zones in geothermal areas. The numerical model was created based on results from a previous seismic reflection experiment. A suite of fault models was investigated including blind faults and faults with surface expressions. The seismic data suggest that blind faults can be detected by a sudden attenuation of seismic wave amplitudes, as long the fault is located below the receiver array. Additionally, a conversion from P- to S-waves indicates the reflection and refraction of the P-waves while propagating across the fault. The drop in amplitudes and the excitation of S-waves can be used to estimate the location of the fault at depth. The accuracy of the numerical modeling depends on the availability of a priori in situ information (velocity and density) from borehole experiments in the geothermal area.

  6. Low-Temperature Geothermal Resources, Geothermal Technologies Program (GTP) (Fact Sheet)

    SciTech Connect

    Not Available

    2010-05-01

    This document highlights the applications of low-temperature geothermal resources and the potential for future uses as well as current Geothermal Technologies Program-funded projects related to low-temperature resources.

  7. Geothermal Technologies Program - Geothermal Energy: Putting Creative Ideas to Work (Green Jobs)

    SciTech Connect

    2010-06-01

    Rapid expansion of U.S. geothermal capacity is opening new job opportunities across the nation. With more than 3,000 megawatts (MW) already installed, the United States leads the world in existing geothermal capacity.

  8. Monitoring of Acoustic Emissions Within Geothermal Areas in Iceland: A new Tool for Geothermal Exploration.

    NASA Astrophysics Data System (ADS)

    Brandsdóttir, B.; Gudmundsson, O.

    2007-12-01

    With increased emphasis on geothermal development new exploration methods are needed in order to improve general understanding of geothermal reservoirs, characterize their extent and assess the potential for sustainable power production. Monitoring of acoustic emissions within geothermal areas may provide a new tool to evaluate the spatial extent of geothermal fields and model rock-fluid interactions. Three-dimensional seismic data have been used to assess the spatial and temporal distribution of noise within several high-temperature geothermal fields in Iceland. Seismic noise in the 4-6 Hz range within the Svartsengi field can be attributed to steam hydraulics and pressure oscillations within the geothermal reservoirs. Seismic noise surveys compliment electrical resistivity soundings and TEM-surveys by providing information pertinent to the current geothermal activity and extent of steam fields within the uppermost crust of the geothermal reservoir. Information related to acoustic emissions can thus help define targets for future wells.

  9. Water Resource Assessment of Geothermal Resources and Water Use in Geopressured Geothermal Systems

    SciTech Connect

    Clark, C. E.; Harto, C. B.; Troppe, W. A.

    2011-09-01

    This technical report from Argonne National Laboratory presents an assessment of fresh water demand for future growth in utility-scale geothermal power generation and an analysis of fresh water use in low-temperature geopressured geothermal power generation systems.

  10. National Geothermal Data System (NGDS) Geothermal Data: Community Requirements and Information Engineering

    SciTech Connect

    Anderson, Arlene; Blackwell, David; Chickering, Cathy; Boyd, Toni; Horne, Roland; MacKenzie, Matthew; Moore, Joseph; Nickull, Duane; Richard, Stephen; Shevenell, Lisa A.

    2013-10-01

    To satisfy the critical need for geothermal data to advance geothermal energy as a viable renewable energy contender, the U.S. Department of Energy is investing in the development of the National Geothermal Data System (NGDS). This paper outlines efforts among geothermal data providers nationwide to supply cutting edge geo-informatics. NGDS geothermal data acquisition, delivery, and methodology are discussed. In particular, this paper addresses the various types of data required to effectively assess geothermal energy potential and why simple links to existing data are insufficient. To create a platform for ready access by all geothermal stakeholders, the NGDS includes a work plan that addresses data assets and resources of interest to users, a survey of data providers, data content models, and how data will be exchanged and promoted, as well as lessons learned within the geothermal community.

  11. Proceedings of a Topical Meeting On Small Scale Geothermal Power Plants and Geothermal Power Plant Projects

    SciTech Connect

    1986-02-12

    These proceedings describe the workshop of the Topical Meeting on Small Scale Geothermal Power Plants and Geothermal Power Plant Projects. The projects covered include binary power plants, rotary separator, screw expander power plants, modular wellhead power plants, inflow turbines, and the EPRI hybrid power system. Active projects versus geothermal power projects were described. In addition, a simple approach to estimating effects of fluid deliverability on geothermal power cost is described starting on page 119. (DJE-2005)

  12. Network reliability

    NASA Technical Reports Server (NTRS)

    Johnson, Marjory J.

    1985-01-01

    Network control (or network management) functions are essential for efficient and reliable operation of a network. Some control functions are currently included as part of the Open System Interconnection model. For local area networks, it is widely recognized that there is a need for additional control functions, including fault isolation functions, monitoring functions, and configuration functions. These functions can be implemented in either a central or distributed manner. The Fiber Distributed Data Interface Medium Access Control and Station Management protocols provide an example of distributed implementation. Relative information is presented here in outline form.

  13. Geothermal demonstration: Zunil food dehydration facility

    SciTech Connect

    Maldonado, O. ); Altseimer, J.; Thayer, G.R. ); Cooper, L. ); Caicedo, A. . Inst. Nacional de Electrificacion)

    1991-08-01

    A food dehydration facility was constructed near the town of Zunil, Guatemala, to demonstrate the use of geothermal energy for industrial applications. The facility, with some modifications to the design, was found to work quite satisfactorily. Tests using five different products were completed during the time geothermal energy was used in the plant. During the time the plant was not able to use geothermal energy, a temporary diesel-fueled boiler provided the energy to test dehydration on seven other crops available in this area. The system demonstrates that geothermal heat can be used successfully for dehydrating food products. Many other industrial applications of geothermal energy could be considered for Zunil since a considerable amount of moderate-temperature heat will become available when the planned geothermal electrical facility is constructed there. 6 refs., 15 figs., 7 tabs.

  14. Geothermal direct use engineering and design guidebook

    SciTech Connect

    Lienau, P.J.; Lunis, B.C.

    1990-01-01

    The use of low- and moderate-temperature (50 to 300{degree}F) geothermal resources for direct use applications has increased significantly since the late 1970s. As a result of this growth, and the need for state-of-the-art information on geothermal direct use project development, the Geothermal Direct Use Engineering and Design Guidebook was published. The book contains 20 chapters titled: Introduction; Demonstration projects lessons learned; Nature of geothermal resources; Exploration for direct heat resources; Geothermal fluid sampling techniques; Drilling and well construction; Well testing and reservoir evaluation; Materials selection guidelines; Well pumps; Piping geothermal fluids; Heat exchangers; Space heating equipment; Heat pumps; Absorption refrigeration; Greenhouses; Aquaculture; Industrial applications; Engineering cost analysis; Regulatory and commercial aspects; and Environmental considerations.

  15. The National Geothermal Energy Research Program

    NASA Technical Reports Server (NTRS)

    Green, R. J.

    1974-01-01

    The continuous demand for energy and the concern for shortages of conventional energy resources have spurred the nation to consider alternate energy resources, such as geothermal. Although significant growth in the one natural steam field located in the United States has occurred, a major effort is now needed if geothermal energy, in its several forms, is to contribute to the nation's energy supplies. From the early informal efforts of an Interagency Panel for Geothermal Energy Research, a 5-year Federal program has evolved whose objective is the rapid development of a commercial industry for the utilization of geothermal resources for electric power production and other products. The Federal program seeks to evaluate the realistic potential of geothermal energy, to support the necessary research and technology needed to demonstrate the economic and environmental feasibility of the several types of geothermal resources, and to address the legal and institutional problems concerned in the stimulation and regulation of this new industry.

  16. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, Pascal M.

    1982-01-01

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carry-over through the turbine causes corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  17. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, P.M.

    1979-12-27

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carryover through the turbine causing corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  18. Geothermal energy: tomorrow's alternative today. A handbook for geothermal-energy development in Delaware

    SciTech Connect

    Mancus, J.; Perrone, E.

    1982-08-01

    This is a general procedure guide to various technical, economic, and institutional aspects of geothermal development in Delaware. The following are covered: geothermal as an alternative, resource characteristics, geology, well mechanics and pumping systems, fluid disposal, direct heat utilization-feasibility, environmental and legal issues, permits and regulations, finance and taxation, and steps necessary for geothermal development. (MHR)

  19. Geothermal fracture stimulation technology. Volume III. Geothermal fracture fluids

    SciTech Connect

    Not Available

    1981-01-01

    A detailed study of all available and experimental frac fluid systems is presented. They have been examined and tested for physical properties that are important in the stimulation of hot water geothermal wells. These fluids consist of water-based systems containing high molecular weight polymers in the uncrosslinked and crosslinked state. The results of fluid testing for many systems are summarized specifically at geothermal conditions or until breakdown occurs. Some of the standard tests are ambient viscosity, static aging, high temperature viscosity, fluid-loss testing, and falling ball viscosity at elevated temperatures and pressures. Results of these tests show that unalterable breakdown of the polymer solutions begins above 300/sup 0/F. This continues at higher temperatures with time even if stabilizers or other high temperature additives are included.

  20. Geothermal programs at Lawrence Livermore National Laboratory

    SciTech Connect

    Kasameyer, P.W.; Younker, L.W.

    1987-07-10

    Lawrence Livermore National Laboratory has a number of geothermal programs supported through two offices in the Department of Energy: the Office of Renewable Technologies, Geothermal Technologies Division, and the Office of Basic Energy Sciences, Division of Engineering, Mathematics and Geosciences. Within these programs, we are carrying out research in injection monitoring, optical instrumentation for geothermal wells, seismic imaging methods, geophysical and drilling investigations of young volcanic systems in California, and fundamental studies of the rock and mineral properties.

  1. Plant support capabilities of a geothermal fluid

    SciTech Connect

    Robinson, F.E.; Singh, K.; Berry, W.; Thomas, T.R.

    1980-09-01

    Geothermal fluids and shallow groundwater from Republic Geothermal, Inc. lease area of East Mesa in Imperial County, California were used successfully to irrigate sugar beet, alfalfa, asparagus, date palm, tamarisk, and desert climax vegetation. Chemical characteristics of the two irrigation fluids differed, but total dissolved solids content of the fluids were similar and within the 2000 mg/l range. The geothermal fluid contains elements which could be harmful to irrigated plants or plant consumers.

  2. Origins of acid fluids in geothermal reservoirs

    USGS Publications Warehouse

    Truesdell, Alfred

    1991-01-01

    Acid fluids in geothermal reservoirs are rare. Their occurrence in geothermal systems associated with recent volcanism (Tatun, Sumikawa, Miravalles) probably indicates that the geothermal reservoir fluid was derived from volcanic fluid incompletely neutralized by reaction with feldspars and micas. Superheated steam containing HCl (Larderello, The Geysers) forms acid where it condenses or mixes with liquid at moderate temperatures (325??C). Cryptoacidity occurs at Los Humeros where HCl acidity is formed and neutralized without reaching the surface.

  3. Geothermal drilling research in the United States

    SciTech Connect

    Varnado, S.G.; Maish, A.B.

    1980-01-01

    The high cost of drilling and completing geothermal wells is an impediment to the development of this resource. The Department of Energy (DOE), Division of Geothermal Energy (DGE), is conducting an R and D program directed at reducing well costs through improvements in geothermal drilling and completion technology. This program includes R and D activities in high temperature drilling hardware, drilling fluids, lost circulation control methods, completion technology, and advanced drilling systems. An overview of the program is presented.

  4. Direct-flash-steam geothermal-power-plant assessment. Final report

    SciTech Connect

    Alt, T.E.

    1982-01-01

    The objective of the project was to analyze the capacity and availability factors of an operating direct flash geothermal power plant. The analysis was to include consideration of system and component specifications, operating procedures, maintenance history, malfunctions, and outage rate. The plant studied was the 75 MW(e) geothermal power plant at Cerro Prieto, Mexico, for the years 1973 to 1979. To describe and assess the plant, the project staff reviewed documents, visited the plant, and met with staff of the operating utility. The high reliability and availability of the plant was documented and actions responsible for the good performance were identified and reported. The results are useful as guidance to US utilities considering use of hot water geothermal resources for power generation through a direct flash conversion cycle.

  5. Hawaii Energy Resource Overviews. Volume 1. Potential noise issues with geothermal development in Hawaii

    SciTech Connect

    Burgess, J.C.

    1980-06-01

    This report concerns primarily the environmental noise expected to arise from construction and operation at HGP-A. A brief discussion of expected noise effects if the geothermal field is developed is included. Some of this discussion is applicable to noise problems that may arise if other geothermal fields are found and developed, but site-specific discussion of other fields can be formulated only when exact locations are identified. There is information concerning noise at other geothermal fields, especially the Geysers. This report includes only second-hand references to such information. No measurements of ambient sound levels near the HGP-A are available, no reliable and carefully checked sound level measurements from the HGP-A well operation are available.

  6. Materials for Geothermal Production

    SciTech Connect

    Kukacka, Lawrence E.

