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.

Fluid inclusions in minerals from the geothermal fields of Tuscany, Italy

USGS Publications Warehouse

Belkin, H.; de Vivo, B.; Gianelli, G.; Lattanzi, P.

1985-01-01

A reconnaissance study on fluid inclusions from the geothermal fields of Tuscany indicates that the hydrothermal minerals were formed by fluids which were, at least in part, boiling. Four types of aqueous inclusions were recognized: (A) two-phase (liquid + vapor) liquid rich, (B) two-phase (vapor + liquid) vapor rich, (C) polyphase hypersaline liquid rich and (D) three phase-H2O liquid + CO2 liquid + CO2-rich vapor. Freezing and heating microthermometric determinations are reported for 230 inclusions from samples from six wells. It is suggested that boiling of an originally homogeneous, moderately saline, CO2-bearing liquid phase produced a residual hypersaline brine and a CO2-rich vapor phase. There are indications of a temperature decrease in the geothermal field of Larderello, especially in its peripheral zones. ?? 1985.

Quantifying the undiscovered geothermal resources of the United States

USGS Publications Warehouse

Williams, Colin F.; Reed, Marshall J.; DeAngelo, Jacob; Galanis, S. Peter

2009-01-01

In 2008, the U.S. Geological Survey (USGS) released summary results of an assessment of the electric power production potential from the moderate- and high-temperature geothermal resources of the United States (Williams et al., 2008a; USGS Fact Sheet 2008-3082; http://pubs.usgs.gov/fs/2008/3082). In the assessment, the estimated mean power production potential from undiscovered geothermal resources is 30,033 Megawatts-electric (MWe), more than three times the estimated mean potential from identified geothermal systems: 9057 MWe. The presence of significant undiscovered geothermal resources has major implications for future exploration and development activities by both the government and private industry. Previous reports summarize the results of techniques applied by the USGS and others to map the spatial distribution of undiscovered resources. This paper describes the approach applied in developing estimates of the magnitude of the undiscovered geothermal resource, as well as the manner in which that resource is likely to be distributed among geothermal systems of varying volume and temperature. A number of key issues constrain the overall estimate. One is the degree to which characteristics of the undiscovered resources correspond to those observed among identified geothermal systems. Another is the evaluation of exploration history, including both the spatial distribution of geothermal exploration activities relative to the postulated spatial distribution of undiscovered resources and the probability of successful discoveries from the application of standard geothermal exploration techniques. Also significant are the physical, chemical, and geological constraints on the formation and longevity of geothermal systems. Important observations from this study include the following. (1) Some of the largest identified geothermal systems, such as The Geysers vapor-dominated system in northern California and the diverse geothermal manifestations found in Yellowstone

Gases in steam from Cerro Prieto geothermal wells with a discussion of steam/gas ratio measurements

USGS Publications Warehouse

Nehring, N.L.; Fausto, L.J.J.

1979-01-01

As part of a joint USGS-CFE geochemical study of Cerro Prieto, steam samples were collected for gas analyses in April, 1977. Analyses of the major gas components of the steam were made by wet chemistry (for H2O,CO2,H2S and NH3) and by gas chromatography (He,H2,Ar,O2,N2 and hydrocarbons). The hydrocarbon gases in Cerro Prieto steam closely resemble hydrocarbons in steam from Larderello, Italy and The Geysers, California which, although they are vapor-dominated rather than hot-water geothermal systems, also have sedimentary aquifer rocks. These sedimentary geothermal hydrocarbons are characterized by the presence of branched C4-6 compounds and a lack of unsaturated compounds other than benzene. Relatively large amounts of benzene may be characteristic of high-temperature geothermal systems. All hydrocarbons in these gases other than methane most probably originate from the thermal metamorphosis of organic matter contained in the sediments. ?? 1979.

An Embedded 3D Fracture Modeling Approach for Simulating Fracture-Dominated Fluid Flow and Heat Transfer in Geothermal Reservoirs

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

Johnston, Henry; Wang, Cong; Winterfeld, Philip

An efficient modeling approach is described for incorporating arbitrary 3D, discrete fractures, such as hydraulic fractures or faults, into modeling fracture-dominated fluid flow and heat transfer in fractured geothermal reservoirs. This technique allows 3D discrete fractures to be discretized independently from surrounding rock volume and inserted explicitly into a primary fracture/matrix grid, generated without including 3D discrete fractures in prior. An effective computational algorithm is developed to discretize these 3D discrete fractures and construct local connections between 3D fractures and fracture/matrix grid blocks of representing the surrounding rock volume. The constructed gridding information on 3D fractures is then added tomore » the primary grid. This embedded fracture modeling approach can be directly implemented into a developed geothermal reservoir simulator via the integral finite difference (IFD) method or with TOUGH2 technology This embedded fracture modeling approach is very promising and computationally efficient to handle realistic 3D discrete fractures with complicated geometries, connections, and spatial distributions. Compared with other fracture modeling approaches, it avoids cumbersome 3D unstructured, local refining procedures, and increases computational efficiency by simplifying Jacobian matrix size and sparsity, while keeps sufficient accuracy. Several numeral simulations are present to demonstrate the utility and robustness of the proposed technique. Our numerical experiments show that this approach captures all the key patterns about fluid flow and heat transfer dominated by fractures in these cases. Thus, this approach is readily available to simulation of fractured geothermal reservoirs with both artificial and natural fractures.« less

Reservoir controling factors in the Karaha-Telaga Bodas geothermal field, Indonesia

USGS Publications Warehouse

Nemcok, M.; Moore, J.N.; Christensen, Carl; Allis, R.; Powell, T.; Murray, B.; Nash, G.

2005-01-01

Karaha - Telaga Bodas geothermal system consists of: 1) a caprock, ranging from several hundred meters to 1600 m thick that is characterized by steep, conductive temperature gradients and low permeabilities; 2) an underlying vapor-dominated zone that extends below sea level; and 3) a deep liquid-dominated zone with measured temperatures up to 353??C. Heat is provided by a 3 km deep tabular granodiorite stock. The effective base of the reservoir is controlled by the stress regime's effect on fractures within volcanic rocks located above the brittle/ductile deformation boundary. The base of the caprock is controlled by the distribution of initially low-permeability lithologies above the reservoir; the extent of pervasive clay alteration that has reduced initial permeabilities; the distribution of secondary minerals deposited by descending waters; and by a downward change from a strike-slip to an extensional stress regime. Producing zones are controlled by both matrix and fracture permeabilities.

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.

Performance of deep geothermal energy systems

NASA Astrophysics Data System (ADS)

Manikonda, Nikhil

Geothermal energy is an important source of clean and renewable energy. This project deals with the study of deep geothermal power plants for the generation of electricity. The design involves the extraction of heat from the Earth and its conversion into electricity. This is performed by allowing fluid deep into the Earth where it gets heated due to the surrounding rock. The fluid gets vaporized and returns to the surface in a heat pipe. Finally, the energy of the fluid is converted into electricity using turbine or organic rankine cycle (ORC). The main feature of the system is the employment of side channels to increase the amount of thermal energy extracted. A finite difference computer model is developed to solve the heat transport equation. The numerical model was employed to evaluate the performance of the design. The major goal was to optimize the output power as a function of parameters such as thermal diffusivity of the rock, depth of the main well, number and length of lateral channels. The sustainable lifetime of the system for a target output power of 2 MW has been calculated for deep geothermal systems with drilling depths of 8000 and 10000 meters, and a financial analysis has been performed to evaluate the economic feasibility of the system for a practical range of geothermal parameters. Results show promising an outlook for deep geothermal systems for practical applications.

Third workshop on geothermal reservoir engineering: Proceedings

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

Ramey, H.J. Jr.; Kruger, P.

1977-12-15

The Third Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 14, 1977, with 104 attendees from six nations. In keeping with the recommendations expressed by the participants at the Second Workshop, the format of the Workshop was retained, with three days of technical sessions devoted to reservoir physics, well and reservoir testing, field development, and mathematical modeling of geothermal reservoirs. The program presented 33 technical papers, summaries of which are included in these Proceedings. Although the format of the Workshop has remained constant, it is clear from a perusal of the Table of Contents that considerable advancesmore » have occurred in all phases of geothermal reservoir engineering over the past three years. Greater understanding of reservoir physics and mathematical representations of vapor-dominated and liquid-dominated reservoirs are evident; new techniques for their analysis are being developed, and significant field data from a number of newer reservoirs are analyzed. The objectives of these workshops have been to bring together researchers active in the various physical and mathematical disciplines comprising the field of geothermal reservoir engineering, to give the participants a forum for review of progress and exchange of new ideas in this rapidly developing field, and to summarize the effective state of the art of geothermal reservoir engineering in a form readily useful to the many government and private agencies involved in the development of geothermal energy. To these objectives, the Third Workshop and these Proceedings have been successfully directed. Several important events in this field have occurred since the Second Workshop in December 1976. The first among these was the incorporation of the Energy Research and Development Administration (ERDA) into the newly formed Department of Energy (DOE) which continues as the leading Federal agency in geothermal reservoir engineering research

Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California

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

Galbraith, R.M.

1978-05-01

The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was stronglymore » influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characcterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the accoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet.« less

Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California

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

Galbraith, R.M.

1978-05-01

The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was stronglymore » influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet.« less

Hydrogeologic controls on saturation profiles in heat-pipe-like hydrothermal systems: numerical study

NASA Astrophysics Data System (ADS)

Pervin, Mollika; Ghergut, Iulia; Graf, Thomas; Peche, Aaron

2016-04-01

Most geothermal reservoirs are of the liquid-dominated type, and their unexploited-state pressure profile approximately follows the hydrostatic gradient. In very hot liquid-dominated systems, temperature typically follows a boiling-point-for-depth (BPD) relationship. By contrast, vapor-dominated systems exhibit (in their unexploited state) surprisingly small vertical gradients of temperature and pressure, such that a constantly high temperature is encountered over a large vertical thickness, while their pressure approximately follows vapour pressure, pvap(T°). This implies that (Pruess 1985, Truesdell and White 1973): (i) for a vapor-dominated reservoir to exist, it must be sealed laterally - otherwise it would be flooded by neighboring groundwaters with hydrostatic p profile, and (ii) liquid water should somehow be present in the whole system - otherwise p values would not be constrained by the pvap(T°) relationship for water. Historically, one of the most puzzling aspects of vapor-dominated systems was the large amount of heat flowing upwards, while vertical T° gradients remained negligible. This mechanism was deemed as 'heat pipe'(HP) (Eastman 1968): In the central zone of a vapor-dominated system, both vapor and liquid are mobile; vapor flows upwards, condenses at shallower depth, and the liquid condensate flows downwards. Due to the large amount of latent enthalpy released in vapor condensation, the vapor-liquid counter-flow can generate large rates of heat flow with negligible net mass transport (Pruess 1985). In order to be able to exploit two-phase (including vapor-dominated) reservoirs in a sustainable manner, one first needs to understand the conditions under which a two-phase (or a vapor-dominated) system has evolved naturally, and which have led to its present (quasi-) steady undisturbed state. Past studies have found that HP can exist in two distinct states, corresponding to liquid-dominated and vapor-dominated p profiles, respectively. Within this

Analysis of geothermal temperatures for heat pumps application in Paraná (Brasil)

NASA Astrophysics Data System (ADS)

Santos, Alexandre F.; de Souza, Heraldo J. L.; Cantao, Mauricio P.; Gaspar, Pedro D.

2016-11-01

Geothermal heat pumps are broadly used in developed countries but scarcely in Brazil, in part because there is a lack of Brazilian soil temperature data. The aims of this work are: to present soil temperature measurements and to compare geothermal heat pump system performances with conventional air conditioning systems. Geothermal temperature measurement results are shown for ten Paraná State cities, representing different soil and climate conditions. The measurements were made yearlong with calibrated equipment and digital data acquisition system in different measuring stations. Geothermal and ambient temperature data were used for simulations of the coeficient of performance (COP), by means of a working fluid pressure-enthalpy diagram based software for vapor-compression cycle. It was verified that geothermal temperature measured between January 13 to October 13, 2013, varied from 16 to 24 °C, while room temperature has varied between 2 and 35 °C. Average COP values for conventional system were 3.7 (cooling mode) and 5.0 kW/kW (heating mode), corresponding to 5.9 and 7.9 kW/kW for geothermal system. Hence it was verified an average eficiency gain of 59%with geothermal system utilization in comparison with conventional system.

Phase relations and adiabats in boiling seafloor geothermal systems

USGS Publications Warehouse

Bischoff, J.L.; Pitzer, Kenneth S.

1985-01-01

Observations of large salinity variations and vent temperatures in the range of 380-400??C suggest that boiling or two-phase separation may be occurring in some seafloor geothermal systems. Consideration of flow rates and the relatively small differences in density between vapors and liquids at the supercritical pressures at depth in these systems suggests that boiling is occurring under closed-system conditions. Salinity and temperature of boiling vents can be used to estimate the pressure-temperature point in the subsurface at which liquid seawater first reached the two-phase boundary. Data are reviewed to construct phase diagrams of coexisting brines and vapors in the two-phase region at pressures corresponding to those of the seafloor geothermal systems. A method is developed for calculating the enthalpy and entropy of the coexisting mixtures, and results are used to construct adiabats from the seafloor to the P-T two-phase boundary. Results for seafloor vents discharging at 2300 m below sea level indicate that a 385??C vent is composed of a brine (7% NaCl equivalent) in equilibrium with a vapor (0.1% NaCl). Brine constitutes 45% by weight of the mixture, and the fluid first boiled at approximately 1 km below the seafloor at 415??C, 330 bar. A 400??C vent is primarily vapor (88 wt.%, 0.044% NaCl) with a small amount of brine (26% NaCl) and first boiled at 2.9 km below the seafloor at 500??C, 520 bar. These results show that adiabatic decompression in the two-phase region results in dramatic cooling of the fluid mixture when there is a large fraction of vapor. ?? 1985.

Idaho Geothermal Commercialization Program. Idaho geothermal handbook

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

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

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)

Geothermal Project Consulting | Geothermal Technologies | NREL

Science.gov Websites

Geothermal Project Consulting Geothermal Project Consulting When consulting on projects, NREL focuses on identifying specific barriers or challenges that are likely to impact geothermal project , validation, and deployment of geothermal technologies Assess and evaluate geothermal R&D projects

The role of thermal vapor diffusion in the subsurface hydrologic evolution of Mars

NASA Technical Reports Server (NTRS)

Clifford, Stephen M.

1991-01-01

The hydrologic response of groundwater to the thermal evolution of the early martian crust is considered. When a temperature gradient is present in a moist porous medium, it gives rise to a vapor-pressure gradient that drives the diffusion of water vapor from regions of high to low temperature. By this process, a geothermal gradient as small as 15 K/km could drive the vertical transport of 1 km of water to the freezing front at the base of the martian crysophere every 10 exp 6-10 exp 7 years, or the equivalent of about 100-1000 km of water over the course of martian geologic history. Models of the thermal history of Mars suggest that this thermally-driven vapor flux may have been as much as 3-5 times greater in the past. The magnitude of this transport suggests that the process of geothermally-induced vapor diffusion may have played a critical role in the initial emplacement of ground ice and the subsequent geomorphic and geochemical evolution of the martian crust.

Sedimentary and Enhanced Geothermal Systems | Geothermal Technologies |

Science.gov Websites

NREL Sedimentary and Enhanced Geothermal Systems Sedimentary and Enhanced Geothermal Systems To innovative technologies, such as sedimentary and enhanced geothermal systems (EGS). Photo of a geothermal power plant in Imperial California. Capabilities To advance EGS and sedimentary geothermal systems, NREL

Soil degassing at the Los Humeros geothermal field (Mexico)

NASA Astrophysics Data System (ADS)

Peiffer, Loïc; Carrasco-Núñez, Gerardo; Mazot, Agnès; Villanueva-Estrada, Ruth Esther; Inguaggiato, Claudio; Bernard Romero, Rubén; Rocha Miller, Roberto; Hernández Rojas, Javier

2018-05-01

The Los Humeros geothermal field is the third most important producer of geothermal electricity (70 MW) in Mexico. Geothermal fluids are hosted in fractured andesitic lavas and mostly consist of high enthalpy steam with limited water content (vapor fraction > 0.9). Despite the high reservoir temperature ( 300-400 °C), thermal manifestations at the surface are scarce and locally appear as steaming grounds, weak steam vents and advanced argillic alteration. Geothermal fluid upflow from the reservoir towards the surface is limited by welded ignimbrite deposits that act as a low-permeability barrier. In this study, we present the first measurements of CO2, CH4 and H2S degassing rates from the soil performed at Los Humeros. Flux measurements were complemented with δ13C composition of degassing CO2 and soil temperatures to discuss gas origin and thermal anomalies. We measured high soil degassing rates (up to 7530 g m-2 d-1 CO2, 33 g m-2 d-1 CH4 and 22 g m-2 d-1 H2S) in three localized areas (Humeros North - HN, Humeros South - HS and Xalapazco - XA) as well as high soil temperatures reaching the boiling temperature at the local altitude (90.6 °C). The particular location of these three areas suggests that the steam-dominated reservoir degases to the surface through permeable faults crossing the ignimbritic deposits. The remaining surveyed areas are characterized by weak CO2 fluxes (≤44 g m-2 d-1), non-detectable CH4 and H2S fluxes, and lower soil temperatures (5-21 °C). The compositions in δ13CCO2 from HN-HS-XA areas (δ13CCO2 = -7.94 to -2.73‰) reflect a magmatic source with some possible contribution from the sedimentary basement, as well as fractionation induced by boiling and CO2 dissolution in shallow water bodies. We also discuss the processes causing the spread in CO2/CH4 flux ratios. Finally, we estimate the heat output from the three high degassing areas to a value of 16.4 MWt.

Realizing the geothermal electricity potential—water use and consequences

NASA Astrophysics Data System (ADS)

Shankar Mishra, Gouri; Glassley, William E.; Yeh, Sonia

2011-07-01

Electricity from geothermal resources has the potential to supply a significant portion of US baseload electricity. We estimate the water requirements of geothermal electricity and the impact of potential scaling up of such electricity on water demand in various western states with rich geothermal resources but stressed water resources. Freshwater, degraded water, and geothermal fluid requirements are estimated explicitly. In general, geothermal electricity has higher water intensity (l kWh - 1) than thermoelectric or solar thermal electricity. Water intensity decreases with increase in resource enthalpy, and freshwater gets substituted by degraded water at higher resource temperatures. Electricity from enhanced geothermal systems (EGS) could displace 8-100% of thermoelectricity generated in most western states. Such displacement would increase stress on water resources if re-circulating evaporative cooling, the dominant cooling system in the thermoelectric sector, is adopted. Adoption of dry cooling, which accounts for 78% of geothermal capacity today, will limit changes in state-wide freshwater abstraction, but increase degraded water requirements. We suggest a research and development focus to develop advanced energy conversion and cooling technologies that reduce water use without imposing energy and consequent financial penalties. Policies should incentivize the development of higher enthalpy resources, and support identification of non-traditional degraded water sources and optimized siting of geothermal plants.

Geochemistry of thermal fluids in NW Honduras: New perspectives for exploitation of geothermal areas in the southern Sula graben

NASA Astrophysics Data System (ADS)

Capaccioni, Bruno; Franco, Tassi; Alberto, Renzulli; Orlando, Vaselli; Marco, Menichetti; Salvatore, Inguaggiato

2014-06-01

The results of a geochemical survey on thermal waters and, for the first time for this site, gas discharges in five geothermal sites (Azacualpa "La Cueva", Río Ulua, Río Gualcarque, El Olivar and Laguna de Agua Caliente) in NW Honduras are here presented and discussed. El Olivar and Laguna de Agua Caliente, in the southern part of the Sula graben are very close to a Quaternary basaltic field, whereas Azacualpa "La Cueva", Río Ulua and Río Gualcarque, located to the southwest of the Yojoa Lake, direcly emerge from the Cretaceous limestone deposits. The measured temperatures range between 37.5 and 104.8 °C. "Mature", alkaline, Na-SO4 thermal waters discharge from Azacualpa "La Cueva", while those from El Olivar and Laguna de Agua Caliente are "immature" and show a Na-HCO3 composition. Chemical equilibria of waters and gases from the Azacualpa "La Cueva" thermal springs indicate temperatures ranging from 150 to 200 °C. Conversely, gas discharges from El Olivar and Laguna de Agua Caliente have attained a partial chemical equilibrium in the liquid phase at slightly higher temperatures (200-250 °C), although gas-gas faster reactions involving CO seem to be adjusted in an isothermally separated vapor phase. Unlike Azacualpa, SiO2 geothermometer at El Olivar and Laguna de Agua Caliente indicates equilibrium temperatures for the liquid phase much lower than those calculated for the gas phase (≤ 120 °C). We conclude that thermal waters from the Azacualpa area likely represent the direct emergence of a water dominated reservoir having temperatures ≤ 150-200 °C. By contrast, at El Olivar and Laguna de Agua Caliente hot springs are supplied by a boiling shallow aquifer fed by a vapor phase rising from a steam-dominated zone. The above geochemical model is consistent with a geothermal reservoir hosted within the Cretaceous carbonate sequences of the Yojoa Group in the whole investigated sites. The reservoir extensively crops out in the Azacualpa area whereas the

Geothermal Research | Geothermal Technologies | NREL

Science.gov Websites

. Impact Analysis Conducting analyses to determine the viability of geothermal energy production and Hybrid Systems Exploring the potential benefits of combining geothermal with other renewable energy Designing new models and studying new techniques to increase the production of geothermal energy.

Phase 0 study for a geothermal superheated water proof of concept facility

NASA Technical Reports Server (NTRS)

Douglass, R. H.; Pearson, R. O.

1974-01-01

A Phase 0 study for the selection of a representative liquid-dominated geothermal resource of moderate salinity and temperature is discussed. Selection and conceptual design of a nominal 10-MWe energy conversion system, and implementation planning for Phase 1: subsystem (component, experiments) and Phase 2: final design, construction, and operation of experimental research facilities are reported. The objective of the overall program is to demonstrate the technical and economic viability of utilizing moderate temperature and salinity liquid-dominated resources with acceptable environmental impact, and thus encourage commercial scale development of geothermal electrical power generation.

DEVELOPMENT OF A SOFTWARE DESIGN TOOL FOR HYBRID SOLAR-GEOTHERMAL HEAT PUMP SYSTEMS IN HEATING- AND COOLING-DOMINATED BUILDINGS

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

Yavuzturk, C. C.; Chiasson, A. D.; Filburn, T. P.

This project provides an easy-to-use, menu-driven, software tool for designing hybrid solar-geothermal heat pump systems (GHP) for both heating- and cooling-dominated buildings. No such design tool currently exists. In heating-dominated buildings, the design approach takes advantage of glazed solar collectors to effectively balance the annual thermal loads on the ground with renewable solar energy. In cooling-dominated climates, the design approach takes advantage of relatively low-cost, unglazed solar collectors as the heat rejecting component. The primary benefit of hybrid GHPs is the reduced initial cost of the ground heat exchanger (GHX). Furthermore, solar thermal collectors can be used to balance themore » ground loads over the annual cycle, thus making the GHX fully sustainable; in heating-dominated buildings, the hybrid energy source (i.e., solar) is renewable, in contrast to a typical fossil fuel boiler or electric resistance as the hybrid component; in cooling-dominated buildings, use of unglazed solar collectors as a heat rejecter allows for passive heat rejection, in contrast to a cooling tower that consumes a significant amount of energy to operate, and hybrid GHPs can expand the market by allowing reduced GHX footprint in both heating- and cooling-dominated climates. The design tool allows for the straight-forward design of innovative GHP systems that currently pose a significant design challenge. The project lays the foundations for proper and reliable design of hybrid GHP systems, overcoming a series of difficult and cumbersome steps without the use of a system simulation approach, and without an automated optimization scheme. As new technologies and design concepts emerge, sophisticated design tools and methodologies must accompany them and be made usable for practitioners. Lack of reliable design tools results in reluctance of practitioners to implement more complex systems. A menu-driven software tool for the design of hybrid solar GHP systems

Synthetic Modeling of A Geothermal System Using Audio-magnetotelluric (AMT) and Magnetotelluric (MT)

NASA Astrophysics Data System (ADS)

Mega Saputra, Rifki; Widodo

2017-04-01

Indonesia has 40% of the world’s potential geothermal resources with estimated capacity of 28,910 MW. Generally, the characteristic of the geothermal system in Indonesia is liquid-dominated systems, which driven by volcanic activities. In geothermal exploration, electromagnetic methods are used to map structures that could host potential reservoirs and source rocks. We want to know the responses of a geothermal system using synthetic data of Audio-magnetotelluric (AMT) and Magnetotelluric (MT). Due to frequency range, AMT and MT data can resolve the shallow and deeper structure, respectively. 1-D models have been performed using AMT and MT data. The results indicate that AMT and MT data give detailed conductivity distribution of geothermal structure.

Hybrid Geothermal Heat Pumps for Cooling Telecommunications Data Centers

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

Beckers, Koenraad J; Zurmuhl, David P.; Lukawski, Maciej Z.

The technical and economic performance of geothermal heat pump (GHP) systems supplying year-round cooling to representative small data centers with cooling loads less than 500 kWth were analyzed and compared to air-source heat pumps (ASHPs). A numerical model was developed in TRNSYS software to simulate the operation of air-source and geothermal heat pumps with and without supplementary air cooled heat exchangers - dry coolers (DCs). The model was validated using data measured at an experimental geothermal system installed in Ithaca, NY, USA. The coefficient of performance (COP) and cooling capacity of the GHPs were calculated over a 20-year lifetime andmore » compared to the performance of ASHPs. The total cost of ownership (TCO) of each of the cooling systems was calculated to assess its economic performance. Both the length of the geothermal borehole heat exchangers (BHEs) and the dry cooler temperature set point were optimized to minimize the TCO of the geothermal systems. Lastly, a preliminary analysis of the performance of geothermal heat pumps for cooling dominated systems was performed for other locations including Dallas, TX, Sacramento, CA, and Minneapolis, MN.« less

Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources

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

Hays, Lance G

2014-07-07

A variable phase turbine assembly will be designed and manufactured having a turbine, operable with transcritical, two-phase or vapor flow, and a generator – on the same shaft supported by process lubricated bearings. The assembly will be hermetically sealed and the generator cooled by the refrigerant. A compact plate-fin heat exchanger or tube and shell heat exchanger will be used to transfer heat from the geothermal fluid to the refrigerant. The demonstration turbine will be operated separately with two-phase flow and with vapor flow to demonstrate performance and applicability to the entire range of low temperature geothermal resources. The vapormore » leaving the turbine is condensed in a plate-fin refrigerant condenser. The heat exchanger, variable phase turbine assembly and condenser are all mounted on single skids to enable factory assembly and checkout and minimize installation costs. The system will be demonstrated using low temperature (237F) well flow from an existing large geothermal field. The net power generated, 1 megawatt, will be fed into the existing power system at the demonstration site. The system will demonstrate reliable generation of inexpensive power from low temperature resources. The system will be designed for mass manufacturing and factory assembly and should cost less than $1,200/kWe installed, when manufactured in large quantities. The estimated cost of power for 300F resources is predicted to be less than 5 cents/kWh. This should enable a substantial increase in power generated from low temperature geothermal resources.« less

Physical factors determining the fraction of stored energy recoverable from hydrothermal convection systems and conduction-dominated areas

USGS Publications Warehouse

Nathenson, Manuel

1975-01-01

This report contains background analyses for the estimates of Nathenson and Muffler (1975) of geothermal resources in hydrothermal convection systems and conduction-dominated areas. The first section discusses heat and fluid recharge potential of geothermal reservoirs. The second section analyzes the physical factors that determine the fraction of stored energy obtainable at the surface from a geothermal reservoir. Conversion of heat to electricity and the use of geothermal energy for direct-heating applications are discussed in the last two sections. Nathenson, Manuel, and Muffler, L.J.P., 1975, Geothermal resources in hydrothermal convection systems and conduction dominated areas, in White, D.E., and Williams, D.L., eds., Assessment of the Geothermal Resources of the United States--1975: U.S. Geological Survey Circular 726, p. 104-121, available at http://pubs.er.usgs.gov/usgspubs/cir/cir726

Analysis of Low-Temperature Utilization of Geothermal Resources

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

Anderson, Brian

Full realization of the potential of what might be considered “low-grade” geothermal resources will require that we examine many more uses for the heat than traditional electricity generation. To demonstrate that geothermal energy truly has the potential to be a national energy source we will be designing, assessing, and evaluating innovative uses for geothermal-produced water such as hybrid biomass-geothermal cogeneration of electricity and district heating and efficiency improvements to the use of cellulosic biomass in addition to utilization of geothermal in district heating for community redevelopment projects. The objectives of this project were: 1) to perform a techno-economic analysis ofmore » the integration and utilization potential of low-temperature geothermal sources. Innovative uses of low-enthalpy geothermal water were designed and examined for their ability to offset fossil fuels and decrease CO2 emissions. 2) To perform process optimizations and economic analyses of processes that can utilize low-temperature geothermal fluids. These processes included electricity generation using biomass and district heating systems. 3) To scale up and generalize the results of three case study locations to develop a regionalized model of the utilization of low-temperature geothermal resources. A national-level, GIS-based, low-temperature geothermal resource supply model was developed and used to develop a series of national supply curves. We performed an in-depth analysis of the low-temperature geothermal resources that dominate the eastern half of the United States. The final products of this study include 17 publications, an updated version of the cost estimation software GEOPHIRES, and direct-use supply curves for low-temperature utilization of geothermal resources. The supply curves for direct use geothermal include utilization from known hydrothermal, undiscovered hydrothermal, and near-hydrothermal EGS resources and presented these results at the

Effect of microporosity on the permeability of geothermal systems, case study of Los Humeros geothermal fie

NASA Astrophysics Data System (ADS)

Carrasco, Gerardo; Cid, Hector; Ortega, Dante

2017-04-01

Los Humeros is the largest silicic caldera complex of the Trans-Mexican Volcanic Belt (TMVB), with an active geothermal field, which is currently producing around 65 MW. It is located in the northern part of the eastern TMVB. Its evolution includes voluminous caldera-forming eruption producing two large caldera structures (Los Humeros and Los Potreros calderas) with alternated episodes of effusive and explosive activity until the Holocene. The geothermal reservoir is located at a depth of about 1,500 m comprising a thick succession of porphyritic andesitic lava flows, and perhaps which overlay in a highly discordant contact a meta-sedimentary basement sequence dominated by altered limestone and skarn rocks. A NW/N-S structural system seems to be the main control of geothermal field distribution within the central part of the youngest caldera. Permeability in the geothermal reservoir has been associated with that system observed on the surficial geology, but also to some hidden secondary faulting and associated fracturing. Primary porosity has been considered negligible due to the low macroporosity observed in the volcanic rocks. However, a detailed analysis of the microporosity determined by X-ray microtomography new developed techniques, allow us to determine precise values of microporosity that were using for numerical simulation to obtain values of effective porosity, which reveals an interesting alternative solution to the permeability of the subsurface of Los Humeros geothermal field that should be taking into account to the final permeability of the system.

Distribution and diversity of Verrucomicrobia methanotrophs in geothermal and acidic environments.

PubMed

Sharp, Christine E; Smirnova, Angela V; Graham, Jaime M; Stott, Matthew B; Khadka, Roshan; Moore, Tim R; Grasby, Stephen E; Strack, Maria; Dunfield, Peter F

2014-06-01

Recently, methanotrophic members of the phylum Verrucomicrobia have been described, but little is known about their distribution in nature. We surveyed methanotrophic bacteria in geothermal springs and acidic wetlands via pyrosequencing of 16S rRNA gene amplicons. Putative methanotrophic Verrucomicrobia were found in samples covering a broad temperature range (22.5-81.6°C), but only in acidic conditions (pH 1.8-5.0) and only in geothermal environments, not in acidic bogs or fens. Phylogenetically, three 16S rRNA gene sequence clusters of putative methanotrophic Verrucomicrobia were observed. Those detected in high-temperature geothermal samples (44.1-81.6°C) grouped with known thermoacidiphilic 'Methylacidiphilum' isolates. A second group dominated in moderate-temperature geothermal samples (22.5-40.1°C) and a representative mesophilic methanotroph from this group was isolated (strain LP2A). Genome sequencing verified that strain LP2A possessed particulate methane monooxygenase, but its 16S rRNA gene sequence identity to 'Methylacidiphilum infernorum' strain V4 was only 90.6%. A third group clustered distantly with known methanotrophic Verrucomicrobia. Using pmoA-gene targeted quantitative polymerase chain reaction, two geothermal soil profiles showed a dominance of LP2A-like pmoA sequences in the cooler surface layers and 'Methylacidiphilum'-like pmoA sequences in deeper, hotter layers. Based on these results, there appears to be a thermophilic group and a mesophilic group of methanotrophic Verrucomicrobia. However, both were detected only in acidic geothermal environments. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

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)…

Geothermal Today: 2003 Geothermal Technologies Program Highlights (Revised)

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

Not Available

2004-05-01

This outreach publication highlights milestones and accomplishments of the DOE Geothermal Technologies Program for 2003. Included in this publication are discussions of geothermal fundamentals, enhanced geothermal systems, direct-use applications, geothermal potential in Idaho, coating technology, energy conversion R&D, and the GeoPowering the West initiative.

Geothermal Technologies News | Geothermal Technologies | NREL

Science.gov Websites

for this avid biker. The reason though is unusual. Passionate about geothermal energy research, he Geothermal Energy Program In her new role, Young will work closely with NREL management to establish the lab's geothermal energy portfolio, including research and development geared toward advancing the use of

Geothermal Exploration and Resource Assessment | Geothermal Technologies |

Science.gov Websites

, drilling, and resource assessments and the widespread adoption of under-utilized low-temperature resources -temperature geothermal resource technologies. Drilling The drilling of wells to find and develop geothermal low-temperature, sedimentary, co-produced, and enhanced geothermal system resources. We also work to

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.

The thermodynamic cycle models for geothermal power plants by considering the working fluid characteristic

NASA Astrophysics Data System (ADS)

Mulyana, Cukup; Adiprana, Reza; Saad, Aswad H.; M. Ridwan, H.; Muhammad, Fajar

2016-02-01

The scarcity of fossil energy accelerates the development of geothermal power plant in Indonesia. The main issue is how to minimize the energy loss from the geothermal working fluid so that the power generated can be increased. In some of geothermal power plant, the hot water which is resulted from flashing is flown to injection well, and steam out from turbine is condensed in condenser, while the temperature and pressure of the working fluid is still high. The aim of this research is how the waste energy can be re-used as energy source to generate electric power. The step of the research is started by studying the characteristics of geothermal fluid out from the well head. The temperature of fluid varies from 140°C - 250°C, the pressure is more than 7 bar and the fluid phase are liquid, gas, or mixing phase. Dry steam power plant is selected for vapor dominated source, single or multiple flash power plant is used for dominated water with temperature > 225°C, while the binary power plant is used for low temperature of fluid < 160°C. Theoretically, the process in the power plant can be described by thermodynamic cycle. Utilizing the heat loss of the brine and by considering the broad range of working fluid temperature, the integrated geothermal power plant has been developed. Started with two ordinary single flash power plants named unit 1 and unit 2, with the temperature 250°C resulting power is W1'+W2'. The power is enhanced by utilizing the steam that is out from first stage of the turbine by inputting the steam to the third stage, the power of the plant increase with W1''+W2" or 10% from the original power. By using flasher, the water from unit 1 and 2 is re-flashed at 200°C, and the steam is used to drive the turbine in unit 3, while the water is re-flashed at the temperature170°C and the steam is flown to the same turbine (unit 3) resulting the power of W3+W4. Using the fluid enthalpy, the calculated power of these double and triple flash power plant

Heat flow in vapor dominated areas of the Yellowstone Plateau volcanic field: implications for the thermal budget of the Yellowstone Caldera

USGS Publications Warehouse

Hurwitz, Shaul; Harris, Robert; Werner, Cynthia Anne; Murphy, Fred

2012-01-01

Characterizing the vigor of magmatic activity in Yellowstone requires knowledge of the mechanisms and rates of heat transport between magma and the ground surface. We present results from a heat flow study in two vapor dominated, acid-sulfate thermal areas in the Yellowstone Caldera, the 0.11 km2 Obsidian Pool Thermal Area (OPTA) and the 0.25 km2 Solfatara Plateau Thermal Area (SPTA). Conductive heat flux through a low permeability layer capping large vapor reservoirs is calculated from soil temperature measurements at >600 locations and from laboratory measurements of soil properties. The conductive heat output is 3.6 ± 0.4 MW and 7.5 ± 0.4 MW from the OPTA and the SPTA, respectively. The advective heat output from soils is 1.3 ± 0.3 MW and 1.2 ± 0.3 MW from the OPTA and the SPTA, respectively and the heat output from thermal pools in the OPTA is 6.8 ± 1.4 MW. These estimates result in a total heat output of 11.8 ± 1.4 MW and 8.8 ± 0.4 MW from OPTA and SPTA, respectively. Focused zones of high heat flux in both thermal areas are roughly aligned with regional faults suggesting that faults in both areas serve as conduits for the rising acid vapor. Extrapolation of the average heat flux from the OPTA (103 ± 2 W·m−2) and SPTA (35 ± 3 W·m−2) to the ~35 km2 of vapor dominated areas in Yellowstone yields 3.6 and 1.2 GW, respectively, which is less than the total heat output transported by steam from the Yellowstone Caldera as estimated by the chloride inventory method (4.0 to 8.0 GW).

New geochemical investigations in Platanares and Azacualpa geothermal sites (Honduras)

NASA Astrophysics Data System (ADS)

Barberi, Franco; Carapezza, Maria Luisa; Cioni, Roberto; Lelli, Matteo; Menichini, Matia; Ranaldi, Massimo; Ricci, Tullio; Tarchini, Luca

2013-05-01

Platanares and Azacualpa geothermal sites of Honduras are located in an inner part of the Caribbean Plate far from the active volcanic front of Central America. Here geology indicates that there are not the conditions for the occurrence of shallow magmatic heat sources for high-enthalpy geothermal resources. Geothermal perspectives are related to the possibility of a deep circulation of meteoric water along faults and the storage of the heated fluid in fractured permeable reservoirs. Geochemical geothermometers indicate a temperature for the deeper part of the geothermal reservoir close to 200 °C for Platanares and of 150-170 °C for Azacualpa. Calcite scaling, with subordinate silica deposition has to be expected in both sites. CO2 soil flux investigations have been carried out in both areas and reveal the presence of positive anomalies likely corresponding to the presence at depth of fractured degassing geothermal reservoirs. Compared with the geothermal areas of Central Italy whose reservoirs are hosted in carbonate rocks, e.g. Latera (Chiodini et al., 2007), the CO2 soil flux measured in Honduras is significantly lower (mean of 17 g/m2day at Platanares and of 163 g/m2day at Azacualpa) probably because of the dominant silicate nature of the deep reservoirs.

Self-organizing maps in geothermal exploration-A new approach for understanding geochemical processes and fluid evolution

NASA Astrophysics Data System (ADS)

Brehme, Maren; Bauer, Klaus; Nukman, Mochamad; Regenspurg, Simona

2017-04-01

Understanding geochemical processes is an important part of geothermal exploration to get information about the source and evolution of geothermal fluids. However, in most cases knowledge of fluid properties is based on few parameters determined in samples from the shallow subsurface. This study presents a new approach that allows to conclude from the combination of a variety of these data on processes occurring at depth in a geothermal reservoir. The neural network clustering technique called "self-organizing maps" (SOMs) successfully distinguished two different geothermal settings based on a hydrochemical database and disclosed the source, evolution and flow pathways of geothermal fluids. Scatter plots, as shown in this study, are appropriate presentations of element concentrations and the chemical interaction of water and rock at depth. One geological setting presented here is marked by fault dominated fluid pathways and minor influence of volcanic affected fluids with high concentrations of HCO3, Ca and Sr. The second is a magmatically dominated setting showing strong alteration features in volcanic rocks and accommodates acidic fluids with high SO4 and Si concentrations. Former studies, i.e., Giggenbach (1988), suggested Cl, HCO3 and SO4 to be generally the most important elements for understanding hydrochemical processes in geothermal reservoirs. Their relation has been widely used to classify different water types in geothermal fields. However, this study showed that non-standard elements are at least of same importance to reveal different fluid types in geothermal systems. Therefore, this study is an extended water classification approach using SOM for element correlations. SOM have been proven to be a successful method for analyzing even relatively small hydrochemical datasets in geothermal applications.

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

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

Anderson, Arlene; Blackwell, David; Chickering, Cathy

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 allmore » 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.« less

Structural Controls of the Tuscarora Geothermal Field, Elko County, Nevada

NASA Astrophysics Data System (ADS)

Dering, Gregory M.

Detailed geologic mapping, structural analysis, and well data have been integrated to elucidate the stratigraphic framework and structural setting of the Tuscarora geothermal area. Tuscarora is an amagmatic geothermal system that lies in the northern part of the Basin and Range province, ˜15 km southeast of the Snake River Plain and ˜90 km northwest of Elko, Nevada. The Tuscarora area is dominated by late Eocene to middle Miocene volcanic and sedimentary rocks, all overlying Paleozoic metasedimentary rocks. A geothermal power plant was constructed in 2011 and currently produces 18 MWe from an ˜170°C reservoir in metasedimentary rocks at a depth of 1740 m. Analysis of drill core reveals that the subsurface geology is dominated to depths of ˜700-1000 m by intracaldera deposits of the Eocene Big Cottonwood Canyon caldera, including blocks of basement-derived megabreccia. Furthermore, the Tertiary-Paleozoic nonconformity within the geothermal field has been recognized as the margin of this Eocene caldera. Structural relations combined with geochronologic data from previous studies indicate that Tuscarora has undergone extension since the late Eocene, with significant extension in the late Miocene-Pliocene to early Pleistocene. Kinematic analysis of fault slip data reveal an east-west-trending least principal paleostress direction, which probably reflects an earlier episode of Miocene extension. Two distinct structural settings at different scales appear to control the geothermal field. The regional structural setting is a 10-km wide complexly faulted left step or relay ramp in the west-dipping range-bounding Independence-Bull Run Mountains normal fault system. Geothermal activity occurs within the step-over where sets of east- and west-dipping normal faults overlap in a northerly trending accommodation zone. The distribution of hot wells and hydrothermal surface features, including boiling springs, fumaroles, and siliceous sinter, indicate that the geothermal

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.

Reservoir Changes Derived from Seismic Observations at The Geysers Geothermal Field, CA, USA

NASA Astrophysics Data System (ADS)

Gritto, R.; Jarpre, S.

2012-04-01

Induced seismicity associated with the exploitation of geothermal fields is used as a tool to characterize and delineate changes associated with injection and production of fluids from the reservoir. At the same time public concern of felt seismicity has led to objections against the operation of geothermal reservoirs in close proximity to population centers. Production at the EGS sites in Basel (Switzerland) was stopped after renewed seismicity caused concern and objection from the public in the city. Operations in other geothermal reservoirs had to be scaled back or interrupted due to an unexpected increase in seismicity (Soultz-sous-forêt, France, Berlín, El Salvador). As a consequence of these concerns and in order to optimize the use of induced seismicity for reservoir engineering purposes, it becomes imperative to understand the relationship between seismic events and stress changes in the reservoir. We will address seismicity trends at The Geysers Geothermal Reservoir, CA USA, to understand the role of historical seismicity associated with past injection of water and/or production of steam. Our analysis makes use of a comprehensive database of earthquakes and associated phase arrivals from 2004 to 2011. A high-precision sub-set of the earthquake data was selected to analyze temporal changes in seismic velocities and Vp/Vs-ratio throughout the whole reservoir. We find relatively low Vp/Vs values in 2004 suggestive of a vapor dominated reservoir. With passing time, however, the observed temporal increase in Vp/Vs, coupled with a decrease in P- and S-wave velocities suggests the presence of fluid-filled fractured rock. Considering the start of a continuous water injection project in 2004, it can be concluded that the fluid saturation of the reservoir has successfully recovered. Preliminary results of 3-D velocity inversions of seismic data appear to corroborate earlier findings that the lowest Vp/Vs estimates are observed in the center of the reservoir

Geothermal Money Book [Geothermal Outreach and Project Financing

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

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 ismore » 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

Geothermal Coproduction and Hybrid Systems | Geothermal Technologies | NREL

Science.gov Websites

systems. Geothermal and Oil and Gas NREL experts are working to find ways to effectively use renewable resources in combination with fossil energy. Geothermal and oil and gas hybrid systems make use of wells already drilled by oil and gas developers. Using coproduced geothermal fluids for power production from

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.

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)

Isotopic constraints on ice age fluids in active geothermal systems: Reykjanes, Iceland

NASA Astrophysics Data System (ADS)

Pope, Emily C.; Bird, Dennis K.; Arnórsson, Stefán; Fridriksson, Thráinn; Elders, Wilfred A.; Fridleifsson, Gudmundur Ó.

2009-08-01

The Reykjanes geothermal system is located on the landward extension of the Mid-Atlantic Ridge in southwest Iceland, and provides an on-land proxy to high-temperature hydrothermal systems of oceanic spreading centers. Previous studies of elemental composition and salinity have shown that Reykjanes geothermal fluids are likely hydrothermally modified seawater. However, δD values of these fluids are as low as -23‰, which is indicative of a meteoric water component. Here we constrain the origin of Reykjanes hydrothermal solutions by analysis of hydrogen and oxygen isotope compositions of hydrothermal epidote from geothermal drillholes at depths between 1 and 3 km. δDEPIDOTE values from wells RN-8, -9, -10 and -17 collectively range from -60 to -78‰, and δ18OEPIDOTE in these wells are between -3.0 and 2.3‰. The δD values of epidote generally increase along a NE trend through the geothermal field, whereas δ18O values generally decrease, suggesting a southwest to northeast migration of the geothermal upflow zone with time that is consistent with present-day temperatures and observed hydrothermal mineral zones. For comparative analysis, the meteoric-water dominated Nesjavellir and Krafla geothermal systems, which have a δDFLUID of ˜ -79‰ and -89‰, respectively, show δDEPIDOTE values of -115‰ and -125‰. In contrast, δDEPIDOTE from the mixed meteoric-seawater Svartsengi geothermal system is -68‰; comparable to δDEPIDOTE from well RN-10 at Reykjanes. Stable isotope compositions of geothermal fluids in isotopic equilibrium with the epidotes at Reykjanes are computed using published temperature dependent hydrogen and oxygen isotope fractionation curves for epidote-water, measured isotope composition of the epidotes and temperatures approximated from the boiling point curve with depth. Calculated δD and δ18O of geothermal fluids are less than 0‰, suggesting that fluids of meteoric or glacial origin are a significant component of the geothermal

Geothermal mineralized scales in the pipe system of the geothermal Piancastagnaio power plant (Mt. Amiata geothermal area): a key to understand the stibnite, cinnabarite and gold mineralization of Tuscany (central Italy)

NASA Astrophysics Data System (ADS)

Morteani, Giulio; Ruggieri, Giovanni; Möller, Peter; Preinfalk, Christine

2011-02-01

The CO2-rich geothermal fluids produced in the Piancastagnaio geothermal field (Mt. Amiata geothermal area, Southern Tuscany, Italy) show temperatures up to 360°C and pressures of about 200 bar at depths of around 3,500 m (Giolito, Ph.D. thesis, Università degli Studi di Firenze, Italy, pp 1-147, 2005). CaCO3- and/or SiO2-dominated scales are deposited in the pipes leading to the pressure and atmospheric separators of the geothermal wells. High content of metastibnite and/or stibnite in both calcite and silica scales and Sb contents of up to 50 mg/L in the fluids indicate their mineralising potential. The red or black colours of the scales depend on the predominance of red metastibnite or black stibnite, respectively. In our condensation experiments, as well as during deposition of the scales, metastibnite is the first Sb2S3 mineral to form. In a second stage, metastibnite is transformed to stibnite. During depressurization the Hg content of geothermal fluids partitions preferentially into the gas phase, whereas Sb and As remain in the liquid phase. This separation explains the often observed areal separation of Hg and Sb mineralization. The multistage deposition of Sb in the mining district of Tuscany is due to a periodic restoration of the permeability of the ore-bearing faults by microseismic events and subsequent host rock brecciation. The still ongoing microseismic events are induced by the accumulation of high-pressure CO2-rich fluids along faults followed by mechanical failure of the faults.

Structural controls on fluid circulation at the Caviahue-Copahue Volcanic Complex (CCVC) geothermal area (Chile-Argentina), revealed by soil CO2 and temperature, self-potential, and helium isotopes

NASA Astrophysics Data System (ADS)

Roulleau, Emilie; Bravo, Francisco; Pinti, Daniele L.; Barde-Cabusson, Stéphanie; Pizarro, Marcela; Tardani, Daniele; Muñoz, Carlos; Sanchez, Juan; Sano, Yuji; Takahata, Naoto; de la Cal, Federico; Esteban, Carlos; Morata, Diego

2017-07-01

produces a high vapor-dominated zone close to the surface, whereas the WNW-striking faults could act as a boundary of the Copahue geothermal area to the south.

Stable-isotope studies of rocks and secondary minerals in a vapor-dominated hydrothermal system at The Geysers, Sonoma County, California

NASA Astrophysics Data System (ADS)

Lambert, Steven J.; Epstein, Samuel

1992-11-01

The Geysers, a vapor-dominated hydrothermal system, is developed in host rock of the Franciscan Formation, which contains veins of quartz and calcite whose δ 18O values record the temperatures and isotopic compositions of fluids prevailing during at least two different episodes of rock-fluid interaction. The first episode took place at about 200°C, during which marine silica and carbonate apparently interacted with ocean water entrapped in the sediments to form veins of quartz and calcite whose δ 18O values were around +19 and +16%, respectively. The calculated water/mineral ratios were less than unity. The water may have profoundly influenced the δ 18O values of spilitic basalts during their metamorphism to greenstones. Serpentinization and structural emplacement of ophiolite slabs were isotopically unrelated to this episode, which was essentially a low-grade (post-Cretaceous?) burial metamorphism. D/H ratios of actinolite, chlorite, and micas in host rocks were more profoundly altered during this episode than were 18O/ 16O ratios. A paleogeothermal gradient of about 53°C/km has been inferred for this episode, from δ 18O-depth distributions of vein minerals. The second episode, in part recorded by cogenetic vein quartz and calcite δ 18O values of +4 to +6% and +1 to +3%, respectively, began with large quantities of meteoric water circulating in fractures in the rock at temperatures of 160-180°C in response to the initiation of the Pliocene-Pleistocene Clear Lake magmatism. The temperature rose, and with the restricted circulation of fluids the ancestral hot-water system evolved into the presently active vapor-dominated system, which according to the cogenetic vein quartz and calcite δ 18O values involved temperatures as high as 320°C and fluid/mineral ratios near unity. The change in the oxygen-isotopic composition of the serpentinite within the host rock during this later activity was negligible. The δ 13C values of vein calcite at The Geysers reflect

Geothermal Impact Analysis | Geothermal Technologies | NREL

Science.gov Websites

on potential geothermal growth scenarios, jobs and economic impacts, clean energy manufacturing geothermal resources. We: Perform resource analysis Develop techno-economic models Quantify environmental growth scenarios across multiple market sectors. Learn more about the GeoVision Study. Jobs and Economic

Review of subduction and its association with geothermal system in Sumatera-Java

NASA Astrophysics Data System (ADS)

Ladiba, A. F.; Putriyana, L.; Sibarani, B. br.; Soekarno, H.

2017-12-01

Java and Sumatera have the largest geothermal resources in Indonesia, in which mostly are spatially associated with volcanoes of subduction zones. However, those volcanoes are not distributed in a regular pattern due to the difference of subduction position. Subduction position in java is relatively more perpendicular to the trench than in Sumatera. In addition, Java has a concentration of large productive geothermal field with vapour dominated system in the western part of Java, which may be caused by the various subduction dip along the island. In order to understand the relationship between the subduction process and geothermal system in the subduction zone volcanoes, we examined several kinematic parameters of subduction that potentially relevant to the formation of geothermal system in overriding plate such as slab dip, subduction rate, and direction of subduction. Data and information regarding tectonic setting of Sumatera and Java and productive geothermal field in Sumatera and Java have been collected and evaluated. In conclusion, there are three condition that caused the geothermal fluid to be more likely being in vapour phase, which are: the subduction is in an orthogonal position, the slab dip is high, and rate of subduction is high. Although there are plenty researches of subduction zone volcanoes, only a few of them present information about its formation and implication to the geothermal system. The result of this study may be used as reference in exploration of geothermal field in mutual geologic environment.

From source to surface: Tracking magmatic boron and chlorine input into the geothermal systems of the Taupo Volcanic Zone, New Zealand

NASA Astrophysics Data System (ADS)

Bégué, Florence; Deering, Chad D.; Gravley, Darren M.; Chambefort, Isabelle; Kennedy, Ben M.

2017-10-01

The magmatic contribution into geothermal fluids in the central Taupo Volcanic Zone (TVZ), New Zealand, has been attributed to either andesitic, 'arc-type' fluids, or rhyolitic, 'rift-type' fluids to explain the compositional diversity of discharge waters. However, this model relies on outdated assumptions related to geochemical trends associated with the magma at depth of typical arc to back-arc settings. Current tectonic models have shown that the TVZ is situated within a rifting arc and hosts magmatic systems dominated by distinct rhyolite types, that are likely to have evolved under different conditions than the subordinate andesites. Therefore, a new appraisal of the existing models is required to further understand the origin of the spatial compositional diversity observed in the geothermal fluids and its relationship to the structural setting. Here, we use volatile concentrations (i.e. H2O, Cl, B) from rhyolitic and andesitic mineral-hosted melt inclusions to evaluate the magmatic contribution to the TVZ geothermal systems. The andesite and two different types of rhyolites (R1 and R2) are each distinct in Cl/H2O and B/Cl, which will affect volatile solubility and phase separation (vapor vs. hydrosaline liquid) of the exsolved volatile phase. Ultimately, these key differences in the magmatic volatile constituents will play a significant role in governing the concentration of Cl discharged into geothermal systems. We estimate bulk fluid compositions (B and Cl) in equilibrium with the different melt types to show the potential contribution of 'parent' fluids to the geothermal systems throughout the TVZ. The results of this analysis show that the variability in fluid compositions partly reflects degassing from previously unaccounted for distinct magma source compositions. We suggest the geothermal systems that appear to have an 'arc-type' andesitic fluid contribution are actually derived from a rhyolite melt in equilibrium with a highly crystalline andesite

Geothermal pilot study final report: creating an international geothermal energy community

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

Bresee, J.C.; Yen, W.W.S.; Metzler, J.E.

The Geothermal Pilot Study under the auspices of the Committee on the Challenges of Modern Society (CCMS) was established in 1973 to apply an action-oriented approach to international geothermal research and development, taking advantage of the established channels of governmental communication provided by the North Atlantic Treaty Organization (NATO). The Pilot Study was composed of five substudies. They included: computer-based information systems; direct application of geothermal energy; reservoir assessment; small geothermal power plants; and hot dry rock concepts. The most significant overall result of the CCMS Geothermal Pilot Study, which is now complete, is the establishment of an identifiable communitymore » of geothermal experts in a dozen or more countries active in development programs. Specific accomplishments include the creation of an international computer file of technical information on geothermal wells and fields, the development of studies and reports on direct applications, geothermal fluid injection and small power plants, and the operation of the visiting scientist program. In the United States, the computer file has aready proven useful in the development of reservoir models and of chemical geothermometers. The state-of-the-art report on direct uses of geothermal energy is proving to be a valuable resource document for laypersons and experts in an area of increasing interest to many countries. Geothermal fluid injection studies in El Salvador, New Zealand, and the United States have been assisted by the Reservoir Assessment Substudy and have led to long-range reservoir engineering studies in Mexico. At least seven small geothermal power plants are in use or have been planned for construction around the world since the Small Power Plant Substudy was instituted--at least partial credit for this increased application can be assigned to the CCMS Geothermal Pilot Study. (JGB)« less

Geothermal tomorrow 2008

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

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.

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.

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.

Basics of applied geothermal engineering

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

Wehlage, E.F.

1976-01-01

The following chapters are included: (1) born of fire, (2) milestones with tectonics, (3) a world in geothermal review, (4) simple mechanical and electrical facts for geothermal, (5) elementary hydraulics and pumping, (6) elementary heat, (7) application of steam, (8) geothermal hydroponics, (9) designing for a geothermal diary, (10) review of geothermal prime movers for power production, (11) design procedures-geothermal house heating, (12) cooling with geothermal refrigeration, and (13) geothermal synthesis-new heat for the world. (MOW)

Guidebook to Geothermal Finance

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

Salmon, J. P.; Meurice, J.; Wobus, N.

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.

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.

Radon and temperature as tracer of geothermal flow system: application to Arxan geothermal system, Northeastern China

NASA Astrophysics Data System (ADS)

Gu, X.; Shao, J.; Cui, Y.

2017-12-01

In this work, hydrogeological and hydrochemical investigations were applied to explain geothermal system factors controlling groundwater mineralization in Arxan geothermal system, Northeastern China. Geothermal water samples were collected from different locations (thermal baths and wells). Radon concentrations of water samples representing different water types and depths were controlled using RAD7. In addition to radon concentration, physical parameters such as temperature (T), pH, electrical conductivity (EC) and TDS were measured in situ, while major ions were analyzed in laboratory. Temperature spatial variability in the study area was described using kriging interpolation method. Hydrochemical analysis and thermal parameters suggest two distinct hydrogeological systems. The first type was dominated by a moderate temperature (25 41°C) with a chemical facies Na-HCO3, which characterizes Jurassic deep water. The second water type was characterized by Ca.Na-HCO3 type with a temperature <25 °C and represents the shallow aquifer. Superficial aquifer displays higher radon concentration (37 to 130 Bq/L), while deep groundwater from Jurassic aquifer shows relatively a low radon concentration (6 to 57.4 Bq/L). Seasonal and geographical variations of radon give insight into the processes controlling radon activities in the Arxan groundwater. Radon concentrations along with spatial distribution of water temperature reveal the existence of vertical communication between shallow aquifer and deep Jurassic aquifer through vertical faults and fractures system, the emanation of radon from thermal water and groundwater is controlled by the geological structure of the area. Furthermore, the knowledge and conclusion demonstrates that combined use of radon and temperature as tracers can give insight into the characteristics of geological structure and geothermal flow system.

Microbes in mercury-enriched geothermal springs in western North America.

PubMed

Geesey, Gill G; Barkay, Tamar; King, Sue

2016-11-01

Because geothermal environments contain mercury (Hg) from natural sources, microorganisms that evolved in these systems have likely adapted to this element. Knowledge of the interactions between microorganisms and Hg in geothermal systems may assist in understanding the long-term evolution of microbial adaptation to Hg with relevance to other environments where Hg is introduced from anthropogenic sources. A number of microbiological studies with supporting geochemistry have been conducted in geothermal systems across western North America. Approximately 1 in 5 study sites include measurements of Hg. Of all prokaryotic taxa reported across sites with microbiological and accompanying physicochemical data, 42% have been detected at sites in which Hg was measured. Genes specifying Hg reduction and detoxification by microorganisms were detected in a number of hot springs across the region. Archaeal-like sequences, representing two crenarchaeal orders and one order each of the Euryarchaeota and Thaumarchaeota, dominated in metagenomes' MerA (the mercuric reductase protein) inventories, while bacterial homologs were mostly found in one deeply sequenced metagenome. MerA homologs were more frequently found in metagenomes of microbial communities in acidic springs than in circumneutral or high pH geothermal systems, possibly reflecting higher bioavailability of Hg under acidic conditions. MerA homologs were found in hot springs prokaryotic isolates affiliated with Bacteria and Archaea taxa. Acidic sites with high Hg concentrations contain more of Archaea than Bacteria taxa, while the reverse appears to be the case in circumneutral and high pH sites with high Hg concentrations. However, MerA was detected in only a small fraction of the Archaea and Bacteria taxa inhabiting sites containing Hg. Nevertheless, the presence of MerA homologs and their distribution patterns in systems, in which Hg has yet to be measured, demonstrates the potential for detoxification by Hg reduction

Geothermal energy

NASA Astrophysics Data System (ADS)

Manzella, A.

2017-07-01

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 the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, 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. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades 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.

Structural controls on a geothermal system in the Tarutung Basin, north central Sumatra

NASA Astrophysics Data System (ADS)

Nukman, Mochamad; Moeck, Inga

2013-09-01

The Sumatra Fault System provides a unique geologic setting to evaluate the influence of structural controls on geothermal activity. Whereas most of the geothermal systems in Indonesia are controlled by volcanic activity, geothermal systems at the Sumatra Fault System might be controlled by faults and fractures. Exploration strategies for these geothermal systems need to be verified because the typical pattern of heat source and alteration clays are missing so that conventional exploration with magnetotelluric surveys might not provide sufficient data to delineate favorable settings for drilling. We present field geological, structural and geomorphological evidence combined with mapping of geothermal manifestations to allow constraints between fault dynamics and geothermal activity in the Tarutung Basin in north central Sumatra. Our results indicate that the fault pattern in the Tarutung Basin is generated by a compressional stress direction acting at a high angle to the right-lateral Sumatra Fault System. NW-SE striking normal faults possibly related to negative flower structures and NNW-SSE to NNE-SSW oriented dilative Riedel shears are preferential fluid pathways whereas ENE-WSW striking faults act as barriers in this system. The dominant of geothermal manifestations at the eastern part of the basin indicates local extension due to clockwise block rotation in the Sumatra Fault System. Our results support the effort to integrate detailed field geological surveys to refined exploration strategies even in tropical areas where outcrops are limited.

Advanced Geothermal Turbodrill

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

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 largemore » 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.« less

Geothermal Energy Summary

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

J. L. Renner

2007-08-01

Following is complete draft.Geothermal Summary for AAPG Explorer J. L. Renner, Idaho National Laboratory Geothermal energy is used to produce electricity in 24 countries. The United States has the largest capacity (2,544 MWe) followed by Philippines (1,931 MWe), Mexico (953 MWe), Indonesia (797 MWe), and Italy (791 MWe) (Bertani, 2005). When Chevron Corporation purchased Unocal Corporation they became the leading producer of geothermal energy worldwide with projects in Indonesia and the Philippines. The U. S. geothermal industry is booming thanks to increasing energy prices, renewable portfolio standards, and a production tax credit. California (2,244 MWe) is the leading producer, followedmore » by Nevada (243 MWe), Utah (26 MWe) and Hawaii (30 MWe) and Alaska (0.4 MWe) (Bertani, 2005). Alaska joined the producing states with two 0.4 KWe power plants placed on line at Chena Hot Springs during 2006. The plant uses 30 liters per second of 75°C water from shallow wells. Power production is assisted by the availability of gravity fed, 7°C cooling water (http://www.yourownpower.com/) A 13 MWe binary power plant is expected to begin production in the fall of 2007 at Raft River in southeastern Idaho. Idaho also is a leader in direct use of geothermal energy with the state capital building and several other state and Boise City buildings as well as commercial and residential space heated using fluids from several, interconnected geothermal systems. The Energy Policy Act of 2005 modified leasing provisions and royalty rates for both geothermal electrical production and direct use. Pursuant to the legislation the Bureau of Land management and Minerals Management Service published final regulations for continued geothermal leasing, operations and royalty collection in the Federal Register (Vol. 72, No. 84 Wednesday May 2, 2007, BLM p. 24358-24446, MMS p. 24448-24469). Existing U. S. plants focus on high-grade geothermal systems located in the west. However, interest in

Geothermal System Extensions

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

Gunnerson, Jon; Pardy, James J.

This material is based upon work supported by the Department of Energy under Award Number DE-EE0000318. The City of Boise operates and maintains the nation’s largest geothermal heating district. Today, 91 buildings are connected, providing space heating to over 5.5 million square feet, domestic water heating, laundry and pool heating, sidewalk snowmelt and other related uses. Approximately 300 million gallons of 177°F geothermal water is pumped annually to buildings and institutions located in downtown Boise. The closed loop system returns all used geothermal water back into the aquifer after heat has been removed via an Injection Well. Water injected backmore » into the aquifer has an average temperature of 115°F. This project expanded the Boise Geothermal Heating District (Geothermal System) to bring geothermal energy to the campus of Boise State University and to the Central Addition Eco-District. In addition, this project also improved the overall system’s reliability and increased the hydraulic capacity.« less

Geothermal Data Collection and Interpretation in the State of Alabama: Early Results from the ARRA Geothermal Energy Initiative

NASA Astrophysics Data System (ADS)

Hills, D. J.; Osborne, T. E.; McIntyre, M. R.; Pashin, J. C.

2011-12-01

The Geological Survey of Alabama (GSA) is expanding its efforts to collect, develop, maintain, and analyze statewide geothermal data and to make this information widely and easily accessible to the public through the National Geothermal Data System. The online availability of this data will aid in the effective development of geothermal energy applications and reduce the risks associated with the initial stages of geothermal project development. To this end, the GSA is participating in a collaborative project that the Arizona Geological Survey is coordinating in cooperation with the Association of American State Geologists and with the support of the U.S. Department of Energy as part of the American Reinvestment and Recovery Act. Wells drilled for the exploration and production of hydrocarbons are the primary sources of geothermal data in Alabama. To date, more than 1,200 wells in coalbed methane (CBM) fields in the Black Warrior Basin (BWB) have been examined, in addition to over 500 conventional wells in the basin. Pottsville Formation (Pennsylvanian) bottom-hole temperatures (BHTs) range from less than 80°F to more than 140°F in wells reaching total depth between 1,000 and 6,000 feet (ft). Temperature and depth correlate with a coefficient of determination (r2) of 0.72, reflecting significant variation of the modern geothermal gradient. Mapping and statistical analysis confirm that geothermal gradient in the CBM fairway is typically between 6 and 12°F/1,000 ft. BHTs in the conventional wells penetrating the BWB show even greater variation, with temperature and depth correlating with an r2 of only 0.27. This variability owes to numerous factors, including stratigraphy, lithology, thermal conductivity, and geothermal gradient. Indeed, these wells reach total depth between 500 and 12,000 ft in carbonate and siliciclastic formations ranging in age from Cambrian to Mississippian. The Cambrian section is dominated by low conductivity shale, whereas the Ordovician

Publications | Geothermal Technologies | NREL

Science.gov Websites

Publications Publications NREL publishes a variety of publications related to geothermal energy geothermal energy research. Featured Publications Mexico's Geothermal Market Assessment Report NREL Technical investment in the country's geothermal energy sector. Since 2013, Mexico has enacted comprehensive reforms to

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

Hot and Steamy Fractures in the Philippines: The Geological Characterization and Permeability Evaluation of Fractures in the Southern Negros Geothermal Field, Philippines

NASA Astrophysics Data System (ADS)

Pastoriza, L. R.; Holdsworth, R.; McCaffrey, K. J. W.; Dempsey, E. D.; Walker, R. J.; Gluyas, J.; Reyes, J. K.

2016-12-01

Fluid flow pathway characterization is critical to geothermal exploration and exploitation. It requires a good understanding of the structural evolution, fault distribution and fluid flow properties. A dominantly fieldwork-based approach has been used to evaluate the potential fracture permeability characteristics of a typical high-temperature geothermal reservoir in the Southern Negros Geothermal Field, Philippines. This is a liquid-dominated geothermal resource hosted in the andesitic to dacitic Quaternary Cuernos de Negros Volcano in Negros Island. Fieldwork reveals two main fracture groups based on fault rock characteristics, alteration type, relative age of deformation, and associated thermal manifestation, with the younger fractures mainly related to the development of the modern geothermal system. Palaeostress analyses of cross-cutting fault and fracture arrays reveal a progressive counterclockwise rotation of stress axes from the (?)Pliocene up to the present-day, which is consistent with the regional tectonic models. A combined slip and dilation tendency analysis of the mapped faults indicates that NW-SE structures should be particularly promising drilling targets. Frequency versus length and aperture plots of fractures across six to eight orders of magnitude show power-law relationships with a change in scaling exponent in the region of 100 to 500m length-scales. Finally, evaluation of the topology of the fracture branches shows the dominance of Y-nodes that are mostly doubly connected suggesting good connectivity and permeability within the fracture networks. The results obtained in this study illustrate the value of methods that can be globally applied during exploration to better characterize fracture systems in geothermal reservoirs using multiscale datasets.

Identification of geothermal system using 2D audio magnetotelluric method in Telomoyo volcanic area

NASA Astrophysics Data System (ADS)

Romadlon, Arriqo'Fauqi; Niasari, Sintia Windhi

2017-07-01

Geothermal area of Candi Umbul Telomoyo is one of geothermal fields in Indonesia. This geothermal field is located in the Grabag district, Magelang, Central Java. This geothermal field was formed in a volcanic quarter. The main aim in this study is to identify geothermal system at Telomoyo volcanic area through synthetic model analysis. There are surface manifestations such as warm springs and altered rocks. Results of geochemistry study showed reservoir's temperature was 230°C. The Warm spring in Candi Umbul was the outflow zone of the Telomoyo geothermal system. The Telomoyo geothermal system was indicated chloride-bicarbonate type of warm spring. In addition, the results of geological mapping indicate that the dominant fault structure has southwest-northeast orientation. The fault was caused by the volcanic activity of mount Telomoyo. In this research conducted data analysis from synthetics model. It aims to estimate the response of magnetotelluric methods in various models of geothermal systems. In this study, we assumed three models of geothermal system in Candi Umbul-Telomoyo area. From the data analysis it was known that the model 1 and model 2 can be distinguished if the measurements were conducted in a frequency range of 0.01 Hz to 1000 Hz. In response of tipper (Hz) had a small value on all models at all measurement points, so the tipper cannot distinguish between model 1, model 2 and model 3. From this analysis was known that TM mode is more sensitive than TE mode at the resistivity and phase responses.

Seismic properties of fluid bearing formations in magmatic geothermal systems: can we directly detect geothermal activity with seismic methods?

NASA Astrophysics Data System (ADS)

Grab, Melchior; Scott, Samuel; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart

2016-04-01

Seismic methods are amongst the most common techniques to explore the earth's subsurface. Seismic properties such as velocities, impedance contrasts and attenuation enable the characterization of the rocks in a geothermal system. The most important goal of geothermal exploration, however, is to describe the enthalpy state of the pore fluids, which act as the main transport medium for the geothermal heat, and to detect permeable structures such as fracture networks, which control the movement of these pore fluids in the subsurface. Since the quantities measured with seismic methods are only indirectly related with the fluid state and the rock permeability, the interpretation of seismic datasets is difficult and usually delivers ambiguous results. To help overcome this problem, we use a numerical modeling tool that quantifies the seismic properties of fractured rock formations that are typically found in magmatic geothermal systems. We incorporate the physics of the pore fluids, ranging from the liquid to the boiling and ultimately vapor state. Furthermore, we consider the hydromechanics of permeable structures at different scales from small cooling joints to large caldera faults as are known to be present in volcanic systems. Our modeling techniques simulate oscillatory compressibility and shear tests and yield the P- and S-wave velocities and attenuation factors of fluid saturated fractured rock volumes. To apply this modeling technique to realistic scenarios, numerous input parameters need to be indentified. The properties of the rock matrix and individual fractures were derived from extensive literature research including a large number of laboratory-based studies. The geometries of fracture networks were provided by structural geologists from their published studies of outcrops. Finally, the physical properties of the pore fluid, ranging from those at ambient pressures and temperatures up to the supercritical conditions, were taken from the fluid physics

Geothermal Energy

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

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.

Geothermal fields of China

NASA Astrophysics Data System (ADS)

Kearey, P.; HongBing, Wei

1993-08-01

There are over 2500 known occurrences of geothermal phenomena in China. These lie mainly in four major geothermal zones: Xizang (Tibet)-Yunnan, Taiwan, East Coast and North-South. Hot water has also been found in boreholes in major Mesozoic-Cenozoic sedimentary basins. This paper presents a summary of present knowledge of these geothermal zones. The geological settings of geothermal occurrences are associated mainly with magmatic activity, fault uplift and depressional basins and these are described by examples of each type. Increased multipurpose utilisation of geothermal resources is planned and examples are given of current usages.

GEOTHERMAL / SOLAR HYBRID DESIGNS: USE OF GEOTHERMAL ENERGY FOR CSP FEEDWATER HEATING

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

Craig Turchi; Guangdong Zhu; Michael Wagner

2014-10-01

This paper examines a hybrid geothermal / solar thermal plant design that uses geothermal energy to provide feedwater heating in a conventional steam-Rankine power cycle deployed by a concentrating solar power (CSP) plant. The geothermal energy represents slightly over 10% of the total thermal input to the hybrid plant. The geothermal energy allows power output from the hybrid plant to increase by about 8% relative to a stand-alone CSP plant with the same solar-thermal input. Geothermal energy is converted to electricity at an efficiency of 1.7 to 2.5 times greater than would occur in a stand-alone, binary-cycle geothermal plant usingmore » the same geothermal resource. While the design exhibits a clear advantage during hybrid plant operation, the annual advantage of the hybrid versus two stand-alone power plants depends on the total annual operating hours of the hybrid plant. The annual results in this draft paper are preliminary, and further results are expected prior to submission of a final paper.« less

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.

Analysis of the unique geothermal microbial ecosystem of the Blue Lagoon.

PubMed

Petursdottir, Solveig K; Bjornsdottir, Snaedis H; Hreggvidsson, Gudmundur O; Hjorleifsdottir, Sigridur; Kristjansson, Jakob K

2009-12-01

Cultivation and culture-independent techniques were used to describe the geothermal ecosystem of the Blue Lagoon in Iceland. The lagoon contains both seawater and freshwater of geothermal origin and is extremely high in silica content. Water samples were collected repeatedly in summer and autumn in 2003 and 2005 and in winter 2006 were analyzed for species composition. The study revealed the typical traits of an extreme ecosystem characterized by dominating species and other species represented in low numbers. A total of 35 taxa were identified. The calculated biodiversity index of the samples was 2.1-2.5. The majority (83%) of analyzed taxa were closely related to bacteria of marine and geothermal origin reflecting a marine character of the ecosystem and the origin of the Blue Lagoon hydrothermal fluid. A high ratio (63%) of analyzed taxa represented putative novel bacterial species. The majority (71%) of analyzed clones were Alphaproteobacteria, of which 80% belonged to the Roseobacter lineage within the family of Rhodobacteraceae. Of seven cultivated species, the two most abundant ones belonged to this lineage. Silicibacter lacuscaerulensis was confirmed as a dominating species in the Blue Lagoon. One group of isolates represented a recently identified species within the genus of Nitratireductor within Rhizobiales. This study implies an annually stable and seasonally dynamic ecosystem in the Blue Lagoon.

The geothermal system of Caviahue-Copahue Volcanic Complex (Chile-Argentina): New insights from self-potential, soil CO2 degassing, temperature measurements and helium isotopes, with structural and fluid circulation implications.

NASA Astrophysics Data System (ADS)

Roulleau, Emilie; Bravo, Francisco; Barde-Cabusson, Stephanie; Pizarro, Marcela; Muños, Carlos; Sanchez, Juan; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; de Cal, Federico; Esteban, Carlos

2016-04-01

Geothermal systems represent natural heat transfer engines in a confined volume of rock which are strongly influenced by the regional volcano-tectonic setting controlling the formation of shallow magmatic reservoirs, and by the local faults/fracture network, that permits the development of hydrothermal circulation cells and promote the vertical migration of fluids and heat. In the Southern Volcanic Zone of Chile-Argentina, geothermal resources occur in close spatial relationship with active volcanism along the Cordillera which is primarily controlled by the 1000 km long, NNE Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system, associated with second-order intra-arc anisotropy of overall NE-SW (extensional) and NW-SE orientation (compressional). However there is still a lack of information on how fault network (NE and WNW strinking faults) and lithology control the fluid circulation. In this study, we propose new data of dense self-potential (SP), soil CO2 emanation and temperature (T) measurements within the geothermal area from Caviahue-Copahue Volcanic Complex (CCVC), coupled with helium isotopes ratios measured in fumaroles and thermal springs. We observe that inside the geothermal system the NE-striking faults, characterized by a combination of SP-CO2 and T maxima with high 3He/4He ratios (7.86Ra), promote the formation of high vertical permeability pathways for fluid circulation. Whereas, the WNW-striking faults represent low permeability pathways for hydrothermal fluids ascent associated with moderate 3He/4He ratios (5.34Ra), promoting the infiltration of meteoric water at shallow depth. These active zones are interspersed by SP-CO2- T minima, which represent self-sealed zones (e.g. impermeable altered rocks) at depth, creating a barrier inhibiting fluids rise. The NE-striking faults seem to be associated with the upflow zones of the geothermal system, where the boiling process produces a high vapor-dominated zone close to the

Geothermal Maps | Geospatial Data Science | NREL

Science.gov Websites

presented in these maps was aggregated from the Geothermal Energy Association 2014 Annual U.S. and Global Geothermal Maps Geothermal Maps Our geothermal map collection covers U.S. geothermal power plants , geothermal resource potential, and geothermal power generation. If you have difficulty accessing these maps

Geothermal exploration in the Virunga Prospect, Northern Rwanda

NASA Astrophysics Data System (ADS)

Jolie, E.

2009-04-01

German technical cooperation has taken the initiative to support partner countries in geothermal energy use. Therefore the Federal Institute for Geosciences and Natural Resources (BGR) on behalf of the Federal Ministry for Economic Cooperation and Development (BMZ) is carrying out the technical cooperation programme GEOTHERM. As an example of the ongoing project activities, preliminary results of studies carried out in the Virunga geothermal prospect in Northern Rwanda will be presented. The study area is located along the Western branch of the East African Rift System. Weak geothermal surface manifestations, e.g. hot springs and bubbling pools, indicate an existing hydrothermal system. Previous studies did not determine location, distribution, quality and quantity of the heat source. Consequently the aim of this study is to detect and assess the heat source with a multi method approach. Remote sensing techniques, geochemical analyses and geophysical measurements have been applied to make a first serious attempt. More detailed geophysical investigations and gas measurements are planned to start in spring 2009. Aerial photographs and satellite images were used for a high-resolution structural analysis to determine major fault zones, which are dominating the flow paths of hydrothermal fluids. In the frame of a regional geophysical survey (Magnetotellurics and Transient Electromagnetics) a zone of low resistivity values could be detected SW of the Karisimbi stratovolcano, which is corresponding with the results of the geochemical analyses. Assumptions are made that a magmatic body may exist in a depth of 5 km below surface.

Geothermal Energy Basics | NREL

Science.gov Websites

Geothermal Energy Basics Geothermal Energy Basics Many technologies have been developed to take advantage of geothermal energy-the heat from the earth. This heat can be drawn from several sources: hot hot spring. The Earth's heat-called geothermal energy-escapes as steam at a hot springs in Nevada

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)

New Zealand geothermal: Wairakei -- 40 years

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

NONE

This quarterly bulletin highlights the geothermal developments in New Zealand with the following articles: A brief history of the Wairakei geothermal power project; Geothermal resources in New Zealand -- An overview; Domestic and commercial heating and bathing -- Rotorua area; Kawerau geothermal development: A case study; Timber drying at Kawerau; Geothermal greenhouses at Kawerau; Drying of fibrous crops using geothermal steam and hot water at the Taupo Lucerne Company; Prawn Park -- Taupo, New Zealand; Geothermal orchids; Miranda hot springs; and Geothermal pipeline.

Hot and steamy fractures in the Philippines: the characterisation and permeability evaluation of fractures of the Southern Negros Geothermal Field, Negros Oriental, Philippines

NASA Astrophysics Data System (ADS)

Pastoriza, Loraine; Holdsworth, Robert; McCaffrey, Kenneth; Dempsey, Eddie; Walker, Richard; Gluyas, Jon; Reyes, Jonathan

2017-04-01

Fluid flow pathway characterisation is critical to geothermal exploration and exploitation. It requires a good understanding of the structural evolution, fault distribution and fluid flow properties. A dominantly fieldwork-based approach has been used to evaluate the potential fracture permeability characteristics of a typical high-temperature geothermal reservoir in the Southern Negros Geothermal Field, Philippines. This is a liquid-dominated geothermal resource hosted in the andesitic to dacitic Quaternary Cuernos de Negros Volcano in Negros Island. Fieldwork reveals two main fracture groups based on fault rock characteristics, alteration type, relative age of deformation, and associated thermal manifestation, with the younger fractures mainly related to the development of the modern geothermal system. Palaeostress analyses of cross-cutting fault and fracture arrays reveal a progressive counterclockwise rotation of stress axes from the (?)Pliocene up to the present-day, which is consistent with the regional tectonic models. A combined slip and dilation tendency analysis of the mapped faults indicates that NW-SE structures should be particularly promising drilling targets. Frequency versus length and aperture plots of fractures across six to eight orders of magnitude show power-law relationships with a change in scaling exponent in the region of 100 to 500m length-scales. Finally, evaluation of the topology of the fracture branches shows the dominance of Y-nodes that are mostly doubly connected suggesting good connectivity and permeability within the fracture networks. The results obtained in this study illustrate the value of methods that can be globally applied during exploration to better characterize fracture systems in geothermal reservoirs using multiscale datasets.