    1992-03-24

    Advances in the development of new materials continue to be made in the Geothermal Materials Project. Many successes have already been accrued and the results used commercially. In FY 1991, work was focused on reducing well drilling, fluid transport and energy conversion costs. Specific activities performed included lightweight CO{sub 2}-resistant well cements, thermally conductive and scale resistant protective liner systems, chemical systems for lost circulation control, corrosion mitigation in process components at The Geysers, and elastomer-metal bonding systems. Efforts to transfer the technologies developed in these efforts to other energy-related sectors of the economy continued and considerable success was achieved. Laboratory testing of BNL-developed phosphate modified calcium aluminate cements confirmed their hydrolytic stability in 300 C brine and their resistance to chemical attack by CO{sub 2}. Specimens were found to be >20 times more resistant to carbonation than Class H cement and twice as resistant as unmodified calcium aluminate cements. Testing of thermally conductive polymer cements as potential corrosion resistant liner materials for use in heat exchanger applications was continued. Field test were conducted in flowing hypersaline brine and the results indicated scale deposition rates lower than those on a high alloy steel. Additional tests for bottoming cycle heat exchange use are planned for FY 1992. Progress was also made with chemical systems for lost circulation control. If materials placement is to be performed by pumping through an open drillpipe or through a drillable straddle packer, a bentonite-ammonium polyphosphate-borax-magnesium oxide formulation, containing fibers or particulates when large fissures are encountered, can be used. This system was ready for demonstration in FY 1991, but a suitable test site did not become available. Optimization of this and three other formulations for use with other Sandia National Laboratories

  7. Reliability of biomass burning estimates from savanna fires: Biomass burning in northern Australia during the 1999 Biomass Burning and Lightning Experiment B field campaign

    NASA Astrophysics Data System (ADS)

    Russell-Smith, Jeremy; Edwards, Andrew C.; Cook, Garry D.

    2003-02-01

    This paper estimates the two-daily extent of savanna burning and consumption of fine (grass and litter) fuels from an extensive 230,000 km2 region of northern Australia during August-September 1999 encompassing the Australian continental component of the Biomass Burning and Lightning Experiment B (BIBLE B) campaign [, 2002]. The extent of burning for the study region was derived from fire scar mapping of imagery from the advanced very high resolution radiometer (AVHRR) on board the National Oceanic and Atmospheric Administration (NOAA) satellite. The mapping was calibrated and verified with reference to one Landsat scene and associated aerial transect validation data. Fine fuel loads were estimated using published fuel accumulation relationships for major regional fuel types. It is estimated that more than 43,000 km2 was burnt during the 25 day study period, with about 19 Mt of fine (grass and litter) fuels. This paper examines assumptions and errors associated with these estimates. It is estimated from uncalibrated fire mapping derived from AVHRR imagery that 417,500 km2 of the northern Australian savanna was burnt in 1999, of which 136,405 km2, or 30%, occurred in the Northern Territory study region. Using generalized fuel accumulation equations, such biomass burning consumed an estimated 212.3 Mt of fine fuels, but no data are available for consumption of coarse fuels. This figure exceeds a recent estimate, based on fine fuels only, for the combined Australian savanna and temperate grassland biomass burning over the period 1990-1999 but is lower than past estimates derived from classification approaches. We conclude that (1) fire maps derived from coarse-resolution optical imagery can be applied relatively reliably to estimate the extent of savanna fires, generally with 70-80% confidence using the approach adopted here, over the major burning period in northern Australia and (2) substantial further field assessment and associated modeling of fuel accumulation

  8. Geothermal Resources of the Cascades: USGS Workshop

    NASA Astrophysics Data System (ADS)

    Guffanti, Marianne; Muffler, Patrick

    Since 1979, the Geothermal Research Program of the U.S. Geological Survey (USGS) has carried out a multidisciplinary research effort in the Cascade Range. The goal of this effort is to understand the tectonics, geology, and hydrology of the Cascades as a framework for characterizing and quantifying its geothermal resources. In May 1985, 5 years after an initial USGS-sponsored Cascades conference [Bacon, 1980], the Geothermal Research Program again sponsored a workshop on geothermal resources of the Cascade Range. Motivation for the workshop came primarily from the conviction within the Geothermal Research Program that the Cascade effort had advanced sufficiently that a forum with an explicitly geothermal focus was needed to promote the synthesis of ideas from diverse research projects. In addition, it was thought that research drilling plans in the Cascades that were being formulated by various other agencies also could benefit from the examination and evaluation that a workshop would foster. Accordingly, the workshop was designed to develop a common understanding of the status of various investigations among USGS and other scientists working in the Cascades, to stimulate renewed interest in understanding the geothermal regime of this volcanic chain, and to encourage the tectonic, geologic, and hydrologic synthesis necessary for a quantitative assessment of geothermal resources of the Cascades, a major objective of the USGS Geothermal Research Program.

  9. Geothermal Energy Information Dissemination and Outreach

    SciTech Connect

    Dr. John W. Lund

    2005-12-31

    The objective of this project is to continue on-going work by the Geo-Heat Center to develop and disseminate information; provide educational materials; develop short courses and workshops; maintain a comprehensive geothermal resource database; respond to inquiries from the public, industry and government; provide engineering, economic and environmental information and analysis on geothermal technology to potential users and developers; and provide information on market opportunities for geothermal development. These efforts are directed towards increasing the utilization of geothermal energy in the US and developing countries, by means of electric power generation and direct-use.

  10. Washington: a guide to geothermal energy development

    SciTech Connect

    Bloomquist, R.G.; Basescu, N.; Higbee, C.; Justus, D.; Simpson, S.

    1980-06-01

    Washington's geothermal potential is discussed. The following topics are covered: exploration, drilling, utilization, legal and institutional setting, and economic factors of direct use projects. (MHR)

  11. Uncertainty analysis of geothermal energy economics

    NASA Astrophysics Data System (ADS)

    Sener, Adil Caner

    This dissertation research endeavors to explore geothermal energy economics by assessing and quantifying the uncertainties associated with the nature of geothermal energy and energy investments overall. The study introduces a stochastic geothermal cost model and a valuation approach for different geothermal power plant development scenarios. The Monte Carlo simulation technique is employed to obtain probability distributions of geothermal energy development costs and project net present values. In the study a stochastic cost model with incorporated dependence structure is defined and compared with the model where random variables are modeled as independent inputs. One of the goals of the study is to attempt to shed light on the long-standing modeling problem of dependence modeling between random input variables. The dependence between random input variables will be modeled by employing the method of copulas. The study focuses on four main types of geothermal power generation technologies and introduces a stochastic levelized cost model for each technology. Moreover, we also compare the levelized costs of natural gas combined cycle and coal-fired power plants with geothermal power plants. The input data used in the model relies on the cost data recently reported by government agencies and non-profit organizations, such as the Department of Energy, National Laboratories, California Energy Commission and Geothermal Energy Association. The second part of the study introduces the stochastic discounted cash flow valuation model for the geothermal technologies analyzed in the first phase. In this phase of the study, the Integrated Planning Model (IPM) software was used to forecast the revenue streams of geothermal assets under different price and regulation scenarios. These results are then combined to create a stochastic revenue forecast of the power plants. The uncertainties in gas prices and environmental regulations will be modeled and their potential impacts will be

  12. Updated U.S. Geothermal Supply Characterization

    SciTech Connect

    Petty, S.; Porro, G.

    2007-03-01

    This paper documents the approach taken to characterize and represent an updated assessment of U.S. geothermal supply for use in forecasting the penetration of geothermal electrical generation in the National Energy Modeling System (NEMS). This work is motivated by several factors: The supply characterization used as the basis of several recent U.S. Department of Energy (DOE) forecasts of geothermal capacity is outdated; additional geothermal resource assessments have been published; and a new costing tool that incorporates current technology, engineering practices, and associated costs has been released.

  13. Geothermal Progress Monitor. Report No. 15

    SciTech Connect

    Not Available

    1993-12-01

    Two themes dominate this issue of the Geothermal Progress Monitor, the 15th since its inception in 1980. The first of these is the significance of the government/industry partnership role in geothermal development. This joint effort is reflected in the continued, measured growth in the use of geothermal energy, for both power generation and direct use applications, in this country and abroad, as well as in the development of new, innovative technologies to ensure a bright future for the resource. The second theme is the growing popularity of geothermal heat pumps (GHPs) among utilities, their customers, and federal agencies, all with disparate interests in the technology.

  14. Fiscal 1991 geothermal development promotion energy

    NASA Astrophysics Data System (ADS)

    1993-02-01

    The paper surveys the spouting of geothermal fluids in test boring wells, the well logging, and the status of geothermal fluids, as a part of the geothermal development promotion survey in the Mizuwake-Toge south area. In the spouting test of N3-MW-6 well, the 53rd swabbing led successfully to spouting. The spouting amounted to 3.6 tons/h in steam and geothermal water, but stopped spontaneously in 100 minutes. Results of the logging are hardly different between before and after the spouting indicating a maximum temperature of 200 C, barometric pressure of 75, and water levels of a 250-300m section. The geothermal water is a neutral Cl deep-area type. N2-MW-2 well spouted immediately after the 10th swabbing, indicating steam of 3 tons/h at the stable time, geothermal water of 7.3 tons/h, pH9, Cl of 1500ppm, and the total spouting time of 4029 minutes. The place where the geothermal fluid flows in is 635m deep, and when the well head pressure was 1.7-3.9 barometric pressure, the spouted fluid temperature was 199-198 C. The geothermal water is a Cl-HCO3 type. In both wells geothermal water is ground water originated from meteoric water which reacted with peripheral rocks by volcanic heating and was formed in the deep area.

  15. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    NASA Astrophysics Data System (ADS)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  16. Coupling of hydrogeological models with hydrogeophysical data to characterize seawater intrusion and shallow geothermal systems

    NASA Astrophysics Data System (ADS)

    Beaujean, J.; Kemna, A.; Engesgaard, P. K.; Hermans, T.; Vandenbohede, A.; Nguyen, F.

    2013-12-01

    While coastal aquifers are being stressed due to climate changes and excessive groundwater withdrawals require characterizing efficiently seawater intrusion (SWI) dynamics, production of geothermal energy is increasingly being used to hinder global warming. To study these issues, we need both robust measuring technologies and reliable predictions based on numerical models. SWI models are currently calibrated using borehole observations. Similarly, geothermal models depend mainly on the temperature field at few locations. Electrical resistivity tomography (ERT) can be used to improve these models given its high sensitivity to TDS and temperature and its relatively high lateral resolution. Inherent geophysical limitations, such as the resolution loss, can affect the overall quality of the ERT images and also prevent the correct recovery of the desired hydrochemical property. We present an uncoupled and coupled hydrogeophysical inversion to calibrate SWI and thermohydrogeologic models using ERT. In the SWI models, we demonstrate with two synthetic benchmarks (homogeneous and heterogeneous coastal aquifers) the ability of cumulative sensitivity-filtered ERT images using surface-only data to recover the hydraulic conductivity. Filtering of ERT-derived data at depth, where resolution is poorer, and the model errors make the dispersivity more difficult to estimate. In the coupled approach, we showed that parameter estimation is significantly improved because regularization bias is replaced by forward modeling only. Our efforts are currently focusing on applying the uncoupled/coupled approaches on a real life case study using field data from the site of Almeria, SE Spain. In the thermohydrogeologic models, the most sensitive hydrologic parameters responsible for heat transport are estimated from surface ERT-derived temperatures and ERT resistance data. A real life geothermal experiment that took place on the Campus De Sterre of Ghent University, Belgium and a synthetic

  17. Reliability Handbook

    DTIC Science & Technology

    1979-07-01

    44 a . One-sided level ................................. 44 b. Two-sided level .......................................... 44 H. Testing...is at a level of severity at which approximately 50 percent of the test specimens can be expected to fail. This type of experiment is highly efficient...throughout the experiment. D. Choice of Factor Levels a . Number of levels , The number of levels used in the designs described in this manual has been

  18. Regional geothermal exploration in Egypt

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Swanberg, C. A.

    1983-01-01

    A study is presented of the evaluation of the potential geothermal resources of Egypt using a thermal gradient/heat flow technique and a groundwater temperature/chemistry technique. Existing oil well bottom-hole temperature data, as well as subsurface temperature measurements in existing boreholes, were employed for the thermal gradient/heat flow investigation before special thermal gradient holes were drilled. The geographic range of the direct subsurface thermal measurements was extended by employing groundwater temperature and chemistry data. Results show the presence of a regional thermal high along the eastern margin of Egypt with a local thermal anomaly in this zone. It is suggested that the sandstones of the Nubian Formation may be a suitable reservoir for geothermal fluids. These findings indicate that temperatures of 150 C or higher may be found in this reservoir in the Gulf of Suez and Red Sea coastal zones where it lies at a depth of 4 km and deeper.

  19. Boise geothermal district heating system

    SciTech Connect

    Hanson, P.J.

    1985-10-01

    This document describes the Boise geothermal district heating project from preliminary feasibility studies completed in 1979 to a fully operational system by 1983. The report includes information about the two local governments that participated in the project - the City of Boise, Idaho and the Boise Warm Springs Water District. It also discusses the federal funding sources; the financial studies; the feasibility studies conducted; the general system planning and design; design of detailed system components; the legal issues involved in production; geological analysis of the resource area; distribution and disposal; the program to market system services; and the methods of retrofitting buildings to use geothermal hot water for space heating. Technically this report describes the Boise City district heating system based on 170/sup 0/F water, a 4000 gpm production system, a 41,000 foot pipeline system, and system economies. Comparable data are also provided for the Boise Warm Springs Water District. 62 figs., 31 tabs.

  20. Volcanostratigraphy for supporting geothermal exploration

    NASA Astrophysics Data System (ADS)

    Bronto, S.; Sianipar, J. Y.; Pratopo, A. K.