Transient-pressure analysis in geothermal steam reservoirs with an immobile vaporizing liquid phase

USGS Publications Warehouse

Moench, A.F.; Atkinson, P.G.

1978-01-01

A finite-difference model for the radial horizontal flow of steam through a porous medium is used to evaluate transient-pressure behavior in the presence of an immobile vaporizing or condensing liquid phase. Graphs of pressure drawdown and buildup in terms of dimensionless pressure and time are obtained for a well discharging steam at a constant mass flow rate for a specified time. The assumptions are made that the steam is in local thermal equilibrium with the reservoir rocks, that temperature changes are due only to phase change, and that effects of vapor-pressure lowering are negligible. Computations show that when a vaporizing liquid phase is present the pressure drawdown exhibits behavior similar to that observed in noncondensable gas reservoirs, but delayed in time. A theoretical analysis allows for the computation of this delay and demonstrates that it is independent of flow geometry. The response that occurs upon pressure buildup is markedly different from that in a noncondensable gas system. This result may provide a diagnostic tool for establishing the existence of phase-change phenomena within a reservoir. ?? 1979.

Geothermal Potential Analysis Using Landsat 8 and Sentinel 2 (Case Study: Mount Ijen)

NASA Astrophysics Data System (ADS)

Sukojo, B. M.; Mardiana, R.

2017-12-01

Geothermal energy is also a heat energy contained in the earth’s internal. Indonesia has a total geothermal potential of around 27 GWe. The government is eager for the development of geothermal in Indonesia can run well so that geothermal can act as one of the pillars of national energy. However, the geothermal potential has not been fully utilized. One of the geothermal potention is Mount Ijen. Mount Ijen is a strato volcano that has a crater lake with a depth of about 190 m and has a very high degree of acidity and the volume of lake water is very large. With the abundance of potential geothermal potential in Indonesia, it is necessary to have an activity in the form of integrated geoscience studies to be able to maximize the potential content that exists in a geothermal area. One of the studies conducted is to do potential mapping. This research performs image data processing of Landsat 8, Sentinel 2, RBI Map, and preliminary survey data. This research carried out the Vegetation Index, surface temperature and altitude. The equipment used in this research includes image processing software, number processing software, GPS Handheld and Laptop. Surface Temperatures in the Mount Ijen have anomalies with large temperatures ranging between 18° C to 38° C. The best correlation value of altitude and ground surface temperature is -0.89 ie the correlation of January surface temperature. While the correlation value of Landsat 8 and Sentinel 2 vegetation index was 0.81. The land cover confidence matrix scored 80%. Land cover in the research area is dominated by forests by 35% of the research area. There is a potential area of geothermal potential is very high on Mount Ijen with an area of 39.43 hectares located in Wongsorejo District and adjacent to District Sempol.

Hydrochemical-isotopic and hydrogeological conceptual model of the Las Tres Vírgenes geothermal field, Baja California Sur, México

NASA Astrophysics Data System (ADS)

Portugal, E.; Birkle, P.; Barragán R, R. M.; Arellano G, V. M.; Tello, E.; Tello, M.

2000-09-01

Based on geological, structural, hydrochemical and isotopic data, a hydrogeological conceptual model for the geothermal reservoir, shallow wells and springs at the Las Tres Vírgenes geothermal field and its surroundings is proposed. The model explains the genesis of different types of thermal and cold groundwater in the NW (El Azufre Valley, Las Tres Vírgenes and Aguajito complex), NE (Reforma complex) and S (Sierra Mezquital) areas. Shallow groundwater of sulfate type in the NW zone is explained by the rise of CO2-H2S vapor from a shallow magma chamber and the subsequent heating up of a shallow aquifer. Vertical communication between the reservoir and the surface is facilitated by a series of extensional, NW-SE-trending normal faults, forming the graben structures of the Santa Rosalía Basin. Low-permeability characteristics of the geological formations of the study area support the hypothesis of a fracture and fault-dominated, subterranean-flow circulation system. The Na- (Cl-HCO3) composition of springs in the NE and SE zones indicates influence of ascending geothermal fluids, facilitated by radial fault systems of the Reforma caldera and probably the existence of a shallow magma chamber. Close to the surface, the rising geothermal fluids are mixed up with meteoric water from a shallow aquifer. The Las Tres Vírgenes and the Reforma complex are separated by younger, N-S-trending lateral shearing faults, such as the Cimarrón fault; such disposition explains the genesis of different hydrogeological flow regimes on both sides. HCO3-type surface water from the southern zone between San Ignacio and Mezquital is of typical meteoric origin, with no influence of geothermal fluids. Due to arid climatic conditions in the study zone, recent recharge in the geothermal area seems improbable; thus, recent interaction between the surface and the geothermal reservoir can be excluded. Furthermore, isotopic and hydrochemical data exclude the presence of marine water from the

"Assistance to States on Geothermal Energy"

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

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 outreachmore » 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

GEOTHERM user guide

USGS Publications Warehouse

Swanson, James R.

1977-01-01

GEOTHERM is a computerized geothermal resources file developed by the U.S. Geological Survey. The file contains data on geothermal fields, wells, and chemical analyses from the United states and international sources. The General Information Processing System (GIPSY) in the IBM 370/155 computer is used to store and retrieve data. The GIPSY retrieval program contains simple commands which can be used to search the file, select a narrowly defined subset, sort the records, and output the data in a variety of forms. Eight commands are listed and explained so that the GEOTHERM file can be accessed directly by geologists. No programming experience is necessary to retrieve data from the file.

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.

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

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

Wendt, Daniel; Mines, Greg; Turchi, Craig

There are numerous technical merits associated with a renewable geothermal-solar hybrid plant concept. The performance of air-cooled binary plants is lowest when ambient temperatures are high due to the decrease in air-cooled binary plant performance that occurs when the working fluid condensing temperature, and consequently the turbine exhaust pressure, increases. Electrical power demand is generally at peak levels during periods of elevated ambient temperature and it is therefore especially important to utilities to be able to provide electrical power during these periods. The time periods in which air-cooled binary geothermal power plant performance is lowest generally correspond to periods ofmore » high solar insolation. Use of solar heat to increase air-cooled geothermal power plant performance during these periods can improve the correlation between power plant output and utility load curves. While solar energy is a renewable energy source with long term performance that can be accurately characterized, on shorter time scales of hours or days it can be highly intermittent. Concentrating solar power (CSP), aka solar-thermal, plants often incorporate thermal energy storage to ensure continued operation during cloud events or after sunset. Hybridization with a geothermal power plant can eliminate the need for thermal storage due to the constant availability of geothermal heat. In addition to the elimination of the requirement for solar thermal storage, the ability of a geothermal/solar-thermal hybrid plant to share a common power block can reduce capital costs relative to separate, stand-alone geothermal and solar-thermal power plant installations. The common occurrence of long-term geothermal resource productivity decline provides additional motivation to consider the use of hybrid power plants in geothermal power production. Geothermal resource productivity decline is a source of significant risk in geothermal power generation. Many, if not all, geothermal

Geothermal energy - Ready for use

NASA Astrophysics Data System (ADS)

Miskell, J. T.

1980-11-01

The use of geothermal energy in the United States for heating applications is discussed. The three major forms of geothermal energy, hydrothermal, pertrothermal and geopressured, are briefly reviewed, with attention given to the types of energy available from each. Federally supported projects demonstrating the use of geothermal hot water to heat homes in Boise, Idaho, and hot dry rocks in Fenton Hill, New Mexico to produce electricity are presented. Data available from existing geothermal energy applications are presented which show that geothermal is cost competitive with conventional energy sources using existing technology, and government economic incentives to the producers and users of geothermal energy are indicated. Finally, advanced equipment currently under development for the generation of electricity from geothermal resources at reduced costs is presented.

Geothermal Data | Geospatial Data Science | NREL

Science.gov Websites

Identified Onshore Geopressured Geothermal Energy in Texas and Louisiana provides additional information on Geothermal Data Geothermal Data These datasets detail the geothermal resource available in the Metadata Geothermal Zip 5.4 MB 03/05/2009 geothermal.xml This dataset is a qualitative assessment of

Classification of public lands valuable for geothermal steam and associated geothermal resources

USGS Publications Warehouse

Godwin, Larry H.; Haigler, L.B.; Rioux, R.L.; White, D.E.; Muffler, L.J.; Wayland, R.G.

1971-01-01

The Organic Act of 1879 (43 U.S.C. 31) that established the U.S. Geological Survey provided, among other things, for the classification of the public lands and for the examination of the geological structure, mineral sources, and products of the national domain. In order to provide uniform executive action in classifying public lands, standards for determining which lands are valuable for mineral resources, for example, leasable mineral lands, or for other products are prepared by the U.S. Geological Survey. This report presents the classification standards for determining which Federal lands are classifiable as geothermal steam and associated geothermal resources lands under the Geothermal Steam Act of 1970 (84 Star. 1566). The concept of a geothermal resources province is established for classification of lands for the purpose of retention in Federal ownership of rights to geothermal resources upon disposal of Federal lands. A geothermal resources province is defined as an area in which higher than normal temperatures are likely to occur with depth and in which there is a reasonable possibility of finding reservoir rocks that will yield steam or heated fluids to wells. The determination of a 'known geothermal resources area' is made after careful evaluation of the available geologic, geochemical, and geophysical data and any evidence derived from nearby discoveries, competitive interests, and other indicia. The initial classification required by the Geothermal Steam Act of 1970 is presented.

Classification of public lands valuable for geothermal steam and associated geothermal resources

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

Goodwin, L.H.; Haigler, L.B.; Rioux, R.L.

1973-01-01

The Organic Act of 1879 (43 USC 31) that established the US Geological Survey provided, among other things, for the classification of the public lands and for the examination of the geological structure, mineral resources, and products of the national domain. In order to provide uniform executive action in classifying public lands, standards for determining which lands are valuable for mineral resources, for example, leasable mineral lands, or for other products are prepared by the US Geological Survey. This report presents the classification standards for determining which Federal lands are classifiable as geothermal steam and associated geothermal resources lands undermore » the Geothermal Steam Act of 1970 (84 Stat. 1566). The concept of a geothermal resouces province is established for classification of lands for the purpose of retention in Federal ownership of rights to geothermal resources upon disposal of Federal lands. A geothermal resources province is defined as an area in which higher than normal temperatures are likely to occur with depth and in which there is a resonable possiblity of finding reservoir rocks that will yield steam or heated fluids to wells. The determination of a known geothermal resources area is made after careful evaluation of the available geologic, geochemical, and geophysical data and any evidence derived from nearby discoveries, competitive interests, and other indicia. The initial classification required by the Geothermal Steam Act of 1970 is presented.« less

Coupling geophysical investigation with hydrothermal modeling to constrain the enthalpy classification of a potential geothermal resource.

USGS Publications Warehouse

White, Jeremy T.; Karakhanian, Arkadi; Connor, Chuck; Connor, Laura; Hughes, Joseph D.; Malservisi, Rocco; Wetmore, Paul

2015-01-01

An appreciable challenge in volcanology and geothermal resource development is to understand the relationships between volcanic systems and low-enthalpy geothermal resources. The enthalpy of an undeveloped geothermal resource in the Karckar region of Armenia is investigated by coupling geophysical and hydrothermal modeling. The results of 3-dimensional inversion of gravity data provide key inputs into a hydrothermal circulation model of the system and associated hot springs, which is used to evaluate possible geothermal system configurations. Hydraulic and thermal properties are specified using maximum a priori estimates. Limited constraints provided by temperature data collected from an existing down-gradient borehole indicate that the geothermal system can most likely be classified as low-enthalpy and liquid dominated. We find the heat source for the system is likely cooling quartz monzonite intrusions in the shallow subsurface and that meteoric recharge in the pull-apart basin circulates to depth, rises along basin-bounding faults and discharges at the hot springs. While other combinations of subsurface properties and geothermal system configurations may fit the temperature distribution equally well, we demonstrate that the low-enthalpy system is reasonably explained based largely on interpretation of surface geophysical data and relatively simple models.

Geothermal studies in China

NASA Astrophysics Data System (ADS)

Ji-Yang, Wang; Mo-Xiang, Chen; Ji-An, Wang; Xiao, Deng; Jun, Wang; Hsien-Chieh, Shen; Liang-Ping, Hsiung; Shu-Zhen, Yan; Zhi-Cheng, Fan; Xiu-Wen, Liu; Ge-Shan, Huang; Wen-Ren, Zhang; Hai-Hui, Shao; Rong-Yan, Zhang

1981-01-01

Geothermal studies have been conducted in China continuously since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research on geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; and (3) geothermal studies in mines. Regional geothermal studies have been conducted recently in North China and more than 2000 values of subsurface temperature have been obtained. Temperatures at a depth of 300 m generally range from 20 to 25°C with geothermal gradients from 20 to 40°C/km. These values are regarded as an average for the region with anomalies related to geological factors. To date, 22 reliable heat flow data from 17 sites have been obtained in North China and the data have been categorized according to fault block tectonics. The average heat flow value at 16 sites in the north is 1.3 HFU, varying from 0.7 to 1.8 HFU. It is apparent that the North China fault block is characterized by a relatively high heat flow with wide variations in magnitude compared to the mean value for similar tectonic units in other parts of the world. It is suggested that although the North China fault block can be traced back to the Archaean, the tectonic activity has been strengthening since the Mesozoic resulting in so-called "reactivation of platform" with large-scale faulting and magmatism. Geothermal resources in China are extensive; more than 2000 hot springs have been found and there are other manifestations including geysers, hydrothermal explosions, hydrothermal steam, fumaroles, high-temperature fountains, boiling springs, pools of boiling mud, etc. In addition, there are many Meso-Cenozoic sedimentary basins with widespread aquifers containing geothermal water resources in abundance. The extensive exploration and exploitation of these geothermal resources began early in the 1970's. Since then

Geothermal exploration in Indonesia

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

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.

Geothermal areas in Pakistan

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

Shuja, T.A.

1986-01-01

In this paper an attempt has been made to correlate the tectonic and geologic features with surface manifestations of geothermal activity in Pakistan to delineate prospective areas for exploration and development of geothermal energy. Underthrusting of the Arabian plate beneath the Eurasian plate has resulted in the formation of Chagai volcanic arc which extends into Iran. Quaternary volcanics in this environment, along with the presence of thermal springs, is an important geotectonic feature revealing the possible existence of geothermal fields. Geothermal activity in the northern areas of Pakistan, as evidenced by thermal springs, is the likely result of collision andmore » underthrusting of the Indian plate beneath the Eurasian plate. Numerous hot springs are found along the Main Mantle thrust and the Main Karakorum thrust in Chilas and Hunza areas respectively. The concentration of hot springs in Sind Province is also indicative of geothermal activity. A string of thermal seepages and springs following the alignment of the Syntaxial Bend in Punjab Province is also noteworthy from the geothermal viewpoint. In Baluchistan Province (southwest Pakistan), Hamun-e-Mushkel, a graben structure, also shows geothermal prospects on the basis of aeromagnetic studies.« less

GeothermalLCOE_NoExclusionsforAtlas

Science.gov Websites

a qualitative assessment of geothermal potential (Enhanced Geothermal System EGS) for the US based from 3 to 10 km provided by Southern Methodist University Geothermal Laboratory (Blackwell & ;http://www.nrel.gov/gis/cfm/data/GIS_Data_Technology_Specific/United_States/Geothermal

Systematic Review of Life Cycle Greenhouse Gas Emissions from Geothermal Electricity

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

Eberle, Annika; Heath, Garvin A.; Carpenter Petri, Alberta C.

The primary goal of this work was to assess the magnitude and variability of published life cycle greenhouse gas (GHG) emission estimates for three types of geothermal electricity generation technologies: enhanced geothermal systems (EGS) binary, hydrothermal (HT) flash, and HT binary. These technologies were chosen to align the results of this report with technologies modeled in National Renewable Energy Laboratory's (NREL's) Regional Energy Deployment Systems (ReEDs) model. Although we did gather and screen life cycle assessment (LCA) literature on hybrid systems, dry steam, and two geothermal heating technologies, we did not analyze published GHG emission estimates for these technologies. Inmore » our systematic literature review of the LCA literature, we screened studies in two stages based on a variety of criteria adapted from NREL's Life Cycle Assessment (LCA) Harmonization study (Heath and Mann 2012). Of the more than 180 geothermal studies identified, only 29 successfully passed both screening stages and only 26 of these included estimates of life cycle GHG emissions. We found that the median estimate of life cycle GHG emissions (in grams of carbon dioxide equivalent per kilowatt-hour generated [g CO2eq/kWh]) reported by these studies are 32.0, 47.0, and 11.3 for EGS binary, HT flash, and HT binary, respectively (Figure ES-1). We also found that the total life cycle GHG emissions are dominated by different stages of the life cycle for different technologies. For example, the GHG emissions from HT flash plants are dominated by the operations phase owing to the flash cycle being open loop whereby carbon dioxide entrained in the geothermal fluids is released to the atmosphere. This is in contrast to binary plants (using either EGS or HT resources), whose GHG emissions predominantly originate in the construction phase, owing to its closed-loop process design. Finally, by comparing this review's literature-derived range of HT flash GHG emissions to data from

Using Facilities And Potential Of Geothermal Resources In The Canakkale Province - NW Turkey

NASA Astrophysics Data System (ADS)

Deniz, Ozan; Acar Deniz, Zahide

2016-04-01

Turkey, due to its geological location, has a rich potential in point of geothermal resources. Çanakkale province is located northwestern (NW) part of Turkey and it has important geothermal fields in terms of geothermal energy potential. Geothermal resources reach to the surface both effects of past volcanic activity and extensions of fault zones associated with complex tectonic systems in the region. The aim of this study is to summarize hydrogeochemical characteristics, using facilities and potential of hot springs and spas located in the Çanakkale province. There are 13 geothermal fields in the region and the surface temperatures of hot springs are ranging between 28 centigrade degree and 175 centigrade degree. Hydrogeochemical compositions of thermal water display variable chemical compositions. Na, Ca, SO4, HCO3 and Cl are the dominant ions in these waters. Thermal waters of Tuzla and Kestanbol geothermal fields which is located the near coastal area can be noted NaCl type. Because these two geothermal waters have high TDS values, scaling problems are seen around the hot springs and pipelines. Geothermal waters in the province are meteoric origin according to oxygen-18, deuterium and tritium isotopes data. Long underground residence times of these waters and its temperatures have caused both more water - rock interaction and low tritium values. Geothermal energy is utilized in many areas in Turkey today. It is generally used for space heating, balneotherapy and electricity generation. Explorations of geothermal resources and investments in geothermal energy sector have risen rapidly in the recent years particularly in western Turkey. High-temperature geothermal fields are generally located in this region related to the Aegean Graben System and the North Anotalian Fault Zone. All geothermal power plants in Turkey are located in this region. Considering the Çanakkale province, most geothermal fields are suitable for multipurpose usage but many of them have

California Geothermal Forum: A Path to Increasing Geothermal Development in California

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

Young, Katherine R.

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 conservationmore » planning efforts, particularly at the Salton Sea.« less

Analysis of induced seismicity at The Geysers geothermal field, California

NASA Astrophysics Data System (ADS)

Emolo, A.; Maercklin, N.; Matrullo, E.; Orefice, A.; Amoroso, O.; Convertito, V.; Sharma, N.; Zollo, A.

2012-12-01

Fluid injection, steam extraction, and reservoir stimulation in geothermal systems lead to induced seismicity. While in rare cases induced events may be large enough to pose a hazard, on the other hand the microseismicity provides information on the extent and the space-time varying properties of the reservoir. Therefore, microseismic monitoring is important, both for mitigation of unwanted effects of industrial operations and for continuous assessment of reservoir conditions. Here we analyze induced seismicity at The Geysers geothermal field in California, a vapor-dominated field with the top of the main steam reservoir some 1-3 km below the surface. Commercial exploitation began in the 1960s, and the seismicity increased with increasing field development. We focus our analyses on induced seismicity recorded between August 2007 and October 2011. Our calibrated waveform database contains some 15000 events with magnitudes between 1.0 and 4.5 and recorded by the LBNL Geysers/Calpine surface seismic network. We associated all data with events from the NCEDC earthquake catalog and re-picked first arrival times. Using selected events with at least 20 high-quality P-wave picks, we determined a minimum 1-D velocity model using VELEST. A well-constrained P-velocity model shows a sharp velocity increase at 1-2 km depth (from 3 to 5 km/s) and then a gradient-like trend down to about 5 km depth, where velocities reach values of 6-7 km/s. The station corrections show coherent, relatively high, positive travel time delays in the NW zone, thus indicating a strong lateral variation of the P-wave velocities. We determined an average Vp-to-Vs ratio of 1.67, which is consistent with estimates from other authors for the same time period. The events have been relocated in the new model using a non-linear probabilistic methods. The seismicity appears spatially diffused in a 15x10 km2 area elongated in NW-SE direction, and earthquake depths range between 0 and 6 km. As in previous

Investment and operating costs of binary cycle geothermal power plants

NASA Technical Reports Server (NTRS)

Holt, B.; Brugman, J.

1974-01-01

Typical investment and operating costs for geothermal power plants employing binary cycle technology and utilizing the heat energy in liquid-dominated reservoirs are discussed. These costs are developed as a function of reservoir temperature. The factors involved in optimizing plant design are discussed. A relationship between the value of electrical energy and the value of the heat energy in the reservoir is suggested.

Geothermal handbook

USGS Publications Warehouse

1976-01-01

The Bureau of Land Management offered over 400,000 hectares (one million acres) for geothermal exploration and development in 1975, and figure is expected to double this year. The Energy Research and Development Administration hopes for 10-15,000 megawatts of geothermal energy by 1985, which would require, leasing over 16.3 million hectares (37 million acres) of land, at least half of which is federal land. Since there is an 8 to 8-1/2 year time laf between initial exploration and full field development, there would have to be a ten-fold increase in the amount of federal land leased within the next three years. Seventy percent of geothermal potential, 22.3 million hectares (55 million acres), is on federal lands in the west. The implication for the Service are enormous and the problems immediate. Geothermal resource are so widespread they are found to some extent in most biomes and ecosystems in the western United States. In most cases exploitation and production of geothermal resources can be made compatible with fish and wildlife management without damage, if probable impacts are clearly understood and provided for before damage has unwittingly been allowed to occur. Planning for site suitability and concern with specific operating techniques are crucial factors. There will be opportunities for enhancement: during exploration and testing many shallow groundwater bodies may be penetrated which might be developed for wildlife use. Construction equipment and materials needed for enhancement projects will be available in areas heretofore considered remote projects will be available in areas heretofore considered remote by land managers. A comprehensive knowledge of geothermal development is necessary to avoid dangers and seize opportunities. This handbook is intended to serve as a working tool in the field. It anticipated where geothermal resource development will occur in the western United States in the near future. A set of environmental assessment procedures are

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.…

Geothermal Heat Pump Basics | NREL

Science.gov Websites

a free source of hot water. Geothermal heat pumps use much less energy than conventional heating resources: Geothermal Heat Pumps U.S. Department of Energy's Office of Energy Efficiency and Renewable Heat Pump Basics Geothermal Heat Pump Basics Geothermal heat pumps take advantage of the nearly

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

Constructing the deep temperature section of the Travale geothermal area in Italy, with the use of an electromagnetic geothermometer

NASA Astrophysics Data System (ADS)

Spichak, V. V.; Zakharova, O. K.

2015-01-01

The technology of electromagnetic geothermometer is applied for constructing the two-dimensional (2D) section of temperature in the Travale geothermal region in Italy up to a depth of 10 km. The joint analysis of this section, together with the previously constructed model of electric resistivity suggests that the heat transfer in the Travale region is rendered by the overheated vapor-gas fluids instead of liquid fluids as it was previously believed based on the interpretation of the resistivity model. Another important conclusion consists in the fact that, instead of two geothermal reservoirs, whose existence was previously tentatively inferred from the interpretation of the electromagnetic and seismic data, it is likely that there is a single deep reservoir with a shallow (near-surface) offshoot. From the constructed temperature distribution it can be seen that the temperature below a depth of 4 km exceeds 500°C, which indicates that drilling down to these depths could be useful for the subsequent exploitation of this geothermal reservoir.

The role of the geothermal gradient in the emplacement and replenishment of ground ice on Mars

NASA Technical Reports Server (NTRS)

Clifford, Stephen M.

1993-01-01

Knowledge of the mechanisms by which ground ice is emplaced, removed, and potentially replenished, are critical to understanding the climatic and hydrologic behavior of water on Mars, as well as the morphologic evolution of its surface. Because of the strong temperature dependence of the saturated vapor pressure of H2O, the atmospheric emplacement or replenishment of ground ice is prohibited below the depth at which crustal temperatures begin to monotonically increase due to geothermal heating. In contrast, the emplacement and replenishment of ground ice from reservoirs of H2O residing deep within the crust can occur by at least three different thermally-driven processes, involving all three phases of water. In this regard, Clifford has discussed how the presence of a geothermal gradient as small as 15 K/km can give rise to a corresponding vapor pressure gradient sufficient to drive the vertical transport of 1 km of water from a reservoir of ground water at depth to the base of the cryosphere every 10(exp 6) - 10(exp 7) years. This abstract expands on this earlier treatment by considering the influence of thermal gradients on the transport of H2O at temperatures below the freezing point.

Geophysical, geochemical, and geological investigations of the Dunes geothermal system, Imperial Valley, California

NASA Technical Reports Server (NTRS)

Elders, W. A.; Combs, J.; Coplen, T. B.; Kolesar, P.; Bird, D. K.

1974-01-01

The Dunes anomaly is a water-dominated geothermal system in the alluvium of the Salton Trough, lacking any surface expression. It was discovered by shallow-temperature gradient measurements. A 612-meter-deep test well encountered several temperature-gradient reversals, with a maximum of 105 C at 114 meters. The program involves surface geophysics, including electrical, gravity, and seismic methods, down-hole geophysics and petrophysics of core samples, isotopic and chemical studies of water samples, and petrological and geochemical studies of the cores and cuttings. The aim is (1) to determine the source and temperature history of the brines, (2) to understand the interaction between the brines and rocks, and (3) to determine the areal extent, nature, origin, and history of the geothermal system. These studies are designed to provide better definition of exploration targets for hidden geothermal anomalies and to contribute to improved techniques of exploration and resource assessment.

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.

Predicting the growth of S i3N4 nanowires by phase-equilibrium-dominated vapor-liquid-solid mechanism

NASA Astrophysics Data System (ADS)

Zhang, Yongliang; Cai, Jing; Yang, Lijun; Wu, Qiang; Wang, Xizhang; Hu, Zheng

2017-09-01

Nanomaterial synthesis is experiencing a profound evolution from empirical science ("cook-and-look") to prediction and design, which depends on the deep insight into the growth mechanism. Herein, we report a generalized prediction of the growth of S i3N4 nanowires by nitriding F e28S i72 alloy particles across different phase regions based on our finding of the phase-equilibrium-dominated vapor-liquid-solid (PED-VLS) mechanism. All the predictions about the growth of S i3N4 nanowires, and the associated evolutions of lattice parameters and geometries of the coexisting Fe -Si alloy phases, are experimentally confirmed quantitatively. This progress corroborates the general validity of the PED-VLS mechanism, which could be applied to the design and controllable synthesis of various one-dimensional nanomaterials.

Research status of geothermal resources in China

NASA Astrophysics Data System (ADS)

Zhang, Lincheng; Li, Guang

2017-08-01

As the representative of the new green energy, geothermal resources are characterized by large reserve, wide distribution, cleanness and environmental protection, good stability, high utilization factor and other advantages. According to the characteristics of exploitation and utilization, they can be divided into high-temperature, medium-temperature and low-temperature geothermal resources. The abundant and widely distributed geothermal resources in China have a broad prospect for development. The medium and low temperature geothermal resources are broadly distributed in the continental crustal uplift and subsidence areas inside the plate, represented by the geothermal belt on the southeast coast, while the high temperature geothermal resources concentrate on Southern Tibet-Western Sichuan-Western Yunnan Geothermal Belt and Taiwan Geothermal Belt. Currently, the geothermal resources in China are mainly used for bathing, recuperation, heating and power generation. It is a country that directly makes maximum use of geothermal energy in the world. However, China’s geothermal power generation, including installed generating capacity and power generation capacity, are far behind those of Western European countries and the USA. Studies on exploitation and development of geothermal resources are still weak.

Chlorine isotope geochemistry of Icelandic thermal fluids: Implications for geothermal system behavior at divergent plate boundaries

NASA Astrophysics Data System (ADS)

Stefánsson, Andri; Barnes, Jaime D.

2016-09-01

The chlorine isotope composition of thermal fluids from Iceland were measured in order to evaluate the source of chlorine and possible chlorine isotope fractionation in geothermal systems at divergent plate boundaries. The geothermal systems studied have a wide range of reservoir temperatures from 40 to 437 °C and in-situ pH of 6.15 to 7.15. Chlorine concentrations range from 5.2 to 171 ppm and δ37 Cl values are -0.3 to + 2.1 ‰ (n = 38). The δ37 Cl values of the thermal fluids are interpreted to reflect the source of the chlorine in the fluids. Geothermal processes such as secondary mineral formation, aqueous and vapor speciation and boiling were found to have minimal effects on the δ37 Cl values. However, further work is needed on incorporation of Cl into secondary minerals and its effect on Cl isotope fractionation. Results of isotope geochemical modeling demonstrate that the range of δ37 Cl values documented in the natural thermal fluids can be explained by leaching of the basaltic rocks by meteoric source water under geothermal conditions. Magmatic gas partitioning may also contribute to the source of Cl in some cases. The range of δ37 Cl values of the fluids result mainly from the large range of δ37 Cl values observed for Icelandic basalts, which range from -0.6 to + 1.2 ‰.

Modelling of hydrogen sulfide dispersion from the geothermal power plants of Tuscany (Italy).

PubMed

Somma, Renato; Granieri, Domenico; Troise, Claudia; Terranova, Carlo; De Natale, Giuseppe; Pedone, Maria

2017-04-01

We applied the Eulerian code DISGAS (DISpersion of GAS) to investigate the dispersion of the hydrogen sulfide (H 2 S) from 32 geothermal power plants (out of 35 active) belonging to the geothermal districts of Larderello, Travale-Radicondoli and Monte Amiata, in Tuscany (Italy). An updated geographic database, for use in a GIS environment, was realized in order to process input data required by the code and to handle the outputs. The results suggest that H 2 S plumes emitted from geothermal power plants are mainly concentrated around the stacks of emission (H 2 S concentration up to 1100μg/m 3 ) and rapidly dilute along the dominant local wind direction. Although estimated values of air H 2 S concentrations are orders of magnitude higher than in unpolluted areas, they do not indicate an immediate health risk for nearby communities, under the more frequent local atmospheric conditions. Starting from the estimated values, validated by measurements in the field, we make some considerations about the environmental impact of the H 2 S emission in all the geothermal areas of the Tuscany region. Copyright © 2017 Elsevier B.V. All rights reserved.

GEOTHERMAL ENVIRONMENTAL IMPACT ASSESSMENT: GROUND WATER MONITORING GUIDELINES FOR GEOTHERMAL DEVELOPMENT

EPA Science Inventory

This report discusses potential ground water pollution from geothermal resource development, conversion, and waste disposal, and proposes guidelines for developing a ground water monitoring plan for any such development. Geothermal processes, borehole logging, and injection well ...

DOE's Geothermal Program still in game

NASA Astrophysics Data System (ADS)

Bush, Susan

In the ongoing search to find cost-effective, renewable forms of energy that neither contribute to global warming nor threaten national security, geothermal energy remains a player. Although Department of Energy funding for geothermal research has declined over the past decade, from its peak in 1979 of $160 million, there is still tremendous potential in terms of geothermal development, said Gladys Hooper, program manager of DOE's Hot Dry Rock and Brine Chemistry divisions. Technology for harnessing geothermal power is by and large there, she said. What is needed is more awareness and publicity regarding the merits of geothermal energy.For fiscal year 1993, proposed DOE funding for geothermal research was $24 million, down from $27 million in fiscal 1992 and nearly $30 million in fiscal 1991. DOE's Geothermal Division oversees the network of national laboratories and universities involved in developing the nation's geothermal resources and bringing them into commercial competitiveness.

Numerical investigation on the implications of spring temperature and discharge rate with respect to the geothermal background in a fault zone

NASA Astrophysics Data System (ADS)

Jiang, Zhenjiao; Xu, Tianfu; Mariethoz, Gregoire

2018-04-01

Geothermal springs are some of the most obvious indicators of the existence of high-temperature geothermal resources in the subsurface. However, geothermal springs can also occur in areas of low average subsurface temperatures, which makes it difficult to assess exploitable zones. To address this problem, this study quantitatively analyzes the conditions associated with the formation of geothermal springs in fault zones, and numerically investigates the implications that outflow temperature and discharge rate from geothermal springs have on the geothermal background in the subsurface. It is concluded that the temperature of geothermal springs in fault zones is mainly controlled by the recharge rate from the country rock and the hydraulic conductivity in the fault damage zone. Importantly, the topography of the fault trace on the land surface plays an important role in determining the thermal temperature. In fault zones with a permeability higher than 1 mD and a lateral recharge rate from the country rock higher than 1 m3/day, convection plays a dominant role in the heat transport rather than thermal conduction. The geothermal springs do not necessarily occur in the place having an abnormal geothermal background (with the temperature at certain depth exceeding the temperature inferred by the global average continental geothermal gradient of 30 °C/km). Assuming a constant temperature (90 °C here, to represent a normal geothermal background in the subsurface at a depth of 3,000 m), the conditions required for the occurrence of geothermal springs were quantitatively determined.

Rare Earth Element Concentrations in Geothermal Wells at the Puna Geothermal Field, Hawaii

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

Fowler, Andrew; Zierenberg, Robert

Rare earth element concentrations in the geothermal wells at the Puna geothermal field, Hawaii. Samples taken from geothermal wells KS-5, KS-6W, KS-9W, KS-14E, and KS-16N. Includes pH and concentrations for Cerium, Dysprosium, Erbium, Europium, Gadolinium, Holmium, Lanthanum, Lutetium, Neodymium, Praseodymium, Samarium, Terbium, Thulium, Yttrium, and Ytterbium. Samples collected on November 11-17, 2016.

Preservation of Microbial Lipids in Geothermal Sinters

NASA Astrophysics Data System (ADS)

Kaur, Gurpreet; Mountain, Bruce W.; Hopmans, Ellen C.; Pancost, Richard D.

2011-04-01

Lipid biomarkers are widely used to study the earliest life on Earth and have been invoked as potential astrobiological markers, but few studies have assessed their survival and persistence in geothermal settings. Here, we investigate lipid preservation in active and inactive geothermal silica sinters, with ages of up to 900 years, from Champagne Pool, Waiotapu, New Zealand. Analyses revealed a wide range of bacterial biomarkers, including free and bound fatty acids, 1,2-di-O-alkylglycerols (diethers), and various hopanoids. Dominant archaeal lipids include archaeol and glycerol dialkyl glycerol tetraethers (GDGTs). The predominance of generally similar biomarker groups in all sinters suggests a stable microbial community throughout Champagne Pool's history and indicates that incorporated lipids can be well preserved. Moreover, subtle differences in lipid distributions suggest that past changes in environmental conditions can be elucidated. In this case, higher archaeol abundances relative to the bacterial diethers, a greater proportion of cyclic GDGTs, the high average chain length of the bacterial diethers, and greater concentrations of hopanoic acids in the older sinters all suggest hotter conditions at Champagne Pool in the past.

Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Chemical controls on alteration and mineralization

USGS Publications Warehouse

Henley, R.W.; Berger, B.R.

2011-01-01

from any external contemporary hydrothermal activity. Subsequent fracturing is localized by the embrittled wallrock to provide high-permeability fracture arrays that constrain vapor expansion with minimization of heat loss. The Sulfide Stage vein sequence is then a consequence of destabilization of metal-vapor species in response to depressurization and decrease in vapor density. The geology, mineralogy, fluid inclusion and stable isotope data and geothermometry for high-sulfidation, bulk-tonnage and lode deposits are quite different from those for epithermal gold-silver deposits such as McLaughlin, California that formed near-surface in groundwater-dominated hydrothermal systems where magmatic fluid has been diluted to less than about 30%. High sulfidation gold deposits are better termed 'Solfataric Gold Deposits' to emphasize this distinction. The magmatic-vapor expansion hypothesis also applies to the phenomenology of acidic geothermal systems in active volcanic systems and equivalent magmatic-vapor discharges on the flanks of submarine volcanoes. ?? 2010.

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.

The helical screw expander evaluation project. [for geothermal wells

NASA Technical Reports Server (NTRS)

Mckay, R. A.

1977-01-01

A positive-displacement helical-screw expander of the Lysholm type has been adapted for geothermal service and successfully demonstrated in a 50 kW prototype power system. Evaluation of the expander by tests of a new model in a 1 MW power system under wellhead conditions in selected liquid-dominated geothermal fields is proposed. The objectives are to determine the performance characteristics of the expander and power system over a broad range of operating conditions and also to examine the concept of wellhead power plants. Throttling and fractionation of the fluids from the test wells is planned to simulate a wide range of wellhead pressures and steam fractions. Variation in the expander exhaust pressure is also planned. The investigation will include expander efficiency, corrosion, erosion, scale formation and control, and endurance testing. Interaction studies with the wells and an electric grid are also proposed.

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

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

Patten, Kim

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.more » 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

Structural control on geothermal circulation in the Tocomar geothermal volcanic area (Puna plateau, Argentina)

NASA Astrophysics Data System (ADS)

Giordano, Guido

2016-04-01

The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous thermal springs. This study presents new stratigraphic, structural, volcanological, geochemical and hydrogeological data on the geothermal field. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field.

Analysis of gravity data beneath Endut geothermal prospect using horizontal gradient and Euler deconvolution

NASA Astrophysics Data System (ADS)

Supriyanto, Noor, T.; Suhanto, E.

2017-07-01

The Endut geothermal prospect is located in Banten Province, Indonesia. The geological setting of the area is dominated by quaternary volcanic, tertiary sediments and tertiary rock intrusion. This area has been in the preliminary study phase of geology, geochemistry, and geophysics. As one of the geophysical study, the gravity data measurement has been carried out and analyzed in order to understand geological condition especially subsurface fault structure that control the geothermal system in Endut area. After precondition applied to gravity data, the complete Bouguer anomaly have been analyzed using advanced derivatives method such as Horizontal Gradient (HG) and Euler Deconvolution (ED) to clarify the existance of fault structures. These techniques detected boundaries of body anomalies and faults structure that were compared with the lithologies in the geology map. The analysis result will be useful in making a further realistic conceptual model of the Endut geothermal area.

Industrially induced changes in Earth structure at the geysers geothermal area, California

USGS Publications Warehouse

Foulger, G.R.; Grant, C.C.; Ross, A.; Julian, B.R.

1997-01-01

Industrial exploitation is causing clearly-measurable changes in Earth structure at The Geysers geothermal area, California. Production at The Geysers peaked in the late 1980s at ???3.5 ?? 103 kg s-1 of steam and 1800 MW of electricity. It subsequently decreased by about 10% per year [Barker et al., 1992] because of declining reservoir pressure. The steam reservoir coincides with a strong negative anomaly (???0.16, ???9%) in the compressional-to-shear seismic wave speed ratio vP/vS, consistent with the expected effects of low-pressure vapor-phase pore fluid [Julian et al., 1996]. Between 1991 and 1994 this anomaly increased in amplitude by up to about 0.07 (???4%). This is consistent with the expected effects of continued pressure reduction and conversion of pore water to steam as a result of exploitation. These unique results show that vP/vS tomography can easily detect saturation changes caused by exploitation of reservoirs, and is a potentially valuable technique for monitoring environmental change. They also provide geophysical observational evidence that geothermal energy is not a renewable energy source.