    2016-09-01

    Volcanostratigraphy is stratigraphy related to volcanism and its products. This includes stratigraphy for a general scoping of a regional area and detailed analysis in a local area. On the basis of Indonesian Stratigraphic Code 1996, from low to high rank, volcanostratigraphic units are Hummock (Gumuk), Crown (Khuluk), Brigade (Bregada), Super Brigade (Manggala), and Arc (Busur). For more detailed stratigraphic study these ranked units can be classified into genetic rock units based on source location, processes and absolute age. Genetic processes include transportation and cooling or deposition mechanisms. These lead to physical- and chemical- properties of the volcanic rocks and provide the history of volcanism and potentially geothermal processes in an area. For many areas in Indonesia the understanding of the volcanostratigraphy is an important dataset for geothermal exploration.

  1. Boron sorption from aqueous solution by hydrotalcite and its preliminary application in geothermal water deboronation.

    PubMed

    Guo, Qinghai; Zhang, Yin; Cao, Yaowu; Wang, Yanxin; Yan, Weide

    2013-11-01

    Hydrotalcite and its calcination product were used to treat pure water spiked with various concentrations of boron and geothermal water containing boron as a major undesirable element. The kinetics process of boron sorption by uncalcined hydrotalcite is controlled by the diffusion of boron from bulk solution to sorbent-solution boundary film and its exchange with interlayer chloride of hydrotalcite, whereas the removal rate of boron by calcined hydrotalcite rests with the restoration process of its layered structure. The results of isotherm sorption experiments reveal that calcined hydrotalcite generally has much stronger ability to lower solution boron concentration than uncalcined hydrotalcite. The combination of adsorption of boron on the residue of MgO-Al2O3 solid solution and intercalation of boron into the reconstructed hydrotalcite structure due to "structural memory effect" is the basic mechanism based on which the greater boron removal by calcined hydrotalcite was achieved. As 15 geothermal water samples were used to test the deboronation ability of calcined hydrotalcite at 65 °C, much lower boron removal efficiencies were observed. The competitive sorption of the other anions in geothermal water, such as HCO3-, SO4(2-), and F-, is the reason why calcined hydrotalcite could not remove boron from geothermal water as effectively as from pure boron solution. However, boron removal percents ranging from 89.3 to 99.0% could be obtained if 50 times of sorbent were added to the geothermal water samples. Calcined hydrotalcite is a good candidate for deboronation of geothermal water.

  2. Semiannual progress report for the Idaho Geothermal Program, October 1, 1979-March 31, 1980

    SciTech Connect

    Ihrig, R.R.

    1980-07-01

    Progress is reported for the Idaho Geothermal program between October 1, 1979 and March 31, 1980. Progress on the 5-MW Pilot Power Plant at the Raft River Geothermal Test Site is summarized including construction, steady-state and transient analyses by computer modeling, the geothermal water treatment program, and additional experimental and theoretical work on direct contact heat exchangers. Asbestos-cement pipe failures in the geothermal fluid supply and injection system are also summarized. The successful automatic control-mode testing of the Prototype Power Plant is reported. A continuing direct applications experiment in aquaculture is outlined, and a proposal to study various ramifications of irrigating agricultural and range lands with spent geothermal fluid is described briefly. Also outlined is the second experimental hydraulic fracture treatment of a geothermal well at Raft River as part of the National Well Stimulation Program. The improvements to the Raft River site facilities are described, and progress in providing technical information and assistance in the Outreach, or User Assistance program presented. Also presented is a new DOE program, the User Coupled Confirmation Drilling Program, which is intended to reduce the financial risk of hydrothermal reservoir exploration by the private sector. Progress reports are also included on DOE's Program Opportunity Notice (PON) Program demonstration projects and Program Research and Development Announcement (PRDA) Program study projects.

  3. Geothermal systems of northern Nevada

    USGS Publications Warehouse

    Hose, Richard Kenneth; Taylor, Bruce Edward

    1974-01-01

    Hot springs are numerous and nearly uniformly distributed in northern Nevada. Most occur on the flanks of basins, along Basin and Range (late Miocene to Holocene) faults, while some occur in the inner parts of the basins. Surface temperatures of the springs range from slightly above ambient to, boiling; some springs are superheated. Maximum subsurface water temperatures calculated on the basis of quartz solubility range as high as 252?C, although most are below 190?C. Flows range from a trickle to several hundred liters per minute. The Nevada geothermal systems differ markedly from the power-producing system at The Geysers, Calif., and from those areas with a high potential, for power production (e.g., Yellowstone Park, Wyo.; Jemez Mountains, N. Mex.). These other systems are associated with Quaternary felsic volcanic rocks and probably derive their heat from cooling magma rather high in the crust. In northern Nevada, however, felsic volcanic rocks are virtually all older than 10 million years, and. analogous magmatic heat sources are, therefore, probably lacking. Nevada is part of an area of much higher average heat flow than the rest of the United States. In north-central Nevada, geothermal gradients are as great as 64?C per kilometer in bedrock and even higher in basin fill. The high gradients probably result from a combination of thin crust and high temperature upper mantle. We suggest that the geothermal systems of northern Nevada result from circulation of meteoric waters along Basin and Range faults and that their temperature chiefly depends upon (1) depth of circulation and (2) the geothermal gradient near the faults.

  4. Annotated geothermal bibliography of Utah

    SciTech Connect

    Budding, K.E.; Bugden, M.H.

    1986-01-01

    The bibliography includes all the Utah geothermal references through 1984. Some 1985 citations are listed. Geological, geophysical, and tectonic maps and reports are included if they cover a high-temperature thermal area. The references are indexed geographically either under (1) United States (national studies), (2) regional - western United States or physiographic province, (3) Utah - statewide and regional, or (4) county. Reports concerning a particular hot spring or thermal area are listed under both the thermal area and the county names.

  5. Process for purifying geothermal steam

    DOEpatents

    Li, Charles T.

    1980-01-01

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

  6. Process for purifying geothermal steam

    DOEpatents

    Li, C.T.

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

  7. Reliability Centered Maintenance - Methodologies

    NASA Technical Reports Server (NTRS)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  8. Geothermal Prospector: Supporting Geothermal Analysis Through Spatial Data Visualization and Querying Tools

    SciTech Connect

    Getman, Daniel; Anderson, Arlene; Augustine, Chad

    2015-09-02

    Determining opportunities for geothermal energy can involve a significant investment in data collection and analysis. Analysts within a variety of industry and research domains collect and use these data; however, determining the existence and availability of data needed for a specific analysis activity can be challenging and represents one of the initial barriers to geothermal development [2]. This paper describes the motivating factors involved in designing and building the Geothermal Prospector application, how it can be used to reduce risks and costs related to geothermal exploration, and where it fits within the larger collection of tools that is the National Geothermal Data System (NGDS) [5].

  9. Statistical modeling of software reliability

    NASA Technical Reports Server (NTRS)

    Miller, Douglas R.

    1992-01-01

    This working paper discusses the statistical simulation part of a controlled software development experiment being conducted under the direction of the System Validation Methods Branch, Information Systems Division, NASA Langley Research Center. The experiment uses guidance and control software (GCS) aboard a fictitious planetary landing spacecraft: real-time control software operating on a transient mission. Software execution is simulated to study the statistical aspects of reliability and other failure characteristics of the software during development, testing, and random usage. Quantification of software reliability is a major goal. Various reliability concepts are discussed. Experiments are described for performing simulations and collecting appropriate simulated software performance and failure data. This data is then used to make statistical inferences about the quality of the software development and verification processes as well as inferences about the reliability of software versions and reliability growth under random testing and debugging.

  10. Archean geotherms and supracrustal assemblages

    NASA Astrophysics Data System (ADS)

    Condie, Kent C.

    1984-06-01

    Metamorphic mineral assemblages suggest the existence of variable geotherms and lithospheric thicknesses beneath late Archean continental crust. Archean granite-greenstone terranes reflect steep geotherms (50-70°C/km) while high-grade terranes reflect moderate geotherms similar to present continental crust with high heat flow (25-40°C/km). Corresponding lithosphere thicknesses for each terrane during the late Archean are 35-50 km and 50-75 km, respectively. Early Archean (⩾ 3.0 b.y.) greenstones differ from late Archean (˜ 2.7 b.y.) greenstones by the rarity or absence of andesite and graywacke and the relative abundance of pelite, quartzite, and komatiite. Mature clastic sediments in early greenstones reflect shallow-water, stable-basin deposition. Such rocks, together with granite-bearing conglomerate and felsic volcanics imply the existence of still older granitic source terranes. The absence or rarity of andesite in early greenstones reflects the absence of tectonic conditions in which basaltic and tonalitic magmas are modified to produce andesite. A model is presented in which early Archean greenstones form at the interface between tonalite islands and oceanic lithosphere, over convective downcurrents; high-grade supracrustals form on stable continental edges or interiors; and late Archean greenstones form in intracontinental rifts over mantle plumes.

  11. Klamath Falls geothermal field, Oregon

    SciTech Connect

    Lienau, P.J.; Culver, G.; Lund, J.W.

    1989-09-01

    Klamath Falls, Oregon, is located in a Known Geothermal Resource Area which has been used by residents, principally to obtain geothermal fluids for space heating, at least since the turn of the century. Over 500 shallow-depth wells ranging from 90 to 2,000 ft (27 to 610 m) in depth are used to heat (35 MWt) over 600 structures. This utilization includes the heating of homes, apartments, schools, commercial buildings, hospital, county jail, YMCA, and swimming pools by individual wells and three district heating systems. Geothermal well temperatures range from 100 to 230{degree}F (38 to 110{degree}C) and the most common practice is to use downhole heat exchangers with city water as the circulating fluid. Larger facilities and district heating systems use lineshaft vertical turbine pumps and plate heat exchangers. Well water chemistry indicates approximately 800 ppM dissolved solids, with sodium sulfate having the highest concentration. Some scaling and corrosion does occur on the downhole heat exchangers (black iron pipe) and on heating systems where the geo-fluid is used directly. 73 refs., 49 figs., 6 tabs.

  12. A method for temperature estimation in high-temperature geothermal reservoirs by using synthetic fluid inclusions

    NASA Astrophysics Data System (ADS)

    Ruggieri, Giovanni; Orlando, Andrea; Chiarantini, Laura; Borrini, Daniele; Weisenberger, Tobias B.

    2016-04-01

    Super-hot geothermal systems in magmatic areas are a possible target for the future geothermal exploration either for the direct exploitation of fluids or as a potential reservoirs of Enhanced Geothermal Systems. Reservoir temperature measurements are crucial for the assessment of the geothermal resources, however temperature determination in the high-temperature (>380°C) zone of super-hot geothermal systems is difficult or impossible by using either mechanical temperature and pressure gauges (Kuster device) and electronic devices. In the framework of Integrated Methods for Advanced Geothermal Exploration (IMAGE) project, we developed a method to measure high reservoir temperature by the production of synthetic fluid inclusions within an apparatus that will be placed in the high-temperature zone of geothermal wells. First experiments were carried out by placing a gold capsule containing pre-fractured quartz and an aqueous solution (10 wt.% NaCl + 0.4 wt.% NaOH) in an externally heated pressure vessel. Experimental pressure-temperature conditions (i.e. 80-300 bars and 280-400°C) were set close to the liquid/vapour curve of pure H2O or along the H2O critical isochore. The experiments showed that synthetic fluid inclusions form within a relatively short time (even in 48 hours) and that temperatures calculated from homogenization temperatures and isochores of newly formed inclusions are close to experimental temperatures. A second set of laboratory experiments were carried out by using a stainless steel micro-rector in which a gold capsule (containing the pre-fractured quartz and the aqueous solution) was inserted together with an amount of distilled water corresponding to the critical density of water. These experiments were conducted by leaving the new micro-reactor within a furnace at 400°C and were aimed to reproduce the temperature existing in super-hot geothermal wells. Synthetic fluid inclusions formed during the experiments had trapping temperature

  13. Update and assessment of geothermal economic models, geothermal fluid flow and heat distribution models, and geothermal data bases

    SciTech Connect

    Kenkeremath, D.

    1985-05-01

    Numerical simulation models and data bases that were developed for DOE as part of a number of geothermal programs have been assessed with respect to their overall stage of development and usefulness. This report combines three separate studies that focus attention upon: (1) economic models related to geothermal energy; (2) physical geothermal system models pertaining to thermal energy and the fluid medium; and (3) geothermal energy data bases. Computerized numerical models pertaining to the economics of extracting and utilizing geothermal energy have been summarized and catalogued with respect to their availability, utility and function. The 19 models that are discussed in detail were developed for use by geothermal operators, public utilities, and lending institutions who require a means to estimate the value of a given resource, total project costs, and the sensitivity of these values to specific variables. A number of the models are capable of economically assessing engineering aspects of geothermal projects. Computerized simulations of heat distribution and fluid flow have been assessed and are presented for ten models. Five of the models are identified as wellbore simulators and five are described as reservoir simulators. Each model is described in terms of its operational characteristics, input, output, and other pertinent attributes. Geothermal energy data bases are reviewed with respect to their current usefulness and availability. Summaries of eight data bases are provided in catalogue format, and an overall comparison of the elements of each data base is included.

  14. The total flow concept for geothermal energy conversion

    NASA Technical Reports Server (NTRS)

    Austin, A. L.

    1974-01-01

    A geothermal development project has been initiated at the Lawrence Livermore Laboratory (LLL) to emphasize development of methods for recovery and conversion of the energy in geothermal deposits of hot brines. Temperatures of these waters vary from 150 C to more than 300 C with dissolved solids content ranging from less than 0.1% to over 25% by weight. Of particular interest are the deposits of high-temperature/high-salinity brines, as well as less saline brines, known to occur in the Salton Trough of California. Development of this resource will depend on resolution of the technical problems of brine handling, scale and precipitation control, and corrosion/erosion resistant systems for efficient conversion of thermal to electrical energy. Research experience to date has shown these problems to be severe. Hence, the LLL program emphasizes development of an entirely different approach called the Total Flow concept.