Modeling thermal stress propagation during hydraulic stimulation of geothermal wells

NASA Astrophysics Data System (ADS)

Jansen, Gunnar; Miller, Stephen A.

2017-04-01

A large fraction of the world's water and energy resources are located in naturally fractured reservoirs within the earth's crust. Depending on the lithology and tectonic history of a formation, fracture networks can range from dense and homogeneous highly fractured networks to single large scale fractures dominating the flow behavior. Understanding the dynamics of such reservoirs in terms of flow and transport is crucial to successful application of engineered geothermal systems (also known as enhanced geothermal systems or EGS) for geothermal energy production in the future. Fractured reservoirs are considered to consist of two distinct separate media, namely the fracture and matrix space respectively. Fractures are generally thin, highly conductive containing only small amounts of fluid, whereas the matrix rock provides high fluid storage but typically has much smaller permeability. Simulation of flow and transport through fractured porous media is challenging due to the high permeability contrast between the fractures and the surrounding rock matrix. However, accurate and efficient simulation of flow through a fracture network is crucial in order to understand, optimize and engineer reservoirs. It has been a research topic for several decades and is still under active research. Accurate fluid flow simulations through field-scale fractured reservoirs are still limited by the power of current computer processing units (CPU). We present an efficient implementation of the embedded discrete fracture model, which is a promising new technique in modeling the behavior of enhanced geothermal systems. An efficient coupling strategy is determined for numerical performance of the model. We provide new insight into the coupled modeling of fluid flow, heat transport of engineered geothermal reservoirs with focus on the thermal stress changes during the stimulation process. We further investigate the interplay of thermal and poro-elastic stress changes in the reservoir

Geothermal Financing Workbook

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

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)

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

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

None

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.

Geothermal Energy | Climate Neutral Research Campuses | NREL

Science.gov Websites

Geothermal Energy Geothermal Energy Research campuses can take advantage of geothermal resources sections that describe how examining geothermal energy may fit into your climate action plans. Campus Options Considerations Sample Project Related Links Campus Geothermal Energy Options Campuses can use

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

Microbial diversity in nonsulfur, sulfur and iron geothermal steam vents.

PubMed

Benson, Courtney A; Bizzoco, Richard W; Lipson, David A; Kelley, Scott T

2011-04-01

Fumaroles, commonly called steam vents, are ubiquitous features of geothermal habitats. Recent studies have discovered microorganisms in condensed fumarole steam, but fumarole deposits have proven refractory to DNA isolation. In this study, we report the development of novel DNA isolation approaches for fumarole deposit microbial community analysis. Deposit samples were collected from steam vents and caves in Hawaii Volcanoes National Park, Yellowstone National Park and Lassen Volcanic National Park. Samples were analyzed by X-ray microanalysis and classified as nonsulfur, sulfur or iron-dominated steam deposits. We experienced considerable difficulty in obtaining high-yield, high-quality DNA for cloning: only half of all the samples ultimately yielded sequences. Analysis of archaeal 16S rRNA gene sequences showed that sulfur steam deposits were dominated by Sulfolobus and Acidianus, while nonsulfur deposits contained mainly unknown Crenarchaeota. Several of these novel Crenarchaeota lineages were related to chemoautotrophic ammonia oxidizers, indicating that fumaroles represent a putative habitat for ammonia-oxidizing Archaea. We also generated archaeal and bacterial enrichment cultures from the majority of the deposits and isolated members of the Sulfolobales. Our results provide the first evidence of Archaea in geothermal steam deposits and show that fumaroles harbor diverse and novel microbial lineages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Relative Contributions of Geothermal Pumping and Long-Term Earthquake Rate to Seismicity at California Geothermal Fields

NASA Astrophysics Data System (ADS)

Weiser, D. A.; Jackson, D. D.

2015-12-01

In a tectonically active area, a definitive discrimination between geothermally-induced and tectonic earthquakes is difficult to achieve. We focus our study on California's 11 major geothermal fields: Amedee, Brawley, Casa Diablo, Coso, East Mesa, The Geysers, Heber, Litchfield, Salton Sea, Susanville, and Wendel. The Geysers geothermal field is the world's largest geothermal energy producer. California's Department of Oil Gas and Geothermal Resources provides field-wide monthly injection and production volumes for each of these sites, which allows us to study the relationship between geothermal pumping activities and seismicity. Since many of the geothermal fields began injecting and producing before nearby seismic stations were installed, we use smoothed seismicity since 1932 from the ANSS catalog as a proxy for tectonic earthquake rate. We examine both geothermal pumping and long-term earthquake rate as factors that may control earthquake rate. Rather than focusing only on the largest earthquake, which is essentially a random occurrence in time, we examine how M≥4 earthquake rate density (probability per unit area, time, and magnitude) varies for each field. We estimate relative contributions to the observed earthquake rate of M≥4 from both a long-term earthquake rate (Kagan and Jackson, 2010) and pumping activity. For each geothermal field, respective earthquake catalogs (NCEDC and SCSN) are complete above at least M3 during the test period (which we tailor to each site). We test the hypothesis that the observed earthquake rate at a geothermal site during the test period is a linear combination of the long-term seismicity and pumping rates. We use a grid search to determine the confidence interval of the weighting parameters.

Fluid geochemistry of Fault zone hydrothermal system in the Yidun-Litang area, eastern Tibetan Plateau geothermal belt

NASA Astrophysics Data System (ADS)

Shi, Z.; Wang, G.

2017-12-01

Understanding the geochemical and geothermal characteristic of the hydrothermal systems provide useful information in appropriate evaluating the geothermal potential in this area. In this paper, we investigate the chemical and isotopic composition of thermal water in an underexploited geothermal belt, Yidun-Litang area, in eastern Tibetan Plateau geothermal belt. 24 hot springs from the Yidun and Litang area were collected and analyzed. The chemical facies of the hot springs are mainly Na-HCO3 type water. Water-rock interaction, cation exchange are the dominant hydrogeochemical processes in the hydrothermal evolution. All the hot springs show long-time water-rock interaction and significant 18O shift occurred in the Yindun area. Tritium data indicate the long-time water-rock interaction time in the hydrothermal system. According to the isotope and geochemical data, the hydrothermal systems in Yidun and Litang area may share a common deep parent geothermal liquid but receive different sources of meteoric precipitation and undergone different geochemical processes. The Yidun area have relative high reservoir equilibrium temperature (up to 230 °C) while the reservoir temperature at Litang area is relative low (up to 128 °C).

Greider geothermal statement, based on testimony presented to Lt. Gov. Dymally Committee. [Development of geothermal industry

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

Greider, B.

Factors that contribute to the delay of geothermal development by utilities are discussed. These include: the increasingly complex regulations on the Geysers field; low quality and sizes of hot water resources; economics of financing geothermal exploration; professional experience; and lack of faith in the technology of conversion of hot water into electricity. Key issues that must be resolved before geothermal development can significantly penetrate the electricity generation industry are presented. It is pointed out that legislation to stimulate development of California's geothermal resources should be based on consideration of the following items: streamlined controls which allow geothermal exploration and developmentmore » to proceed under a minimum of effective regulation; reasonable tax provisions encouraging exploration, research, development, and production of geothermal energy; and suitable economic incentives for utility companies that will encourage early commitment to construct generating plants. (LBS)« less

Technical support for geopressured-geothermal well activities in Louisiana

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

Not Available

1991-07-01

Continuous recording microearthquake monitoring networks have been established around US Department of Energy (DOE) geopressured-geothermal design wells in southwestern Louisiana and southeastern Texas since summer 1980 to assess the effects well development may have had on subsidence and growth-fault activation. This monitoring has shown several unusual characteristics of Gulf Coast seismic activity. The observed activity is classified into two dominant types, one with identifiable body phases (type 1) and the other with only surface-wave signatures (type 2). During this reporting period no type 1 or body-wave events were reported. A total of 230 type 2 or surface-wave events were recorded.more » Origins of the type 2 events are still not positively understood; however, little or no evidence is available to connect them with geopressured-geothermal well activity. We continue to suspect sonic booms from military aircraft or some other human-induced source. 37 refs., 16 figs., 6 tabs.« less

Tectonic Constraints on the Evolution of Geothermal Systems in the Central Andean Volcanic Zone (CAVZ)

NASA Astrophysics Data System (ADS)

Veloso, E. E.; Tardani, D.; Aron, F.; Elizalde, J. D.; Sanchez-Alfaro, P.; Godoy, B.

2017-12-01

South of 19°S, geothermal fields and Pliocene-to-Holocene volcanic centers of the Central Andean Volcanic Zone are spatially associated with distinct, large-scale fault systems disrupting the volcanic arc, which control the architecture and dynamics of the fluids reservoirs at shallow crustal levels. Based on an extensive compilation of structural, lithological and isotopic data, and satellite imagery band-ratio analyses, we produced detailed maps of 13 areas comprising 19 identified and/or potential geothermal fields, to examine if particular local-scale tectonic configurations are associated to fluids migrating from different crustal levels. We defined three main tectonic environments according to the specific, kilometer-scale structural arrangement and its spatial relation to the geothermal surface manifestations. T1, dominated by left-lateral, pure strike-slip motion on a NW-trending duplex-like geometry with geothermal fields located along the faults - in turn distributed into five major subparallel zones cutting across the orogenic belt between ca. 20° and 27°S. T2, dominated by shortening on a series of N-trending thrust faults and fault-propagated folds, cut and displaced by the above mentioned NW-trending faults, with geothermal fields hosted at fault intersections and at fold hinges. And T3, characterized by transtension accommodated by NW-to-WNW-trending left-lateral/normal faults, with hot-springs lying along the fault traces. Interestingly, each of the independently defined tectonic environments has distinctive helium (in fluids) and strontium (in lavas) isotopic signatures and estimated geothermal reservoir temperatures. T1 shows a large 4He contribution, low 87Sr/86Sr ratio and temperatures varying between ca. 220°-310°C; T3 low 4He and high 87Sr/86Sr ratio and temperature (260°-320°C); T2 isotopic values fall between T1 and T3, yet showing the lowest (130°-250°C) temperatures. We suggest that these particular isotopic signatures are due to

Research Staff | Geothermal Technologies | NREL

Science.gov Websites

Position Email Phone Akar, Sertac Energy Analyst - Geothermal Sertac.Akar@nrel.gov 303-275-3725 Augustine -Geoscience Kate Young joined NREL in 2008. She has worked on analysis of geothermal exploration, drilling ) Toolkit, the Geothermal Resource Portfolio Optimization and Reporting Technique (GeoRePORT), and the

Geothermal energy abstract sets. Special report No. 14

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

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)

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.

Structural control on geothermal circulation in the Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Argentina)

NASA Astrophysics Data System (ADS)

Giordano, Guido; Pinton, Annamaria; Cianfarra, Paola; Baez, Walter; Chiodi, Agostina; Viramonte, José; Norini, Gianluca; Groppelli, Gianluca

2013-01-01

The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous springs. This study presents new stratigraphic and hydrogeological data on the geothermal field, together with the analysis from remote sensed image analysis of morphostructural evidences associated with the structural framework and active tectonics. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field. Away from the main tectonic features, such as at the Cerro Tuzgle field, the less developed network of faults and fractures allows only a moderate upwelling of geothermal fluids and a mixing between hot and shallow cold waters. The integration of field-based and remote-sensing analyses at the Cerro Tuzgle-Tocomar area proved to be effective in approaching the prospection of remote geothermal fields, and in defining the conceptual model for geothermal circulation.

Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

USGS Publications Warehouse

Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

1999-01-01

The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

Rare earth elements in sinters from the geothermal waters (hot springs) on the Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Feng, Jin-Liang; Zhao, Zhen-Hong; Chen, Feng; Hu, Hai-Ping

2014-10-01

The mineralogical and geochemical composition of sinters from the geothermal areas on the Tibetan Plateau was determined. They occur as siliceous, salty and calcareous sinters but biogenic siliceous sinters were also found. The analyses indicate that there are no distinct inter -element relationships between individual rare earth elements (REEs) and other elements. Formed from the same geothermal water, the mineralogical and chemical composition of the sinters is influenced by their genesis and formation conditions. The REE distributions depend on the origin of the sinters. Fe-Mn phases in sinters tend to scavenge more REEs from geothermal water. Neither the REE fractionation nor the Ce anomaly seems to be associated with Fe-Mn phases in the sinters. The fourth tetrads of some sinters display weak W-type (concave) effects. In contrast, the third tetrads present large effects in some sinters due to positive Gd anomalies. The origin of the positive Eu anomalies in some sinters seems to be caused by preferential dissolution of feldspars during water-rock interaction. The complexing ligands in geothermal water may contribute significantly to the fractionation of REEs in sinters. The dominant CO32- and HCO3- complexing in geothermal water favors enrichment of heavy REEs in calcareous sinters.

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

Federal Geothermal Research Program Update - Fiscal Year 2004

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

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. Geothermalmore » 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

Federal Geothermal Research Program Update Fiscal Year 2004

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

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. Geothermalmore » 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

Environmental Assessment Lakeview Geothermal Project

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

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 alternativesmore » 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.« less

Abrupt physical and chemical changes during 1992-1999, Anderson Springs, SE Geyser Geothermal Field, California

USGS Publications Warehouse

Janik, Cathy J.; Goff, Fraser; Walter, Stephen R.; Sorey, Michael L.; Counce, Dale; Colvard, Elizabeth M.

2000-01-01

The Anderson Springs area is located about 90 miles (145 kilometers) north of San Francisco, California, in the southwestern part of Lake County. The area was first developed in the late 1800s as a health resort, which was active until the 1930s. Patrons drank a variety of cool to hot mineral waters from improved springs, swam in various baths and pools, and hiked in the rugged hills flanking Anderson Creek and its tributaries. In the bluffs to the south of the resort were four small mercury mines of the eastern Mayacmas quicksilver district. About 1,260 flasks of mercury were produced from these mines between 1909 and 1943. By the early 1970s, the higher ridges south and west of Anderson Springs became part of the southeast sector of the greater Geysers geothermal field. Today, several electric power plants are built on these ridges, producing energy from a vapor-dominated 240 °C reservoir. Only the main hot spring at Anderson Springs has maintained a recognizable identity since the 1930s. The hot spring is actually a cluster of seeps and springs that issue from a small fault in a ravine southwest of Anderson Creek. Published and unpublished records show that the maximum temperature (Tm) of this cluster fell gradually from 63°C in 1889 to 48°C in 1992. However, Tm of the cluster climbed to 77°C in 1995 and neared boiling (98°C) in 1998. A new cluster of boiling vents and small fumaroles (Tm = 99.3°C) formed in 1998 about 30 m north of the old spring cluster. Several evergreen trees on steep slopes immediately above these vents apparently were killed by the new activity. Thermal waters at Anderson Hot Springs are mostly composed of near-surface ground waters with some added gases and condensed steam from The Geysers geothermal system. Compared to gas samples from Southeast Geysers wells, the hot spring gases are higher in CO2 and lower in H2S and NH3. As the springs increased in temperature, however, the gas composition became more like the mean composition

Deep Seawater Intrusion Enhanced by Geothermal Through Deep Faults in Xinzhou Geothermal Field in Guangdong, China

NASA Astrophysics Data System (ADS)

Lu, G.; Ou, H.; Hu, B. X.; Wang, X.

2017-12-01

This study investigates abnormal sea water intrusion from deep depth, riding an inland-ward deep groundwater flow, which is enhanced by deep faults and geothermal processes. The study site Xinzhou geothermal field is 20 km from the coast line. It is in southern China's Guangdong coast, a part of China's long coastal geothermal belt. The geothermal water is salty, having fueled an speculation that it was ancient sea water retained. However, the perpetual "pumping" of the self-flowing outflow of geothermal waters might alter the deep underground flow to favor large-scale or long distant sea water intrusion. We studied geochemical characteristics of the geothermal water and found it as a mixture of the sea water with rain water or pore water, with no indication of dilution involved. And we conducted numerical studies of the buoyancy-driven geothermal flow in the deep ground and find that deep down in thousand meters there is favorable hydraulic gradient favoring inland-ward groundwater flow, allowing seawater intrude inland for an unusually long tens of kilometers in a granitic groundwater flow system. This work formed the first in understanding geo-environment for deep ground water flow.

Equipment of the binary-cycle geothermal power unit at the Pauzhet geothermal power station

NASA Astrophysics Data System (ADS)

Tomarov, G. V.; Nikol'skii, A. I.; Semenov, V. N.; Shipkov, A. A.

2014-06-01

The equipment of and technological processes in the pilot industrial model of the domestically produced binary-cycle geothermal power unit operating on the discharge separate at the Pauzhet geothermal power station are considered. The development principles, the design and operational features, and the data on selecting the metal in manufacturing the main equipment of the 2.5-MW binary power unit of the geothermal power station are described.

Geothermal and volcanism in west Java

NASA Astrophysics Data System (ADS)

Setiawan, I.; Indarto, S.; Sudarsono; Fauzi I, A.; Yuliyanti, A.; Lintjewas, L.; Alkausar, A.; Jakah

2018-02-01

Indonesian active volcanoes extend from Sumatra, Jawa, Bali, Lombok, Flores, North Sulawesi, and Halmahera. The volcanic arc hosts 276 volcanoes with 29 GWe of geothermal resources. Considering a wide distribution of geothermal potency, geothermal research is very important to be carried out especially to tackle high energy demand in Indonesia as an alternative energy sources aside from fossil fuel. Geothermal potency associated with volcanoes-hosted in West Java can be found in the West Java segment of Sunda Arc that is parallel with the subduction. The subduction of Indo-Australian oceanic plate beneath the Eurasian continental plate results in various volcanic products in a wide range of geochemical and mineralogical characteristics. The geochemical and mineralogical characteristics of volcanic and magmatic rocks associated with geothermal systems are ill-defined. Comprehensive study of geochemical signatures, mineralogical properties, and isotopes analysis might lead to the understanding of how large geothermal fields are found in West Java compared to ones in Central and East Java. The result can also provoke some valuable impacts on Java tectonic evolution and can suggest the key information for geothermal exploration enhancement.

Project Title: Geothermal Play Fairway Analysis of Potential Geothermal Resources in NE California, NW Nevada, and Southern Oregon: A Transition between Extension$-$Hosted and Volcanically$-$Hosted Geothermal Fields

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

McClain, James S.; Dobson, Patrick; Glassley, William

Final report for the UCD-LBNL effort to apply Geothermal Play Fairway Analysis to a transition zone between a volcanically-hosted and extensionally-hosted geothermal. The project focusses on the geothermal resources in northeastern California.

Structural Controls of Neal Hot Springs Geothermal Field, Malhuer County, Oregon

NASA Astrophysics Data System (ADS)

Edwards, J. H.; Faulds, J. E.

2012-12-01

, show various dip directions and gentle tilting. Extensive alluvial fan cover hinders collection of fault kinematic data, which coupled with limited regional seismicity, precludes careful calculation of local stress field orientations. However, the proximity of Neal (4 km) to the active, N- to NW-striking, oblique-normal slip Cottonwood Mountain fault and active hot springs (~90°C), opaline sinter mounds, and geothermal fluid flow at Neal suggest that the geothermal field lies within a reactived (Quaternary), southward-terminating, left-stepping, fault zone, which probably accommodates oblique-slip with a dominant normal component. Sugarloaf Butte (completely silicified and replaced) lies within a left step of this fault zone, ~5 km of Neal Hot Springs and is possibly related to the evolution of the geothermal system. Epithermal deposits and argillic to propylitic alteration in other nearby areas (e.g., Hope Butte, ~3 Ma, 5 km N) indicate previous geothermal activity.

Microbial community dynamics in Inferno Crater Lake, a thermally fluctuating geothermal spring

PubMed Central

Ward, Laura; Taylor, Michael W; Power, Jean F; Scott, Bradley J; McDonald, Ian R; Stott, Matthew B

2017-01-01

Understanding how microbial communities respond and adjust to ecosystem perturbation is often difficult to interpret due to multiple and often simultaneous variations in observed conditions. In this research, we investigated the microbial community dynamics of Inferno Crater Lake, an acidic geothermal spring in New Zealand with a unique thermal cycle that varies between 30 and 80 °C over a period of 40–60 days. Using a combination of next-generation sequencing, geochemical analysis and quantitative PCR we found that the microbial community composition was predominantly chemolithotrophic and strongly associated with the thermal cycle. At temperatures >65 °C, the microbial community was dominated almost exclusively by sulphur-oxidising archaea (Sulfolobus-like spp.). By contrast, at mesophilic temperatures the community structure was more mixed, comprising both archaea and bacteria but dominated primarily by chemolithotrophic sulphur and hydrogen oxidisers. Multivariate analysis of physicochemical data confirmed that temperature was the only significant variable associated with community turnover. This research contributes to our understanding of microbial community dynamics in variable environments, using a naturally alternating system as a model and extends our limited knowledge of acidophile ecology in geothermal habitats. PMID:28072418

Microbial community dynamics in Inferno Crater Lake, a thermally fluctuating geothermal spring.

PubMed

Ward, Laura; Taylor, Michael W; Power, Jean F; Scott, Bradley J; McDonald, Ian R; Stott, Matthew B

2017-05-01

Understanding how microbial communities respond and adjust to ecosystem perturbation is often difficult to interpret due to multiple and often simultaneous variations in observed conditions. In this research, we investigated the microbial community dynamics of Inferno Crater Lake, an acidic geothermal spring in New Zealand with a unique thermal cycle that varies between 30 and 80 °C over a period of 40-60 days. Using a combination of next-generation sequencing, geochemical analysis and quantitative PCR we found that the microbial community composition was predominantly chemolithotrophic and strongly associated with the thermal cycle. At temperatures >65 °C, the microbial community was dominated almost exclusively by sulphur-oxidising archaea (Sulfolobus-like spp.). By contrast, at mesophilic temperatures the community structure was more mixed, comprising both archaea and bacteria but dominated primarily by chemolithotrophic sulphur and hydrogen oxidisers. Multivariate analysis of physicochemical data confirmed that temperature was the only significant variable associated with community turnover. This research contributes to our understanding of microbial community dynamics in variable environments, using a naturally alternating system as a model and extends our limited knowledge of acidophile ecology in geothermal habitats.

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.

Geothermal Program Review XIV: proceedings. Keeping Geothermal Energy Competitive in Foreign and Domestic Markets

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

NONE

The U.S. Department of Energy`s Office of Geothermal Technologies conducted its annual Program Review XIV in Berkeley, April 8-10, 1996. The geothermal community came together for an in-depth review of the federally-sponsored geothermal research and development program. This year`s theme focused on ``Keeping Geothermal Energy Competitive in Foreign and Domestic Markets.`` This annual conference is designed to promote technology transfer by bringing together DOE-sponsored researchers; utility representatives; geothermal developers; equipment and service suppliers; representatives from local, state, and federal agencies; and others with an interest in geothermal energy. Program Review XIV consisted of eight sessions chaired by industry representatives. Introductorymore » and overview remarks were presented during every session followed by detailed reports on specific DOE-funded research projects. The progress of R&D projects over the past year and plans for future activities were discussed. The government-industry partnership continues to strengthen -- its success, achievements over the past twenty years, and its future direction were highlighted throughout the conference. The comments received from the conference evaluation forms are published in this year`s proceedings. Individual papers have been processed for inclusion in the Energy Science and Technology Database.« less

Geothermal energy in Tibet

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

Lund, J.W.; McEuen, R.B.; Roberts, A.

1984-09-01

During the fall of 1983, a American delegation of 14 geothermal experts visited the People's Republic of China. The three-week trip included visits to Beijing (Peking), Chengdu, Lhasa, Yangbajing, and Kunming. By far the highlight of the trip was the journey to Tibet where the geothermal field and power station at Yangbajing were toured. Technical exchanges with Chinese and Tibetan geothermal scientists and engineers were made at Beijing, Lhasa, Yangbajing and Kunming. At Kunming in Yunnan Province, the geothermal field in the western part of the province was discussed, but not visited. This latter field is in the process ofmore » extensive investigation, but only minor direct-use development such as sulfur collection and wool washing is being undertaken. The drilling of wells and power plant construction is anticipated in the Rehai and Ridian fields in the near future. In general, Yunnan has one of the largest geothermal potentials in China with over 600 sites identified so far. The sites are widespread throughout the province, but the high temperature sites are located in the western part, a very mountainous area.« less

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.

NREL: Renewable Resource Data Center - Geothermal Resource Publications

Science.gov Websites

Publications For a list of Geothermal publications, go to Geothermal Technologies Publication page . For a list of legacy Geothermal publications, check out Geothermal Technologies Legacy Collection . NREL Publications Database For a comprehensive list of other NREL geothermal resource publications

High geothermal energy utilization geothermal/fossil hybrid power cycle: a preliminary investigation

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

Grijalva, R. L.; Sanemitsu, S. K.

1978-11-01

Combining geothermal and fossil fuel energy into the so-called hybrid cycle is compared with a state-of-the-art double-flash geothermal power cycle using resources which vary from 429/sup 0/K (312/sup 0/F) to 588/sup 0/K (598/sup 0/F). It is demonstrated that a hybrid plant can compete thermodynamically with the combined output from both a fossil-fired and a geothermal plant operating separately. Economic comparison of the hybrid and double-flash cycles is outlined, and results are presented that indicate the performance of marginal hydrothermal resources may be improved enough to compete with existing power cycles on a cost basis. It is also concluded that onmore » a site-specific basis a hybrid cycle is capable of complementing double-flash cycles at large-capacity resources, and can operate in a cycling load mode at constant geothermal fluid flow rate.« less

Alaska Geothermal Sites Map and Database: Bringing together legacy and new geothermal data for research, exploration and development

NASA Astrophysics Data System (ADS)

Clough, J. G.; Harun, N. T.; Hughes, C. A.; Weakland, J. R.; Cameron, C. E.

2013-12-01

Geothermal exploration activities in Alaska from the late 1970s into the 1980s generated vast quantities of scientific data that currently is in unpublished, forgotten and obscure, as well as published formats. Alaska has 61 hot springs (hotter than 50°C) and 34 'warm to cool springs' (cooler than 50°C). Thirty-seven thermal springs are located within the Aleutian and Alaska Peninsula volcanic arc into and are related to elevated heat flows in areas of arc volcanism as well as crustal scale faults associated with accretionary tectonism. The central interior belt that extends from the Seward Peninsula to Circle Hot Springs contains 37 thermal springs that formed due to mostly extensional tectonic forces. An additional 17 thermal springs are in southeast Alaska and 4 are in the Wrangell Mountains. A new cycle of geothermal exploration is underway in Alaska and is producing a wealth of new geothermal data. The Alaska Division of Geological and Geophysical Surveys (ADGGS), funded by the National Geothermal Data System, is compiling both new and legacy geothermal data into a comprehensive database accessible on the ADGGS website. ADGGS has created a new ';Geothermal Sites of Alaska Map' and associated database that includes data on geothermal hot springs, direct use of geothermal resources, volcanic vents, aqueous geochemistry, borehole temperatures, core descriptions, rock chemistry, earthquakes in proximity to hot springs, and active faults. Geothermal hot springs includes locality, temperature, flow rate, sources and related resources. Direct use of geothermal resources contains facilities, capacity, energy use, temperature, flow rate and contact information from geothermal hot springs that are or have recently been used for recreational use, space heating, agricultural or energy use. Volcanic vents records 395 volcanic vents and fumaroles throughout the state that are Holocene or younger. It includes their age, location, elevation, geologic history, composition

Federal Geothermal Research Program Update Fiscal Year 2002

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

Not Available

2003-09-01

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The goals are: (1) Double the number of States with geothermal electric power facilities to eight by 2006; (2) Reduce the levelized cost of generating geothermal power to 3-5 cents per kWh by 2007; and (3) Supply the electrical power or heat energy needs of 7 million homes and businesses in themore » United States by 2010. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2002. 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. balanced strategy for the Geothermal Program.« less

Federal Geothermal Research Program Update Fiscal Year 2003

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

Not Available

2004-03-01

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office. The goals are: (1) Reduce the levelized cost of generating geothermal power to 3-5 cents per kWh by 2007; (2) Double the number of States with geothermal electric power facilities to eight by 2006; and (3) Supply the electricalmore » power or heat energy needs of 7 million homes and businesses in the United States by 2010. This Federal Geothermal Program Research Update reviews the accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2003. 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. balanced strategy for the Geothermal Program.« less

Collective phenomena in the early stages of relativistic heavy-ion collisions

NASA Astrophysics Data System (ADS)

Ryblewski, Radoslaw

Geophysical signatures of volcano-hosted geothermal systems in Indonesia are compiled and synthesized. Parameters include electrical resistivity, seismicity, downhole logging, and pressure/temperature data; temperature and pressure states of systems are simulated through numerical models. The systems are Sungai Penuh, Hululais, Lumutbalai, Ulubelu, Kamojang, Kotamobagu, Tompaso, and Lahendong. The general resistivity structure of the systems comprises a vertical conductor under the volcano peak (<10 ohm.m), a lateral conductor under the volcano flank (<10 ohm.m), and an intermediate resistivity zone under the lateral conductor. Background formations are generally resistive with a resistivity >70 ohm.m. The vertical conductor is the expression of either an active or inactive volcanic neck / magmatic chimney. The lateral conductor is the claycap of the geothermal system containing an argillic alteration zone that keeps the hot fluids and the heat inside the reservoir. The topography of the volcano dictates the hydrology and shapes the extent of the lateral conductor. The hydrothermal fluids themselves are kept within the intermediate resistivity region, 10--60 ohm.m for a liquid-dominated system, and up to 100 ohm.m for a vapor-dominated system, preferably with the temperature of 200--300 ° C. On the margins, the reservoir may have either sharp or diffuse contact with the background or the claycap; vapor-dominated systems have a sharp contact. A diffuse contact is usually associated with a gradational change in temperature, with temperature reversal at depth. The caprock of a geothermal system has an aseismic character possibly due to its ductile behavior from the clay and from its low permeability structure. The low permeability property impedes liquid movement and flashing that could induce seismicity. The propylitic reservoir is seismogenic due to less clay content and its high permeability that promotes liquid movement and flashing into steam which induces

Federal Geothermal Research Program Update Fiscal Year 1999

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

Not Available

2004-02-01

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal and Wind Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office of Geothermal and Wind Technologies. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 1999. The information contained in this Research Update illustrates howmore » the mission and goals of the Office of Geothermal and Wind 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.« less

Geothermal development in the Philippines

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

Elizagaque, R.F.; Tolentino, B.S.

1982-06-01

The development of geothermal resources and energy in the Philippines is discussed. Philippine National Oil Company-Energy Development Corporation initiated the first semi-commercial generation of geothermal power in July 1977 with the installation of a 3MWe plant. By 1980 the country had 440 MWe on line at Mak-Ban and Tiwi. This placed the Philippines second after the US among countries using geothermal energy for power generation. Before the end of 1981, PNOC-EDC added 6 additional MWe of geothermal power generating capacity to increase the total to 446 MWe. As part of the five-year National Energy Development Programme covering the period 1981-1985,more » additional power plants will be installed in various project areas to increase the share of geothermal power generation from the present 9.8% to 18.6% of the nationwide power-generation total, or the equivalent of 16.6 million barrels of oil per year. (MJF)« less

Geothermal development plan: Yuma County

NASA Astrophysics Data System (ADS)

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

1982-08-01

The potential for utilizing geothermal energy was evaluated. Four potential geothermal resource areas with temperatures less than 900C (1940F) were identified, and in addition, two areas are inferred to contain geothermal resources with intermediate temperature potential. The resource areas are isolated. One resource site contains a hot dry rock resource. Anticipated population growth in the county is expected to be 2% 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 adverse affect on agriculture. In addition, several agricultural processors were found, concentrated in citrus processing and livestock raising. It is suggested 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.

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.

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.

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.

NREL: Renewable Resource Data Center - Geothermal Resource Information

Science.gov Websites

Energy's Office of Energy Efficiency and Renewable Energy Geothermal Technologies Program. Its collection , and thermal springs. View NREL's Geothermal resource maps as well as maps for other renewable energy Geothermal Resource Information Geothermal Prospector Start exploring U.S. geothermal resources

Industrially induced changes in Earth structure at the Geysers Geothermal Area, California

NASA Astrophysics Data System (ADS)

Foulger, G. R.; Grant, C. C.; Ross, A.; Julian, B. R.

Industrial exploitation is causing clearly-measurable changes in Earth structure at The Geysers geothermal area, California. Production at The Geysers peaked in the late 1980s at ˜3.5 × 10³ kg s-1 of steam and 1800 MW of electricity. It subsequently decreased by about 10% per year [Barker et al., 1992] because of declining reservoir pressure. The steam reservoir coincides with a strong negative anomaly (˜0.16, ˜9%) in the compressional-to-shear seismic wave speed ratio VP/ VS, consistent with the expected effects of low-pressure vapor-phase pore fluid [Julian et al., 1996]. Between 1991 and 1994 this anomaly increased in amplitude by up to about 0.07 (˜4%). This is consistent with the expected effects of continued pressure reduction and conversion of pore water to steam as a result of exploitation. These unique results show that VP/VS tomography can easily detect saturation changes caused by exploitation of reservoirs, and is a potentially valuable technique for monitoring environmental change. They also provide geophysical observational evidence that geothermal energy is not a renewable energy source.

The Geysers Geothermal Field Update1990/2010

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

Brophy, P.; Lippmann, M.; Dobson, P.F.

2010-10-01

view across all technical fields, as related to The Geysers steam-dominated geothermal system. The Geysers has seen many fundamental changes between 1990-2010 and yet the geothermal resource seems still to be robust to the extent that, long after its anticipated life span, we are seeing new geothermal projects being developed on the north and west peripheries of the field. It is hoped that this report provides a focused data source particularly for those just starting their geothermal careers, as well as those who have been involved in the interesting and challenging field of geothermal energy for many years. Despite many hurdles The Geysers has continued to generate electrical power for 50 years and its sustainability has exceeded many early researchers expectations. It also seems probable that, with the new projects described above, generation will continue for many years to come. The success of The Geysers is due to the technical skills and the financial acumen of many people, not only over the period covered by this report (1990-2010), but since the first kilowatt of power was generated in 1960. This Special Report celebrates those 50 years of geothermal development at The Geysers and attempts to document the activities that have brought success to the project so that a permanent record can be maintained. It is strongly hoped and believed that a publication similar to this one will be necessary in another 20 years to document further activities in the field.« less

Entropy production and optimization of geothermal power plants

NASA Astrophysics Data System (ADS)

Michaelides, Efstathios E.

2012-09-01

Geothermal power plants are currently producing reliable and low-cost, base load electricity. Three basic types of geothermal power plants are currently in operation: single-flashing, dual-flashing, and binary power plants. Typically, the single-flashing and dual-flashing geothermal power plants utilize geothermal water (brine) at temperatures in the range of 550-430 K. Binary units utilize geothermal resources at lower temperatures, typically 450-380 K. The entropy production in the various components of the three types of geothermal power plants determines the efficiency of the plants. It is axiomatic that a lower entropy production would improve significantly the energy utilization factor of the corresponding power plant. For this reason, the entropy production in the major components of the three types of geothermal power plants has been calculated. It was observed that binary power plants generate the lowest amount of entropy and, thus, convert the highest rate of geothermal energy into mechanical energy. The single-flashing units generate the highest amount of entropy, primarily because they re-inject fluid at relatively high temperature. The calculations for entropy production provide information on the equipment where the highest irreversibilities occur, and may be used to optimize the design of geothermal processes in future geothermal power plants and thermal cycles used for the harnessing of geothermal energy.

NREL: Renewable Resource Data Center - Geothermal Resource Related Links

Science.gov Websites

from the following sources: U.S. Department of Energy Geothermal Technologies Office. National Geothermal Resource Related Links Comprehensive geothermal resource information is also available Geothermal Data System A portal to geothermal data. Southern Methodist University Geothermal Laboratory The

The Coso geothermal area: A laboratory for advanced MEQ studies for geothermal monitoring

USGS Publications Warehouse

Julian, B.R.; Foulger, G.R.; Richards-Dinger, K.

2004-01-01

The permanent 16-station network of three-component digital seismometers at the Coso geothermal area, California, supplemented by 14 temporary instruments deployed in connection with the DOE Enhanced Geothermal Systems (EGS) Project, provides high-quality microearthquake (MEQ) recordings that are well suited to monitoring a producing geothermal area. We are currently using these data to investigate structure and active processes within the geothermal reservoir by applying three advanced methods: a) high-precision MEQ hypocenter location; b) time-dependent tomography; c) complete (moment tensor) MEQ source mechanism determination. Preliminary results to date resolve seismogenic structures in the producing field more clearly than is possible with conventional earthquake-location techniques. A shallow part of the producing field shows clear changes in the ratio of the seismic wave speeds, Vp/V s, between 1996 and 2002, which are probably related to physical changes in the reservoir caused by fluid extraction.

AASG State Geothermal Data Repository for the National Geothermal Data System.

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

2012-01-01

This Drupal metadata and documents capture and management system is a repository, used for maintenance of metadata which describe resources contributed to the AASG State Geothermal Data System. The repository also provides an archive for files that are not hosted by the agency contributing the resource. Data from all 50 state geological surveys is represented here, and is contributed in turn to the National Geothermal Data System.

Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

NASA Astrophysics Data System (ADS)

Uwiduhaye, Jean d.'Amour; Mizunaga, Hideki; Saibi, Hakim

2018-03-01

A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from -52 to -35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

Radiator Enhanced Geothermal System - A Revolutionary Method for Extracting Geothermal Energy

NASA Astrophysics Data System (ADS)

Karimi, S.; Marsh, B. D.; Hilpert, M.

2017-12-01

A new method of extracting geothermal energy, the Radiator Enhanced Geothermal System (RAD-EGS) has been developed. RAD-EGS attempts to mimic natural hydrothermal systems by 1) generating a vertical vane of artificially produced high porosity/permeability material deep in a hot sedimentary aquifer, 2) injecting water at surface temperatures to the bottom of the vane, where the rock is the hottest, 3) extracting super-heated water at the top of the vane. The novel RAD-EGS differs greatly from the currently available Enhanced Geothermal Systems in vane orientation, determined in the governing local crustal stress field by Shmax and Sl (meaning it is vertical), and in the vane location in a hot sedimentary aquifer, which naturally increases the longevity of the system. In this study, we explore several parameters regimes affecting the water temperature in the extraction well, keeping in mind that the minimum temperature of the extracted water has to be 150 °C in order for a geothermal system to be commercially viable. We used the COMSOL finite element package to simulate coupled heat and fluid transfer within the RAD-EGS model. The following geologic layers from top to bottom are accounted for in the model: i) confining upper layer, ii) hot sedimentary aquifer, and iii) underlying basement rock. The vane is placed vertically within the sedimentary aquifer. An injection well and an extraction well are also included in the simulation. We tested the model for a wide range of various parameters including background heat flux, thickness of geologic layers, geometric properties of the vane, diameter and location of the wells, fluid flow within the wells, regional hydraulic gradient, and permeability and porosity of the layers. The results show that among the aforementioned parameters, background heat flux and the depth of vane emplacement are highly significant in determining the level of commercial viability of the geothermal system. These results indicate that for the

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.

An evaluation of the deep reservoir conditions of the Bacon-Manito geothermal field, Philippines using well gas chemistry

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

D'Amore, Franco; Maniquis-Buenviaje, Marinela; Solis, Ramonito P.

1993-01-28

Gas chemistry from 28 wells complement water chemistry and physical data in developing a reservoir model for the Bacon-Manito geothermal project (BMGP), Philippines. Reservoir temperature, T HSH, and steam fraction, y, are calculated or extrapolated from the grid defined by the Fischer-Tropsch (FT) and H 2-H 2S (HSH) gas equilibria reactions. A correction is made for H 2 that is lost due to preferential partitioning into the vapor phase and the reequilibration of H 2S after steam loss.

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

China starts tapping rich geothermal resources

NASA Astrophysics Data System (ADS)

Guang, D.

1980-09-01

Attention is given to the electric and power installation running on geothermal energy at Yangbajain, Tibet. Other geothermal projects in Tibet, the Yunnan Province and the North China Plain are also outlined. Applications of geothermal energy are described, including the heating of homes and factories, spinning, weaving, paper-making and the making of wine.

Federal Geothermal Research Program Update - Fiscal Year 2001

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

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.

Analysis geothermal prospect of Mt. Endut using geochemistry methods

NASA Astrophysics Data System (ADS)

Sobirin, R.; Permadi, A. N.; Akbar, A. M.; Wildan, D.; Supriyanto

2017-07-01

Mt. Endut geothermal area is located in Lebak district, Banten province, about 40 km to the south of the town of Rangkasbitung. There are four manifestations of hot springs i.e: Handeuleum hot springs, Cikawah 1, Cikawah 2, and Gajrug. Based on geochemical analysis using Na-K-Mg triangular diagrams, Cl-Li-B, and Cl-SO4-HCO3, it is known that Cikawah 1 hot springs is chloride type and the other springs are bicarbonate type. Reservoir temperature range is from 162°C to 180°C are predicted by SiO2 and NaK geothermometers. In general all hot springs are out flows, but there is an hypothesis that Cikawah 1 is the up flow. Because it is in partial equilibrium and chloride type. Mount Endut has a hydrothermal system with a fluid reservoir in the form of hot water or water dominated system. The geothermal prospect area of Mount Endut is located around the Cikawah manifestation to the western part of the Endut mountain. Further research is required by conducting geophysical surveys around the Mount Endut.

Metagenomic Evaluation of Bacterial and Archaeal Diversity in the Geothermal Hot Springs of Manikaran, India

PubMed Central

Pathak, Ashish; Green, Stefan J.; Joshi, Amit; Chauhan, Ashvini

2015-01-01

Bacterial and archaeal diversity in geothermal spring water were investigated using 16S rRNA gene amplicon metagenomic sequencing. This revealed the dominance of Firmicutes, Aquificae, and the Deinococcus-Thermus group in this thermophilic environment. A number of sequences remained taxonomically unresolved, indicating the presence of potentially novel microbes in this unique habitat. PMID:25700403

Using geochemical and isotopic techniques for exploration of geothermal energy in Southern Sabalan geothermal field, NW Iran

NASA Astrophysics Data System (ADS)

Masoumi, Rahim

2017-04-01

From a hydrogeochemical point of view the geothermal fluids in the study area can be divided into two categories, (1) Na-Cl and (2) Na-Ca-HCO3. In the study area, the hot water samples depict temperature and pH ranges of 22 °C to 77 °C and 6.4 to 7.3, respectively. The total dissolved solids vary from 456 mg/L to 7006 mg/L. The concentration of rare metallic and non-metallic elements such as Li, Rb, B, Ba, Sr, CS, Se, Al, As, Hg in cold and hot spring waters in the Bushdi area were also analyzed. The utmost concentration belongs to Se which ranges from 135 mg/L to 273 mg/L. Boron also shows notable concentration values, in most samples it exceeds 20 mg/L, and in certain samples it ranges from 28 mg/L to 33.5 mg/L. The concentration value of arsenic ranges from 3 mg/L to 4 mg/L. The maximum concentration value of mercury is 0.01 mg/L. The δ18O values of these samples vary from -12.4 ‰ to -7.5 ‰ and the δD values range from -78.6 ‰ to -70.6 ‰. Plotting δ18O versus δD demonstrates that the data points are clustered close to both, the global meteoric water line (GMWL) with the equation δD = 8 δ18O + 10 and, the national meteoric water line (NMWL) with the equation δD = 6.89 δ18O + 6.57. As can be observed, the geothermal fluids in the Bushdi area show relatively slight increase in δ18O values that may be caused by interaction of hot fluids with host volcanic rocks. In fact, this relatively slight increment in δ18O values may indicate the low to moderate temperature of the geothermal system. The δD values, in general, do not show notable variation because of very low hydrogen content of the host rocks. The slight increase in δD, however, may be in conjunction with vaporization and isotopic interaction with the host rocks. The 3H content of the cold and hot waters in the Bushdi area is relatively high and varies from 0.65 TU to 41.4 TU. This may be caused either by mixing with meteoric sources or rapid fluid flow within the system in a shorter time

Methods for regional assessment of geothermal resources

USGS Publications Warehouse

Muffler, P.; Cataldi, R.

1978-01-01

future. In a manner similar to mineral and fuel assessment, this recoverability is expressed as a "recovery factor". For an ideally permeable hot-water system, the recovery factor may be as much as 50% and seems to be independent of temperature. It must decrease as effective porosity (??e) decreases, but the relation between the two is little more than a guess. On the other hand, for favorable systems like Larderello that produce steam by a mechanism of intergranular vaporization, the recovery factor is probably around 15-20%, decreasing to zero at an effective porosity of zero. According to the anlysis of Bodvarsson (1974), it increases with decreasing reservoir temperature, and as pointed out by Nathenson (1975a) is limited at low temperatures by the need to have sufficient reservoir pressure for extraction and use. The extent to which a geothermal reservoir can be resupplied with heat during "industrial" times of 10-100 yr can be evaluated using simple analytical models. The results, combined with gravity and levelling data of Hunt (1977) for Wairakei and Isherwood (1977) for The Geysers, confirm earlier conclusions by Ramey (1970) and Nathenson (1975a) that resupply to reservoirs producing only steam can be neglected, and the conclusion of Nathenson (1975a) that it may be significant for hot-water systems of high natural discharge. Major subjects that demand continuing investigation include: 1. 1. Determination of recovery factors as functions of temperature and effective porosity, particularly for hot-water systems. 2. 2. Evaluation of fluid recharge and heat resupply by repetitive gravity, levelling and underground temperature surveys in producing geothermal fields. 3. 3. Analysis of the extent to which a recovery factor can be enhanced by stimulation and by use of confined circulation loops. ?? 1979.

Geothermal industry employment: Survey results & analysis

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

Not Available

2005-09-01

The Geothermal Energy Association (GEA) is ofteh asked about the socioeconomic and employment impact of the industry. Since available literature dealing with employment involved in the geothermal sector appeared relatively outdated, unduly focused on certain activities of the industry (e.g. operation and maintenance of geothermal power plants) or poorly reliable, GEA, in consultation with the DOE, decided to conduct a new employment survey to provide better answers to these questions. The main objective of this survey is to assess and characterize the current workforce involved in geothermal activities in the US. Several initiatives have therefore been undertaken to reach asmore » many organizations involved in geothermal activities as possible and assess their current workforce. The first section of this document describes the methodology used to contact the companies involved in the geothermal sector. The second section presents the survey results and analyzes them. This analysis includes two major parts. The first part analyzes the survey responses, presents employment numbers that were captured and describes the major characteristics of the industry that have been identified. The second part of the analysis estimates the number of workers involved in companies that are active in the geothermal business but did not respond to the survey or could not be reached. Preliminary conclusions and the study limits and restrictions are then presented. The third section addresses the potential employment impact related to manufacturing and construction of new geothermal power facilities. Indirect and induced economic impacts related with such investment are also investigated.« less

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.

Materials selection guidelines for geothermal energy utilization systems

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

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 aremore » 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)« less

Federal Geothermal Research Program Update, FY 2000

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

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 hydrothermalmore » 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.« less

Power-poor Philippines taps geothermal pool

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

Not Available

1982-04-15

The current energy situation in the Philippines (75% imported oil) is reviewed and current and future activities in the area of geothermal energy use is discussed. It is estimated that by 1986, $830 million will be spent to develop the extensive geothermal sources to produce 13% of the nation's total energy. The high-quality geothermal sources are described as producing 162/sup 0/C water-steam mixture at a pressure of 6.68 kg/sec. Energy producing systems are described briefly as well as the environmental and equipment problems encountered already. The cost of geothermal energy is discussed (2.5 cents/kWh) and compared with energy costs ofmore » fossil-fuel and hydroelectricity. It is concluded that the geothermal energy sources should be a major contributor to the Philippines for at least 30 years. (MJJ)« less

Cumulative biological impacts of The Geysers geothermal development

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

Brownell, J.A.

1981-10-01

The cumulative nature of current and potential future biological impacts from full geothermal development in the steam-dominated portion of The Geysers-Calistoga KGRA are identified by the California Energy Commission staff. Vegetation, wildlife, and aquatic resources information have been reviewed and evaluated. Impacts and their significance are discussed and staff recommendations presented. Development of 3000 MW of electrical energy will result in direct vegetation losses of 2790 acres, based on an estimate of 11.5% loss per lease-hold of 0.93 acres/MW. If unmitigated, losses will be greater. Indirect vegetation losses and damage occur from steam emissions which contain elements (particularly boron) toxicmore » to vegetation. Other potential impacts include chronic low-level boron exposure, acid rain, local climate modification, and mechanical damage. A potential exists for significant reduction and changes in wildlife from direct habitat loss and development influences. Highly erosive soils create the potential for significant reduction of aquatic resources, particularly game fish. Toxic spills have caused some temporary losses of aquatic species. Staff recommends monitoring and implementation of mitigation measures at all geothermal development stages.« less

Neutron imaging for geothermal energy systems

NASA Astrophysics Data System (ADS)

Bingham, Philip; Polsky, Yarom; Anovitz, Lawrence

2013-03-01

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.

Geothermal Loan Guaranty Program and its impact on geothermal exploration and development

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

Nasr, L.H.

1978-05-01

The study showed that the Geothermal Loan Guaranty Program has had only a negligible effect on geothermal development and the response to the program was far less than expected. The streamlining of environmental regulations and leasing policies, and the granting of intangible drilling cost write-offs and depletion allowances to operators would have had a greater impact on geothermal energy development. The loan guaranty program did not promote the undertaking of any new projects that would not have been undertaken without it. The program only accelerated the pace for some development which might have commenced in the future. Included in themore » study are recommendations for improving the operation of the program thereby increasing its attractiveness to potential applicants.« less

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.

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.

Simulating the influence of groundwater table fluctuation on vapor intrusion

NASA Astrophysics Data System (ADS)

Huo, J.

2017-12-01

The migration of volatile chemicals from groundwater to an overlying building is a commonly existing phenomenon around the world. Due to the distinction of hydrologic conditions among vapor intrusion sites, it is necessary to consider the effect of dominant hydrologic factors in order to obtain a precise site evaluation and a health risk assessment during the screening process. This study mainly discusses the impact of groundwater table fluctuation and other hydrological factors including porosity, permeability and soil moisture on the vapor intrusion transport. A two-dimensional model is configured to inject different typical volatile organic contaminants from EPA's Vapor Intrusion Database. Through quantifying the contaminant vapor concentration attenuation factors under the effect of groundwater table fluctuation, this study provides suggestions for indoor air sample and vapor intrusion assessment.

Modelling of hydrogen sulfide dispersion from the geothermal power plants of Tuscany (Italy)

NASA Astrophysics Data System (ADS)

Renato, Somma; Domenico, Granieri; Claudia, Troise; Carlo, Terranova; Natale Giuseppe, De; Maria, Pedone

2017-04-01

The hydrogen sulfide (H2S) is one of the main gaseous substances contained in deep fluids exploited by geo-thermoelectric plant. Therefore, it is a "waste" pollutant product by plants for energy production. Hydrogen sulfide is perceived by humans at very low concentrations in the air ( 0,008 ppm, World Health Organization, hereafter WHO, 2003) but it becomes odorless in higher concentrations (> 100 ppm, WHO, 2003) and, for values close to the ones lethal (> 500 ppm), produces an almost pleasant smell. The typical concentration in urban areas is <0.001ppm (<1ppb); in volcanic plumes it reaches values between 0.1 and 0.5 ppm. WHO defines the concentration and relative effects on human health. We applied the Eulerian code DISGAS (DISpersion of GAS) to investigate the dispersion of the hydrogen sulfide (H2S) from 32 geothermal power plants (out of 35 active) belonging to the geothermal districts of Larderello, Travale-Radicondoli and Monte Amiata, in Tuscany (Italy). DISGAS code has simulated scenarios consistent with the prevailing wind conditions, estimating reasonable H2S concentrations for each area, and for each active power plant. The results suggest that H2S plumes emitted from geothermal power plants are mainly concentrated around the stacks of emission (H2S concentration up to 1100 ug/m3) and rapidly dilute along the dominant local wind direction. Although estimated values of air H2S concentrations are orders of magnitude higher than in unpolluted areas, they do not indicate an immediate health risk for nearby communities, under the more frequent local atmospheric conditions. Starting from the estimated values, validated by measurements in the field, we make some considerations about the environmental impact of the H2S emission in all the geothermal areas of the Tuscany region. Furthermore, this study indicates the potential of DISGAS as a tool for an improved understanding of the atmospheric and environmental impacts of the H2S continuous degassing from

The USGS national geothermal resource assessment: An update

USGS Publications Warehouse

Williams, C.F.; Reed, M.J.; Galanis, S.P.; DeAngelo, J.

2007-01-01

The U. S. Geological Survey (USGS) is working with the Department of Energy's (DOE) Geothermal Technologies 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 volumes, and limits to temperatures and depths for electric power production. It will also include the potential impact of evolving Enhanced Geothermal Systems (EGS) technology. An important focus in the assessment project is on the development of geothermal resource models consistent with the production histories and observed characteristics of exploited geothermal fields. New models for the recovery of heat from heterogeneous, fractured reservoirs provide a physically realistic basis for evaluating the production potential of both natural geothermal reservoirs and reservoirs that may be created through the application of EGS technology. Project investigators have also made substantial progress studying geothermal systems and the factors responsible for their formation through studies in the Great Basin-Modoc Plateau region, Coso, Long Valley, the Imperial Valley and central Alaska, Project personnel are also entering the supporting data and resulting analyses into geospatial databases that will be produced as part of the resource assessment.

Use of a Geothermal-Solar Hybrid Power Plant to Mitigate Declines in Geothermal Resource Productivity

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

Dan Wendt; Greg Mines

2014-09-01

Many, if not all, geothermal resources are subject to decreasing productivity manifested in the form of decreasing brine temperature, flow rate, or both during the life span of the associated power generation project. The impacts of resource productivity decline on power plant performance can be significant; a reduction in heat input to a power plant not only decreases the thermal energy available for conversion to electrical power, but also adversely impacts the power plant conversion efficiency. The reduction in power generation is directly correlated to a reduction in revenues from power sales. Further, projects with Power Purchase Agreement (PPA) contractsmore » in place may be subject to significant economic penalties if power generation falls below the default level specified. A potential solution to restoring the performance of a power plant operating from a declining productivity geothermal resource involves the use of solar thermal energy to restore the thermal input to the geothermal power plant. There are numerous technical merits associated with a renewable geothermal-solar hybrid plant in which the two heat sources share a common power block. The geo-solar hybrid plant could provide a better match to typical electrical power demand profiles than a stand-alone geothermal plant. The hybrid plant could also eliminate the stand-alone concentrated solar power plant thermal storage requirement for operation during times of low or no solar insolation. This paper identifies hybrid plant configurations and economic conditions for which solar thermal retrofit of a geothermal power plant could improve project economics. The net present value of the concentrated solar thermal retrofit of an air-cooled binary geothermal plant is presented as functions of both solar collector array cost and electricity sales price.« less

Characterization of Hydrologic and Thermal Properties at Brady Geothermal Field, NV

NASA Astrophysics Data System (ADS)

Patterson, J.; Cardiff, M. A.; Lim, D.; Coleman, T.; Wang, H. F.; Feigl, K. L.

2017-12-01

Understanding and predicting the temperature evolution of geothermal reservoirs is a primary focus for geothermal power plant operators ensuring continued financial sustainability of the resource. Characterization of reservoir properties - such as thermal diffusivity and hydraulic conductivity - facilitates modeling efforts to develop a better understanding of temperature evolution. As part of the integrated "PoroTomo" experiment, borehole pressure measurements were collected in three monitoring wells of various depths under varying operational conditions at the Brady Geothermal Field near Reno, NV. During normal operational conditions, a vertical profile of borehole temperature to 330 m depth was collected using distributed temperature sensing (DTS) for a period of 5 days. Borehole pressure data indicates 2D flow and shows rapid responses to changes in pumping /injection rates, likely indicating fault-dominated flow. The temperature data show that borehole temperature recovery following cold water slug injection is variable with depth. Late time vertical temperature profiles show the borehole following a shallow geotherm to a depth of approximately 275 meters, below which the temperature declines until a depth of approximately 320 meters, with a stable zone of cold water forming below this, possibly indicating production-related thermal drawdown. A validated heat transfer model is used in conjunction with the temperature data to determine depth-dependent reservoir thermal properties. Hydraulic reservoir properties are determined through inversion of the collected pressure data using MODFLOW. These estimated thermal and hydraulic properties are synthesized with existing structural and stratigraphic datasets at Brady. The work presented herein was funded in part by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy, under Award Number DE-EE0006760.

Geothermal Energy Retrofit

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

Bachman, Gary

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.

Geothermal development plan: Cochise/Santa Cruz Counties

NASA Astrophysics Data System (ADS)

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

1982-08-01

The regional market potential for utilizing geothermal energy was evaluated. Three potential geothermal resource areas with potential for resource temperatures less than 900C (1940F) were identified. Population growth rates are expected to average 3% per year over the next 30 years in Willcox; Bowie and San Simon are expected to grow much slower. Regional employment is based on agriculture and copper mining, though future growth in trade, services and international trade is expected. A regional energy use analysis is included. Urban use, copper mining and agriculture are the principal water users in the region and substantial reductions in water use are anticipated in the future. The development plan identifies potential geothermal energy users in the region. Geothermal energy utilization projections suggest that by the year 2000, geothermal energy might economically provide the energy equivalent of 3,250,000 barrels of oil per year to the industrial sector. In addition, geothermal energy utilization might help stimulate an agricultural and livestock processing industry.

Archaeal and bacterial diversity in two hot spring microbial mats from a geothermal region in Romania.

PubMed

Coman, Cristian; Drugă, Bogdan; Hegedus, Adriana; Sicora, Cosmin; Dragoş, Nicolae

2013-05-01

The diversity of archaea and bacteria was investigated in two slightly alkaline, mesophilic hot springs from the Western Plain of Romania. Phylogenetic analysis showed a low diversity of Archaea, only three Euryarchaeota taxa being detected: Methanomethylovorans thermophila, Methanomassiliicoccus luminyensis and Methanococcus aeolicus. Twelve major bacterial groups were identified, both springs being dominated by Cyanobacteria, Chloroflexi and Proteobacteria. While at the phylum/class-level the microbial mats share a similar biodiversity; at the species level the geothermal springs investigated seem to be colonized by specific consortia. The dominant taxa were filamentous heterocyst-containing Fischerella, at 45 °C and non-heterocyst Leptolyngbya and Geitlerinema, at 55 °C. Other bacterial taxa (Thauera sp., Methyloversatilis universalis, Pannonibacter phragmitetus, Polymorphum gilvum, Metallibacterium sp. and Spartobacteria) were observed for the first time in association with a geothermal habitat. Based on their bacterial diversity the two mats were clustered together with other similar habitats from Europe and part of Asia, most likely the water temperature playing a major role in the formation of specific microbial communities that colonize the investigated thermal springs.

Geothermal energy for greenhouses

Treesearch

Jacky Friedman

2009-01-01

Geothermal energy is heat (thermal) derived from the earth (geo). The heat flows along a geothermal gradient from the center of the earth to the surface. Most of the heat arrives at the surface of the earth at temperatures too low for much use. However, plate tectonics ensure that some of the heat is concentrated at temperatures and depths favorable for its commercial...

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)

Geothermal resources assessed in Honduras

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

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. Severalmore » 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.« less

Assessment of Deep Seated Geothermal Reservoirs in Selected European Sedimentary Environments

NASA Astrophysics Data System (ADS)

Ungemach, Pierre; Antics, Miklos

2014-05-01

Europe at large enjoys a variety of sedimentary environments. They most often host dependable geothermal reservoirs thus favouring the farming of hot fluids, within the low to medium enthalpy range, among which geothermal district heating (GDH) and combined heat and power (CHP) undertakings hold a dominant share. Three selected reservoir settings, addressing carbonate and clastic deposits, the Central part of the Paris Basin, the Southern Germany Molasse Basin in the Münich area and the Netherland Basin respectively will be presented and the exploratory, modeling and development strategies discussed accordingly. Whereas 2D (reprocessed) and 3D seismics have become a standard in matching the distinctive (reef facies, an echelon faulting, carbonate platform layering) features of a deep buried karst and a key to drilling success in the Molasse Basin, thus emphasizing a leading exploratory rationale, the Netherland and Paris Basin instead benefit from a mature data base inherited from extensive hydrocarbon exploration campaigns, with concerns focused on reservoir modeling and sustainable management issues. As a result the lessons learned from the foregoing have enabled to build up a nucleus of expertise in the whole chain from resource identification to reservoir assessment and market penetration. The seismic risk, indeed a sensitive though somewhat emotional issue, which is requiring special attention and due microseismic monitoring from the geothermal community will also be commented.

Pumpernickel Valley Geothermal Project Thermal Gradient Wells

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

Z. Adam Szybinski

2006-01-01

The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined withmore » geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells

The Geothermal Potential, Current and Opportunity in Taiwan

NASA Astrophysics Data System (ADS)

Song, Sheng-Rong

2016-04-01

Located in the west Pacific Rim of Fire, Taiwan possesses rich geothermal resources due to volcanic activities and rapid uplifting of plate collision. Based on available data prior to 1980, Taiwan may have about 1 GWe of potential shallow geothermal energy, which is less than 3% of the national gross power generation. A 3-Mw pilot power plant, therefore, was constructed in 1981 and terminated in 1993 in the Chingshui geothermal field of Ilan, northeastern Taiwan. Recently, one of the National Science & Technology Program (NSTP) projects has been conducting research and reevaluating the island-wide deep geothermal energy. Four hot potential sites have been recognized. They are: (1) Tatun Volcano Group of northern Taiwan; (2) I-Lan Plain of NE Taiwan; (3) Lu-Shan area of Central Taiwan; and (4) Hua-Tung area of eastern Taiwan. We found that the geothermal resource in Taiwan may be as high as 160 GWe, with 33.6 GWe of exploitable geothermal energy. There are no any commercial geothermal power plants until now in Taiwan, although the potential is great. However, geothermal energy has been listed as one of major tasks of National Energy Program, Phase II (NEP-II) in Taiwan. We will conduct more detailed geothermal energy surveys on some proposed hot sites and to construct an EGS pilot geothermal plant with 1 MWe capability in a few years. Currently, there are three nuclear power plants, named No. 1, 2 & 3, in operations, which produce 16.5% gross generation of electricity and one (No. 4) is under construction, but is stopped and sealed now in Taiwan. Furthermore, the life-span of 40-year operation for those three power plants will be close-at hand and retire in 2018-2019, 2021-2023 and 2024-2025, respectively. Therefore, to find alternative energy sources, especially on the clean, renewable and sustainable ones for generating electricity are emergent and important for Taiwan's government in next few years. Among various energy sources, geothermal energy can be as base

Development of Genetic Occurrence Models for Geothermal Prospecting

NASA Astrophysics Data System (ADS)

Walker, J. D.; Sabin, A.; Unruh, J.; Monastero, F. C.; Combs, J.

2007-12-01

Exploration for utility-grade geothermal resources has mostly relied on identifying obvious surface manifestations of possible geothermal activity, e.g., locating and working near steaming ground or hot springs. This approach has lead to the development of over 130 resources worldwide, but geothermal exploration done in this manner is akin to locating hydrocarbon plays by searching for oil seeps. Confining exploration to areas with such features will clearly not discover a blind resource, that is, one that does not have surface expression. Blind resources, however, constitute the vast majority of hydrocarbon plays; this may be the case for geothermal resources as well. We propose a geothermal exploration strategy for finding blind systems that is based on an understanding of the geologic processes that transfer heat from the mantle to the upper crust and foster the conditions for hydrothermal circulation or enhanced geothermal exploration. The strategy employs a genetically based screening protocol to assess potential geothermal sites. The approach starts at the plate boundary scale and progressively focuses in on the scale of a producing electrical-grade field. Any active margin or hot spot is a potential location for geothermal resources. Although Quaternary igneous activity provides a clear indication of active advection of hot material into the upper crust, it is not sufficient to guarantee a potential utility-grade resource. Active faulting and/or evidence of high strain rates appear to be the critical features associated with areas of utility-grade geothermal potential. This is because deformation on its own can advect sufficient heat into the upper crust to create conditions favorable for geothermal exploitation. In addition, active deformation is required to demonstrate that open pathways for circulation of geothermal fluids are present and/or can be maintained. The last step in the screening protocol is to identify any evidence of geothermal activity

Quantitative Analysis of Existing Conditions and Production Strategies for the Baca Geothermal System, New Mexico

NASA Astrophysics Data System (ADS)

Faust, Charles R.; Mercer, James W.; Thomas, Stephen D.; Balleau, W. Pete

1984-05-01

The Baca geothermal reservoir and adjacent aquifers in the Jemez Mountains of New Mexico comprise an integrated hydrogeologic system. Analysis of the geothermal reservoir either under natural conditions or subject to proposed development should account for the mass (water) and energy (heat) balances of adjacent aquifers as well as the reservoir itself. A three-dimensional model based on finite difference approximations is applied to this integrated system. The model simulates heat transport associated with the flow of steam and water through an equivalent porous medium. The Baca geothermal reservoir is dominated by flow in fractures and distinct strata, but at the scale of application the equivalent porous media concept is appropriate. The geothermal reservoir and adjacent aquifers are simulated under both natural conditions and proposed production strategies. Simulation of natural conditions compares favorably with observed pressure, temperature, and thermal discharge data. The history matching simulations show that the results used for comparison are most sensitive to vertical permeability and the area of an assumed high-permeability zone connecting the reservoir to a deep hydrothermal source. Simulations using proposed production strategies and optimistic estimates of certain hydrologic parameters and reservoir extent indicate that a 50-MW power plant could be maintained for a period greater than 30 years. This production, however, will result in significant decreases in the total water discharge to the Jemez River.

Prioritizing High-Temperature Geothermal Resources in Utah

USGS Publications Warehouse

Blackett, R.E.; Brill, T.C.; Sowards, G.M.

2002-01-01

The Utah Geological Survey and the Utah Energy Office recently released geothermal resource information for Utah as a "digital atlas." We are now expanding this project to include economic analyses of selected geothermal sites and previously unavailable resource information. The enhancements to the digital atlas will include new resource, demographic, regulatory, economic, and other information to allow analyses of economic factors for comparing and ranking geothermal resource sites in Utah for potential electric power development. New resource information includes temperature gradient and fluid chemistry data, which was previously proprietary. Economic analyses are based upon a project evaluation model to assess capital and operating expenses for a variety of geothermal powerplant configuration scenarios. A review of legal and institutional issues regarding geothermal development coupled with water development will also be included.

A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

NASA Astrophysics Data System (ADS)

Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

2016-04-01

Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

The Zugspitze radiative closure experiment for quantifying water vapor absorption over the terrestrial and solar infrared - Part 1: Setup, uncertainty analysis, and assessment of far-infrared water vapor continuum

NASA Astrophysics Data System (ADS)

Sussmann, Ralf; Reichert, Andreas; Rettinger, Markus

2016-09-01

Quantitative knowledge of water vapor radiative processes in the atmosphere throughout the terrestrial and solar infrared spectrum is still incomplete even though this is crucial input to the radiation codes forming the core of both remote sensing methods and climate simulations. Beside laboratory spectroscopy, ground-based remote sensing field studies in the context of so-called radiative closure experiments are a powerful approach because this is the only way to quantify water absorption under cold atmospheric conditions. For this purpose, we have set up at the Zugspitze (47.42° N, 10.98° E; 2964 m a.s.l.) a long-term radiative closure experiment designed to cover the infrared spectrum between 400 and 7800 cm-1 (1.28-25 µm). As a benefit for such experiments, the atmospheric states at the Zugspitze frequently comprise very low integrated water vapor (IWV; minimum = 0.1 mm, median = 2.3 mm) and very low aerosol optical depth (AOD = 0.0024-0.0032 at 7800 cm-1 at air mass 1). All instruments for radiance measurements and atmospheric-state measurements are described along with their measurement uncertainties. Based on all parameter uncertainties and the corresponding radiance Jacobians, a systematic residual radiance uncertainty budget has been set up to characterize the sensitivity of the radiative closure over the whole infrared spectral range. The dominant uncertainty contribution in the spectral windows used for far-infrared (FIR) continuum quantification is from IWV uncertainties, while T profile uncertainties dominate in the mid-infrared (MIR). Uncertainty contributions to near-infrared (NIR) radiance residuals are dominated by water vapor line parameters in the vicinity of the strong water vapor bands. The window regions in between these bands are dominated by solar Fourier transform infrared (FTIR) calibration uncertainties at low NIR wavenumbers, while uncertainties due to AOD become an increasing and dominant contribution towards higher NIR wavenumbers

Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

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

NONE

This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. Themore » characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region of reference.« less

Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

NASA Astrophysics Data System (ADS)

1994-10-01

This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. The characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region.

Work with Us | Geothermal Technologies | NREL

Science.gov Websites

work with us and leverage our geothermal research, facilities, and expertise. Contact Us Photo of develop, test, and evaluate geothermal technologies. Commercialize Your Technology Accelerate the transfer

Geothermal Development and the Use of Categorical Exclusions (Poster)

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

Levine, A.; Young, K. R.

2014-09-01

The federal environmental review process under the National Environmental Policy Act of 1969 (NEPA) can be complex and time consuming. Currently, a geothermal developer may have to complete the NEPA process multiple times during the development of a geothermal project. One mechanism to reduce the timeframe of the federal environmental review process for activities that do not have a significant environmental impact is the use of Categorical Exclusions (CXs), which can exempt projects from having to complete an Environmental Assessment or Environmental Impact Statement. This study focuses primarily on the CX process and its applicability to geothermal exploration. In thismore » paper, we Provide generalized background information on CXs, including previous NEPA reports addressing CXs, the process for developing CXs, and the role of extraordinary circumstances; Examine the history of the Bureau of Land Management's (BLM) geothermal CXs;Compare current CXs for oil, gas, and geothermal energy; Describe bills proposing new statutory CXs; Examine the possibility of standardizing geothermal CXs across federal agencies; and Present analysis from the Geothermal NEPA Database and other sources on the potential for new geothermal exploration CXs. As part of this study, we reviewed Environmental Assessments (EAs) conducted in response to 20 geothermal exploration drilling permit applications (Geothermal Drilling Permits or Notices of Intents) since the year 2001, the majority of which are from the last 5 years. All 20 EAs reviewed for this study resulted in a Finding of No Significant Impact (FONSI). While many of these FONSI's involved proponent proposed or federal agency required mitigation, this still suggests it may be appropriate to create or expand an exploration drilling CX for geothermal, which would have a significant impact on reducing geothermal exploration timelines and up-front costs. Ultimately, federal agencies tasked with permitting and completing

Geothermal Energy; (USA)

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

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.

Compilation of geothermal information: exploration

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

Not Available

1978-01-01

The Database for Geothermal Energy Exploration and Evaluation is a printout of selected references to publications covering the development of geothermal resources from the identification of an area to the production of elecric power. This annotated bibliography contains four sections: references, author index, author affiliation index, and descriptor index.

Multipurpose Use of Geothermal Energy

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

Lienau, Paul J.; Lund, John W.

1974-10-09

The conference was organized to review the non-electric, multipurpose uses of geothermal energy in Hungary, Iceland, New Zealand, United States and the USSR. The international viewpoint was presented to provide an interchange of information from countries where non-electric use of geothermal energy has reached practical importance.

Federal Geothermal Research Program Update Fiscal Year 2000

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

Renner, J.L.

2001-08-15

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 hydrothermalmore » 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.« less

The nature of magmatism at Palinpinon geothermal field, Negros Island, Philippines: implications for geothermal activity and regional tectonics

NASA Astrophysics Data System (ADS)

Rae, Andrew J.; Cooke, David R.; Phillips, David; Zaide-Delfin, Maribel

2004-01-01

The Palinpinon geothermal field, Negros Island, Philippines is a high-temperature, liquid-dominated geothermal system in an active island-arc volcanic setting. This paper presents a regional context for the Palinpinon geology, discusses the petrogenetic evolution of magmatism in the district and assesses the genetic relationships between intrusion and geothermal circulation. The oldest rock formation, the Lower Puhagan Volcanic Formation (Middle Miocene), is part of a volcanic sequence that is traceable throughout the Visayas region and is related to subduction of the Sulu Sea oceanic basin in a southeasterly direction beneath the Sulu arc. Late Miocene to Early Pliocene times mark a period of regional subsidence and marine sedimentation. A thick sequence of calcareous sediments (Okoy Formation) was deposited during this period. Magmatism in Early Pliocene to Recent times coincided with commencement of subduction at the Negros-Sulu Arc. This produced basaltic andesites and andesites belonging to the Southern Negros and Cuernos Volcanic Formations. During this time the Puhagan dikes and the Nasuji Pluton intruded Middle Miocene, Late Miocene and Early-Late Pliocene formations. Based on radiogenic ( 40Ar/ 39Ar) dating of hornblende, the Puhagan dikes are 4.1-4.2 Ma and the Nasuji Pluton 0.3-0.7 Ma. This age difference confirms these intrusions are not genetically related. The Early Pliocene age of the Puhagan dikes also confirms they are not the heat source for the current geothermal system and that a much younger intrusion is situated beyond drill depths. Igneous rock formations in southern Negros are the products of regional island-arc magmatism with medium K, calc-alkaline, basaltic to dacitic compositions. Their adakitic affinity implies that the melting of subducted oceanic basalt has influenced magmatism in this region. Considering the regional tectonic history the most likely scenarios for the generation of slab melts are: (1) during the Middle Miocene, by the

Low-grade geothermal energy conversion by organic Rankine cycle turbine generator

NASA Astrophysics Data System (ADS)

Zarling, J. P.; Aspnes, J. D.

Results of a demonstration project which helped determine the feasibility of converting low-grade thermal energy in 49 C water into electrical energy via an organic Rankine cycle 2500 watt (electrical) turbine-generator are presented. The geothermal source which supplied the water is located in a rural Alaskan village. The reasons an organic Rankine cycle turbine-generator was investigated as a possible source of electric power in rural Alaska are: (1) high cost of operating diesel-electric units and their poor long-term reliability when high-quality maintenance is unavailable and (2) the extremely high level of long-term reliability reportedly attained by commercially available organic Rankine cycle turbines. Data is provided on the thermal and electrical operating characteristics of an experimental organic Rankine cycle turbine-generator operating at a uniquely low vaporizer temperature.

Crafting regulations in emerging geothermal countries: The Peru example

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

Armstrong, A.J.

1996-12-31

Conventional wisdom holds that no prudent investor or lender will ante up a penny of investment money in a geothermal project unless and until there is a geothermal resources law in place. Since every law depends on a regulatory regime to make the law work in actual practice, implemented regulations are equally important conditions precedent for geothermal development. In recognition of the importance of assisting geothermal regulatory development in the emerging geothermal countries of Latin America, during the 1995 to 1996 timeframe, the Geothermal Energy Association has acted in an advisory capacity to the Ministry of Energy and Mines ofmore » Peru, in the drafting of geothermal regulations for Peru. These regulations are designed to promote developmental investment in the geothermal resources of Peru, while simultaneously establishing reasonable standards for the protection of the people and the environment of the country. While these regulations are specific to Peru, they may well serve as a model for other countries of Latin America. Thus, the lessons learned in crafting the Peru regulatory regime may have applicability in other countries in which the geothermal industry is now working or may work in the future.« less

Geothermal Program Review XI: proceedings. Geothermal Energy - The Environmental Responsible Energy Technology for the Nineties

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

Not Available

1993-10-01

These proceedings contain papers pertaining to current research and development of geothermal energy in the USA. The seven sections of the document are: Overview, The Geysers, Exploration and Reservoir Characterization, Drilling, Energy Conversion, Advanced Systems, and Potpourri. The Overview presents current DOE energy policy and industry perspectives. Reservoir studies, injection, and seismic monitoring are reported for the geysers geothermal field. Aspects of geology, geochemistry and models of geothermal exploration are described. The Drilling section contains information on lost circulation, memory logging tools, and slim-hole drilling. Topics considered in energy conversion are efforts at NREL, condensation on turbines and geothermal materials.more » Advanced Systems include hot dry rock studies and Fenton Hill flow testing. The Potpourri section concludes the proceedings with reports on low-temperature resources, market analysis, brines, waste treatment biotechnology, and Bonneville Power Administration activities. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.« less

JEDI Geothermal Model | Jobs and Economic Development Impact Models | NREL

Science.gov Websites

Geothermal Model JEDI Geothermal Model The Jobs and Economic Development Impacts (JEDI) Geothermal Model allows users to estimate economic development impacts from geothermal projects and includes

The significance of "geothermal microzonation" for the correct planning of low-grade source geothermal systems

NASA Astrophysics Data System (ADS)

Viccaro, Marco; Pezzino, Antonino; Belfiore, Giuseppe Maria; Campisano, Carlo

2016-04-01

Despite the environmental-friendly energy systems are solar thermal technologies, photovoltaic and wind power, other advantageous technologies exist, although they have not found wide development in countries such as Italy. Given the almost absent environmental impact and the rather favorable cost/benefit ratio, low-enthalpy geothermal systems are, however, likely to be of strategic importance also in Italy during the next years. The importance of geology for a sustainable exploitation of the ground through geothermal systems from low-grade sources is becoming paramount. Specifically, understanding of the lithological characteristics of the subsurface along with structures and textures of rocks is essential for a correct planning of the probe/geo-exchanger field and their associated ground source heat pumps. The complex geology of Eastern Sicily (Southern Italy), which includes volcanic, sedimentary and metamorphic units over limited extension, poses the question of how thermal conductivity of rocks is variable at the scale of restricted areas (even within the same municipality). This is the innovative concept of geothermal microzonation, i.e., how variable is the geothermal potential as a function of geology at the microscale. Some pilot areas have been therefore chosen to test how the geological features of the subsurface can influence the low-enthalpy geothermal potential of an area. Our geologically based evaluation and micro-zonation of the low-grade source geothermal potential of the selected areas have been verified to be fundamental for optimization of all the main components of a low-enthalpy geothermal system. Saving realization costs and limiting the energy consumption through correct sizing of the system are main ambitions to have sustainable development of this technology with intensive utilization of the subsurface. The variegated territory of countries such as Italy implies that these goals can be only reached if, primarily, the geological features

DARPA Workshop on Geothermal Energy for Military Operations

DTIC Science & Technology

2010-05-01

is administered by its Geothermal Program Office (GPO) at the Navy Air Weapons Station, China Lake, CA. GPO manages the Coso Geo- thermal Field at...advanced geothermal technologies might reduce the risk and cost to the point where the U.S. military would be able to take advantage. Supplying geothermal...was con- vened to explore whether investment in advanced geothermal technologies might reduce the risk and cost to the point where the U.S. military

Sulphur isotope applications in two Philippine geothermal systems

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

Bayon, F.E.B.

1996-12-31

A general and very preliminary study of sulphur isotope geochemistry is presented in this paper. Data from the Mt. Apo and Palinpinon geothermal fields are used to demonstrate the use of sulphur isotopes in geothermometry and correlation of sulphur species. Sulphur and oxygen isotope geothermometers applied to Mt. Apo data show very good agreement with temperatures estimated using other established geothermometers, as well as bore measured temperatures. This signifies that sulphur isotopes in S-species in fluids of the Mt. Apo hydrothermal system are in equilibrium at drilled depths. In Palinpinon, on the other hand, temperature estimates from fluid and mineralmore » sulphur isotope geothermometry calculations do not agree with, and are commonly higher than, well measured temperatures and temperatures estimated from other geothermometers. Sulphur isotopes in the presently-exploited Palinpinon fluid are not in equilibrium, and sulphur isotope geothermometry may be reflective of isotopic equilibrium of the deeper portions of the hydrothermal system. Dissolved sulphate in both the Palinpinon and Mt. Apo geothermal fluids appear to originate from the disproportionation of magmatic SO{sub 2} at temperatures below 400{degrees}C. Hydrogen sulphide in well discharge fluids are dominantly directly derived from the magma, with a minor amount coming from SO{sub 2} disproportionation.« less

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…

Ground heat flux and power sources of low-enthalpy geothermal systems

NASA Astrophysics Data System (ADS)

Bayer, Peter; Blum, Philipp; Rivera, Jaime A.