  15. Photovoltaic module reliability workshop

    SciTech Connect

    Mrig, L.

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  16. Photovoltaic module reliability workshop

    NASA Astrophysics Data System (ADS)

    Mrig, L.

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986 to 1990. The reliability photovoltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warrantees available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the U.S., PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  17. Feasibility study of sedimentary enhanced geothermal systems using reservoir simulation

    NASA Astrophysics Data System (ADS)

    Cho, Jae Kyoung

    The objective of this research is to evaluate the preliminary feasibility of commercial geothermal projects, from a sedimentary reservoir with low permeability that requires productivity enhancement, using numerical reservoir simulation. The performance of a sedimentary geothermal reservoir is investigated in terms of reservoir hydraulics and thermal evolution. To build a reliable benchmark for simulation study, validation of the numerical reservoir model with respect to an analytical model is presented, and the process to achieve an acceptable match between the numerical and analytical solutions is described. The analytical model used in this study is based on the work of Gringarten (1978), which consists of a conceptual geothermal reservoir, considering an injection and production well doublet in a homogeneous porous media. A commercial thermal reservoir simulator (STARS from Computer Modeling Group, CMG) is used in this work for numerical modeling. In order to reproduce the analytical model results, the numerical simulation model is modified to include the same assumptions of the analytical model. Simulation model parameters that make the numerical results deviate from the analytical solution, such as the grid block size, time step and no-flow boundary are identified and investigated. An analytical tracer test model proposed by Shook (2000) is numerically modeled. This model allows us to predict the time when the temperature of the produced water decreases by capturing a tracer component at production well. Reservoir simulation models with different porosity and permeability distribution are tested to see the effects of reservoir inhomogeneity and anisotropy. In particular, premature thermal breakthrough due to the presence of high permeability streak in a reservoir model is simulated. In an effort to apply the knowledge we obtained from the analytical solutions, the effects of reservoir rock and water properties, as a function of pressure and temperature, are

  18. Geothermal Research and Development Program. Quarterly technical report, September--December 1992

    SciTech Connect

    Not Available

    1993-01-25

    Results are reported on adsorption of water vapor on reservoir rocks, physics of injection of water into vapor-dominated geothermal reservoirs, earth-tide effects on downhole pressures, injection optimization at the Geysers, effects of salinity in adsorption experiments, interpreting multiwell pressure data from Ohaaki, and estimation of adsorption parameters from transient experiments.

  19. Method to Recover Media Ligand Losses During Sorption of Rare Earth Elements from Simulated Geothermal Brines

    SciTech Connect

    Dean Stull

    2016-05-24

    This document describes the method and results of an in-situ experiment used to confirm that ligand bleed from a sorptive media can be contained. The experiment focused on maintaining the media's sorption of rare earth elements (REE) obtained from a simulated geothermal brine doped with known mineral concentrations.

  20. Evaluating Geothermal Potential in Germany by Numerical Reservoir Modeling of Engineered Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Jain, Charitra; Vogt, Christian; Clauser, Christoph

    2014-05-01

    We model hypothetical Engineered Geothermal System (EGS) reservoirs by solving coupled partial differential equations governing fluid flow and heat transport. Building on EGS's strengths of inherent modularity and storage capability, it is possible to implement multiple wells in the reservoir to extend the rock volume accessible for circulating water in order to increase the heat yield. By varying parameters like flow rates and well-separations in the subsurface, this study looks at their long-term impacts on the reservoir development. This approach allows us to experiment with different placements of the engineered fractures and propose several EGS layouts for achieving optimized heat extraction. Considering the available crystalline area and accounting for the competing land uses, this study evaluates the overall EGS potential and compares it with those of other used renewables in Germany. There is enough area to support 13450 EGS plants, each with six reversed-triplets (18 wells) and an average electric power of 35.3MWe. When operated at full capacity, these systems can collectively supply 4155TWh of electric energy in one year which would be roughly six times the electric energy produced in Germany in the year 2011. Engineered Geothermal Systems make a compelling case for contributing towards national power production in a future powered by a sustainable, decentralized energy system.

  1. Using a new Geothermal Well Field as a Field Laboratory to Facilitate Comprehensive Knowledge

    NASA Astrophysics Data System (ADS)

    Neumann, K.; Dowling, C. B.

    2011-12-01

    In Fall 2010, the faculty of the Department of Geological Sciences at Ball State University (BSU) took advantage of several recently drilled monitoring wells within BSU's newly constructed ground-source geothermal well field, currently the largest in the U.S., to create an undergraduate field laboratory for hydrogeological experiments. Using the Investigative Case-Based Learning approach, upper-level undergraduate students developed research projects that would assist BSU's Facilities in evaluating and maintaining the geothermal fields. The students designed original hypotheses and explored how to test them with the available equipment within one semester. They focused on observing and measuring the potential impact of the geothermal well field on groundwater temperature and flow direction using two shallow monitoring wells in gravel (~30 ft) and eight deeper monitoring wells in limestone (~70 ft). The results will be used for comparisons when the geothermal plant goes online in Fall 2011. Undergraduate and graduate students will perform experiments throughout this initial period and continue even after the geothermal field is activated. Through the use of different assessment tools, including peer evaluation, instructors' assessment and an assessment of understanding, we determined that twenty-five percent of the class gained full comprehensive understanding. These students were able to design new experiments by assessing their semester data, integrating their knowledge from previous classes, and synthesizing new hypotheses. The majority of the class was able to further expand their understanding of the scientific process, but not to the extent as the top students.

  2. Assessment of Geothermal Data Resources and Requirements

    SciTech Connect

    none,

    2008-09-01

    This paper is a review of Geothermal Technologies Program activities and archives related to data collection and analysis. It includes an assessment of the current state of geothermal data, future program and stakeholder data needs, existence of and access to critical data, and high-level direction and prioritization of next steps to meet the Program’s data needs.

  3. Geothermal Progress Monitor report No. 11

    SciTech Connect

    Not Available

    1989-12-01

    This issue of the Geothermal Progress Monitor (GPM) is the 11th since the inception of the publication in 1980. It continues to synthesize information on all aspects of geothermal development in this country and abroad to permit identification and quantification of trends in the use of this energy technology. In addition, the GPM is a mechanism for transferring current information on geothermal technology development to the private sector, and, over time, provides a historical record for those interested in the development pathway of the resource. In sum, the Department of Energy makes the GPM available to the many diverse interests that make up the geothermal community for the multiple uses it may serve. This issue of the GPM points up very clearly how closely knit many of those diverse interests have become. It might well be called an international issue'' since many of its pages are devoted to news of geothermal development abroad, to the efforts of the US industry to participate in overseas development, to the support given those efforts by federal and state agencies, and to the formation of the International Geothermal Association (IGA). All of these events indicate that the geothermal community has become truly international in character, an occurrence that can only enhance the future of geothermal energy as a major source of energy supply worldwide. 15 figs.

  4. Geothermal Energy Contract List: Fiscal Year 1990

    SciTech Connect

    Not Available

    1991-10-01

    The Geothermal Division of the US Department of Energy (DOE) is charged with the lead federal role in the research and development (R D) of technologies that will assist industry in economically exploiting the nation's vast geothermal resources. The Geothermal Energy R D Program represents a comprehensive, balanced approach to establishing all forms of geothermal energy as significant contributors to the nation's energy supply. The program is structured both to maintain momentum in the growth of the existing hydrothermal industry and to develop long-term options offering the greatest promise for practical applications. The Geothermal Energy Contract List, Fiscal Year 1990 is a tabulation of geothermal R D contracts that were begun, ongoing, or completed during FY 1990 (October 1, 1989 through September 30, 1990). The R D activities are performed by national laboratories or industrial, academic, and nonprofit research institutions. The contract list is organized in accordance with the Geothermal Division R D work breakdown structure. The structure hierarchy consists of Resource Category (hydrothermal, geopressured-geothermal, hot dry rock, and magma energy), Project (hard rock penetration, reservoir technology, etc.), and Task (lost circulation control, rock penetration mechanics, etc.). For each contract, the contractor, the FY 1990 funding, and a brief description of the milestones planned for FY 1991 are provided.

  5. Civil litigation and the geothermal industry

    SciTech Connect

    Moore, George M.

    1991-01-01

    This paper offers some reflections on the interactions between the legal profession and the realm of the geothermal scientist and engineer. The author, now a litigation attorney, became an attorney after about fifteen years as an engineer and physicist. Over the past several years the author was involved in litigation related to geothermal contracts.

  6. Environmental overview of geothermal development: northern Nevada

    SciTech Connect

    Slemmons, D.B.; Stroh, J.M.; Whitney, R.A.

    1980-08-01

    Regional environmental problems and issues associated with geothermal development in northern Nevada are studied to facilitate environmental assessment of potential geothermal resources. The various issues discussed are: environmental geology, seismicity of northern Nevada, hydrology and water quality, air quality, Nevada ecosystems, noise effects, socio-economic impacts, and cultural resources and archeological values. (MHR)

  7. Puna Geothermal Venture Hydrologic Monitoring Program

    SciTech Connect

    1990-04-01

    This document provides the basis for the Hydrologic Monitoring Program (HMP) for the Puna Geothermal Venture. The HMP is complementary to two additional environmental compliance monitoring programs also being submitted by Puma Geothermal Venture (PGV) for their proposed activities at the site. The other two programs are the Meteorology and Air Quality Monitoring Program (MAQMP) and the Noise Monitoring Program (NMP), being submitted concurrently.

  8. Missing a trick in geothermal exploration

    NASA Astrophysics Data System (ADS)

    Younger, Paul L.

    2014-07-01

    Expansion of geothermal energy use across the globe is restricted by out-of-date prejudices. It is time for geothermal exploration to be extended to a broader range of environments and rejuvenated with the latest insights from relevant geoscience disciplines.

  9. Geothermal well completions in Cerro Prieto

    SciTech Connect

    Dominguez, B.; Cobo Rivera, J.M.

    1981-01-01

    Geothermal well completion criteria have evolved from 1964 to this date. The evolution started with the common techniques used in oil-well completion and gradually changed to accommodate the parameters directly related to the mineralogic characteristics of the geothermal fluids. While acceptable completions can now be achieved, research techniques and data collection should be improved to optimize the procedures.

  10. Survey of Geothermal Solid Toxic Waste

    SciTech Connect

    Darnell, A.J.; Gay, R.L.; Klenck, M.M.; Nealy, C.L.

    1982-09-30

    This is an early survey and analysis of the types and quantities of solid toxic wastes to be expected from geothermal power systems, particularly at the Salton Sea, California. It includes a literature search (48 references/citations), descriptions of methods for handling wastes, and useful quantitative values. It also includes consideration of reclaiming metals and mineral byproducts from geothermal power systems. (DJE 2005)

  11. Geothermal gradient map of the United States

    SciTech Connect

    Kron, A.; Heiken, G.

    1980-01-01

    A geothermal gradient map is needed in order to determine the hot dry rock (HDR) geothermal resource of the United States. Based on published and unpublished data (including new measurements) the HDR program will produce updated gradient maps annually, to be used as a tool for resource evaluation and exploration. The 1980 version of this map is presented.

  12. Forecast of geothermal-drilling activity

    SciTech Connect

    Mansure, A.J.; Brown, G.L.

    1982-07-01

    The number of geothermal wells that will be drilled to support electric power production in the United States through 2000 A.D. are forecasted. Results of the forecast are presented by 5-year periods for the five most significant geothermal resources.

  13. Geothermal Cogeneration: Iceland's Nesjavellir Power Plant

    ERIC Educational Resources Information Center

    Rosen, Edward M.

    2008-01-01

    Energy use in Iceland (population 283,000) is higher per capita than in any other country in the world. Some 53.2% of the energy is geothermal, which supplies electricity as well as heated water to swimming pools, fish farms, snow melting, greenhouses, and space heating. The Nesjavellir Power Plant is a major geothermal facility, supplying both…

  14. Careers in Geothermal Energy: Power from below

    ERIC Educational Resources Information Center

    Liming, Drew

    2013-01-01

    In the search for new energy resources, scientists have discovered ways to use the Earth itself as a valuable source of power. Geothermal power plants use the Earth's natural underground heat to provide clean, renewable energy. The geothermal energy industry has expanded rapidly in recent years as interest in renewable energy has grown. In 2011,…

  15. Geothermal Energy Potential in Western United States

    ERIC Educational Resources Information Center

    Pryde, Philip R.

    1977-01-01

    Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)

  16. Geothermal progress monitor. Progress report No. 4

    SciTech Connect

    Not Available

    1980-09-01

    The following are included: geothermal power plants proposed and on-line; direct heat applications proposed and operational; trends in drilling activities; exploration; leases; outreach and technical assistance; feasibility studies and application demonstrations; geothermal loan guaranty program; research and development activities; legal, institutional, and regulatory activities; environmental activities; reports and publications; and a directory. (MHR)

  17. Report on Hawaii Geothermal Power Plant Project

    SciTech Connect

    Not Available

    1983-06-01

    The report describes the design, construction, and operation of the Hawaii Geothermal Generator Project. This power plant, located in the Puna District on the island of Hawaii, produces three megawatts of electricity from the steam phase of a geothermal well. (ACR)

  18. Geothermal development issues: Recommendations to Deschutes County

    SciTech Connect

    Gebhard, C.