2015-04-01

Geothermal heat pumps commonly extract energy from the shallow ground at depths as low as approximately 400 m. Vertical borehole heat exchangers are often applied, which are seasonally operated for decades. During this lifetime, thermal anomalies are induced in the ground and surface-near aquifers, which often grow over the years and which alleviate the overall performance of the geothermal system. As basis for prediction and control of the evolving energy imbalance in the ground, focus is typically set on the ground temperatures. This is reflected in regulative temperature thresholds, and in temperature trends, which serve as indicators for renewability and sustainability. In our work, we examine the fundamental heat flux and power sources, as well as their temporal and spatial variability during geothermal heat pump operation. The underlying rationale is that for control of ground temperature evolution, knowledge of the primary heat sources is fundamental. This insight is also important to judge the validity of simplified modelling frameworks. For instance, we reveal that vertical heat flux from the surface dominates the basal heat flux towards a borehole. Both fluxes need to be accounted for as proper vertical boundary conditions in the model. Additionally, the role of horizontal groundwater advection is inspected. Moreover, by adopting the ground energy deficit and long-term replenishment as criteria for system sustainability, an uncommon perspective is adopted that is based on the primary parameter rather than induced local temperatures. In our synthetic study and dimensionless analysis, we demonstrate that time of ground energy recovery after system shutdown may be longer than what is expected from local temperature trends. In contrast, unrealistically long recovery periods and extreme thermal anomalies are predicted without account for vertical ground heat fluxes and only when the energy content of the geothermal reservoir is considered.

Geothermal Monitoring in Yellowstone National Park

NASA Astrophysics Data System (ADS)

Heasler, H. P.; Jaworowski, C.; Susong, D. D.; Lowenstern, J. B.

2007-12-01

When the first exploring parties surveyed the Yellowstone region in the late 19th Century, it was the geologic wonders - geysers, hot springs, mudpots, fumaroles - that captured their imaginations. Because of these treasures, the U.S. Congress set aside and dedicated this land of "natural curiosities" as the world's first "public pleasuring ground". Protection of Yellowstone's unique geothermal features is a key mission of Yellowstone National Park as mandated by U. S. Congressional law. In response to that mandate, the Yellowstone National Park Geology Program developed a peer-reviewed, Geothermal Monitoring Plan in 2003. With partial Congressional funding of the Plan in 2005, implementation of a scientific monitoring effort began. Yellowstone's scientific geothermal monitoring effort includes the acquisition of time-temperature data using electronic data loggers, basic water quality data, chloride flux data, estimates of radiative heat flux using airborne, thermal infrared imagery, geothermal gas monitoring, and the monitoring of groundwater wells. Time- temperature data are acquired for geysers, hot springs, steam vents, wells, rivers, and the ground. Uses of the time-temperature data include public safety, calibrating airborne thermal infrared-imagery, monitoring selected thermal features for potential hydrothermal explosions, and determining the spatial and temporal changes in thermal areas. Since 2003, upgrades of Yellowstone's stream gaging network have improved the spatial and temporal precision of the chloride flux, water quality, and groundwater components of the Geothermal Monitoring Plan. All of these methods serve both for geothermal monitoring and volcano monitoring as part of the Yellowstone Volcano Observatory. A major component of the Geothermal Monitoring Plan is remote sensing of the Yellowstone volcano and its active hydrothermal areas at various scales. The National Center for Landscape Fire Analysis at the University of Montana and the USDA

Geothermal Exploration Case Studies on OpenEI (Presentation)

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

Young, K.; Bennett, M.; Atkins, D.

2014-03-01

The U.S. Geological Survey (USGS) resource assessment (Williams et al., 2008) outlined a mean 30 GWe of undiscovered hydrothermal resource in the western United States. One goal of the U.S. Department of Energy's (DOE) Geothermal Technology Office (GTO) is to accelerate the development of this undiscovered resource. DOE has focused efforts on helping industry identify hidden geothermal resources to increase geothermal capacity in the near term. Increased exploration activity will produce more prospects, more discoveries, and more readily developable resources. Detailed exploration case studies akin to those found in oil and gas (e.g. Beaumont and Foster, 1990-1992) will give developersmore » central location for information gives models for identifying new geothermal areas, and guide efficient exploration and development of these areas. To support this effort, the National Renewable Energy Laboratory (NREL) has been working with GTO to develop a template for geothermal case studies on the Geothermal Gateway on OpenEI. In 2012, the template was developed and tested with two case studies: Raft River Geothermal Area (http://en.openei.org/wiki/Raft_River_Geothermal_Area) and Coso Geothermal Area (http://en.openei.org/wiki/Coso_Geothermal_Area). In 2013, ten additional case studies were completed, and Semantic MediaWiki features were developed to allow for more data and the direct citations of these data. These case studies are now in the process of external peer review. In 2014, NREL is working with universities and industry partners to populate additional case studies on OpenEI. The goal is to provide a large enough data set to start conducting analyses of exploration programs to identify correlations between successful exploration plans for areas with similar geologic occurrence models.« less

Unified Application Vapor Screen Flow Visualization and Pressure Sensitive Paint Measurement Techniques to Vortex- and Shock Wave-Dominated Flow Fields

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2008-01-01

Laser vapor screen (LVS) flow visualization and pressure sensitive paint (PSP) techniques were applied in a unified approach to wind tunnel testing of slender wing and missile configurations dominated by vortex flows and shock waves at subsonic, transonic, and supersonic speeds. The off-surface cross-flow patterns using the LVS technique were combined with global PSP surface static pressure mappings to characterize the leading-edge vortices and shock waves that coexist and interact at high angles of attack (alpha). The synthesis of LVS and PSP techniques was also effective in identifying the significant effects of passive surface porosity and the presence of vertical tail surfaces on the flow topologies. An overview is given of LVS and PSP applications in selected experiments on small-scale models of generic slender wing and missile configurations in the NASA Langley Research Center (NASA LaRC) Unitary Plan Wind Tunnel (UPWT) and 8-Foot Transonic Pressure Tunnel (8-Foot TPT).

Water vapor distribution in protoplanetary disks

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

Du, Fujun; Bergin, Edwin A., E-mail: fdu@umich.edu

Water vapor has been detected in protoplanetary disks. In this work, we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorption by water of Lyα photons, since the Lyα line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapormore » with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more extended distribution of warm water vapor, while dust growth and settling tends to reduce the amount of warm water vapor. Based on typical assumptions regarding the elemental oxygen abundance and the water chemistry, the column density of warm water vapor can be as high as 10{sup 22} cm{sup –2}. A small amount of hot water vapor with temperature higher than ∼300 K exists in a more extended region in the upper atmosphere of the disk. Cold water vapor with temperature lower than 100 K is distributed over the entire disk, produced by photodesorption of the water ice.« less

Energy 101: Geothermal Heat Pumps

ScienceCinema

None

2018-02-13

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.

Geothermal Progress Monitor, report No. 13

NASA Astrophysics Data System (ADS)

1992-02-01

Geothermal Progress Monitor (GPM) Issue No. 13 documents that most related factors favor the growth and geographic expansion of the US geothermal industry and that the industry is being technologically prepared to meet those challenges into the next century. It is the function of GPM to identify trends in the use of this resource and to provide a historical record of its development pathway. The information assembled for this issue of GPM indicates that trends in the use of geothermal energy in this country and abroad continue to be very positive. Favorable sentiments as well as pertinent actions on the part of both government and industry are documented in almost every section. The FEDERAL BEAT points up that the National Energy Strategy (NES) developed at the highest levels of the US government recognizes the environmental and energy security advantages of renewable energy, including geothermal, and makes a commitment to 'substantial diversification' of US sources of energy. With the announcement of the construction of several new plants and plant expansions, the INDUSTRY SCENE illustrates industry's continued expectation that the use of geothermal energy will prove profitable to investors. In DEVELOPMENT STATUS, spokesmen for both an investor-owned utility and a major geothermal developer express strong support for geothermal power, particularly emphasizing its environmental advantages. DEVELOPMENT STATUS also reports that early successes have been achieved by joint DOE/industry R & D at The Geysers which will have important impacts on the future management of this mature field. Also there is increasing interest in hot dry rock. Analyses conducted in support of the NES indicate that if all the postulated technology developments occur in this field, the price of energy derived from hot dry rock in the US could drop.

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.

Geothermal Workforce Education, Development, and Retention

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

Calvin, Wendy

2014-03-31

The work funded under this award was the formation of a National Geothermal Academy to develop the human resources that will be needed to transform and grow the US energy infrastructure to achieve the utilization of America’s vast geothermal resource base. The NGA has worked to create the new intellectual capital that will be needed by centralizing and unifying our national assets. The basic idea behind the Academy was to create a centrally located, convening organization for developing and conducting instructional programs in geothermal science and technology to educate and train the next generation of US scientists, engineers, plant operators,more » technicians, and policy makers. Broad participation of staff, faculty, and students from a consortium of US universities along with scientists and other professionals from industry and national laboratories were utilized. Geothermal experts from the US and other countries were recruited to serve as instructors to develop relevant curricula. Given the long history of geothermal development in the US, there is a large group of experienced individuals who effectively hold the “corporate memory” of geothermal development in the US, many of whom are nearing the end of their professional careers, while some have recently retired. We planned to capture this extremely valuable intellectual resource by engaging a number of these individuals in developing course curricula, leading training workshops, providing classroom instruction and mentoring future instructors.« less

NREL: Renewable Resource Data Center - Geothermal Resource Data

Science.gov Websites

sites Data related to geothermal technology and energy Resource Data The following geothermal resource data collections can be found in the Renewable Resource Data Center (RReDC). Geothermal Resource Data The datasets on this page offer a qualitative

30 CFR 1202.351 - Royalties on geothermal resources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Royalties on geothermal resources. 1202.351 Section 1202.351 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE ROYALTIES Geothermal Resources § 1202.351 Royalties on geothermal resources. (a)(1...

30 CFR 1202.351 - Royalties on geothermal resources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Royalties on geothermal resources. 1202.351 Section 1202.351 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE ROYALTIES Geothermal Resources § 1202.351 Royalties on geothermal resources. (a)(1...

30 CFR 1202.351 - Royalties on geothermal resources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Royalties on geothermal resources. 1202.351 Section 1202.351 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE ROYALTIES Geothermal Resources § 1202.351 Royalties on geothermal resources. (a)(1...

Fracture development within a stratovolcano: The Karaha-Telaga Bodas geothermal field, Java volcanic arc

USGS Publications Warehouse

Nemcok, M.; Moore, J.N.; Allis, R.; McCulloch, J.

2004-01-01

Karaha-Telaga Bodas, a vapour-dominated geothermal system located in an active volcano in western Java, is penetrated by more than two dozen deep geothermal wells reaching depths of 3 km. Detailed paragenetic and fluid-inclusion studies from over 1000 natural fractures define the liquid-dominated, transitional and vapour-dominated stages in the evolution of this system. The liquid-dominated stage was initiated by ashallow magma intrusion into the base of the volcanic cone. Lava and pyroclastic flows capped a geothermal system. The uppermost andesite flows were only weakly fractured due to the insulating effect of the intervening altered pyroclastics, which absorbed the deformation. Shear and tensile fractures that developed were filled with carbonates at shallow depths, and by quartz, epidote and actinolite at depths and temperatures over 1 km and 300??C. The system underwent numerous cycles of overpressuring, documented by subhorizontal tensile fractures, anastomosing tensile fracture patterns and implosion breccias. The development of the liquidsystem was interrupted by a catastrophic drop in fluid pressures. As the fluids boiled in response to this pressure drop, chalcedony and quartz were selectively deposited in fractures that had the largest apertures and steep dips. The orientations of these fractures indicate that the escaping overpressured fluids used the shortest possible paths to the surface. Vapour-dominated conditions were initiated at this time within a vertical chimney overlying the still hot intrusion. As pressures declined, these conditions spread outward to form the marginal vapour-dominated region encountered in the drill holes. Downward migration of the chimney, accompanied by growth of the marginal vapour-dominated regime, occurred as the intrusion cooled and the brittle-ductile transition migrated to greater depths. As the liquids boiled off, condensate that formed at the top of the vapour-dominated zone percolated downward and low

Geothermal power development in Hawaii. Volume 1. Review and analysis

NASA Astrophysics Data System (ADS)

1982-06-01

The history of geothermal exploration in Hawaii is reviewed briefly. The nature and occurrences of geothermal resources are presented island by island. An overview of geothermal markets is presented. Other topics covered are: potential markets of the identified geothermal areas, well drilling technology, hydrothermal fluid transport, overland and submarine electrical transmission, community aspects of geothermal development, legal and policy issues associated with mineral and land ownership, logistics and infrastructure, legislation and permitting, land use controls, Regulation 8, public utilities commission, political climate and environment, state plans, county plans, geothermal development risks, and business planning guidelines.

Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

NASA Astrophysics Data System (ADS)

Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

2016-04-01

In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was

Symposium in the field of geothermal energy

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

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 bemore » 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.« less

Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

PubMed

Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

2018-02-01

The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

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)

Age and thermal history of the Geysers plutonic complex (felsite unit), Geysers geothermal field, California: A 40Ar/39Ar and U-Pb study

USGS Publications Warehouse

Dalrymple, G.B.; Grove, M.; Lovera, O.M.; Harrison, T.M.; Hulen, J.B.; Lanphere, M.A.

1999-01-01

Sixty-nine ion microprobe spot analyses of zircons from four granite samples from the plutonic complex that underlies the Geysers geothermal field yield 207Pb/206Pb vs. 238U/206Pb concordia ages ranging from 1.13 ?? 0.04 Ma to 1.25 ?? 0.04 (1??) Ma. The weighted mean of the U/Pb model ages is 1.18 ?? 0.03 Ma. The U-Pb ages coincide closely with 40Ar/39Ar age spectrum plateau and 'terminal' ages from coexisting K-feldspars and with the eruption ages of overlying volcanic rocks. The data indicate that the granite crystallized at 1.18 Ma and had cooled below 350??C by ~0.9-1.0 Ma. Interpretation of the feldspar 40Ar/39Ar age data using multi-diffusion domain theory indicates that post-emplacement rapid cooling was succeeded either by slower cooling from 350??to 300??C between 1.0 and 0.4 Ma or transitory reheating to 300-350??C at about 0.4-0.6 Ma. Subsequent rapid cooling to below 260??C between 0.4 and 0.2 Ma is in agreement with previous proposals that vapor-dominated conditions were initiated within the hydrothermal system at this time. Heat flow calculations constrained with K-feldspar thermal histories and the present elevated regional heat flow anomaly demonstrate that appreciable heat input from sources external to the known Geysers plutonic complex is required to maintain the geothermal system. This requirement is satisfied by either a large, underlying, convecting magma chamber (now solidified) emplaced at 1.2 Ma or episodic intrusion of smaller bodies from 1.2 to 0.6 Ma.

STABLE ISOTOPE GEOCHEMISTRY OF THERMAL FLUIDS FROM LASSEN VOLCANIC NATIONAL PARK, CALIFORNIA.

USGS Publications Warehouse

Janik, Cathy J.; Nehring, Nancy L.; Truesdell, Alfred H.

1983-01-01

In the Lassen vapor-dominated geothermal system, surface manifestations of thermal fluids at high elevations (1800-2500 m) include superheated and drowned fumaroles, steam-heated acid-sulfate hot springs, and low-chloride bicarbonate springs. Neutral high-chloride hot water discharges at lower elevations. Deuterium and oxygen-18 data establish genetic connections between these fluids and with local meteoric waters. Steam from the highest temperature fumarole at Bumpass Hell and water from the highest chloride hot spring have isotopic compositions corresponding to vapor-liquid equilibrium at 235 degree C. Carbon and sulfur isotope data suggest that the CO//2 and H//2S in the system did not entirely originate from magmatic sources, but probably include contributions from thermal metamorphism of marine sedimentary rocks. Observations suggest that carbon and sulfur isotope variations are useful indicators of gas reactions and flow paths in geothermal systems. Refs.

Raft River Geothermal Area Data Models - Conceptual, Logical and Fact Models

DOE Data Explorer

Cuyler, David

2012-07-19

Conceptual and Logical Data Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses at Raft River a. Logical Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 b. Fact Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 Derived from Tables, Figures and other Content in Reports from the Raft River Geothermal Project: "Technical Report on the Raft River Geothermal Resource, Cassia County, Idaho," GeothermEx, Inc., August 2002. "Results from the Short-Term Well Testing Program at the Raft River Geothermal Field, Cassia County, Idaho," GeothermEx, Inc., October 2004.

Geothermal Power/Oil & Gas Coproduction Opportunity

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

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.

Geoelectrical Characterization of the Punta Banda System: A Possible Structural Control for the Geothermal Anomalies

NASA Astrophysics Data System (ADS)

Arango-Galvan, C.; Flores-Marquez, E.; Prol-Ledesma, R.; Working Group, I.

2007-05-01

The lack of sufficient drinking water in México has become a very serious problem, especially in the northern desert regions of the country. In order to give a real solution to this phenomenon the IMPULSA research program has been created to develope novel technologies based on desalination of sea and brackish water using renewable sources of energy to face the problem. The Punta Banda geothermal anomaly is located towards the northern part of Baja California Peninsula (Mexico). High water temperatures in some wells along the coast depicted a geothermal anomaly. An audiomagnetotelluric survey was carried out in the area as a preliminary study, both to understand the process generating these anomalous temperatures and to assess its potential exploitation to supply hot water to desalination plants. Among the electromagnetic methods, the audiomagnetotellurics (AMT) method is appropriated for deep groundwater and geothermal studies. The survey consisted of 27 AMT stations covering a 5 km profile along the Agua Blanca Fault. The employed array allowed us to characterize the geoelectrical properties of the main structures up to 500 m depth. Two main geoelectrical zones were identified: 1) a shallow low resistivity media located at the central portion of the profile, coinciding with the Maneadero valley and 2) two high resitivity structures bordering the conductive zone possibly related to NS faulting, already identified by previous geophysical studies. These results suggest that the main geothermal anomalies are controlled by the dominant structural regime in the zone.

Aerated drilling cutting transport analysis in geothermal well

NASA Astrophysics Data System (ADS)

Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

2017-12-01

Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

Geothermal Produced Fluids: Characteristics, Treatment Technologies, and Management Options

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

Finster, Molly; Clark, Corrie; Schroeder, Jenna

2015-10-01

Geothermal power plants use geothermal fluids as a resource and create waste residuals as part of the power generation process. Both the geofluid resource and the waste stream are considered produced fluids. The chemical and physical nature of produced fluids can have a major impact on the geothermal power industry and can influence the feasibility of geothermal power development, exploration approaches, power plant design, operating practices, and the reuse or disposal of residuals. In general, produced fluids include anything that comes out of a geothermal field and that subsequently must be managed on the surface. These fluids vary greatly dependingmore » on the geothermal reservoir being harnessed, power plant design, and the life cycle stage in which the fluid exists, but generally include water and fluids used to drill geothermal wells, fluids used to stimulate wells in enhanced geothermal systems, and makeup and/or cooling water used during operation of a geothermal power plant. Additional geothermal-related produced fluids include many substances that are similar to waste streams from the oil and gas industry, such as scale, flash tank solids, precipitated solids from brine treatment, hydrogen sulfide, and cooling-tower-related waste. This review paper aims to provide baseline knowledge on specific technologies and technology areas associated with geothermal power production. Specifically, this research focused on the management techniques related to fluids produced and used during the operational stage of a geothermal power plant; the vast majority of which are employed in the generation of electricity. The general characteristics of produced fluids are discussed. Constituents of interest that tend to drive the selection of treatment technologies are described, including total dissolved solids, noncondensable gases, scale and corrosion, silicon dioxide, metal sulfides, calcium carbonate, corrosion, metals, and naturally occurring radioactive material

The Pawsey Supercomputer geothermal cooling project

NASA Astrophysics Data System (ADS)

Regenauer-Lieb, K.; Horowitz, F.; Western Australian Geothermal Centre Of Excellence, T.

2010-12-01

The Australian Government has funded the Pawsey supercomputer in Perth, Western Australia, providing computational infrastructure intended to support the future operations of the Australian Square Kilometre Array radiotelescope and to boost next-generation computational geosciences in Australia. Supplementary funds have been directed to the development of a geothermal exploration well to research the potential for direct heat use applications at the Pawsey Centre site. Cooling the Pawsey supercomputer may be achieved by geothermal heat exchange rather than by conventional electrical power cooling, thus reducing the carbon footprint of the Pawsey Centre and demonstrating an innovative green technology that is widely applicable in industry and urban centres across the world. The exploration well is scheduled to be completed in 2013, with drilling due to commence in the third quarter of 2011. One year is allocated to finalizing the design of the exploration, monitoring and research well. Success in the geothermal exploration and research program will result in an industrial-scale geothermal cooling facility at the Pawsey Centre, and will provide a world-class student training environment in geothermal energy systems. A similar system is partially funded and in advanced planning to provide base-load air-conditioning for the main campus of the University of Western Australia. Both systems are expected to draw ~80-95 degrees C water from aquifers lying between 2000 and 3000 meters depth from naturally permeable rocks of the Perth sedimentary basin. The geothermal water will be run through absorption chilling devices, which only require heat (as opposed to mechanical work) to power a chilled water stream adequate to meet the cooling requirements. Once the heat has been removed from the geothermal water, licensing issues require the water to be re-injected back into the aquifer system. These systems are intended to demonstrate the feasibility of powering large-scale air

Application of geochemical techniques to deduce the reservoir performance of the Palinpinon Geothermal Field, Philippines - an update

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

Ramos-Candelaria, M.N.; Garcia, S.E.; Hermoso, D.Z.

1997-12-31

Regular monitoring of various geochemical parameters in the water and vapor phases of the production wells at the Palinpinon I and II sectors of the Southern Negros Geothermal Field have been useful in the identification of the dominant reservoir processes occurring related to the present exploitation strategy. Observed geochemical and physical changes in the output of production wells have dictated production and injection strategies adopted to maximize production to meet the steam requirements of the power plant. Correlation of both physical and chemical data have identified the following reservoir processes: (1) Injection breakthrough via the Ticala Fault of the highlymore » mineralized (Cl {approximately}8,000-10,500 mg/kg), isotopically enriched ({delta}{sup 18}O = -3.00{per_thousand}, {delta}{sup 2} H = -39{per_thousand}), and gas depleted brine for wells in the SW and central Puhagan. Injection breakthrough is also occurring in Palinpinon II and has resulted in temperature drops of 5-10{degrees}C.2. Pressure drawdown enhanced boiling in the liquid reservoir with steam separation of 220-240{degrees}C, feeding wells tapping the natural steam zone. However, enhanced drawdown has induced the entry of shallow acid steam condensate fluids in some wells (e.g. OK-7, PN-29D, PN-18D), which if not arrested could reduce production.« less

Middlesex Community College Geothermal Project

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

Klein, Jessie; Spaziani, Gina

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.

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.

Perspectives on geopressured resources within the geothermal program

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

Dibona, B.

1980-06-01

This work reviews the potential of geothermal energy in the U.S. Current sources of and uses for geothermal energy are described. The study outlines how geopressured resources fit into the geothermal program of the U.S. Department of Energy (DOE). Description of the program status includes progress in drilling and assessing geopressured resources. The Division of Geothermal Energy within DOE is responsible for geothermal resources comprising point heat sources (igneous); high heat flow regions such as those between the Sierras and the Rockies; radiogenic heat sources of moderate temperatures of the eastern U.S. coast; geopressured zones; and hot dry rock systems.more » Interest in these resources focuses on electric power production, direct heat application, and methane production from the geopressured aquifers.« less

The calculation of aquifer chemistry in hot-water geothermal systems

USGS Publications Warehouse

Truesdell, Alfred H.; Singers, Wendy

1974-01-01

The temperature and chemical conditions (pH, gas pressure, and ion activities) in a geothermal aquifer supplying a producing bore can be calculated from the enthalpy of the total fluid (liquid + vapor) produced and chemical analyses of water and steam separated and collected at known pressures. Alternatively, if a single water phase exists in the aquifer, the complete analysis (including gases) of a sample collected from the aquifer by a downhole sampler is sufficient to determine the aquifer chemistry without a measured value of the enthalpy. The assumptions made are that the fluid is produced from a single aquifer and is homogeneous in enthalpy and chemical composition. These calculations of aquifer chemistry involving large amounts of ancillary information and many iterations require computer methods. A computer program in PL-1 to perform these calculations is available from the National Technical Information Service as document PB-219 376.

Geothermal resources and energy complex use in Russia

NASA Astrophysics Data System (ADS)

Svalova, V.

2009-04-01

mineralization and propensity for scaling, the extraction of mineral components should be considered. The mineral-extraction direction is basic for geothermal waters, containing valuable components in industrial quantities. Thus, the ability to extract minerals is dependent upon the use and maturity of recovery technologies. For such waters the heat is an added product, which use can raise efficiency of basic mineral production processes and even to save fuel. The process of extraction of valuable components should be dominant in such systems. The most significant deposits of thermal waters represent the brines containing from 35 up to 400 and more g/l of salts. They are mineral raw materials for many chemical elements. Many brines can become deposits of valuable chemical elements: cesium, boron, strontium, tantalum, magnesium, calcium, tungsten, etc. Basically it is possible to recover iodine, bromine, boron, chloride salts of ammonium, potassium, sodium, calcium and magnesium from natural solutions using inexpensive technological solutions. Extraction of other chemical elements is complicated due to high cost of technology. There is a perspective method of ion-exchange pitches for selective extraction of certain components from natural waters. In a basis of the method there is the principle of selective sorption of ions of useful elements or their complexes in solutions with special compounds. Works of some scientific institutes in Russia strive to create the procedures of chemical processing of hydrothermal minerals to expand the spheres of its economic application. Many laboratory and natural tests on extraction of valuable components from thermal waters confirm the necessity and an opportunity of complex use of this nonconventional raw material. It is planned to recover I, Br, KCl, CaCl, NaCl from brines in Yaroslavl area. New methods of mineral and valuable elements extraction from industrial solutions are developed on the basis of biosorbent use.

Temperature gradient effects on vapor diffusion in partially-saturated porous media

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

Webb, S.W.

1999-07-01

Vapor diffusion in porous media in the presence of its own liquid may be enhanced due to pore-scale processes, such as condensation and evaporation across isolated liquid islands. Webb and Ho (1997) developed one-and two-dimensional mechanistic pore-scale models of these processes in an ideal porous medium. For isothermal and isobaric boundary conditions with a concentration gradient, the vapor diffusion rate was significantly enhanced by these liquid island processes compared to a dry porous media. The influence of a temperature gradient on the enhanced vapor diffusion rate is considered in this paper. The two-dimensional pore network model which is used inmore » the present study is shown. For partially-saturated conditions, a liquid island is introduced into the top center pore. Boundary conditions on the left and right sides of the model are specified to give the desired concentration and temperature gradients. Vapor condenses on one side of the liquid island and evaporates off the other side due to local vapor pressure lowering caused by the interface curvature, even without a temperature gradient. Rather than acting as an impediment to vapor diffusion, the liquid island actually enhances the vapor diffusion rate. The enhancement of the vapor diffusion rate can be significant depending on the liquid saturation. Vapor diffusion is enhanced by up to 40% for this single liquid island compared to a dry porous medium; enhancement factors of up to an order of magnitude have been calculated for other conditions by Webb and Ho (1997). The dominant effect on the enhancement factor is the concentration gradient; the influence of the temperature gradient is smaller. The significance of these results, which need to be confirmed by experiments, is that the dominant model of enhanced vapor diffusion (EVD) by Philip and deVries (1957) predicts that temperature gradients must exist for EVD to occur. If there is no temperature gradient, there is no enhancement. The present

Improving geothermal power plants with a binary cycle

NASA Astrophysics Data System (ADS)

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

2015-12-01

The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

Geothermal energy development in the Philippines: An overview

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

Sussman, D.; Javellana, S.P.; Benavidez, P.J.

1993-10-01

The Philippines is the third largest producer of geothermal electricity after the US and Mexico. Geothermal exploration was started in 1962, and the first large commercial power plants came on-line in 1979 in two fields. By 1984, four geothermal fields had a combined installed capacity of 890 MWe and in 1992 these plants supplied about 20% of the country`s electric needs. Geothermal energy development was stimulated in the mid-1970s by the oil crisis and rapidly growing power demand, government support, available foreign funding, and a combination of private and government investment and technical expertise. However, no new geothermal capacity hasmore » been added since 1984, despite the growing demand for energy and the continuing uncertainty in the supply of crude oil. The Philippines` geothermal capacity is expected to expand by 270--1,100 MWe by the end of 1999. Factors that will affect the rate growth in this decade include suitable legislation, environmental requirements, financing, degree of private involvement, politics, inter-island electric grid connections, and viability of the remaining prospects.« less

Detecting geothermal anomalies and evaluating LST geothermal component by combining thermal remote sensing time series and land surface model data

USGS Publications Warehouse

Romaguera, Mireia; Vaughan, R. Greg; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C. A.; van der Meer, F.D.

2018-01-01

This paper explores for the first time the possibilities to use two land surface temperature (LST) time series of different origins (geostationary Meteosat Second Generation satellite data and Noah land surface modelling, LSM), to detect geothermal anomalies and extract the geothermal component of LST, the LSTgt. We hypothesize that in geothermal areas the LSM time series will underestimate the LST as compared to the remote sensing data, since the former does not account for the geothermal component in its model.In order to extract LSTgt, two approaches of different nature (physical based and data mining) were developed and tested in an area of about 560 × 560 km2 centered at the Kenyan Rift. Pre-dawn data in the study area during the first 45 days of 2012 were analyzed.The results show consistent spatial and temporal LSTgt patterns between the two approaches, and systematic differences of about 2 K. A geothermal area map from surface studies was used to assess LSTgt inside and outside the geothermal boundaries. Spatial means were found to be higher inside the geothermal limits, as well as the relative frequency of occurrence of high LSTgt. Results further show that areas with strong topography can result in anomalously high LSTgt values (false positives), which suggests the need for a slope and aspect correction in the inputs to achieve realistic results in those areas. The uncertainty analysis indicates that large uncertainties of the input parameters may limit detection of LSTgt anomalies. To validate the approaches, higher spatial resolution images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data over the Olkaria geothermal field were used. An established method to estimate radiant geothermal flux was applied providing values between 9 and 24 W/m2 in the geothermal area, which coincides with the LSTgt flux rates obtained with the proposed approaches.The proposed approaches are a first step in estimating LSTgt

Tectonic and Structural Controls of Geothermal Activity in the Great Basin Region, Western USA

NASA Astrophysics Data System (ADS)

Faulds, J. E.; Hinz, N.; Kreemer, C. W.

2012-12-01

faults connect major structures and fluids can flow readily through highly fractured, dilational quadrants, and b) normal fault terminations or tip-lines (22%), where horse-tailing generates closely-spaced faults and increased permeability. Other settings include accommodation zones (i.e., belts of intermeshing, oppositely dipping normal faults; 8%), major range-front faults (5-6%), and pull-aparts in strike-slip faults (4%). In addition, Quaternary faults lie within or near most systems. The relative scarcity of geothermal systems along displacement-maxima of major normal faults may be due to reduced permeability in thick zones of clay gouge and periodic release of stress in major earthquakes. Step-overs, terminations, intersections, and accommodation zones correspond to long-term, critically stressed areas, where fluid pathways are more likely to remain open in networks of closely-spaced, breccia-dominated fractures. These findings may help guide future exploration efforts, especially for blind geothermal systems, which probably comprise the bulk of the geothermal resources in the Great Basin.

Energy Savings Potential and RD&D Opportunities for Non-Vapor-Compression HVAC Technologies

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

none,

While vapor-compression technologies have served heating, ventilation, and air-conditioning (HVAC) needs very effectively, and have been the dominant HVAC technology for close to 100 years, the conventional refrigerants used in vapor-compression equipment contribute to global climate change when released to the atmosphere. This Building Technologies Office report: --Identifies alternatives to vapor-compression technology in residential and commercial HVAC applications --Characterizes these technologies based on their technical energy savings potential, development status, non-energy benefits, and other factors affecting end-user acceptance and their ability to compete with conventional vapor-compression systems --Makes specific research, development, and deployment (RD&D) recommendations to support further development ofmore » these technologies, should DOE choose to support non-vapor-compression technology further.« less

Hydrogeological Modelling of the Geothermal Waters of Alaşehir in the Continental Rift Zone of the Gediz, Western Anatolia, Turkey

NASA Astrophysics Data System (ADS)

Ӧzgür, Nevzat; Bostancı, Yesim; Anilır Yürük, Ezgi

2017-12-01

In western Anatolia, Turkey, the continental rift zones of the Büyük Menderes, Küçük Menderes and Gediz were formed by extensional tectonic features striking E-W generally and representing a great number of active geothermal systems, epithermal mineralizations and volcanic rocks from Middle Miocene to recent. The geothermal waters are associated with the faults which strike preferentially NW-SE and NE-SW and locate diagonal to general strike of the rift zones of the Menderes Massif. These NW-SE and NE-SW striking faults were probably generated by compressional tectonic regimes which leads to the deformation of uplift between two extensional rift zones in the Menderes Massif. The one of these rift zones is Gediz which is distinguished by a great number of geothermal waters such as Alaşehir, Kurşunlu, Çamurlu, Pamukkale and Urganlı. The geothermal waters of Alaşehir form the biggest potential in the rift zone of Gediz with a capacity of about 100 to 200 MWe. Geologically, the gneisses from the basement rocks in the study area which are overlain by an Paleozoic to Mesozoic intercalation of mica schists, quartzites and marbles, a Miocene intercalation of conglomerates, sandstones and clay stones and Plio-Quaternary intercalation of conglomerates, sandstones and clay stones discordantly. In the study area, Paleozoic to Mesozoic quartzites and marbles form the reservoir rocks hydrogeologically. The geothermal waters anions with Na+K>Ca>Mg dominant cations and HCO3>Cl> dominant anions are of Na-HCO3 type and can be considered as partial equilibrated waters. According to the results of geochemical thermometers, the reservoir temperatures area of about 185°C in accordance with measured reservoir temperatures. Stabile isotopes of δ18O versus δ2H of geothermal waters of Alaşehir deviate from the meteoric water line showing an intensive water-rock interaction under high temperature conditions. These data are well correlated with the results of the

Estimate of radon exposure in geothermal spas in Poland.

PubMed

Walczak, Katarzyna; Olszewski, Jerzy; Zmyślony, Marek

2016-01-01

Geothermal waters may contain soluble, radioactive radon gas. Spa facilities that use geothermal water may be a source of an increased radiation dose to people who stay there. It has been necessary to assess the exposure to radon among people: workers and visitors of spa centers that use geothermal waters. In 2013, workers of the Nofer Institute of Occupational Medicine measured concentrations of radon over the geothermal water surfaces in 9 selected Polish spa centers which use geothermal water for recreational and medicinal purposes. The measurements were performed by active dosimetry using Lucas scintillation cells. According to our research, the doses received by the personnel in Polish geothermal spas are < 0.6 mSv/year. In 1 of the investigated spas, the estimated annual dose to the staff may exceed 3 mSv/year. In Polish geothermal spas, neither the workers nor the visitors are at risk of receiving doses that exceed the safe limits. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Sixteenth workshop on geothermal reservoir engineering: Proceedings

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

Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.

1991-01-25

The Sixteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23-25, 1991. The Workshop Banquet Speaker was Dr. Mohinder Gulati of UNOCAL Geothermal. Dr. Gulati gave an inspiring talk on the impact of numerical simulation on development of geothermal energy both in The Geysers and the Philippines. Dr. Gulati was the first recipient of The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy. Dr. Frank Miller presented the award. The registered attendance figure of one hundred fifteen participants was up slightly from last year. There were seven foreign countries represented: Iceland,more » Italy, Philippines, Kenya, the United Kingdom, Mexico, and Japan. As last year, papers on about a dozen geothermal fields outside the United States were presented. There were thirty-six papers presented at the Workshop, and two papers were submitted for publication only. Attendees were welcomed by Dr. Khalid Aziz, Chairman of the Petroleum Engineering Department at Stanford. Opening remarks were presented by Dr. Roland Horne, followed by a discussion of the California Energy Commission's Geothermal Activities by Barbara Crowley, Vice Chairman; and J.E. ''Ted'' Mock's presentation of the DOE Geothermal Program: New Emphasis on Industrial Participation. Technical papers were organized in twelve sessions concerning: hot dry rock, geochemistry, tracer injection, field performance, modeling, and chemistry/gas. As in previous workshops, session chairpersons made major contributions to the program. Special thanks are due to Joel Renner, Jeff Tester, Jim Combs, Kathy Enedy, Elwood Baldwin, Sabodh Garg, Marcel0 Lippman, John Counsil, and Eduardo Iglesias. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Angharad Jones, Rosalee Benelli, Jeanne Mankinen, Ted Sumida, and Terri A. Ramey who also produces the Proceedings

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.

Proceedings and findings of the geothermal commercialization workshop

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

Anderson, J.; Dhillon, H.

The proceedings are presented of a Geothermal Commercialization Workshop conducted by the Division of Geothermal Resource Management, Department of Energy. The workshop was held in January-February 1979 at The MITRE Corporation facility in McLean, Virginia. The workshop addressed geothermal hydrothermal commercialization achievements and needs in the areas of Marketing and Outreach, Economics, Scenarios, and Progress Monitoring.

Technical Feasibility Aspects of the Geothermal Resource Reporting Methodology (GRRM)

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

Badgett, Alex; Young, Katherine R; Dobson, Patrick F.

This paper reviews the technical assessment of the Geothermal Research Reporting Methodology (GRRM, http://en.openei.org/wiki/GRRM) being developed for reporting geothermal resources and project progress. The goal of the methodology is to provide the U.S. Department of Energy's Geothermal Technologies Office (GTO) with a consistent and comprehensible means of evaluating the impacts of its funding programs. The GRRM is designed to provide uniform assessment criteria for geothermal resource grades and developmental phases of geothermal resource exploration and development. This resource grade system provides information on twelve attributes of geothermal resource locations (e.g., temperature, permeability, land access) to indicate potential for geothermal development.more » The GTO plans to use these Protocols to help quantitatively identify the greatest barriers to geothermal development, develop measureable program goals that will have the greatest impact to geothermal deployment, objectively evaluate proposals based (in part) on a project's ability to contribute to program goals, monitor project progress, and report on GTO portfolio performance. The GRRM assesses three areas of geothermal potential: geological, socio-economic, and technical. Previous work and publications have discussed the work done on the geological aspects of this methodology (Young et al. 2015c); this paper details the development of the technical assessment of the GRRM. Technical development attributes considered include: reservoir management, drilling, logistics, and power conversion.« less

Geothermal Potential of Ascension Island, South Atlantic.

DTIC Science & Technology

1982-11-05

7AD-A141 763 GEOTHERMAL POTENTIAL OF ASCENSION ISLAND SOUTH ATLANTIC 1/1. (U) UTAH UNIV RESEARCH IN T SALT LAKE CITY EARTH U LfIS SCIENCE LAB D L...STANDARDS 1%A A ~ 7- ESMC-TR-83-02 Geothermal Potential Of Ascension Island, South Atlantic Dennis L. Nielson Bruce S. Sibbett University Of Utah...Security Classification) Geothermal Potential of Ascension Island, South Atlantic 12 PERSONAL AUTHOR(S) Dennis L. Neilson and Bruce S. Sibbett IIa TYPE

NREL: Renewable Resource Data Center - Geothermal Resource Models and Tools

Science.gov Websites

allow users to determine locations that are favorable to geothermal energy development. List of software Models and Tools The Renewable Resource Data Center (RReDC) features the following geothermal models and tools. Geothermal Prospector The Geothermal Prospector tool provides the information needed to

Microbial Diversity, Distribution and Insight into Their Role in S, Fe and N Biogeochemical Cycling in the Hot Springs at Tengchong Geothermal Fields, Southwest China

NASA Astrophysics Data System (ADS)

Li, J.; Peng, X.; Zhang, L.