    1982-07-01

    This report discusses processes and issues related to geothermal development. It is intended to inform planners and interested individuals in Deschutes County about geothermal energy, and advise County officials as to steps that can be taken in anticipation of resource development. (ACR)

  19. Geothermal progress monitor: Report Number 19

    SciTech Connect

    1997-12-01

    Short articles are presented related to activities in the federal government and the geothermal industry, international developments, state and local government activities, technology development, and technology transfer. Power plant tables and a directory of organizations involved in geothermal resource development are included.

  20. Geothermal Power/Oil & Gas Coproduction Opportunity

    SciTech Connect

    DOE

    2012-02-01

    Coproduced geothermal resources can deliver near-term energy savings, diminish greenhouse gas emissions, extend the economic life of oil and gas fields, and profitably utilize oil and gas field infrastructure. This two-pager provides an overview of geothermal coproduced resources.

  1. Geothermal energy exploitation in New Zealand

    SciTech Connect

    Elder, J.W.

    1980-01-01

    The essential factors, human and technical, which control the operation of geothermal systems, particularly those which allow prediction of behavior during and after exploitation, are sketched. The strategy and co-ordination involved in using New Zealand's geothermal resources for power production are considered. The broader aspects of the technical matters involved in the design of the parasitic plant reservoir system are described. (MHR)

  2. A fourth generation reliability predictor

    NASA Technical Reports Server (NTRS)

    Bavuso, Salvatore J.; Martensen, Anna L.

    1988-01-01

    A reliability/availability predictor computer program has been developed and is currently being beta-tested by over 30 US companies. The computer program is called the Hybrid Automated Reliability Predictor (HARP). HARP was developed to fill an important gap in reliability assessment capabilities. This gap was manifested through the use of its third-generation cousin, the Computer-Aided Reliability Estimation (CARE III) program, over a six-year development period and an additional three-year period during which CARE III has been in the public domain. The accumulated experience of the over 30 establishments now using CARE III was used in the development of the HARP program.

  3. National Geothermal Data System: State Geological Survey Contributions to Date

    NASA Astrophysics Data System (ADS)

    Patten, K.; Allison, M. L.; Richard, S. M.; Clark, R.; Love, D.; Coleman, C.; Caudill, C.; Matti, J.; Musil, L.; Day, J.; Chen, G.

    2012-12-01

    In collaboration with the Association of American State Geologists the Arizona Geological Survey is leading the effort to bring legacy geothermal data to the U.S. Department of Energy's National Geothermal Data System (NGDS). NGDS is a national, sustainable, distributed, interoperable network of data and service (application) providers entering its final stages of development. Once completed the geothermal industry, the public, and policy makers will have access to consistent and reliable data, which in turn, reduces the amount of staff time devoted to finding, retrieving, integrating, and verifying information. With easier access to information, the high cost and risk of geothermal power projects (especially exploration drilling) is reduced. This presentation focuses on the scientific and data integration methodology as well as State Geological Survey contributions to date. The NGDS is built using the U.S. Geoscience Information Network (USGIN) data integration framework to promote interoperability across the Earth sciences community and with other emerging data integration and networking efforts. Core to the USGIN concept is that of data provenance; by allowing data providers to maintain and house their data. After concluding the second year of the project, we have nearly 800 datasets representing over 2 million data points from the state geological surveys. A new AASG specific search catalog based on popular internet search formats enables end users to more easily find and identify geothermal resources in a specific region. Sixteen states, including a consortium of Great Basin states, have initiated new field data collection for submission to the NGDS. The new field data includes data from at least 21 newly drilled thermal gradient holes in previously unexplored areas. Most of the datasets provided to the NGDS are being portrayed as Open Geospatial Consortium (OGC) Web Map Services (WMS) and Web Feature Services (WFS), meaning that the data is compatible with a

  4. Reliability and testing

    NASA Technical Reports Server (NTRS)

    Auer, Werner

    1996-01-01

    Reliability and its interdependence with testing are important topics for development and manufacturing of successful products. This generally accepted fact is not only a technical statement, but must be also seen in the light of 'Human Factors.' While the background for this paper is the experience gained with electromechanical/electronic space products, including control and system considerations, it is believed that the content could be also of interest for other fields.

  5. Spacecraft transmitter reliability

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A workshop on spacecraft transmitter reliability was held at the NASA Lewis Research Center on September 25 and 26, 1979, to discuss present knowledge and to plan future research areas. Since formal papers were not submitted, this synopsis was derived from audio tapes of the workshop. The following subjects were covered: users' experience with space transmitters; cathodes; power supplies and interfaces; and specifications and quality assurance. A panel discussion ended the workshop.

  6. Appendix F - GPRA06 geothermal technologies program documentation

    SciTech Connect

    None, None

    2009-01-18

    The primary goal of the Geothermal Technologies Program is to reduce the cost of geothermal generation technologies, including both conventional and enhanced geothermal systems (EGS). EGS are defined as geothermal systems where the reservoir requires substantial engineering manipulation to make using the reservoir economically feasible.

  7. Geothermal heat pump system assisted by geothermal hot spring

    NASA Astrophysics Data System (ADS)

    Nakagawa, M.; Koizumi, Y.

    2016-01-01

    The authors propose a hybrid geothermal heat pump system that could cool buildings in summer and melt snow on the pedestrian sidewalks in winter, utilizing cold mine water and hot spring water. In the proposed system, mine water would be used as cold thermal energy storage, and the heat from the hot spring after its commercial use would be used to melt snow for a certain section of sidewalks. Neither of these sources is viable for direct use application of geothermal resources, however, they become contributing energy factors without producing any greenhouse gases. To assess the feasibility of the proposed system, a series of temperature measurements in the Edgar Mine (Colorado School of Mines' experimental mine) in Idaho Springs, Colorado, were first conducted, and heat/mass transfer analyses of geothermal hot spring water was carried out. The result of the temperature measurements proved that the temperature of Edgar Mine would be low enough to store cold groundwater for use in summer. The heat loss of the hot spring water during its transportation was also calculated, and the heat requirement for snow melt was compared with the heat available from the hot spring water. It was concluded that the heat supply in the proposed usage of hot spring water was insufficient to melt the snow for the entire area that was initially proposed. This feasibility study should serve as an example of "local consumption of locally available energy". If communities start harnessing economically viable local energy in a responsible manner, there will be a foundation upon which to build a sustainable community.

  8. Analysis of production decline in geothermal reservoirs

    SciTech Connect

    Zais, Elliot J.; Bodvarsson, Gunnar

    1980-09-01

    The major objectives of the Decline Curve project were to: (1) test the decline analysis methods used in the petroleum industry on geothermal production data; (2) examine and/or develop new analysis methods; and (3) develop a standard operating procedure for analyzing geothermal production data. Various analysis methods have long been available but they have not been tested on geothermal data because of the lack of publicly available data. The recent release to publication of substantial data sets from Wairakei, New Zealand, Cerro Prieto, Mexico and The Geysers, USA has made this study possible. Geothermal reservoirs are quite different from petroleum reservoirs in many ways so the analysis methods must be tested using geothermal data.

  9. Electric utility companies and geothermal power

    NASA Technical Reports Server (NTRS)

    Pivirotto, D. S.

    1976-01-01

    The requirements of the electric utility industry as the primary potential market for geothermal energy are analyzed, based on a series of structured interviews with utility companies and financial institution executives. The interviews were designed to determine what information and technologies would be required before utilities would make investment decisions in favor of geothermal energy, the time frame in which the information and technologies would have to be available, and the influence of the governmental politics. The paper describes the geothermal resources, electric utility industry, its structure, the forces influencing utility companies, and their relationship to geothermal energy. A strategy for federal stimulation of utility investment in geothermal energy is suggested. Possibilities are discussed for stimulating utility investment through financial incentives, amelioration of institutional barriers, and technological improvements.

  10. Geothermal development plan: Graham/Greenlee Counties

    NASA Astrophysics Data System (ADS)

    White, D. H.; Goldstone, L. A.

    1982-08-01

    The region wide market potential for utilizing geothermal energy was evaluated. Five potential geothermal resource areas with temperature less than 1000C were identified. Seven areas are inferred to contain higher temperature resources and the Clifton Hot Springs have electrical potential. Geothermal resources occur near Safford and Clifton, the two major population centers. Future population growth in the two counties is expected to average less than 2% per year over the next 40 years. Growth in the mining, trade and services economic sectors provide opportunities for the direct utilization of geothermal energy. A regional energy use analysis is included containing energy use and price projections. Water supplies are found to be adequate for urban needs, through agricultural and mineral water use may be limited in the future. A preliminary economic analysis for two district heating systems and a section matching geothermal resources to potential users is presented.

  11. Geothermal energy and the production of electricity

    NASA Astrophysics Data System (ADS)

    Varet, J.

    Geothermal production of electricity, about 2,500 MW throughout the world, is considered. The types of geothermal resources are reviewed. A geothermal field can be used for the production of electricity only if the layer, a porous and permeable stock located at depths of 500 and 1500 m, is carried by a magmatic source at high temperatures. Prospecting and development of high energy geothermal energy are discussed, including feasibility studies and the construction of electric power stations. Once the existence of a field is determined, exploitation can begin, consisting of drilling, steam collecting and purifying, and the construction of turboalternator power plants. An example, the Bouillante-Guadeloupe geothermal power station, is presented. Production sites across the globe are reviewed, and electrical energy costs are discussed.

  12. Geothermal direct applications hardware systems development and testing. 1979 summary report

    SciTech Connect

    Keller, J.G.

    1980-03-01

    Activities performed during calendar year 1979 for the hardware system development and testing task are presented. The fluidized bed technology was applied to the drying of potato by-products and to the exchange of heat to air in the space heating experiment. Geothermal water was flashed to steam and also used as the prime energy source in the steam distillation of peppermint oil. Geothermal water temperatures as low as 112.8/sup 0/C were utilized to distill alcohol from sugar beet juice, and lower temperature water provided air conditioning through an absorption air conditioning system. These experiments are discussed.

  13. Community Geothermal Technology Program: Electrodeposition of minerals in geothermal brine

    SciTech Connect

    Not Available

    1990-12-31

    Objective was to study the materials electrodeposited from geothermal brine, from the HGP-A well in Puna, Hawaii. Due to limitations, only one good set of electrodeposited material was obtained; crystallography indicates that vaterite forms first, followed by calcite and then perhaps aragonite as current density is increased. While the cost to weight ratio is reasonable, the deposition rate is very slow. More research is needed, such as reducing the brittleness. The electrodeposited material possibly could be used as building blocks, tables, benches, etc. 49 figs, 4 tabs, 7 refs.

  14. Federal Geothermal Research Program Update, FY 2000

    SciTech Connect

    Renner, Joel Lawrence

    2001-08-01

    The Department of Energy's Geothermal Program serves two broad purposes: 1) to assist industry in overcoming near-term barriers by conducting cost-shared research and field verification that allows geothermal energy to compete in today's aggressive energy markets; and 2) to undertake fundamental research with potentially large economic payoffs. The four categories of work used to distinguish the research activities of the Geothermal Program during FY 2000 reflect the main components of real-world geothermal projects. These categories form the main sections of the project descriptions in this Research Update. Exploration Technology research focuses on developing instruments and techniques to discover hidden hydrothermal systems and to explore the deep portions of known systems. Research in geophysical and geochemical methods is expected to yield increased knowledge of hidden geothermal systems. Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal reservoirs and enhanced geothermal systems. Research in various reservoir analysis techniques is generating a wide range of information that facilitates development of improved reservoir management tools. Drilling Technology focuses on developing improved, economic drilling and completion technology for geothermal wells. Ongoing research to avert lost circulation episodes in geothermal drilling is yielding positive results. Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Increased output and improved performance of binary cycles will result from investigations in heat cycle research.

  15. Photovoltaic performance and reliability workshop

    SciTech Connect

    Mrig, L.

    1993-12-01

    This workshop was the sixth in a series of workshops sponsored by NREL/DOE under the general subject of photovoltaic testing and reliability during the period 1986--1993. PV performance and PV reliability are at least as important as PV cost, if not more. In the US, PV manufacturers, DOE laboratories, electric utilities, and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in the field were brought together to exchange the technical knowledge and field experience as related to current information in this evolving field of PV reliability. The papers presented here reflect this effort since the last workshop held in September, 1992. The topics covered include: cell and module characterization, module and system testing, durability and reliability, system field experience, and standards and codes.

  16. Geothermal Energy--Heat from the Earth: New Mexico; GeoPowering the West Series Fact Sheet

    SciTech Connect

    Not Available

    2002-04-01

    New Mexico holds considerable reserves of this clean, reliable form of energy that to date have barely been tapped. New Mexico has more acres of geothermally heated greenhouses than any other state, and aquaculture, or fish farming, is a burgeoning enterprise for state residents. Several electric power generation opportunities also have been identified.

  17. Sensitivity of contemporary sea level trends in a global ocean state estimate to effects of geothermal fluxes

    NASA Astrophysics Data System (ADS)

    Piecuch, Christopher G.; Heimbach, Patrick; Ponte, Rui M.; Forget, Gaël

    2015-12-01

    Geothermal fluxes constitute a sizable fraction of the present-day Earth net radiative imbalance and corresponding ocean heat uptake. Model simulations of contemporary sea level that impose a geothermal flux boundary condition are becoming increasingly common. To quantify the impact of geothermal fluxes on model estimates of contemporary (1993-2010) sea level changes, two ocean circulation model experiments are compared. The two simulations are based on a global ocean state estimate, produced by the Estimating the Circulation and Climate of the Ocean (ECCO) consortium, and differ only with regard to whether geothermal forcing is applied as a boundary condition. Geothermal forcing raises the global-mean sea level trend by 0.11 mm yr-1 in the perturbation experiment by suppressing a cooling trend present in the baseline solution below 2000 m. The imposed forcing also affects regional sea level trends. The Southern Ocean is particularly sensitive. In this region, anomalous heat redistribution due to geothermal fluxes results in steric height trends of up to ± 1 mm yr-1 in the perturbation experiment relative to the baseline simulation. Analysis of a passive tracer experiment suggests that the geothermal input itself is transported by horizontal diffusion, resulting in more thermal expansion over deeper ocean basins. Thermal expansion in the perturbation simulation gives rise to bottom pressure increase over shallower regions and decrease over deeper areas relative to the baseline run, consistent with mass redistribution expected for deep ocean warming. These results elucidate the influence of geothermal fluxes on sea level rise and global heat budgets in model simulations of contemporary ocean circulation and climate.