2014-12-01

Ten sediment samples collected from one acidic and three alkaline high temperature hot springs at Tengchong terrestrial geothermal field, Southwest China, were examined by the mineralogical, geochemical, and molecular biological techniques. The mineralogical and geochemical analyses suggested that these hot springs contain relative high concentrations of S, Fe and N chemical species. Specifically, the acidic hot spring was rich in Fe2+, SO42- and NH4+, while the alkaline hot springs were high in NO3-, H2S and S2O3-. Analyses of 16S rRNA sequences showed their bacterial communities were dominated by Aquificae, Cyanobacteria, Deinococci-Thermus, Firmicutes, Proteobacteria, and Thermodesulfobacteria, while the archeal clone libraries were dominated by Desulfurococcales, Sulfolobales, and Thermoproteales. Among them, the potential S-, N- and Fe-related oxidizing and reducing prokaryote were presenting as a relative high proportion but with a great difference in diversity and metabolic approaches of each sample. These findings provide some significant implications for the microbial function in element biogeochemical cycles within the Tengchong geothermal environments: i). the distinct differences in abundance and diversity of microbial communities of geothermal sediments were related to in situ different physicochemical conditions; ii). the S-, N- and Fe-related prokaryote would take advantage of the strong chemical disequilibria in the hot springs; iii). in return, their metabolic activities can promote the transformation of S, Fe and N chemical species, thus founded the bases of biogeochemical cycles in the terrestrial geothermal environments.

The Colorado School of Mines Nevada geothermal study

NASA Technical Reports Server (NTRS)

Keller, G. V.; Grose, L. T.; Crewpson, R. A.

1974-01-01

Geothermal systems in the Basin and Range Province of the western United States probably differ in many respects from geothermal systems already discovered in other parts of the world because of the unique tectonic setting. To investigate this, a study of the geothermal occurrences at Fly Ranch, approximately 100 miles north of Reno, Nevada, has been undertaken. Ample evidence for a geothermal system exists in this area, including the surface expression of heat flow in the form of hot springs, an extensive area of low electrical resistivity, and a high level of seismicity along faults bounding the thermal area. However, geophysical and geological studies have not yet provided evidence for a local heat source at depth. Additional detailed geophysical and geological studies, as well as drilling, must be completed before the geothermal system can be described fully.

Temporal changes in shear velocity from ambient noise at New Zealand geothermal fields

NASA Astrophysics Data System (ADS)

Civilini, F.; Savage, M. K.; Townend, J.

2016-12-01

We use ambient noise to compare shear velocity changes with geothermal production processes at the Ngatamariki and Rotokawa geothermal fields, located in the central North Island of New Zealand. We calculate shear velocity changes through an analysis of cross correlation functions of diffusive seismic wavefields between stations, which are proportional to Green's functions of the station path. Electricity production at Ngatamariki uses an 82 MW binary type power station manufactured by Ormat Technologies, which began operations in mid-2013 and is owned and operated by Mighty River Power. The "Nga Awa Purua" triple flash power plant at the Rotokawa geothermal field was established in 2010 with parnership between Mighty River Power and Tauhara North No. 2 trust and currently operates 174 MW of generation. The seismometers of both networks, deployed primarily to observe microseismicity within the field, were installed prior to well stimulation and the start of production. Although cultural noise dominates the energy spectrum, a strong natural ambient noise signal can be detected when filtering below 1 Hz. Despite similar noise settings, the signal-to-noise ratio of cross correlation stacks at Rotokawa was more than two times greater than at Ngatamariki. We use stacks of cross correlations between stations prior to the onset of production as references, and compare them with cross correlations of moving stacks in time periods of well stimulation and the onset of electricity production.

Hot Dry Rock; Geothermal Energy

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

None

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 depthmore » 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

Lessons from geothermal gases at Yellowstone

NASA Astrophysics Data System (ADS)

Lowenstern, J. B.; Bergfeld, D.; Evans, W.; Hurwitz, S.

2015-12-01

The magma-hydrothermal system of the Yellowstone Plateau Volcanic Field encompasses over ten thousand individual springs, seeps, and fumaroles spread out over >9000 square kilometers, and produces a range of acid, neutral and alkaline waters. A prominent model (Fournier, 1989 and related papers) concludes that many neutral and alkaline fluids found in hot springs and geysers are derived from a uniform, high-enthalpy parent fluid through processes such as deep boiling and mixing with dilute meteoric groundwater. Acid waters are generally condensates of gas-bearing steam that boils off of subsurface geothermal waters. Our recent studies of gases at Yellowstone (Lowenstern et al., 2015 and references therein) are compatible with such a model, but also reveal that gases are largely decoupled from thermal waters due to open-system addition of abundant deep gas to (comparatively) shallow circulating thermal waters. Fumarole emissions at Yellowstone range from gas-rich (up to 15 mol%) composed of deeply derived CO2, He and CH4, to steam-rich emissions (<0.01% gas) dominated by N2 and Ar. The clear implication is that deep gas is diluted with atmospheric gas boiled off of geothermal liquids. The general trend is antithetical to that predicted by progressive boiling of a parent fluid (Rayleigh or batch degassing), where decreasing gas content should correlate with increasing proportions of soluble gas (i.e., CO2). Deep gas at Yellowstone fits into two general categories: 1) mantle-derived CO2 with a hotspot He isotope signature (>16 RA) and low CH4 and He concentrations and 2) mantle-derived CO2 with much higher CH4 and/or He concentrations and abundant radiogenic He picked up from crustal degassing. Individual thermal areas have distinct CH4/He. It remains unclear whether some gas ratios mainly reflect subsurface geothermal temperatures. Instead, they may simply reflect signatures imparted by local rock types and mixing on timescales too fast for reequilibration. Overall

Physical Vapor Deposition of Thin Films

NASA Astrophysics Data System (ADS)

Mahan, John E.

2000-01-01

A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

Geothermal activity helps life survive glacial cycles

PubMed Central

Fraser, Ceridwen I.; Terauds, Aleks; Smellie, John; Convey, Peter; Chown, Steven L.

2014-01-01

Climate change has played a critical role in the evolution and structure of Earth’s biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to the question of how diverse life can survive glaciations. No comprehensive assessment of this “geothermal glacial refugia” hypothesis has yet been undertaken, but Antarctica provides a unique setting for doing so. The continent has experienced repeated glaciations that most models indicate blanketed the continent in ice, yet many Antarctic species appear to have evolved in almost total isolation for millions of years, and hence must have persisted in situ throughout. How could terrestrial species have survived extreme glaciation events on the continent? Under a hypothesis of geothermal glacial refugia and subsequent recolonization of nongeothermal regions, we would expect to find greater contemporary diversity close to geothermal sites than in nongeothermal regions, and significant nestedness by distance of this diversity. We used spatial modeling approaches and the most comprehensive, validated terrestrial biodiversity dataset yet created for Antarctica to assess spatial patterns of diversity on the continent. Models clearly support our hypothesis, indicating that geothermally active regions have played a key role in structuring biodiversity patterns in Antarctica. These results provide critical insights into the evolutionary importance of geothermal refugia and the history of Antarctic species. PMID:24616489

Mapping temperature and radiant geothermal heat flux anomalies in the Yellowstone geothermal system using ASTER thermal infrared data

USGS Publications Warehouse

Vaughan, R. Greg; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.; Jaworowski, Cheryl; Heasler, Henry

2012-01-01

The purpose of this work was to use satellite-based thermal infrared (TIR) remote sensing data to measure, map, and monitor geothermal activity within the Yellowstone geothermal area to help meet the missions of both the U.S. Geological Survey Yellowstone Volcano Observatory and the Yellowstone National Park Geology Program. Specifically, the goals were to: 1) address the challenges of remotely characterizing the spatially and temporally dynamic thermal features in Yellowstone by using nighttime TIR data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and 2) estimate the temperature, geothermal radiant emittance, and radiant geothermal heat flux (GHF) for Yellowstone’s thermal areas (both Park wide and for individual thermal areas). ASTER TIR data (90-m pixels) acquired at night during January and February, 2010, were used to estimate surface temperature, radiant emittance, and radiant GHF from all of Yellowstone’s thermal features, produce thermal anomaly maps, and update field-based maps of thermal areas. A background subtraction technique was used to isolate the geothermal component of TIR radiance from thermal radiance due to insolation. A lower limit for the Yellowstone’s total radiant GHF was established at ~2.0 GW, which is ~30-45% of the heat flux estimated through geochemical (Cl-flux) methods. Additionally, about 5 km2 was added to the geodatabase of mapped thermal areas. This work provides a framework for future satellite-based thermal monitoring at Yellowstone as well as exploration of other volcanic / geothermal systems on a global scale.

Human Health Science Building Geothermal Heat Pump Systems

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

Leidel, James

2014-12-22

The grant objectives of the DOE grant funded project have been successfully completed. The Human Health Building (HHB) was constructed and opened for occupancy for the Fall 2012 semester of Oakland University. As with any large construction project, some issues arose which all were overcome to deliver the project on budget and on time. The facility design is a geothermal / solar-thermal hybrid building utilizing both desiccant dehumidification and variable refrigerant flow heat pumps. It is a cooling dominant building with a 400 ton cooling design day load, and 150 ton heating load on a design day. A 256 verticalmore » borehole (320 ft depth) ground source heat pump array is located south of the building under the existing parking lot. The temperature swing and performance over 2013 through 2015 shows the ground loop is well sized, and may even have excess capacity for a future building to the north (planned lab facility). The HHB achieve a US Green Building Counsel LEED Platinum rating by collecting 52 of the total 69 available LEED points for the New Construction v.2 scoring checklist. Being Oakland's first geothermal project, we were very pleased with the building outcome and performance with the energy consumption approximately 1/2 of the campus average facility, on a square foot basis.« less

Unified Application of Vapor Screen Flow Visualization and Pressure Sensitive Paint Measurement Techniques to Vortex- and Shock Wave-Dominated Flow Fields

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2010-01-01

Laser vapor screen (LVS) flow visualization and pressure sensitive paint (PSP) techniques were applied in a unified approach to wind tunnel testing of slender wing and missile configurations dominated by vortex flows and shock waves at subsonic, transonic, and supersonic speeds. The off-surface cross-flow patterns using the LVS technique were combined with global PSP surface static pressure mappings to characterize the leading-edge vortices and shock waves that coexist and interact at high angles of attack. The synthesis of LVS and PSP techniques was also effective in identifying the significant effects of passive surface porosity and the presence of vertical tail surfaces on the flow topologies. An overview is given of LVS and PSP applications in selected experiments on small-scale models of generic slender wing and missile configurations in the NASA Langley Research Center (NASA LaRC) Unitary Plan Wind Tunnel (UPWT) and 8-Foot Transonic Pressure Tunnel (8-Foot TPT).

Assessment of the origin and geothermal potential of the thermal waters by hydro-isotope geochemistry: Eskisehir province, Turkey.

PubMed

Yuce, Galip; Italiano, Francesco; Yasin, Didem; Taskiran, Lutfi; Gulbay, Ahmet Hilmi

2017-05-01

The thermal fluids vented over Eskisehir province have been investigated for their origin and to estimate the geothermal potential of the area. Thermal waters as well as bubbling and dissolved gases were collected and analysed for their chemical and isotopic features. Their isotopic composition varies in the range from -11.5 to -7.7 ‰ for δ 18 O, -84 and -57 ‰ for δ 2 H, and 0-7.2 TU for tritium. The gases (bubbling and dissolved) are mostly N 2 -dominated with a significant amount of CO 2 . The helium isotopic ratios are in the range of 0.2-0.66 R/Rac, indicate remarkable mantle-He contribution ranging between 2 and 10 % in the whole study area. Considering the estimated geothermal gradient about three times higher than the normal gradient, and the reservoir temperatures estimated to be between 50 and 100 °C using quartz and chalcedony geothermometers, a circulation model was built where possible mixing with shallow waters cool down the uprising geothermal fluids.

Geothermally Coupled Well-Based Compressed Air Energy Storage

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

Davidson, Casie L.; Bearden, Mark D.; Horner, Jacob A.

2015-12-20

Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storagemore » portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well

Advantage of incorporating geothermal energy into power-station cycles

NASA Astrophysics Data System (ADS)

White, A. A. L.

1980-06-01

The generation of electricity from low-temperature geothermal sources has been hampered by the low conversion efficiencies of Rankine cycle operating below 150 C. It is shown how the electrical output derived from a geothermal borehole may be substantially improved on that expected from these cycles by incorporating the geothermal heat into a conventional steam-cycle power station to provide feedwater heating. This technique can yield thermal conversion efficiencies of 11% which, for a well-head temperature of 100 C, is 50% greater than the output expected from a Rankine cycle. Coupled with the smaller capital costs involved, feedwater heating is thus a more attractive technique of converting heat into electricity. Although power stations above suitable geothermal resources would ideally have the geothermal heat incorporated from the design stage, experiments at Marchwood Power Station have shown that small existing sets can be modified to accept geothermal feedwater heating.

Deep Geothermal Energy for Lower Saxony (North Germany) - Combined Investigations of Geothermal Reservoir Characteristics

NASA Astrophysics Data System (ADS)

Hahne, Barbara; Thomas, Rüdiger

2014-05-01

In Germany, successful deep geothermal projects are mainly situated in Southern Germany in the Molassebecken, furthermore in the Upper Rhine Graben and, to a minor extend, in the North German Basin. Mostly they are hydrothermal projects with the aim of heat production. In a few cases, they are also constructed for the generation of electricity. In the North German Basin temperature gradients are moderate. Therefore, deep drilling of several thousand meters is necessary to reach temperatures high enough for electricity production. However, the porosity of the sedimentary rocks is not sufficient for hydrothermal projects, so that natural fracture zones have to be used or the rocks must be hydraulically stimulated. In order to make deep geothermal projects in Lower Saxony (Northern Germany) economically more attractive, the interdisciplinary research program "Geothermal Energy and High-Performance Drilling" (gebo) was initiated in 2009. It comprises four focus areas: Geosystem, Drilling Technology, Materials and Technical System and aims at improving exploration of the geothermal reservoir, reducing costs of drilling and optimizing exploitation. Here we want to give an overview of results of the focus area "Geosystem" which investigates geological, geophysical, geochemical and modeling aspects of the geothermal reservoir. Geological and rock mechanical investigations in quarrys and core samples give a comprehensive overview on rock properties and fracture zone characteristics in sandstones and carbonates. We also show that it is possible to transfer results of rock property measurements from quarry samples to core samples or to in situ conditions by use of empirical relations. Geophysical prospecting methods were tested near the surface in a North German Graben system. We aim at transferring the results to the prospection of deep situated fracture zones. The comparison of P- and S-wave measurements shows that we can get hints on a possible fluid content of the

INEL Geothermal Environmental Program. 1979 annual report

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

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.

Geothermal Power Potential in the Tatun Volcano Group, Taiwan

NASA Astrophysics Data System (ADS)

Tseng, H. H.; Song, S.

2013-12-01

Recent energy issues have concentrated the attention on finding alternative ones. National demands for renewable and sustainable energy increase rapidly, especially the geothermal power production, which is viewed as the most potential opportunity. This study attempts to estimate the geothermal powers in the Tatung Volcano Group (TVG), Taiwan and evaluate the possibility to develop the Enhanced Geothermal System. Tatung Volcano Group is located at the northwest part of Taiwan. It has violent volcanism during 0.8-0.20Ma, and is still active with many thermal manifestations. The young volcanic activity provides the TVG with high geothermal gradient and is well suitable for exploiting geothermal resources. Many explorations on geothermal energy have been accomplished in this area during1966-1973. They included resistivity survey, magnetic prospecting, gravity method, seismic prospecting and etc. In this study, we base on previous data and apply the probabilistic volumetric method proposed by Geotherm EX Inc., modified from the approach introduced by the USGS to evaluate the geothermal power potential in TVG. Meanwhile, use a Monte Carlo simulation technique to calculate the probability distribution of potentially recoverable energy reserves. The results show that the mean value is 270Mw, and P50 is 254Mw for 30 years, separately. Furthermore, the power potential of enhanced geothermal system in TVG is also estimated by the quantitative model proposed by Massachusetts Institute of Technology (MIT 2006). The results suggest that the mean value is 3,000 MW and P50 is 2,780 MW for 30 years, separately.

The hydrothermal evolution of the Kawerau geothermal system, New Zealand

NASA Astrophysics Data System (ADS)

Milicich, S. D.; Chambefort, I.; Wilson, C. J. N.; Charlier, B. L. A.; Tepley, F. J.

2018-03-01

Hydrothermal alteration zoning and processes provide insights into the evolution of heat source(s) and fluid compositions associated with geothermal systems. Traditional petrological techniques, combined with hydrothermal alteration studies, stable isotope analyses and geochronology can resolve the nature of the fluids involved in hydrothermal processes and their changes through time. We report here new findings along with previous unpublished works on alteration patterns, fluid inclusion measurements and stable isotope data to provide insights into the thermal and chemical evolution of the Kawerau geothermal system, New Zealand. These data indicate the presence of two hydrothermal events that can be coupled with chronological data. The earlier period of hydrothermal activity was initiated at 400 ka, with the heat driving the hydrothermal system inferred to be from the magmatic system that gave rise to rhyolite lavas and sills of the Caxton Formation. Isotopic data fingerprint fluids attributed to this event as meteoric, indicating that the magma primarily served as a heat source driving fluid circulation, and was not releasing magmatic fluids in sufficient quantity to affect the rock mineralogy and thus inferred fluid compositions. The modern Kawerau system was initiated at 16 ka with hydrothermal eruptions linked to shallow intrusion of magma at the onset of activity that gave rise to the Putauaki andesite cone. Likely associated with this later event was a pulse of magmatic CO2, resulting in large-scale deposition of hydrothermal calcite enriched in 18O. Meteoric water-dominated fluids subsequently overwhelmed the magmatic fluids associated with this 18O-rich signature, and both the fluid inclusion microthermometry and stable isotope data reflect a change to the present-day fluid chemistry of low salinity, meteoric-dominated waters.

The Main Problems in the Development of Geothermal Energy Industry in China

NASA Astrophysics Data System (ADS)

Yan, Jiahong; Wang, Shejiao; Li, Feng

2017-04-01

As early as 1980-1985, the geothermal energy research group of the Institute of Geology and Geophisics (Chinese Academy of Sciences) has proposed to pay attention to geothermal energy resources in oil fields. PetroChina began to study the geothermal energy resources in the region of Beijing-Tianjin-Hebei from 1995. Subsequently, the geothermal resources in the Huabei, Daqing and Liaohe oil regions were evaluated. The total recoverable hot water of the three oilfields reached 19.3 × 1011m3. PetroChina and Kenya have carried out geothermal energy development and utilization projects, with some relevant technical achievements.On the basis of many years' research on geothermal energy, we summarized the main problems in the formation and development of geothermal energy in China. First of all, China's geothermal resources research is still unable to meet the needs of the geothermal energy industry. Secondly, the development and utilization of geothermal energy requires multi-disciplinary cooperation. Thirdly, the development and utilization of geothermal energy needs consideration of local conditions. Finally, the development and utilization of geothermal energy resources requires the effective management of local government.

Geological model of supercritical geothermal reservoir related to subduction system

NASA Astrophysics Data System (ADS)

Tsuchiya, Noriyoshi

2017-04-01

Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 �

Geo-electrical and geological strikes of the Mount Lamongan geothermal area, East Java, Indonesia – preliminary results

NASA Astrophysics Data System (ADS)

Nugraheni, L. R.; Niasari, S. W.; Nukman, M.

2018-04-01

Geothermal manifestations located in the Tiris, Mount Lamongan, Probolinggo, consist of warm springs. These warm springs have temperature from 35° until 45°C. Tiris fault has NW-SE dominant orientation, similar to some lineaments of maars and cinder cones around Mount Lamongan. The Mount Lamongan geothermal area is situated between Bromo and Argapura volcanoes. This study aims to map the geo-electrical and geological strikes in the study area. Phase tensor analysis has been performed in this study to determine geo-electrical strike of study area. Geological field campaign has been conducted to measure geological strikes. Then, orientation of geo-electrical strike was compared to geological strike. The result presents that the regional geological strike of study area is NW-SE while the orientation of geo-electrical strike is N-S.

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.

Investigation on effective promotion of geothermal energy development

NASA Astrophysics Data System (ADS)

1991-03-01

Efficient and effective measures for promoting geothermal energy development are studied considering the present status and the problems of the geothermal energy development in Japan. To promote it smoothly, solutions to technical and socioeconomic problems are needed: There are many unclear points about the location and amount of geothermal resources. For geothermal energy development, it is necessary to establish a consensus of procedures for surveying the development and settlement of selling prices, and risk sharing in the development. It is indispensable to consider an adjustment with natural parks and hot springs for the development. Troubles in making an adjustment are seen in many cases, and it is necessary to make efforts for that understanding. Improvement of economical efficiency of geothermal power generation is an important subject. From the above mentioned studies, the conclusion is obtained that it is most effective to make rules for development and to expand and strengthen resource prospecting by the government. If the rules are made, reduction of the development cost and shortening of the development period are planned, and the future of the geothermal energy business is expected to be promising.

Tongonani geothermal power development, Philippines

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

Minson, A.A.C.; Fry, T.J.; Kivell, J.A.

1985-01-01

This paper describes the features, design and construction of a 112 MWe geothermal power project, representing the first stage development of the substantial geothermal resources of the central Philippine region. The project has been undertaken by the Philippine Government. The National Powe Corporation is responsible for generation and distribution facilities and the Philippine National Oil Company Energy Development Corporation is responsible for controlled delivery of steam to the powe station.

Hydrogeochemical exploration of geothermal prospects in the Tecuamburro Volcano region, Guatemala

USGS Publications Warehouse

Janik, C.J.; Goff, F.; Fahlquist, L.; Adams, A.I.; Alfredo, Roldan M.; Chipera, S.J.; Trujillo, P.E.; Counce, D.

1992-01-01

Chemical and isotopic analyses of thermal and nonthermal waters and of gases from springs and fumaroles are used to evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Chemically distinct geothermal surface manifestations generally occur in separate hydrogeologic areas within this 400 km2 region: low-pressure fumaroles with temperatures near local boiling occur at 1470 m elevation in a sulfur mine near the summit of Tecuamburro Volcano; non-boiling acid-sulfate hot springs and mud pots are restricted to the Laguna Ixpaco area, about 5 km NNW of the sulfur mine and 350-400 m lower in elevation; steam-heated and thermal-meteoric waters are found on the flanks of Tecuamburro Volcano and several kilometers to the north in the andesitic highland, where the Infernitos fumarole (97??C at 1180 m) is the primary feature; neutral-chloride hot springs discharge along Rio Los Esclavos, principally near Colmenares at 490 m elevation, about 8-10 km SE of Infernitos. Maximum geothermometer temperatures calculated from Colmenares neutral-chloride spring compositions are ???180??C, whereas maximum subsurface temperatures based on Laguna Ixpaco gas compositions are ???310??C. An exploration core hole drilled to a depth of 808 m about 0.3 km south of Laguna Ixpaco had a bottom-hole temperature of 238??C but did not produce sufficient fluids to confirm or chemically characterize a geothermal reservoir. Hydrogeochemical data combined with regional geologic interpretations indicate that there are probably two hydrothermal-convection systems, which are separated by a major NW-trending structural boundary, the Ixpaco fault. One system with reservoir temperatures near 300??C lies beneath Tecuamburro Volcano and consists of a large vapor zone that feeds steam to the Laguna Ixpaco area, with underlying hot water that flows laterally to feed a small group of warm, chloriderich springs SE of Tecuamburro Volcano. The other system is located beneath the Infernitos

NREL Taps Young to Oversee Geothermal Energy Program | News | NREL

Science.gov Websites

Taps Young to Oversee Geothermal Energy Program News Release: NREL Taps Young to Oversee Geothermal (NREL) promoted Katherine Young to laboratory program manager for geothermal energy. Young has been with NREL since 2008, working as a senior geothermal analyst and engineer in the Strategic Energy Analysis

Geological investigation of the Socorro geothermal area. Final report

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

Chapin, C.E.; Sanford, A.R.; White, D.W.

1979-05-01

The results of a comprehensive geological and geochemical study of the Socorro geothermal area are presented. The following are discussed: geologic setting, structural controls, stratigraphic controls, an ancient geothermal system, modern magma bodies, geothermal potential of the Socorro area, and the Socorro transverse shear zone. (MHR)

Geothermal direct-heat utilization assistance. Quarterly report, January - March 1997

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

Lienau, P.

1997-04-01

This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the second quarter of FY-97. It describes 176 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on well pumping in commercial groundwater heat pump systems. A memorandum of understanding between the GHC and EIA is described. Work accomplishments on the Guidebook are discussed. Outreach activities include the publication of a geothermal direct usemore » Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.« less

The Geothermal Data Repository: Five Years of Open Geothermal Data, Benefits to the Community

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

Weers, Jonathan D; Taverna, Nicole; Anderson, Arlene

In the five years since its inception, the Department of Energy's (DOE) Geothermal Data Repository (GDR) has grown from the simple idea of storing public data in a centralized location to a valuable tool at the center of the DOE open data movement where it is providing a tangible benefit to the geothermal scientific community. Throughout this time, the GDR project team has been working closely with the community to refine the data submission process, improve the quality of submitted data, and embrace modern proper data management strategies to maximize the value and utility of submitted data. This paper exploresmore » some of the motivations behind various improvements to the GDR over the last 5 years, changes in data submission trends, and the ways in which these improvements have helped to drive research, fuel innovation, and accelerate the adoption of geothermal technologies.« less

3D Model of the Tuscarora Geothermal Area

DOE Data Explorer

Faulds, James E.

2013-12-31

The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern

On the definition of dominant force regimes for flow boiling heat transfer by using single mini-tubes

NASA Astrophysics Data System (ADS)

Baba, Soumei; Sawada, Kenichiro; Kubota, Chisato; Kawanami, Osamu; Asano, Hitoshi; Inoue, Koichi; Ohta, Haruhiko

Recent increase in the size of space platforms requires the management of larger amount of waste heat under high heat flux conditions and the transportation of it along a long distance to the radiator. Flow boiling applied to the thermal management system in space attracts much attention as promising means to realize high-performance heat transfer and transport because of large latent heat of vaporization. In microgravity two-phase flow phenomena are quite different from those under 1-g condition because buoyancy effects are significantly reduced and surface tension becomes dominant. By the similar reason, flow boiling characteristics in mini channels are not the same as those in channels of normal sizes. In the present stage, however, the boundary between the regimes of body force dominated and of surface tension dominated is not clear. The design of space thermal devices, operated under the conditions where no effect of gravity is expected, will improve the reliability of their ground tests, provided that the boundaries of dominant force regimes are clarified quantitatively in advance. In flow boiling in mini channels or in parallel channels, back flow could be occurred because of rapid growth of bubbles in a confined space, resulting flow rate fluctuation. Flow boiling heat transfer characteristics in mini channels can be changed considerably by the existence of inlet flow rate fluctuation. It is important to pay attention to experimental accuracy and to use a single circular mini-tube to compare heat transfer characteristics with those of normal size tubes. In the present paper, effects of tube orientations, i.e. vertical upward flow, vertical downward flow and horizontal flow, on flow boiling heat transfer characteristics is investigated for FC72 flowing in single mini-tubes with inner diameters of 0.13 and 0.51 mm to establish a reliable dominant force regime map. If the regime map is described by using dimensionless groups of Bond, Weber and Froude numbers

The cluster model of a hot dense vapor

NASA Astrophysics Data System (ADS)

Zhukhovitskii, D. I.

2015-04-01

We explore thermodynamic properties of a vapor in the range of state parameters where the contribution to thermodynamic functions from bound states of atoms (clusters) dominates over the interaction between the components of the vapor in free states. The clusters are assumed to be light and sufficiently "hot" for the number of bonds to be minimized. We use the technique of calculation of the cluster partition function for the cluster with a minimum number of interatomic bonds to calculate the caloric properties (heat capacity and velocity of sound) for an ideal mixture of the lightest clusters. The problem proves to be exactly solvable and resulting formulas are functions solely of the equilibrium constant of the dimer formation. These formulas ensure a satisfactory correlation with the reference data for the vapors of cesium, mercury, and argon up to moderate densities in both the sub- and supercritical regions. For cesium, we extend the model to the densities close to the critical one by inclusion of the clusters of arbitrary size. Knowledge of the cluster composition of the cesium vapor makes it possible to treat nonequilibrium phenomena such as nucleation of the supersaturated vapor, for which the effect of the cluster structural transition is likely to be significant.

The cluster model of a hot dense vapor

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

Zhukhovitskii, D. I., E-mail: dmr@ihed.ras.ru

2015-04-28

We explore thermodynamic properties of a vapor in the range of state parameters where the contribution to thermodynamic functions from bound states of atoms (clusters) dominates over the interaction between the components of the vapor in free states. The clusters are assumed to be light and sufficiently “hot” for the number of bonds to be minimized. We use the technique of calculation of the cluster partition function for the cluster with a minimum number of interatomic bonds to calculate the caloric properties (heat capacity and velocity of sound) for an ideal mixture of the lightest clusters. The problem proves tomore » be exactly solvable and resulting formulas are functions solely of the equilibrium constant of the dimer formation. These formulas ensure a satisfactory correlation with the reference data for the vapors of cesium, mercury, and argon up to moderate densities in both the sub- and supercritical regions. For cesium, we extend the model to the densities close to the critical one by inclusion of the clusters of arbitrary size. Knowledge of the cluster composition of the cesium vapor makes it possible to treat nonequilibrium phenomena such as nucleation of the supersaturated vapor, for which the effect of the cluster structural transition is likely to be significant.« less

Fifteenth workshop on geothermal reservoir engineering: Proceedings

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

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.

The Geysers-Clear Lake geothermal area, California - an updated geophysical perspective of heat sources

USGS Publications Warehouse

Stanley, W.D.; Blakely, R.J.

1995-01-01

The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. An updated view is presented of the geological/geophysical complexities of the crust in this region in order to address key unanswered questions about the heat source and tectonics. Forward modeling, multidimensional inversions, and ideal body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies have significant contributions from rock property and physical state variations in the upper 7 km and not from "magma' at greater depths. Regional tectonic and magmatic processes are analyzed to develop an updated scenario for pluton emplacement that differs substantially from earlier interpretations. In addition, a rationale is outlined for future exploration for geothermal resources in The Geysers-Clear Lake area. -from Authors

VOC composition of current motor vehicle fuels and vapors, and collinearity analyses for receptor modeling.

PubMed

Chin, Jo-Yu; Batterman, Stuart A

2012-03-01

The formulation of motor vehicle fuels can alter the magnitude and composition of evaporative and exhaust emissions occurring throughout the fuel cycle. Information regarding the volatile organic compound (VOC) composition of motor fuels other than gasoline is scarce, especially for bioethanol and biodiesel blends. This study examines the liquid and vapor (headspace) composition of four contemporary and commercially available fuels: gasoline (<10% ethanol), E85 (85% ethanol and 15% gasoline), ultra-low sulfur diesel (ULSD), and B20 (20% soy-biodiesel and 80% ULSD). The composition of gasoline and E85 in both neat fuel and headspace vapor was dominated by aromatics and n-heptane. Despite its low gasoline content, E85 vapor contained higher concentrations of several VOCs than those in gasoline vapor, likely due to adjustments in its formulation. Temperature changes produced greater changes in the partial pressures of 17 VOCs in E85 than in gasoline, and large shifts in the VOC composition. B20 and ULSD were dominated by C(9) to C(16)n-alkanes and low levels of the aromatics, and the two fuels had similar headspace vapor composition and concentrations. While the headspace composition predicted using vapor-liquid equilibrium theory was closely correlated to measurements, E85 vapor concentrations were underpredicted. Based on variance decomposition analyses, gasoline and diesel fuels and their vapors VOC were distinct, but B20 and ULSD fuels and vapors were highly collinear. These results can be used to estimate fuel related emissions and exposures, particularly in receptor models that apportion emission sources, and the collinearity analysis suggests that gasoline- and diesel-related emissions can be distinguished. Copyright © 2011 Elsevier Ltd. All rights reserved.

Re-examining Potential for Geothermal Energy in United States

NASA Astrophysics Data System (ADS)

Showstack, Randy

New technological initiatives, along with potential policy and economic incentives, could help to bring about a resurgence in geothermal energy development in the United States, said several experts at a 22 May forum in Washington, D.C. The forum was sponsored by the House and Senate Renewable Energy and Energy Efficiency Caucuses, the Sustainable Energy Coalition, and the Environmental and Energy Study Institute. Among these initiatives is an ambitious program of the U.S. Department of Energy to expand existing geothermal energy fields and potentially create new fields through ``enhanced geothermal systems.'' In addition, a program of the Bush administration encourages geothermal development on some public lands, and current legislation would provide tax credits and other incentives for geothermal development.

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.

Geothermal resources and reserves in Indonesia: an updated revision

NASA Astrophysics Data System (ADS)

Fauzi, A.

2015-02-01

More than 300 high- to low-enthalpy geothermal sources have been identified throughout Indonesia. From the early 1980s until the late 1990s, the geothermal potential for power production in Indonesia was estimated to be about 20 000 MWe. The most recent estimate exceeds 29 000 MWe derived from the 300 sites (Geological Agency, December 2013). This resource estimate has been obtained by adding all of the estimated geothermal potential resources and reserves classified as "speculative", "hypothetical", "possible", "probable", and "proven" from all sites where such information is available. However, this approach to estimating the geothermal potential is flawed because it includes double counting of some reserve estimates as resource estimates, thus giving an inflated figure for the total national geothermal potential. This paper describes an updated revision of the geothermal resource estimate in Indonesia using a more realistic methodology. The methodology proposes that the preliminary "Speculative Resource" category should cover the full potential of a geothermal area and form the base reference figure for the resource of the area. Further investigation of this resource may improve the level of confidence of the category of reserves but will not necessarily increase the figure of the "preliminary resource estimate" as a whole, unless the result of the investigation is higher. A previous paper (Fauzi, 2013a, b) redefined and revised the geothermal resource estimate for Indonesia. The methodology, adopted from Fauzi (2013a, b), will be fully described in this paper. As a result of using the revised methodology, the potential geothermal resources and reserves for Indonesia are estimated to be about 24 000 MWe, some 5000 MWe less than the 2013 national estimate.

The competition between liquid and vapor transport in transpiring leaves.

PubMed

Rockwell, Fulton Ewing; Holbrook, N Michele; Stroock, Abraham Duncan

2014-04-01

In leaves, the transpirational flux of water exits the veins as liquid and travels toward the stomata in both the vapor and liquid phases before exiting the leaf as vapor. Yet, whether most of the evaporation occurs from the vascular bundles (perivascular), from the photosynthetic mesophyll cells, or within the vicinity of the stomatal pore (peristomatal) remains in dispute. Here, a one-dimensional model of the competition between liquid and vapor transport is developed from the perspective of nonisothermal coupled heat and water molecule transport in a composite medium of airspace and cells. An analytical solution to the model is found in terms of the energy and transpirational fluxes from the leaf surfaces and the absorbed solar energy load, leading to mathematical expressions for the proportions of evaporation accounted for by the vascular, mesophyll, and epidermal regions. The distribution of evaporation in a given leaf is predicted to be variable, changing with the local environment, and to range from dominantly perivascular to dominantly peristomatal depending on internal leaf architecture, with mesophyll evaporation a subordinate component. Using mature red oak (Quercus rubra) trees, we show that the model can be solved for a specific instance of a transpiring leaf by combining gas-exchange data, anatomical measurements, and hydraulic experiments. We also investigate the effect of radiation load on the control of transpiration, the potential for condensation on the inside of an epidermis, and the impact of vapor transport on the hydraulic efficiency of leaf tissue outside the xylem.

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)

POLLUTION CONTROL GUIDANCE FOR GEOTHERMAL ENERGY DEVELOPMENT

EPA Science Inventory

This report summarizes the EPA regulatory approach toward geothermal energy development. The state of knowledge is described with respect to the constituents of geothermal effluents and emissions, including water, air, solid wastes, and noise. Pollutant effects are discussed. Pol...

ANALYSIS OF GEOTHERMAL WASTES FOR HAZARDOUS COMPONENTS

EPA Science Inventory

Regulations governing the disposal of hazardous wastes led to an assessment for geothermal solid wastes for potentially hazardous properties. Samples were collected from three active geothermal sites in the western United States: The Geysers, Imperial Valley, and northwestern Nev...

Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

NASA Astrophysics Data System (ADS)

1992-10-01

This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.

Identification the geothermal system using 1-D audio-magnetotelluric inversion in Lamongan volcano field, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Ilham, N.; Niasari, S. W.

2018-04-01

Tiris village, Probolinggo, East Java, is one of geothermal potential areas in Indonesia. This area is located in a valley flank of Mount Lamongan and Argopuro volcanic complex. This research aimed to identify a geothermal system at Tiris area, particularly the fluid pathways. The geothermal potential can be seen from the presence of warm springs with temperature ranging 35-45°C. The warm spring locations are aligned in the same orientation with major fault structure in the area. The fault structure shows dominant northwest-southeast orientation. We used audio-magnetotelluric data in the frequency range of 10 Hz until 92 kHz. The total magnetotelluric sites are 6. From the data analysis, most of the data orientation were 2-D with geo-electrical direction north-south. We used 1-D inversion using Newton algorithm. The 1-D inversion resulted in low resistive anomaly that corresponds to Lamongan lavas. Additionally, the depth of the resistor are different between the area to the west (i.e. 75 m) and to the east (i.e. 25 m). This indicates that there is a fault around the aligned maar (e.g. Ranu Air).

Pueblo of Jemez Geothermal Feasibility Study Fianl Report

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

S.A. Kelley; N. Rogers; S. Sandberg

2005-03-31

This project assessed the feasibility of developing geothermal energy on the Pueblo of Jemez, with particular attention to the Red Rocks area. Geologic mapping of the Red Rocks area was done at a scale of 1:6000 and geophysical surveys identified a potential drilling target at a depth of 420 feet. The most feasible business identified to use geothermal energy on the reservation was a greenhouse growing culinary and medicinal herbs. Space heating and a spa were identified as two other likely uses of geothermal energy at Jemez Pueblo. Further geophysical surveys are needed to identify the depth to the Maderamore » Limestone, the most likely host for a major geothermal reservoir.« less

Case studies for utilizing groundwater-source and low-enthalpy geothermal resources in Korea

NASA Astrophysics Data System (ADS)

Kim, K.-H.; Shin, J.; Lee, K.-K.; Lee, T. J.