  18. Long-term predictions of minewater geothermal systems heat resources

    NASA Astrophysics Data System (ADS)

    Harcout-Menou, Virginie; de ridder, fjo; laenen, ben; ferket, helga

    2014-05-01

    Abandoned underground mines usually flood due to the natural rise of the water table. In most cases the process is relatively slow giving the mine water time to equilibrate thermally with the the surrounding rock massif. Typical mine water temperature is too low to be used for direct heating, but is well suited to be combined with heat pumps. For example, heat extracted from the mine can be used during winter for space heating, while the process could be reversed during summer to provide space cooling. Altough not yet widely spread, the use of low temperature geothermal energy from abandoned mines has already been implemented in the Netherlands, Spain, USA, Germany and the UK. Reliable reservoir modelling is crucial to predict how geothermal minewater systems will react to predefined exploitation schemes and to define the energy potential and development strategy of a large-scale geothermal - cold/heat storage mine water systems. However, most numerical reservoir modelling software are developed for typical environments, such as porous media (a.o. many codes developed for petroleum reservoirs or groundwater formations) and cannot be applied to mine systems. Indeed, mines are atypical environments that encompass different types of flow, namely porous media flow, fracture flow and open pipe flow usually described with different modelling codes. Ideally, 3D models accounting for the subsurface geometry, geology, hydrogeology, thermal aspects and flooding history of the mine as well as long-term effects of heat extraction should be used. A new modelling approach is proposed here to predict the long-term behaviour of Minewater geothermal systems in a reactive and reliable manner. The simulation method integrates concepts for heat and mass transport through various media (e.g., back-filled areas, fractured rock, fault zones). As a base, the standard software EPANET2 (Rossman 1999; 2000) was used. Additional equations for describing heat flow through the mine (both

  19. Federal Geothermal Research Program Update - Fiscal Year 2001

    SciTech Connect

    Laney, P.T.

    2002-08-31

    This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2001. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed research activities, is focused on expanding the use of geothermal energy.

  20. Geothermal pump dual cycle system

    SciTech Connect

    Matthews, H.B.

    1982-05-11

    Geothermal deep well energy extraction apparatus is provided of the general kind in which solute-bearing hot water is pumped to the earth's surface from a subterranean location by utilizing thermal energy extracted from the hot water for operating a primary turbine-motor for driving a primary electrical generator at the earth's surface, the solute-bearing water being returned by a reinjection well. A surface-located auxiliary turbine-pump combination with both turbine and brine pump elements acting in series with down-well counterparts to furnish the pressure necessary for reinjection of the brine.

  1. Geothermal-well design handbook

    SciTech Connect

    Not Available

    1982-02-01

    A simplified process is presented for estimating the performance of geothermal wells which are produced by natural, flashing flows. The well diameter and depth, and reservoir conditions must be known; then it is possible to determine the total pressure drop in a flowing well, and therefore to find the fluid pressure, temperature, and steam quality at the wellhead. By applying the handbook process to several input data sets, the user can compile sufficient information to determine the interdependence of input and output parameters. (MHR)

  2. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well cements, and further

  3. Colorado State Capitol Geothermal project

    SciTech Connect

    Shepherd, Lance

    2016-04-29

    Colorado State Capitol Geothermal Project - Final report is redacted due to space constraints. This project was an innovative large-scale ground-source heat pump (GSHP) project at the Colorado State Capitol in Denver, Colorado. The project employed two large wells on the property. One for pulling water from the aquifer, and another for returning the water to the aquifer, after performing the heat exchange. The two wells can work in either direction. Heat extracted/added to the water via a heat exchanger is used to perform space conditioning in the building.

  4. New geothermal database for Utah

    USGS Publications Warehouse

    Blackett, Robert E.; ,

    1993-01-01

    The Utah Geological Survey complied a preliminary database consisting of over 800 records on thermal wells and springs in Utah with temperatures of 20??C or greater. Each record consists of 35 fields, including location of the well or spring, temperature, depth, flow-rate, and chemical analyses of water samples. Developed for applications on personal computers, the database will be useful for geochemical, statistical, and other geothermal related studies. A preliminary map of thermal wells and springs in Utah, which accompanies the database, could eventually incorporate heat-flow information, bottom-hole temperatures from oil and gas wells, traces of Quaternary faults, and locations of young volcanic centers.

  5. Geothermal activity near Clearlake, California

    NASA Astrophysics Data System (ADS)

    Burns, K. L.; Potter, R. M.

    Geothermal activity in the region of high heat flow near the city of Clearlake includes hot springs, fumeroles, vents, and areas of hydrothermal alteration. Onshore, the location is controlled by Quaternary longitudinal NNW-trending faults of the San Andreas systems, and the transverse Burns Valley fault. Offshore, an additional control is arcuate graben-forming faults. The city is bracketed by three hydrothermal 'hot spots,' which are Sulphur Bank hot spring, resurgences in Burns Valley, and the Oak Cove hot spot. All three are associated with sharp 'spikes' in the isotherms and locally enhanced heat flow.

  6. Geothermal : Economic Impacts of Geothermal Development in Skamania County, Washington.

    SciTech Connect

    Lesser, Jonathan A.

    1992-07-01

    This report estimates the local economic impacts that could be anticipated from the development of a 100 megawatt (MW) geothermal power plant in eastern Skamania County, Washington, near Mt. Adams, as shown in Figure 1. The study was commissioned by the Bonneville Power Administration to quantify such impacts as part of regional confirmation work recommended by the Northwest Power Planning Council. Skamania County was chosen due to both identified geothermal resources and developer interest. The analysis will focus on two phases: a plant construction phase, including well field development, generating plant construction, and transmission line construction; and an operations phase. Economic impacts will occur to the extent that construction and operations affect the local economy. These impacts will depend on the existing structure of the Skamania County economy and estimates of revenues that may accrue to the county as a result of plant construction, operation, and maintenance. Specific impacts may include additional direct employment at the plant, secondary impacts from wage payments being used to purchase locally produced goods and services, and impacts due to expenditures of royalty and tax payments received by the county. The basis for the analysis of economic impacts in this study is the US Forest Service IMPLAN input-output modeling system.

  7. New geothermal site identification and qualification. Final report

    SciTech Connect

    Not Available

    2004-04-01

    This study identifies remaining undeveloped geothermal resources in California and western Nevada, and it estimates the development costs of each. It has relied on public-domain information and such additional data as geothermal developers have chosen to make available. Reserve estimation has been performed by volumetric analysis with a probabilistic approach to uncertain input parameters. Incremental geothermal reserves in the California/Nevada study area have a minimum value of 2,800 grosss MW and a most-likely value of 4,300 gross MW. For the state of California alone, these values are 2,000 and 3,000 gross MW, respectively. These estimates may be conservative to the extent that they do not take into account resources about which little or no public-domain information is available. The average capital cost of incremental generation capacity is estimated to average $3,100/kW for the California/Nevada study area, and $2,950/kW for the state of California alone. These cost estimates include exploration, confirmation drilling, development drilling, plant construction, and transmission-line costs. For the purposes of this study, a capital cost of $2,400/kW is considered competitive with other renewable resources. The amount of incremental geothermal capacity available at or below $2,400/kW is about 1,700 gross MW for the California/Nevada study area, and the same amount (within 50-MW rounding) for the state of California alone. The capital cost estimates are only approximate, because each developer would bring its own experience, bias, and opportunities to the development process. Nonetheless, the overall costs per project estimated in this study are believed to be reasonable.

  8. Software reliability report

    NASA Technical Reports Server (NTRS)

    Wilson, Larry

    1991-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Unfortunately, the models appear to be unable to account for the random nature of the data. If the same code is debugged multiple times and one of the models is used to make predictions, intolerable variance is observed in the resulting reliability predictions. It is believed that data replication can remove this variance in lab type situations and that it is less than scientific to talk about validating a software reliability model without considering replication. It is also believed that data replication may prove to be cost effective in the real world, thus the research centered on verification of the need for replication and on methodologies for generating replicated data in a cost effective manner. The context of the debugging graph was pursued by simulation and experimentation. Simulation was done for the Basic model and the Log-Poisson model. Reasonable values of the parameters were assigned and used to generate simulated data which is then processed by the models in order to determine limitations on their accuracy. These experiments exploit the existing software and program specimens which are in AIR-LAB to measure the performance of reliability models.

  9. Geothermal areas as analogues to chemical processes in the near-field and altered zone of the potential Yucca Mountain, Nevada repository

    SciTech Connect

    Bruton, C.J.; Glassley, W.E.; Meike, A.

    1995-02-01

    The need to bound system performance of the potential Yucca Mountain repository for thousands of years after emplacement of high-level nuclear waste requires the use of computer codes. The use of such codes to produce reliable bounds over such long time periods must be tested using long-lived natural and historical systems as analogues. The geothermal systems of the Taupo Volcanic Zone (TVZ) in New Zealand were selected as the site most amenable to study. The rocks of the TVZ are silicic volcanics that are similar in composition to Yucca Mountain. The area has been subjected to temperatures of 25 to 300 C which have produced a variety of secondary minerals similar to those anticipated at Yucca Mountain. The availability of rocks, fluids and fabricated materials for sampling is excellent because of widespread exploitation of the systems for geothermal power. Current work has focused on testing the ability of the EQ3/6 code and thermodynamic data base to describe mineral-fluid relations at elevated temperatures. Welfare starting long-term dissolution/corrosion tests of rocks, minerals and manufactured materials in natural thermal features in order to compare laboratory rates with field-derived rates. Available field data on rates of silica precipitation from heated fluids have been analyzed and compared to laboratory rates. New sets of precipitation experiments are being planned. The microbially influenced degradation of concrete in the Broadlands-Ohaaki geothermal field is being characterized. The authors will continue to work on these projects in FY 1996 and expand to include the study of naturally occurring uranium and thorium series radionuclides, as a prelude to studying radionuclide migration in heated silicic volcanic rocks. 32 refs.

  10. Campi Flegrei Deep Drilling Project and geothermal activities in Campania Region (Southern Italy)

    NASA Astrophysics Data System (ADS)

    De Natale, Giuseppe; Troise, Claudia; Troiano, Antonio; Giulia Di Giuseppe, Maria; Mormone, Angela; Carlino, Stefano; Somma, Renato; Tramelli, Anna; Vertechi, Enrico; Sangianantoni, Agata; Piochi, Monica

    2013-04-01

    The Campanian volcanic area has a huge geothermal potential (Carlino et al., 2012), similar to the Larderello-Radicondoli-Amiata region, in Tuscany (Italy), which has been the first site in the World exploited for electric production. Recently, the Campi Flegrei Deep Drilling Project (CFDDP), sponsored by ICDP and devoted to understand and mitigate the extreme volcanic risk in the area, has also risen new interest for geothermal exploration in several areas of Italy. Following the new Italian regulations which favour and incentivise innovative pilot power plants with zero emission, several geothermal projects have started in the Campania Region, characterized by strict cooperation among large to small industries, Universities and public Research Centers. INGV department of Naples (Osservatorio Vesuviano) has the technical/scientific leadership of such initiatives. Most of such projects are coordinated in the framework of the Regional District for Energy, in which a large part is represented by geothermal resource. Leading geothermal projects in the area include 'FORIO' pilot plant project, aimed to build two small (5 MWe each one) power plants in the Ischia island and two projects aimed to build pilot power plants in the Agnano-Fuorigrotta area in the city of Naples, at the easternmost part of Campi Flegrei caldera. One of the Campi Flegrei projects, 'SCARFOGLIO', is aimed to build a 5 MWe geothermal power plant in the Agnano area, whereas the 'START' project has the goal to build a tri-generation power plant in the Fuorigrotta area, fed mainly by geothermal source improved by solar termodynamic and bio-mass. Meanwhile such projects enter the field work operational phase, the pilot hole drilling of the CFDDP project, recently completed, represents an important experience for several operational aspects, which should contitute an example to be followed by the next geothermal activities in the area. It has been furthermore a source of valuable data for geothermal

  11. An Economic Analysis of the Kilauea Geothermal Development and Inter-Island Cable Project

    SciTech Connect

    1990-03-01

    A study by NEA completed in April 1987 shows that a large scale (500 MW) geothermal development on the big island of Hawaii and the inter-island power transmission cable is economically infeasible. This updated report, utilizing additional information available since 1987, reaches the same conclusion: (1) The state estimate of $1.7 billion for development cost of the geothermal project is low and extremely optimistic. more realistic development costs are shown to be in the range of $3.4 to $4.3 billion and could go as high as $4.6 billion. (2) Compared to alternative sources of power generation, geothermal can be 1.7 to 2.4 times as costly as oil, and 1.2 to 1.7 times as costly as a solar/oil generating system. (3) yearly operation and maintenance costs for the large scale geothermal project are estimated to be 44.7 million, 72% greater than a solar/oil generating system. (4) Over a 40-year period ratepayers could pay, on average, between 1.3 (17.2%) and 2.4 cents (33%) per kWh per year more for electricity produced by geothermal than they are currently paying (even with oil prices stabilizing at $45 per barrel in 2010). (5) A comparable solar/oil thermal energy development project is technologically feasible, could be island specific, and would cost 20% to 40% less than the proposed geothermal development. (6) Conservation is the cheapest alternative of all, can significantly reduce demand, and provides the greatest return to ratepayers. There are better options than geothermal. Before the State commits the people of Hawaii to future indebtedness and unnecessary electricity rate increases, more specific study should be conducted on the economic feasibility, timing, and magnitude of the geothermal project. The California experience at The Geyers points up the fact that it can be a very risky and disappointing proposition. The state should demand that proponents and developers provide specific answers to geothermals troubling questions before they make an

  12. Geothermal Geophysical Research in Electrical Methods at UURI

    SciTech Connect

    Wannamaker, Philip E.; Wright, Phillip M.

    1992-03-24

    The principal objective of electrical geophysical research at UURI has been to provide reliable exploration and reservoir assessment tools for the shallowest to the deepest levels of interest in geothermal fields. Three diverse methods are being considered currently: magnetotellurics (MT, and CSAMT), self-potential, and borehole resistivity. Primary shortcomings in the methods addressed have included a lack of proper interpretation tools to treat the effects of the inhomogeneous structures often encountered in geothermal systems, a lack of field data of sufficient accuracy and quantity to provide well-focused models of subsurface resistivity structure, and a poor understanding of the relation of resistivity to geothermal systems and physicochemical conditions in the earth generally. In MT, for example, interpretation research has focused successfully on the applicability of 2-D models in 3-D areas which show a preferred structural grain. Leading computer algorithms for 2-D and 3-D simulation have resulted and are combined with modern methods of regularized inversion. However, 3-D data coverage and interpretation is seen as a high priority. High data quality in our own research surveys has been assured by implementing a fully remote reference with digital FM telemetry and real-time processing with data coherence sorting. A detailed MT profile across Long Valley has mapped a caldera-wide altered tuff unit serving as the primary hydrothermal aquifer, and identified a low-resistivity body in the middle crust under the west moat which corresponds closely with teleseismic delay and low density models. In the CSAMT method, our extensive tensor survey over the Sulphur Springs geothermal system provides valuable structural information on this important thermal regime and allows a fundamental analysis of the CSAMT method in heterogeneous areas. The self-potential (SP) method is promoted as an early-stage, cost-effective, exploration technique for covered hydrothermal

  13. A study of geothermal drilling and the production of electricity from geothermal energy

    SciTech Connect

    Pierce, K.G.; Livesay, B.J.

    1994-01-01

    This report gives the results of a study of the production of electricity from geothermal energy with particular emphasis on the drilling of geothermal wells. A brief history of the industry, including the influence of the Public Utilities Regulatory Policies Act, is given. Demand and supply of electricity in the United States are touched briefly. The results of a number of recent analytical studies of the cost of producing electricity are discussed, as are comparisons of recent power purchase agreements in the state of Nevada. Both the costs of producing electricity from geothermal energy and the costs of drilling geothermal wells are analyzed. The major factors resulting in increased cost of geothermal drilling, when compared to oil and gas drilling, are discussed. A summary of a series of interviews with individuals representing many aspects of the production of electricity from geothermal energy is given in the appendices. Finally, the implications of these studies are given, conclusions are presented, and program recommendations are made.

  14. A Geothermal GIS for Nevada: Defining Regional Controls and Favorable Exploration Terrains for Extensional Geothermal Systems

    USGS Publications Warehouse

    Coolbaugh, M.F.; Taranik, J.V.; Raines, G.L.; Shevenell, L.A.; Sawatzky, D.L.; Bedell, R.; Minor, T.B.

    2002-01-01

    Spatial analysis with a GIS was used to evaluate geothermal systems in Nevada using digital maps of geology, heat flow, young faults, young volcanism, depth to groundwater, groundwater geochemistry, earthquakes, and gravity. High-temperature (>160??C) extensional geothermal systems are preferentially associated with northeast-striking late Pleistocene and younger faults, caused by crustal extension, which in most of Nevada is currently oriented northwesterly (as measured by GPS). The distribution of sparse young (160??C) geothermal systems in Nevada are more likely to occur in areas where the groundwater table is shallow (<30m). Undiscovered geothermal systems may occur where groundwater levels are deeper and hot springs do not issue at the surface. A logistic regression exploration model was developed for geothermal systems, using young faults, young volcanics, positive gravity anomalies, and earthquakes to predict areas where deeper groundwater tables are most likely to conceal geothermal systems.

  15. Geothermal Resource Analysis and Structure of Basin and Range Systems, Especially Dixie Valley Geothermal Field, Nevada

    SciTech Connect

    David Blackwell; Kenneth Wisian; Maria Richards; Mark Leidig; Richard Smith; Jason McKenna

    2003-08-14

    Publish new thermal and drill data from the Dizie Valley Geothermal Field that affect evaluation of Basin and Range Geothermal Resources in a very major and positive way. Completed new geophysical surveys of Dizie Valley including gravity and aeromagnetics and integrated the geophysical, seismic, geological and drilling data at Dizie Valley into local and regional geologic models. Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dizie Valley data that help to understand the nature of large scale constraints on the location and characteristics of the geothermal systems. Documented a relation between natural heat loss for geothermal and electrical power production potential and determined heat flow for 27 different geothermal systems. Prepared data set for generation of a new geothermal map of North American including industry data totaling over 25,000 points in the US alone.

  16. The first geothermal power generation project by Enhanced Geothermal System (EGS) in Korea

    NASA Astrophysics Data System (ADS)

    Jong Lee, Tae; Song, Yoonho; Yoon, Woon-Sang

    2013-04-01

    Though Korea does not have high-enthalpy geothermal resources from volcanic sources, it still has huge amount of geothermal resources at depth; i.e. technical geothermal potential of 19.6 GWe within 6.5 km deep by enhanced geothermal system (EGS) technologies. The first proof of concept project for geothermal power generation by EGS has started in Pohang, Korea in Dec. 2010. The project aims to develop a pilot geothermal power plant of 1 MW or more of installed capacity from a doublet EGS system in 5 years. This work summarizes our two years efforts including geological/geophysical surveys, site selection, civil engineering, permission for drilling, setting up the drill rig, and setting up the micro-seismic network and monitoring. At the end of Dec. 2012, drilling reached down to 2,250 m deep. Results of borehole investigation will be also discussed about.

  17. Neutron imaging for geothermal energy systems

    SciTech Connect

    Bingham, Philip R; Anovitz, Lawrence {Larry} M; Polsky, Yarom

    2013-01-01

    Geothermal systems extract heat energy from the interior of the earth using a working fluid, typically water. Three components are required for a commercially viable geothermal system: heat, fluid, and permeability. Current commercial electricity production using geothermal energy occurs where the three main components exist naturally. These are called hydrothermal systems. In the US, there is an estimated 30 GW of base load electrical power potential for hydrothermal sites. Next generation geothermal systems, named Enhanced Geothermal Systems (EGS), have an estimated potential of 4500 GW. EGSs lack in-situ fluid, permeability or both. As such, the heat exchange system must be developed or engineered within the rock. The envisioned method for producing permeability in the EGS reservoir is hydraulic fracturing, which is rarely practiced in the geothermal industry, and not well understood for the rocks typically present in geothermal reservoirs. High costs associated with trial and error learning in the field have led to an effort to characterize fluid flow and fracturing mechanisms in the laboratory to better understand how to design and manage EGS reservoirs. Neutron radiography has been investigated for potential use in this characterization. An environmental chamber has been developed that is suitable for reproduction of EGS pressures and temperatures and has been tested for both flow and precipitations studies with success for air/liquid interface imaging and 3D reconstruction of precipitation within the core.

  18. Symposium in the field of geothermal energy

    SciTech Connect

    Ramirez, Miguel; Mock, John E.

    1989-04-01

    Mexico and the US are nations with abundant sources of geothermal energy, and both countries have progressed rapidly in developing their more accessible resources. For example, Mexico has developed over 600 MWe at Cerro Prieto, while US developers have brought in over 2000 MWe at the Geysers. These successes, however, are only a prologue to an exciting future. All forms of energy face technical and economic barriers that must be overcome if the resources are to play a significant role in satisfying national energy needs. Geothermal energy--except for the very highest grade resources--face a number of barriers, which must be surmounted through research and development. Sharing a common interest in solving the problems that impede the rapid utilization of geothermal energy, Mexico and the US agreed to exchange information and participate in joint research. An excellent example of this close and continuing collaboration is the geothermal research program conducted under the auspices of the 3-year agreement signed on April 7, 1986 by the US DOE and the Mexican Comision Federal de Electricidad (CFE). The major objectives of this bilateral agreement are: (1) to achieve a thorough understanding of the nature of geothermal reservoirs in sedimentary and fractured igneous rocks; (2) to investigate how the geothermal resources of both nations can best be explored and utilized; and (3) to exchange information on geothermal topics of mutual interest.

  19. Updated U.S. Geothermal Supply Curve

    SciTech Connect

    Augustine, C.; Young, K. R.; Anderson, A.

    2010-02-01

    This paper documents the approach used to update the U.S. geothermal supply curve. The analysis undertaken in this study estimates the supply of electricity generation potential from geothermal resources in the United States and the levelized cost of electricity (LCOE), capital costs, and operating and maintenance costs associated with developing these geothermal resources. Supply curves were developed for four categories of geothermal resources: identified hydrothermal (6.4 GWe), undiscovered hydrothermal (30.0 GWe), near-hydrothermal field enhanced geothermal systems (EGS) (7.0 GWe) and deep EGS (15,900 GWe). Two cases were considered: a base case and a target case. Supply curves were generated for each of the four geothermal resource categories for both cases. For both cases, hydrothermal resources dominate the lower cost range of the combined geothermal supply curve. The supply curves indicate that the reservoir performance improvements assumed in the target case could significantly lower EGS costs and greatly increase EGS deployment over the base case.

  20. Reno Industrial Park geothermal district heating system

    SciTech Connect

    Lienau, P.J.

    1997-04-01

    Ten miles south of Reno, on U.S. 395 near the junction of the road to historic Virginia City, is Steamboat Hot Springs, a popular stop for travelers since the mid-1800s. Legend has it that Mark Twain named the geothermal area because it looked and sounded like a chugging Mississippi River paddle-wheeler. It is said when he first saw the steam rising from the ground he exclaimed, {open_quotes}Behold! A Steamboat in the desert.{close_quotes} Over the years, the area has been used for its relaxing and curative qualities by Indians, settlers, and geothermal experts. Since the mid-1980s five geothermal power plants have been built at Steamboat Springs and in December 1996 it was announced that the proposed largest geothermal district heating system in the U.S. would supply an industrial park in the area. The active geothermal area is located within the north-south trending graben like trough between the Carson and Virginia Ranges at the southern end of Truckee Meadows. Hot springs and other geothermal features occur over an area of about one square mile. The mid-basin location is controlled by faulting more or less parallel to the major mountain-front faults. It is believed that the heat source for the system is a cooling magmatic body at depth. The Steamboat geothermal area consists of a deep, high-temperature (215{degrees}C to 240{degrees} C) geothermal system, a shallower, moderate-temperature (160{degrees}C to 18{degrees} C) system, and a number of shallow low-temperature (30{degrees}C to 80{degrees}C) subsystems. The higher temperature systems are used for electric-power generation. It is proposed that the exit fluids from the electric power plants be used for the geothermal district heating system.

  1. Geothermal Drilling in Cerro Prieto

    SciTech Connect

    Aguirre, B. D.; Garcia, G. S.

    1981-01-01

    To date, 71 geothermal wells have been drilled in Cerro Prieto. The activity has been divided into several stages, and, in each stage, attempts have been made to correct deficiencies that were gradually detected. Some of these problems have been solved; others, such as those pertaining to well casing, cement, and cementing jobs, have persisted. The procedures for well completion--the most important aspect for the success of a well--that were based on conventional oil well criteria have been improved to meet the conditions of the geothermal reservoir. Several technical aspects that have improved should be further optimized, even though the resolutions are considered to be reasonably satisfactory. Particular attention has been given to the development of a high-temperature drilling fluid capable of being used in drilling through lost circulation zones. Conventional oil well drilling techniques have been used except where hole-sloughing is a problem. Sulfonate lignitic mud systems have been used with good results. When temperatures exceed 300 C (572 F), it has been necessary to use an organic polymer to stabilize the mud properties.

  2. Geothermal Field Development in Mexico

    SciTech Connect

    Espinosa, Hector Alonso

    1983-12-15

    Mexico is a Country characterized by its diversified means of Power Gerneration. Actual installed capacity is almost 19000 MW, of which 205 MW corresponds to Geothermal Plants, that is, 180 MW in Cerro Prieto and 25 MW of Portable Plants in Los Azufres. To date, 346 area with exploitation possibilites, are known. They are mainly distributed along the Volcanic Belt where the most prominent are, Los Azufres, La Primavera, Los Humeros, Ixtlan De Los Hervores and Los Negritos, among others. Proved reserves are 920 MW, and the accessible resource base are 4600 MW identified and 6000 MW undiscovered. The long range construction studies intends to achieve a total installed capacity of 100000 MW, by the end of this century, including 2000 MW Geothermal, through conventional and Portable Plants. It is not a definite program but a development strategy. The carrying out of a definite program, will depend upon the confirmation of Hypothesis made in previous studies, and the economic decisions related to the financial sources availability, and techologies to be used in the future as well.

  3. THE FUTURE OF GEOTHERMAL ENERGY

    SciTech Connect

    J. L. Renner

    2006-11-01

    Recent national focus on the value of increasing our supply of indigenous, renewable energy underscores the need for reevaluating all alternatives, particularly those that are large and welldistributed nationally. This analysis will help determine how we can enlarge and diversify the portfolio of options we should be vigorously pursuing. One such option that is often ignored is geothermal energy, produced from both conventional hydrothermal and Enhanced (or engineered) Geothermal Systems (EGS). An 18-member assessment panel was assembled in September 2005 to evaluate the technical and economic feasibility of EGS becoming a major supplier of primary energy for U.S. base-load generation capacity by 2050. This report documents the work of the panel at three separate levels of detail. The first is a Synopsis, which provides a brief overview of the scope, motivation, approach, major findings, and recommendations of the panel. At the second level, an Executive Summary reviews each component of the study, providing major results and findings. The third level provides full documentation in eight chapters, with each detailing the scope, approach, and results of the analysis and modeling conducted in each area.

  4. Geothermal eel farm in Slovakia

    SciTech Connect

    Lund, J.W.; Thomka, J.; Sarlinova, K.

    1998-12-01

    Turcianske Teplice, a small town in west-central Slovakia, has written records of using thermal waters since 1281. In 1992, an eel raising farm was started on the outskirts of the town and since 1994, it has been operated by the firm of Janex Slovensko. The farm, using a specialized water recirculation system, raises a species of migrating eels (Anguilla anguilla). A 220-meter deep well at 42 C provides 48 gpm to the facility for heating through a plate heat exchanger. This is the maximum flow permitted, so as not to influence the springs and wells at the spa about 1 km away. For this reason, the flow is monitored carefully by the state. A second geothermal well at 52 C and 1,500 meters deep is used only as an observation well. Cold water, which is heated by the geothermal water, is pumped from wells near the Turiec River 1.8 km away at 8 to 12 C, depending upon the season, for use in the various holding or raising tanks. The operation of the farm is described.

  5. Parts, Materials, and Processes Experience Summary. Volume 1; [Catalog of ALERT and Other Information on Basic Design, Reliability, Quality and Applications Programs

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The ALERT program, a system for communicating common problems with parts, materials, and processes, is condensed and catalogued. Expanded information on selected topics is provided by relating the problem area (failure) to the cause, the investigations and findings, the suggestions for avoidance (inspections, screening tests, proper part applications), and failure analysis procedures. The basic objective of ALERT is the avoidance of the recurrence of parts, materials, and processed problems, thus improving the reliability of equipment produced for and used by the government.

  6. Hydrogen Sulfide Sequestration and Storage in Geothermal System: New Mitigation Strategy to Reduce H2S from the Atmosphere and Detect its Mineralization with Multiple Sulfur Isotopic Systematics

    NASA Astrophysics Data System (ADS)

    Marieni, C.; Stefansson, A.; Gudbrandsson, S.; Gunnarsson, I.; Aradottir, E. S.; Gunnarsson Robin, J.; Ono, S.

    2015-12-01

    Hydrogen sulfide (H2S) is one of the major components in geothermal fluids and is commonly emitted into the atmosphere from geothermal power plants causing potential environmental problems. Among several mitigation methods proposed to reduce the H2S emissions, is H2S sequestration into geothermal systems. Reykjavík Energy is undertaking a pilot project at Hellisheidi geothermal system (SW Iceland) called Sulfix project where H2S is being injected into the geothermal reservoir for permanent sequestration into pyrite. The SulFix project started its operation in June 2014: the soluble geothermal gases are dissolved in geothermal waste water, and injected at 8 bars into the high temperature reservoir (>200˚C) at 750 m below the wellhead. The reactions involving sulfur in the geothermal reservoir may be traced using sulfur fluid chemistry and multiple sulfur isotope systematics (32S, 33S, 34S and 36S), including mixing between the reservoir geothermal fluid and the injection fluid, sulfide mineralization and oxidation of sulfide to sulfate. In this study we investigated the multiple sulfur isotope systematics upon sulfide mineralization under geothermal conditions. High temperature flow through experiments were carried out in basaltic glass at 200-250°C and ~5 mmol/kg H2S to study the fluid-rock interaction. The results indicate that the sulfide mineralization occurs rapidly under geothermal conditions, highlighting the leaching rate of iron from the basaltic glass as the mineralization rate determining factor. Moreover, the formation of sulfide may be traced using the δ34S-Δ33S relationship in the fluids and pyrite formation - for example to determine if non-reactive mixing between the injection fluids and reservoir fluids occurs at Hellisheidi. The experimental results have been further supported by geochemical modeling involving multiple sulfur isotope fractionation between aqueous sulfide species and rocks upon basalt dissolution and secondary pyrite formation.

  7. Projected Geothermal Energy Development in Canada

    SciTech Connect

    Souther, Jack G.

    1980-12-01

    A systematic evaluation of geothermal energy resources in Canada was begun in 1973 with the compilation of an inventory of thermal springs and young igneous centres (11) and a study of the thermal regime of the Central Canada Plains (15). The status of this work is still very preliminary. The nature, distribution and grade of the geothermal resource-base can be estimated within reasonable limits but the impact of future economic and political constraints, and the rate of development of new conversion technologies are more difficult to forecast. Thus, projections of geothermal energy development in Canada are necessarily less precise than estimate of the resource-base.

  8. Geothermal training centers in the world

    SciTech Connect

    Dickson, M.H.; Fanelli, M.

    1998-12-01

    The first geothermal training centers began operating in Pisa (Italy) and Kyushu (Japan) in 1970, at the request of UNESCO. From 1979 on, they were joined by another five training centers in Auckland (New Zealand), Reykjavik (Iceland), Mexicali (Mexico), Skopje (Macedonia), and Los Azufres (Mexico). The courses organized in these centers last from one--two weeks to eight--nine months, and they cover all aspects of the research and utilization of geothermal energy. At the moment, these centers seem capable of providing all the qualified and competent personnel required for geothermal projects currently in-flow; but, this situation could deteriorate in the future.

  9. Washington: a guide to geothermal energy development

    SciTech Connect

    Bloomquist, R.G.; Basescu, N.; Higbee, C.; Justus, D.; Simpson, S.

    1980-01-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  10. Alaska: a guide to geothermal energy development

    SciTech Connect

    Basescu, N.; Bloomquist, R.G.; Higbee, C.; Justus, D.; Simpson, S.

    1980-06-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  11. Oregon: a guide to geothermal energy development

    SciTech Connect

    Justus, D.; Basescu, N.; Bloomquist, R.G.; Higbee, C.; Simpson, S.

    1980-06-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  12. INEL Geothermal Environmental Program. 1979 annual report

    SciTech Connect

    Thurow, T.L.; Sullivan, J.F.

    1980-04-01

    The Raft River Geothermal Environmental Program is designed to assess beneficial and detrimental impacts to the ecosystem resulting from the development of moderate temperature geothermal resources in the valley. The results of this research contribute to developing an understanding of Raft River Valley ecology and provide a basis for making management decisions to reduce potential long-term detrimental impacts on the environment. The environmental monitoring and research efforts conducted during the past six years of geothermal development and planned future research are summarized.

  13. Convective, intrusive geothermal plays: what about tectonics?

    NASA Astrophysics Data System (ADS)

    Santilano, A.; Manzella, A.; Gianelli, G.; Donato, A.; Gola, G.; Nardini, I.; Trumpy, E.; Botteghi, S.

    2015-09-01

    We revised the concept of convective, intrusive geothermal plays, considering that the tectonic setting is not, in our opinion, a discriminant parameter suitable for a classification. We analysed and compared four case studies: (i) Larderello (Italy), (ii) Mt Amiata (Italy), (iii) The Geysers (USA) and (iv) Kizildere (Turkey). The tectonic settings of these geothermal systems are different and a matter of debate, so it is hard to use this parameter, and the results of classification are ambiguous. We suggest a classification based on the age and nature of the heat source and the related hydrothermal circulation. Finally we propose to distinguish the convective geothermal plays as volcanic, young intrusive and amagmatic.

  14. Geothermal Lost Circulation Zone Mapping Tool

    SciTech Connect

    Bauman, T.J.

    1985-01-01

    Lost circulation is an expensive and often encountered problem when drilling into geothermal formations. A method is needed to more accurately describe loss zones encountered during geothermal drilling to allow for more realistic testing since present testing techniques are inadequate. A Lost Circulation Zone Mapping Tool (LCZMT) is being developed that will quickly locate a loss zone and then provide a visual image of this zone as it intersects the wellbore. A modified Sandia high temperature Acoustic Borehole Televiewer should allow modeling of geothermal loss zones, which would in turn lead to testing that can be performed to evaluate lost circulation materials under simulated downhole conditions. 5 refs., 5 figs.

  15. Mapping changes in Yellowstone's geothermal areas

    NASA Astrophysics Data System (ADS)

    Savage, Shannon Lea

    Yellowstone National Park (YNP) contains the world's largest concentration of geothermal features, and is legally mandated to protect and monitor these natural features. Remote sensing is a component of the current geothermal monitoring plan. Landsat satellite data have a substantial historical archive and will be collected into the future, making it the only available thermal imagery for historical analysis and long-term monitoring of geothermal areas in the entirety of YNP. Landsat imagery from Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) sensors was explored as a tool for mapping geothermal heat flux and geothermally active areas within YNP and to develop a change analysis technique for scientists to utilize with additional Landsat data available from 1978 through the foreseeable future. Terrestrial emittance and estimates of geothermal heat flux were calculated for the entirety of YNP with two Landsat images from 2007 (TM) and 2002 (ETM+). Terrestrial emittance for fourteen summer dates from 1986 to 2007 was calculated for defined geothermal areas and utilized in a change analysis. Spatial and temporal change trajectories of terrestrial emittance were examined. Trajectories of locations with known change events were also examined. Relationships between the temporal clusters and spatial groupings and several change vectors (distance to geologic faults, distance to large water bodies, and distance to earthquake swarms) were explored. Finally, TM data from 2007 were used to classify geothermally active areas inside the defined geothermal areas as well as throughout YNP and a 30-km buffer around YNP. Estimations of geothermal heat flux were inaccurate due to inherent limitations of Landsat data combined with complexities arising from the effects of solar radiation and spatial and temporal variation of vegetation, microbes, steam outflows, and other features at each geothermal area. Terrestrial emittance, however, was estimated with acceptable

  16. Geothermal Reservoir Well Stimulation Program: technology transfer

    SciTech Connect

    Not Available

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  17. Next Generation Geothermal Power Plants

    SciTech Connect

    Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

    1995-09-01

    A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine

  18. Geothermal pipeline: Progress and development update from the geothermal progress monitor

    SciTech Connect

    1996-11-01

    This document is a progress and development update from the Geothermal Progress Monitor prepared by the Geo-Heat Center at the Oregon Institute of Technology in Klamath Falls, Oregon. Several upcoming meetings and workshops in the field of geothermal energy and resource development are announced. Geothermal exploration and development projects in several areas are described in this document: New San Luis Valley Training Program, Fish and Alligator Ranching in Idaho, the geothermal drilling operation at Newberry Volcanic Crater near Bend, Oregon, and Australian Red Claw Lobster raised in aquaculture ponds at Belmont Hot Springs, Utah.

  19. California Geothermal Forum: A Path to Increasing Geothermal Development in California

    SciTech Connect

    Young, Katherine R.

    2017-01-01

    The genesis of this report was a 2016 forum in Sacramento, California, titled 'California Geothermal Forum: A Path to Increasing Geothermal Development in California.' The forum was held at the California Energy Commission's (CEC) headquarters in Sacramento, California with the primary goal being to advance the dialogues for the U.S. Department of Energy's Geothermal Technologies Office (GTO) and CEC technical research and development (R&D) focuses for future consideration. The forum convened a diverse group of stakeholders from government, industry, and research to lay out pathways for new geothermal development in California while remaining consistent with critical Federal and State conservation planning efforts, particularly at the Salton Sea.

  20. Robust fusion with reliabilities weights

    NASA Astrophysics Data System (ADS)

    Grandin, Jean-Francois; Marques, Miguel

    2002-03-01

    The reliability is a value of the degree of trust in a given measurement. We analyze and compare: ML (Classical Maximum Likelihood), MLE (Maximum Likelihood weighted by Entropy), MLR (Maximum Likelihood weighted by Reliability), MLRE (Maximum Likelihood weighted by Reliability and Entropy), DS (Credibility Plausibility), DSR (DS weighted by reliabilities). The analysis is based on a model of a dynamical fusion process. It is composed of three sensors, which have each it's own discriminatory capacity, reliability rate, unknown bias and measurement noise. The knowledge of uncertainties is also severely corrupted, in order to analyze the robustness of the different fusion operators. Two sensor models are used: the first type of sensor is able to estimate the probability of each elementary hypothesis (probabilistic masses), the second type of sensor delivers masses on union of elementary hypotheses (DS masses). In the second case probabilistic reasoning leads to sharing the mass abusively between elementary hypotheses. Compared to the classical ML or DS which achieves just 50% of correct classification in some experiments, DSR, MLE, MLR and MLRE reveals very good performances on all experiments (more than 80% of correct classification rate). The experiment was performed with large variations of the reliability coefficients for each sensor (from 0 to 1), and with large variations on the knowledge of these coefficients (from 0 0.8). All four operators reveal good robustness, but the MLR reveals to be uniformly dominant on all the experiments in the Bayesian case and achieves the best mean performance under incomplete a priori information.