2012-04-01

As one of the top 10 oil-consuming countries in the world, Korea recently has had a great interest in extending the ways to utilize renewable energy. In this regard, geothermal energy resource is attracting more concerns from both of the government and the research field. Korea has neither active volcanic sites nor areas with abnormally higher heat flow. In spite of these natural conditions, many efforts have been exerted to utilize geothermal energy. Here, we introduce two case studies of using groundwater-source geothermal energy with relatively low-enthalpy: One is a riverbank filtration facility, which has been using some of its riverbank filtrate water for the indoor air-conditioning. The other is the first EGS plant planning site, where a few fault-related artesian wells reaching 70C were discovered lately. Numerical simulations to predict the temperature evolution of the two sites, which is dominated by several hydrogeologic factors, were carried out and compared. Simulation of temperature profile of riverbank filtrate water using HydroGeoSphere shows that the primary factor in determining filtrate water temperature is the pumping rate. It also shows that maintaining the facility operation with present pumping rate for the next 30 years will not cause any significant change of water temperature. However, following the new plan of the facility to install additional 37 wells with 6 times higher pumping rate than the current rate might cause about 2C decrease in filtrate water temperature in 10 years after the extension. Simulation for the temperature evolution in a faulted geothermal reservoir in EGS planning site under the supposed injection-extraction operating conditions were carried out using TOUGH2. A MINC model including a hydraulic discontinuity, which reflected the analysis from several geophysical explorations, was generated. Temperature distribution calculated from the simulation shows a rise of relatively hot geothermal water along the fault plane

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…

Access to Data Accelerates Innovation and Adoption of Geothermal

Science.gov Websites

Technologies | News | NREL Access to Data Accelerates Innovation and Adoption of Geothermal Technologies Access to Data Accelerates Innovation and Adoption of Geothermal Technologies May 18, 2018 A map of the continental U.S. is overlaid with a colored map showing deep geothermal heat potential. NREL's

Ground Source Geothermal District Heating and Cooling System

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

Lowe, James William

2016-10-21

Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reducemore » worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx« less

Numerical simulations of heat transfer through fractured rock for an enhanced geothermal system development in Seokmodo, Korea

NASA Astrophysics Data System (ADS)

Shin, Jiyoun; Kim, Kyung-Ho; Hyun, Yunjung; Lee, Kang-Keun

2010-05-01

Estimating the expected capacity and efficiency of energy is a crucial issue in the construction of geothermal plant. It is the lasting temperature of extracted geothermal water that determines the effectiveness of enhanced geothermal systems (EGS), so the heat transfer processes in geothermal reservoirs under site-specific geologic conditions should be understood first. The construction of the first geothermal plant in Korea is under planning in Seokmodo, where a few flowing artesian wells showing relatively high water temperature of around 70°C were discovered lately. The site of interest is a part of the island region, consisting of the reclaimed land surrounded by the sea and small mountains. Geothermal gradient measures approximately 45°C/km and the geothermal water is as saline as seawater. Geologic structure in this region is characterized by the fractured granite. In this study, thermo-hydrological (TH) numerical simulations for the temperature evolution in a fractured geothermal reservoir under the supposed injection-extraction operating conditions were carried out using TOUGH2. Multiple porosity model which is useful to calculate the transient interporosity flow in TH coupled heat transfer problem was used in simulations. Several fracture planes which had been investigated in the field were assigned to have highly permeable properties in order to avoid the averaging approximation and describe the dominant flow through the fractures. This heterogeneous model showed the rise of relatively hot geothermal water in the densely fractured region. The temperature of the extracted geothermal water also increased slowly for 50 years due to the rising flow through the fractures. The most sensitive factor which affects the underground thermal distribution and temperature of geothermal water was permeability of the medium. Change in permeabilities of rock and fracture within the range of 1 order might cause such an extreme change in the temperature of geothermal

Characterization of the natural radioactivity of the first deep geothermal doublet in Flanders, Belgium.

PubMed

Vasile, M; Bruggeman, M; Van Meensel, S; Bos, S; Laenen, B

2017-08-01

Deep geothermal energy is a local energy resource that is based on the heat generated by the Earth. As the heat is continuously regenerated, geothermal exploitation can be considered as a renewable and, depending on the techniques used, a sustainable energy production system. In September 2015, the Flemish Institute for Technological Research (VITO) started drilling an exploration well targeting a hot water reservoir at a depth of about 3km on the Balmatt site near Mol. Geothermal hot water contains naturally occurring gases, chemicals and radionuclides at variable concentrations. The actual concentrations and potentially related hazards strongly depend on local geological and hydrogeological conditions. This paper summarizes the radiological characterization of several rock samples obtained from different depths during the drilling, the formation water, the salt and the sediment fraction. The results of our analyses show low values for the activity concentration for uranium and thorium in the formation water and in the precipitate/sediment fraction. Also, the activity concentrations of 210 Pb and 210 Po are low in these samples and the activity concentration of 226 Ra is dominant. From the analysis of the rock samples, it was found that the layer above the reservoir has a higher uranium and thorium concentration than the layer of the reservoir, which on the other hand contains more radium than the layer above it. Copyright © 2016 Elsevier Ltd. All rights reserved.

Monitoring Biological Activity at Geothermal Power Plants

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

Peter Pryfogle

2005-09-01

The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has beenmore » evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.« less

The multi-level perspective analysis: Indonesia geothermal energy transition study

NASA Astrophysics Data System (ADS)

Wisaksono, A.; Murphy, J.; Sharp, J. H.; Younger, P. L.

2018-01-01

The study adopts a multi-level perspective in technology transition to analyse how the transition process in the development of geothermal energy in Indonesia is able to compete against the incumbent fossil-fuelled energy sources. Three levels of multi-level perspective are socio-technical landscape (ST-landscape), socio-technical regime (ST-regime) and niche innovations in Indonesia geothermal development. The identification, mapping and analysis of the dynamic relationship between each level are the important pillars of the multi-level perspective framework. The analysis considers the set of rules, actors and controversies that may arise in the technological transition process. The identified geothermal resource risks are the basis of the emerging geothermal technological innovations in Indonesian geothermal. The analysis of this study reveals the transition pathway, which yields a forecast for the Indonesian geothermal technology transition in the form of scenarios and probable impacts.

Development situation and prospecting division of geothermal resources in Yangshan county, Guangdong Province

NASA Astrophysics Data System (ADS)

Yin, Lijun; Luo, Yizhen; Ma, Huiying; Xie, Yanxiao; Liu, Zhenzhen

2017-03-01

Yangshan County has abundant low-geothermal resources in its northeast, southwest, and midwest regions. These low-temperature geothermal resources in Yangshan County can prove to be beneficial for different purposes such as tourism, recuperation, sauna, and agriculture. Thirteen geothermal hot springs (spots) and seven geothermal anomalies have been discovered till now in this area. The geothermal resources are grouped on the basis of their conditions as follows: The Chengjia-Dianzhan and Dongguan-Jietan geothermal areas are classified as priority development zones, the Huangben-Mazishui and Qigongyuntankeng areas as sub-priority development zones, the Jiangying geothermal area as a general development zone, the Yangshan geothermal area as a potential development zone, and the Chengjia and Longfeng geothermal areas as restricted development zones.

Analytical estimation show low depth-independent water loss due to vapor flux from deep aquifers

NASA Astrophysics Data System (ADS)

Selker, John S.

2017-06-01

Recent articles have provided estimates of evaporative flux from water tables in deserts that span 5 orders of magnitude. In this paper, we present an analytical calculation that indicates aquifer vapor flux to be limited to 0.01 mm/yr for sites where there is negligible recharge and the water table is well over 20 m below the surface. This value arises from the geothermal gradient, and therefore, is nearly independent of the actual depth of the aquifer. The value is in agreement with several numerical studies, but is 500 times lower than recently reported experimental values, and 100 times larger than an earlier analytical estimate.

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)

Honey Lake Geothermal Project, Lassen County, California

NASA Astrophysics Data System (ADS)

1984-11-01

The drilling, completion, and testing of deep well WEN-2 for a hybrid electric power project which will use the area's moderate temperature geothermal fluids and locally procured wood fuel is reported. The project is located within the Wendel-Amedee Known Geothermal Resource Area.

Recovery Act:Rural Cooperative Geothermal development Electric & Agriculture

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

Culp, Elzie Lynn

Surprise Valley Electric, a small rural electric cooperative serving northeast California and southern Oregon, developed a 3mw binary geothermal electric generating plant on a cooperative member's ranch. The geothermal resource had been discovered in 1980 when the ranch was developing supplemental irrigation water wells. The 240°F resource was used for irrigation until developed through this project for generation of electricity. A portion of the spent geothermal fluid is now used for irrigation in season and is available for other purposes, such as greenhouse agriculture, aquaculture and direct heating of community buildings. Surprise Valley Electric describes many of the challenges amore » small rural electric cooperative encountered and managed to develop a geothermal generating plant.« less

The Hydrogeochemistry of Qingshui Geothermal Field, Northeastern Taiwan.

NASA Astrophysics Data System (ADS)

Yu-Wen, Chen; Cheng-Kuo, Lin; Wayne, Lin; Yu-Te, Chang; Pei-Shan, Hsieh

2015-04-01

The Qingshui geothermal field is located at the upstream valley of Lanyang Creek, northeastern Taiwan. It is renowned as a geothermal field. The previous studies demonstrated a higher geothermal gradient, 100oC/km warmer than a normal geotherm. However, Qingshui geothermal field has not been well developed due to the higher mining costs. In the recent years, the Taiwan government has been focusing on developing alternative and renewable energy and initiated a 10 year project, Nation Energy Program. This study is part of this project In general, it is very difficult to collect deep downhole samples without considerable change of hydro- and gas- chemistry of water under high temperature and pressure. A new sampling tool, GTF Sampler, was designed by the research team, Green Energy and Environment Laboratories, Industrial Technology Research Institute. This tool can simultaneously collect high quality geothermal water and gas sample and moreover, the sampling depth can reach up to 800 meters. Accordingly, a more accurate measurements can be conducted in the laboratory. In this study, 10 geothermal samples were collected and measured. The results demonstrate that geothermal water samples are characterized with Na(K)-HCO3 water type and located at the mature water area in Giggenbach Na-K-Mg diagram. Several geothermometers, including silica and cation geothermometry, were used to estimate potential temperature in the geothermal reservoir systems. In general, the geothermoters of Na-K and Na-K-Ca obtain reservoir temperatures between 120-190oC and 130-210oC, respectively, but the silica geothermometer indicates a lower reservoir temperature between 90 and 170oC. There is no big difference among them. It is worth to note that all calculated temperatures are lower than those of in-situ downhole measurements; therefore, more detailed and advanced researches would be needed for the inconsistency. To examine the argument about igneous heat source in the previous studies, rare

Geothermal energy employment and requirements 1977-1990

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

Not Available

1981-12-01

An assessment of the manpower needs of the geothermal industry is presented. The specific objectives were to: derive a base line estimate of the manpower involved in geothermal activities, determine if there is any current or impending likelihood of skill shortages, forecast future employment in the geothermal industry, conduct a technology assessment to ascertain the possibilities of some sudden breakthrough, and suggest alternatives commensurate with the findings. The methodology for fulfilling the objectives is described. Detailed results of these pursuits (objectives) are presented. Alternatives that are suggested, based upon the findings of the study, are summarized.

RiverHeath: Neighborhood Loop Geothermal Exchange System

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

Geall, Mark

2016-07-11

The goal of the RiverHeath project is to develop a geothermal exchange system at lower capital infrastructure cost than current geothermal exchange systems. The RiverHeath system features an innovative design that incorporates use of the adjacent river through river-based heat exchange plates. The flowing water provides a tremendous amount of heat transfer. As a result, the installation cost of this geothermal exchange system is lower than more traditional vertical bore systems. Many urban areas are located along rivers and other waterways. RiverHeath will serve as a template for other projects adjacent to the water.

Improving Geothermal Heat Pump Air Conditioning Efficiency with Wintertime Cooling using Seasonal Thermal Energy Storage (STES). Application Manual

DTIC Science & Technology

2016-11-01

Defense. Reference herein to any specific commercial product , process, or service by trade name, trademark, manufacturer, or otherwise, does not...1 1.3 Cooling-Dominated Buildings and MCAS Beaufort Case Study 4 1.4 Potential Approach for Mitigating Heat Buildup -- Hybrid Geothermal Heat...the ground through another well. This type of system can be very effective, but it requires access to a productive aquifer with associated

The Geothermal Data Repository: Five Years of Open Geothermal Data, Benefits to the Community: Preprint

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

Weers, Jonathan D; Taverna, Nicole; Anderson, Arlene

In the five years since its inception, the Department of Energy's (DOE) Geothermal Data Repository (GDR) has grown from the simple idea of storing public data in a centralized location to a valuable tool at the center of the DOE open data movement where it is providing a tangible benefit to the geothermal scientific community. Throughout this time, the GDR project team has been working closely with the community to refine the data submission process, improve the quality of submitted data, and embrace modern proper data management strategies to maximize the value and utility of submitted data. This paper exploresmore » some of the motivations behind various improvements to the GDR over the last 5 years, changes in data submission trends, and the ways in which these improvements have helped to drive research, fuel innovation, and accelerate the adoption of geothermal technologies.« less

VOC composition of current motor vehicle fuels and vapors, and collinearity analyses for receptor modeling

PubMed Central

Chin, Jo-Yu; Batterman, Stuart A.

2015-01-01

The formulation of motor vehicle fuels can alter the magnitude and composition of evaporative and exhaust emissions occurring throughout the fuel cycle. Information regarding the volatile organic compound (VOC) composition of motor fuels other than gasoline is scarce, especially for bioethanol and bio-diesel blends. This study examines the liquid and vapor (headspace) composition of four contemporary and commercially available fuels: gasoline (<10% ethanol), E85 (85% ethanol and 15% gasoline), ultra-low sulfur diesel (ULSD), and B20 (20% soy-biodiesel and 80% ULSD). The composition of gasoline and E85 in both neat fuel and headspace vapor was dominated by aromatics and n-heptane. Despite its low gasoline content, E85 vapor contained higher concentrations of several VOCs than those in gasoline vapor, likely due to adjustments in its formulation. Temperature changes produced greater changes in the partial pressures of 17 VOCs in E85 than in gasoline, and large shifts in the VOC composition. B20 and ULSD were dominated by C9 to C16 n-alkanes and low levels of the aromatics, and the two fuels had similar headspace vapor composition and concentrations. While the headspace composition predicted using vapor–liquid equilibrium theory was closely correlated to measurements, E85 vapor concentrations were underpredicted. Based on variance decomposition analyses, gasoline and diesel fuels and their vapors VOC were distinct, but B20 and ULSD fuels and vapors were highly collinear. These results can be used to estimate fuel related emissions and exposures, particularly in receptor models that apportion emission sources, and the collinearity analysis suggests that gasoline- and diesel-related emissions can be distinguished. PMID:22154341

Compensated geothermal gradient: new map of old data

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

Ibrahim, M.W.

1986-05-01

Bottom-hole temperature measurement is one of the oldest forms of downhole information acquired by the oil industry. Old and new geothermal maps that are based on these measurements have invariably been drawn with an assumed constant or average ground surface temperature over the mapped areas. However, near ground-surface equilibrium temperature is a variable rather than a constant over any region; therefore, old and current geothermal gradient mapping methods give a false impression of the true thermal level of subsurface strata, and may lead to erroneous results of temperature-based calculations, such as the TTI. In this paper, a geothermal mapping methodmore » is presented in which extrapolated surface temperature is coupled with the corresponding geothermal gradient over the mapped area. The method was tested on areas in the Middle East and Africa. Results indicate that it is especially effective in delineating loci of vertical geothermal heat flux carried upwards by ascending subsurface fluids; such areas are preferential sites for hydrocarbon entrapment, especially in young sedimentary basins where migration is still in progress.« less

Geothermal Play-Fairway Analysis of the Tatun Volcano Group, Taiwan

NASA Astrophysics Data System (ADS)

Chen, Yan-Ru; Song, Sheng-Rong

2017-04-01

Geothermal energy is a sustainable and low-emission energy resource. It has the advantage of low-cost and withstanding nature hazards. Taiwan is located on the western Ring of Fire and characteristic of widespread hot spring and high surface heat flows, especially on the north of Taiwan. Many previous studies reveal that the Tatun Volcano Group (TVG) has great potential to develop the geothermal energy. However, investment in geothermal development has inherent risk and how to reduce the exploration risk is the most important. The exploration risk can be lowered by using the play-fairway analysis (PFA) that integrates existing data representing the composite risk segments in the region in order to define the exploration strategy. As a result, this study has adapted this logic for geothermal exploration in TVG. There are two necessary factors in geothermal energy, heat and permeability. They are the composite risk segments for geothermal play-fairway analysis. This study analyzes existing geologic, geophysical and geochemical data to construct the heat and permeability potential models. Heat potential model is based on temperature gradient, temperature of hot spring, proximity to hot spring, hydrothermal alteration zones, helium isotope ratios, and magnetics. Permeability potential model is based on fault zone, minor fault, and micro-earthquake activities. Then, these two potential models are weighted by using the Analytical Hierarchy Process (AHP) and combined to rank geothermal favorability. Uncertainty model is occurred by the quality of data and spatial accuracy of data. The goal is to combine the potential model with the uncertainty model as a risk map to find the best drilling site for geothermal exploration in TVG. Integrated results indicate where geothermal potential is the highest and provide the best information for those who want to develop the geothermal exploration in TVG.

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.

Geophysics of Geothermal Areas: State of the Art and Future Development

NASA Astrophysics Data System (ADS)

Mabey, Don R.

In May 1980 a workshop organized by the Advanced School of Geophysics of the Ettore Majorana Center for Scientific Culture was held in Erice, Italy. The purpose was to present the state of the art and future development of geophysics as related to exploration for geothermal resources and the environmental impact of the development of geothermal systems. The workshop was addressed to “younger researchers working in scientific institutions and in public or private agencies and who are particularly interested in these aspects of the energy problem.” Fourteen formal lectures were presented to the workshop. This volume contains papers based on 10 of these lectures with a preface, forward, and introduction by the editors. The ten papers are “Heat Transfer in Geothermal Areas,” “Interpretation of Conductive Heat Flow Anomalies,” “Deep Electromagnetic Soundings in Geothermal Exploration,” “A Computation Method for dc Geoelectric Fields,” “Measurement of Ground Deformation in Geothermal Areas,” “Active Seismic Methods in Geothermal Exploration,” “The Role of Geophysical Investigations in the Discovery of the Latera Geothermal Field,” “Geothermal Resources Exploration in the European Community: The Geophysical Case,” “Activity Performed by AGIP (ENI Group) in the Field of Geothermal Energy,” and “Geothermal Exploration in the Western United States.” Six of the authors are from Italy, and one each is from Iceland, the Netherlands, West Germany, and the United States. All of the papers are in English.

Microbial community biofabrics in a geothermal mine adit.

PubMed

Spear, John R; Barton, Hazel A; Robertson, Charles E; Francis, Christopher A; Pace, Norman R

2007-10-01

Speleothems such as stalactites and stalagmites are usually considered to be mineralogical in composition and origin; however, microorganisms have been implicated in the development of some speleothems. We have identified and characterized the biological and mineralogical composition of mat-like biofabrics in two novel kinds of speleothems from a 50 degrees C geothermal mine adit near Glenwood Springs, CO. One type of structure consists of 2- to 3-cm-long, 3- to 4-mm-wide, leather-like, hollow, soda straw stalactites. Light and electron microscopy indicated that the stalactites are composed of a mineralized biofabric with several cell morphotypes in a laminated form, with gypsum and sulfur as the dominant mineral components. A small-subunit rRNA gene phylogenetic community analysis along the stalactite length yielded a diverse gradient of organisms, with a relatively simple suite of main constituents: Thermus spp., crenarchaeotes, Chloroflexi, and Gammaproteobacteria. PCR analysis also detected putative crenarchaeal ammonia monooxygenase subunit A (amoA) genes in this community, the majority related to sequences from other geothermal systems. The second type of speleothem, dumpling-like rafts floating on a 50 degrees C pool on the floor of the adit, showed a mat-like fabric of evidently living organisms on the outside of the dumpling, with a multimineral, amorphous, gypsum-based internal composition. These two novel types of biofabrics are examples of the complex roles that microbes can play in mineralization, weathering, and deposition processes in karst environments.

Philippine geothermal resources: General geological setting and development

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

Datuin, R.T.; Troncales, A.C.

1986-01-01

The Phillippine Archipelago has a composite geologic structure arising from the multi-stage development of volcanic-tectonic events evidenced by volcanism and seismic activity occurring along the active blocks of the major structural lines which traverse most of the major islands of the Phillipines. The widespread volcanic activity located along the active tectonic block has generated regions of high heat flow, where a vast number of potential rich geothermal resources could be exploited as an alternative source of energy. As part of a systematic geothermal development program launched by the Philippine government after the successful pilot study at the Tiwi geothermal fieldmore » in 1967 by the Commission on Volcanology (now called the Philippine Institute of Volcanology-PIV), the Philippines developed four geothermal fields in the period 1972-84. These four areas, Tiwi in Albay, Mak-Ban in Laguna, Tongonan in Leyte, and Palinpinon in Southern Negros, have already contributed 891 MW installed capacity to the total electrical power supply of the country, which is mainly dependent on oil resources. The Philippines envisaged that, with its accelerated geothermal energy programme, it would be able to achieve its target of reducing the country's dependence on imported fossil fuel by about 20% within the next decade through the utilization of its vast geothermal energy resources.« less

NANA Geothermal Assessment Program Final Report

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

Jay Hermanson

2010-06-22

In 2008, NANA Regional Corporation (NRC) assessed geothermal energy potential in the NANA region for both heat and/or electricity production. The Geothermal Assessment Project (GAP) was a systematic process that looked at community resources and the community's capacity and desire to develop these resources. In October 2007, the US Department of Energy's Tribal Energy Program awarded grant DE-FG36-07GO17075 to NRC for the GAP studies. Two moderately remote sites in the NANA region were judged to have the most potential for geothermal development: (1) Granite Mountain, about 40 miles south of Buckland, and (2) the Division Hot Springs area in themore » Purcell Mountains, about 40 miles south of Shungnak and Kobuk. Data were collected on-site at Granite Mountain Hot Springs in September 2009, and at Division Hot Springs in April 2010. Although both target geothermal areas could be further investigated with a variety of exploration techniques such as a remote sensing study, a soil geochemical study, or ground-based geophysical surveys, it was recommended that on-site or direct heat use development options are more attractive at this time, rather than investigations aimed more at electric power generation.« less

Combined Geothermal Potential of Subsurface Urban Heat Islands

NASA Astrophysics Data System (ADS)

Benz, Susanne; Bayer, Peter; Menberg, Kathrin; Blum, Philipp

2016-04-01

The subsurface urban heat island (SUHI) can be seen as a geothermal potential in form of elevated groundwater temperatures caused by anthropogenic heat fluxes into the subsurface. In this study, these fluxes are quantified for an annual timeframe in two German cities, Karlsruhe and Cologne. Our two-dimensional (2D) statistical analytical model determines the renewable and sustainable geothermal potential caused by six vertical anthropogenic heat fluxes into the subsurface: from (1) elevated ground surface temperatures, (2) basements, (3) sewage systems, (4) sewage leakage, (5) subway tunnels, and (6) district heating networks. The results show that at present 2.15 ± 1.42 PJ and 0.99 ± 0.32 PJ of heat are annually transported into the shallow groundwater of Karlsruhe and Cologne, respectively, due to anthropogenic heat fluxes into the subsurface. This is sufficient to sustainably cover 32% and 9% of the annual residential space heating demand of Karlsruhe and Cologne, respectively. However, most of the discussed anthropogenic fluxes into the subsurface are conductive heat fluxes and therefore dependent on the groundwater temperature itself. Accordingly, a decrease in groundwater temperature back to its natural (rural) state, achieved through the use of geothermal heat pumps, will increase these fluxes and with them the sustainable potential. Hence, we propose the introduction of a combined geothermal potential that maximizes the sustainability of urban shallow geothermal energy use and the efficiency of shallow geothermal systems by balancing groundwater temperature with anthropogenic heat fluxes into the subsurface. This will be a key element in the development of a demand-oriented, cost-efficient geothermal management tool with an additional focus on the sustainability of the urban heat sources.

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.

Role of Co-Vapors in Vapor Deposition Polymerization

PubMed Central

Lee, Ji Eun; Lee, Younghee; Ahn, Ki-Jin; Huh, Jinyoung; Shim, Hyeon Woo; Sampath, Gayathri; Im, Won Bin; Huh, Yang–Il; Yoon, Hyeonseok

2015-01-01

Polypyrrole (PPy)/cellulose (PPCL) composite papers were fabricated by vapor phase polymerization. Importantly, the vapor-phase deposition of PPy onto cellulose was assisted by employing different co-vapors namely methanol, ethanol, benzene, water, toluene and hexane, in addition to pyrrole. The resulting PPCL papers possessed high mechanical flexibility, large surface-to-volume ratio, and good redox properties. Their main properties were highly influenced by the nature of the co-vaporized solvent. The morphology and oxidation level of deposited PPy were tuned by employing co-vapors during the polymerization, which in turn led to change in the electrochemical properties of the PPCL papers. When methanol and ethanol were used as co-vapors, the conductivities of PPCL papers were found to have improved five times, which was likely due to the enhanced orientation of PPy chain by the polar co-vapors with high dipole moment. The specific capacitance of PPCL papers obtained using benzene, toluene, water and hexane co-vapors was higher than those of the others, which is attributed to the enlarged effective surface area of the electrode material. The results indicate that the judicious choice and combination of co-vapors in vapor-deposition polymerization (VDP) offers the possibility of tuning the morphological, electrical, and electrochemical properties of deposited conducting polymers. PMID:25673422

Optimizing Geothermal Drilling: Oil and Gas Technology Transfer

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

Denninger, Kate; Eustes, Alfred; Visser, Charles

There is a significant amount of financial risk associated with geothermal drilling. This study of drilling operations seeks opportunities to improve upon current practices and technologies. The scope of this study included analyzing 21 geothermal wells and 21 oil and gas wells. The goal was to determine a 'Perfect Well' using historical data to compare the best oil and gas well to the best geothermal well. Unfortunately, limitations encountered in the study included missing data (bit records, mud information, etc.) and poor data collection practices An online software database was used to format drilling data to IADC coded daily drillingmore » reports and generate figures for analysis. Six major issues have been found in geothermal drilling operations. These problems include lost circulation, rig/ equipment selection, cementing, penetration rate, drilling program, and time management. As a result of these issues, geothermal drilling averaged 56.4 days longer than drilling comparable oil and gas wells in the wells in this study. Roughly $13.9 million was spent on non-productive time in the 21 geothermal wells, compared with only $1.3 million in the oil and gas wells, assuming a cost of $50,000 per day. Comparable events such as drilling the same sized hole, tripping in/out, cementing, and running the same size casing took substantially less time in the oil and gas wells. Geothermal wells were drilled using older and/or less advanced technology to depths less than 10,000 feet, while oil and gas wells reached 12,500 feet faster with purpose built rigs. A new approach is now underway that will optimize drilling programs throughout the drilling industry using Mechanical Specific Energy (MSE) as a tool to realize efficient drilling processes. Potential improvements for current geothermal operations are: the use of electronic records, real time services, and official glossary terms to describe rig operations, and advanced drilling rigs/technology.« less

Optimizing Geothermal Drilling: Oil and Gas Technology Transfer

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

Tilley, Mitch; Eustes, Alfred; Visser, Charles

There is a significant amount of financial risk associated with geothermal drilling; however, there are opportunities to improve upon current practices and technologies used. The scope of this drilling operational study included 21 geothermal wells and 21 oil and gas wells. The goal was to determine a 'perfect well' using historical data to compare the best oil and gas well to the best geothermal well. Unfortunately, limitations encountered in the study included missing data (bit records, mud information, etc.), poor data collection, and difficult to ascertain handwriting. An online software database was used to format drilling data to IADC codedmore » daily drilling reports and generate analysis figures. Six major issues have been found in geothermal drilling operations. These problems include lost circulation, rig/equipment selection, cementing, penetration rate, drilling program, and time management. As a result of these issues, geothermal drilling averages 56.4 days longer than drilling comparable oil and gas wells in the wells in this study. Roughly $13.9 million would be lost due to non-productive time in the 21 geothermal wells and only $1.3 million in the oil and gas wells, assuming a cost of $50,000 per day. Comparable events such as drilling the same sized hole, tripping in/out, cementing, and running the same size casing took substantially less time in the oil and gas wells. Geothermal wells were drilled using older and/or less advanced technology to depths less than 10,000 feet, while oil and gas wells reached 12,500 feet faster with purpose built rigs. A new approach is now underway that will optimize drilling programs throughout the drilling industry. It is the use of Mechanical Specific Energy (MSE) as a tool to realize efficient drilling processes. However, a work-flow must also be established in order for there to be an efficient drilling program. Potential improvements for current geothermal operations are: the use of electronic records, real

Investigations of Very High Enthalpy Geothermal Resources in Iceland.

NASA Astrophysics Data System (ADS)

Elders, W. A.; Fridleifsson, G. O.

2012-12-01

The Iceland Deep Drilling Project (IDDP) is investigating the economic feasibility of producing electricity from supercritical geothermal reservoirs. Earlier modeling indicates that the power output of a geothermal well producing from a supercritical reservoir could potentially be an order of magnitude greater than that from a conventional hot geothermal reservoir, at the same volumetric flow rate. However, even in areas with an unusually high geothermal gradient, for normal hydrostatic pressure gradients reaching supercritical temperatures and pressures will require drilling to depths >4 km. In 2009 the IDDP attempted to drill the first deep supercritical well, IDDP-01, in the caldera of the Krafla volcano, in NE Iceland. However drilling had to be terminated at only 2.1 km depth when ~900°C rhyolite magma flowed into the well. Our studies indicate that this magma formed by partial melting of hydrothermally altered basalts within the Krafla caldera. Although this well was too shallow to reach supercritical pressures, it is highly productive, and is estimated to be capable of generating up to 36 MWe from the high-pressure, superheated steam produced from the upper contact zone of the intrusion. With a well-head temperature of ~440°C, it is at present apparently the hottest producing geothermal well in the world. A pilot plant is investigating the optimal utilization of this magmatically heated resource. A special issue of the journal Geothermics with 16 papers reporting on the IDDP-01 is in preparation. However, in order to continue the search for supercritical geothermal resources, planning is underway to drill a 4.5 km deep well at Reykjanes in SW Iceland in 2013-14. Although drilling deeper towards the heat source of this already developed high-temperature geothermal field will be more expensive, if a supercritical resource is found, this cost increase should be offset by the considerable increase in the power output and lifetime of the Reykjanes geothermal

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…

Geothermal Resource Verification for Air Force Bases,

DTIC Science & Technology

1981-06-01

phase of reservoir - ... geothermal techniques will begin to focus on the deeer, iso ’i fined reservoirs that will have little or no definitive surfa...1976. ;L-ison, D. L., PROGRAM REVIEW, GEOTHERMAL EXPLORATION AND ASSESSMENT TECHNOLOGY PROGRAM, U. S. Department of Energy, DOE/ET/ 27002 -6, December 1979

Optimal Management of Geothermal Heat Extraction

NASA Astrophysics Data System (ADS)

Patel, I. H.; Bielicki, J. M.; Buscheck, T. A.

2015-12-01

Geothermal energy technologies use the constant heat flux from the subsurface in order to produce heat or electricity for societal use. As such, a geothermal energy system is not inherently variable, like systems based on wind and solar resources, and an operator can conceivably control the rate at which heat is extracted and used directly, or converted into a commodity that is used. Although geothermal heat is a renewable resource, this heat can be depleted over time if the rate of heat extraction exceeds the natural rate of renewal (Rybach, 2003). For heat extraction used for commodities that are sold on the market, sustainability entails balancing the rate at which the reservoir renews with the rate at which heat is extracted and converted into profit, on a net present value basis. We present a model that couples natural resource economic approaches for managing renewable resources with simulations of geothermal reservoir performance in order to develop an optimal heat mining strategy that balances economic gain with the performance and renewability of the reservoir. Similar optimal control approaches have been extensively studied for renewable natural resource management of fisheries and forests (Bonfil, 2005; Gordon, 1954; Weitzman, 2003). Those models determine an optimal path of extraction of fish or timber, by balancing the regeneration of stocks of fish or timber that are not harvested with the profit from the sale of the fish or timber that is harvested. Our model balances the regeneration of reservoir temperature with the net proceeds from extracting heat and converting it to electricity that is sold to consumers. We used the Non-isothermal Unconfined-confined Flow and Transport (NUFT) model (Hao, Sun, & Nitao, 2011) to simulate the performance of a sedimentary geothermal reservoir under a variety of geologic and operational situations. The results of NUFT are incorporated into the natural resource economics model to determine production strategies that

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.

Impacts of geothermal energy developments on hydrological environment in hot spring areas

NASA Astrophysics Data System (ADS)

Taniguchi, M.

2015-12-01

Water-energy nexus such as geothermal energy developments and its impacts on groundwater, river water, and coastal water is one of the key issues for the sustainable society. This is because the demand of both water and energy resources will be increasing in near future, and the tradeoff between both resources and conflict between stakeholders will be arisen. Geothermal power generation, hot springs heat power generation, and steam power generation, are developing in hot spring areas in Ring of Fire countries including Japan, as renewable and sustainable energy. Impacts of the wasted hot water after using hot springs heat and steam power generation on ecosystem in the rivers have been observed in Beppu, Oita prefecture, Japan. The number of the fish species with wasted hot water in the Hirata river is much less than that without wasted hot water in Hiyakawa river although the dominant species of tilapia was found in the Hirata river with wasted hot water. The water temperature in Hirata rive is increased by wasted hot water by 10 degree C. The impacts of the developments of steam power generations on hot spring water and groundwater in downstream are also evaluated in Beppu. The decreases in temperature and volume of the hot spring water and groundwater after the development are concerning. Stakeholder analysis related to hot spa and power generation business and others in Beppu showed common interests in community development among stakeholders and gaps in prerequisite knowledge and recognition of the geothermal resource in terms of economic/non-economic value and utilization as power generation/hot-spring. We screened stakeholders of four categories (hot spring resorts inhabitants, industries, supporters, environmentalists), and set up three communities consisting of 50 persons of the above categories. One remarkable result regarding the pros and cons of geothermal power in general terms was that the supporter count increased greatly while the neutralities count

Effects of geothermal activity and primary production on molybdenum isotopes: Lake Mývatn, Iceland

NASA Astrophysics Data System (ADS)

Neely, R.; Gíslason, S. R.; Ólafsson, M.; Pearce, C. R.; Torssander, P.; Eiríksdóttir, E. S.; Burton, K. W.

2016-12-01

Molybdenum (Mo) is highly sensitive to oxidation state and its isotopes are used as a proxy for redox conditions in the palaeoenvironent, particularly in the oceans. Geothermal systems play an important role in element cycles, comprising 10% of the Mo flux to the oceans and the dominant mechanism for Mo ore formation in porphyry deposits. Currently, little is known about Mo isotopes in either geothermal or groundwaters or how these systems may affect global mass balance. This study takes the Lake Mývatn area as a natural laboratory to study both geothermally affected and unaffected groundwaters, along with seasonal variations in a lacustrine environment. We present a comprehensive elemental and Mo isotope study of two groundwater systems from a basaltic terrain in North Iceland. The waters are of meteoric origin, range in sampling temperature from 2-93°C and in Mo isotope composition (δ98MoNIST) from -0.40 to 1.81‰. The Mo isotopic signature of the waters is largely controlled by mixing between cold groundwaters (isotopically light) and a geothermal end member (isotopically heavy). One of these groundwater systems forms the only input into Lake Mývatn: one of the most productive lakes in the northern hemisphere. Here we also present a time series from the Laxá River, which is the only outflow from the lake. Whilst seasonal variations in Mo isotopes are small (from δ98MoNIST 0.1 to 0.3‰) they positively correlate (R2 = 0.8) with variations in δ34S (from δ43S 1.7 to 4.6‰) with a shift to a heavier isotope peaks in late summer (September). This increase in δ98Mo coincides with a documented cyanobacteria bloom in late July to early September, known to preferentially use light isotopes.

Nevada low-temperaure geothermal resource assessment: 1994. Final report

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

Garside, L.J.

Data compilation for the low-temperature program is being done by State Teams in two western states. Final products of the study include: a geothermal database, in hardcopy and as digital data (diskette) listing information on all known low- and moderate- temperature springs and wells in Nevada; a 1:1,000,000-scale map displaying these geothermal localities, and a bibliography of references on Nevada geothermal resources.

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

T. H. Brikowski; D. L. Norton; D. D. Blackwell

Final project report of natural state modeling effort for The Geysers geothermal field, California. Initial models examined the liquid-dominated state of the system, based on geologic constraints and calibrated to match observed whole rock delta-O18 isotope alteration. These models demonstrated that the early system was of generally low permeability (around 10{sup -12} m{sup 2}), with good hydraulic connectivity at depth (along the intrusive contact) and an intact caprock. Later effort in the project was directed at development of a two-phase, supercritical flow simulation package (EOS1sc) to accompany the Tough2 flow simulator. Geysers models made using this package show that ''simmering'',more » or the transient migration of vapor bubbles through the hydrothermal system, is the dominant transition state as the system progresses to vapor-dominated. Such a system is highly variable in space and time, making the rock record more difficult to interpret, since pressure-temperature indicators likely reflect only local, short duration conditions.« less

Subsurface temperatures and geothermal gradients on the North Slope, Alaska

USGS Publications Warehouse

Collett, Timothy S.; Bird, Kenneth J.; Magoon, Leslie B.

1989-01-01

Geothermal gradients as interpreted from a series of high-resolution stabilized well-bore-temperature surveys from 46 North Slope, Alaska, wells vary laterally and vertically throughout the near-surface sediment (0-2,000 m). The data from these surveys have been used in conjunction with depths of ice-bearing permafrost, as interpreted from 102 well logs, to project geothermal gradients within and below the ice-bearing permafrost sequence. The geothermal gradients calculated from the projected temperature profiles are similar to the geothermal gradients measured in the temperature surveys. Measured and projected geothermal gradients in the ice-bearing permafrost sequence range from 1.5??C/100m in the Prudhoe Bay area to 5.1??C/100m in the National Petroleum Reserve in Alaska (NPRA).

Institutional and environmental aspects of geothermal energy development

NASA Technical Reports Server (NTRS)

Citron, O. R.

1977-01-01

Until recently, the majority of work in geothermal energy development has been devoted to technical considerations of resource identification and extraction technologies. The increasing interest in exploiting the variety of geothermal resources has prompted an examination of the institutional barriers to their introduction for commercial use. A significant effort was undertaken by the Jet Propulsion Laboratory as a part of a national study to identify existing constraints to geothermal development and possible remedial actions. These aspects included legislative and legal parameters plus environmental, social, and economic considerations.

The YNP Metagenome Project: Environmental Parameters Responsible for Microbial Distribution in the Yellowstone Geothermal Ecosystem

PubMed Central

Inskeep, William P.; Jay, Zackary J.; Tringe, Susannah G.; Herrgård, Markus J.; Rusch, Douglas B.

2013-01-01

The Yellowstone geothermal complex contains over 10,000 diverse geothermal features that host numerous phylogenetically deeply rooted and poorly understood archaea, bacteria, and viruses. Microbial communities in high-temperature environments are generally less diverse than soil, marine, sediment, or lake habitats and therefore offer a tremendous opportunity for studying the structure and function of different model microbial communities using environmental metagenomics. One of the broader goals of this study was to establish linkages among microbial distribution, metabolic potential, and environmental variables. Twenty geochemically distinct geothermal ecosystems representing a broad spectrum of Yellowstone hot-spring environments were used for metagenomic and geochemical analysis and included approximately equal numbers of: (1) phototrophic mats, (2) “filamentous streamer” communities, and (3) archaeal-dominated sediments. The metagenomes were analyzed using a suite of complementary and integrative bioinformatic tools, including phylogenetic and functional analysis of both individual sequence reads and assemblies of predominant phylotypes. This volume identifies major environmental determinants of a large number of thermophilic microbial lineages, many of which have not been fully described in the literature nor previously cultivated to enable functional and genomic analyses. Moreover, protein family abundance comparisons and in-depth analyses of specific genes and metabolic pathways relevant to these hot-spring environments reveal hallmark signatures of metabolic capabilities that parallel the distribution of phylotypes across specific types of geochemical environments. PMID:23653623

Absence of remote earthquake triggering within the Coso and Salton Sea geothermal production fields

NASA Astrophysics Data System (ADS)

Zhang, Qiong; Lin, Guoqing; Zhan, Zhongwen; Chen, Xiaowei; Qin, Yan; Wdowinski, Shimon

2017-01-01

Geothermal areas are long recognized to be susceptible to remote earthquake triggering, probably due to the high seismicity rates and presence of geothermal fluids. However, anthropogenic injection and extraction activity may alter the stress state and fluid flow within the geothermal fields. Here we examine the remote triggering phenomena in the Coso geothermal field and its surrounding areas to assess possible anthropogenic effects. We find that triggered earthquakes are absent within the geothermal field but occur in the surrounding areas. Similar observation is also found in the Salton Sea geothermal field. We hypothesize that continuous geothermal operation has eliminated any significant differential pore pressure between fractures inside the geothermal field through flushing geothermal precipitations and sediments out of clogged fractures. To test this hypothesis, we analyze the pore-pressure-driven earthquake swarms, and they are found to occur outside or on the periphery of the geothermal production field. Therefore, our results suggest that the geothermal operation has changed the subsurface fracture network, and differential pore pressure is the primary controlling factor of remote triggering in geothermal fields.

Geothermal Economics Calculator (GEC) - additional modifications to final report as per GTP's request.

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

Gowda, Varun; Hogue, Michael

This report will discuss the methods and the results from economic impact analysis applied to the development of Enhanced Geothermal Systems (EGS), conventional hydrothermal, low temperature geothermal and coproduced fluid technologies resulting in electric power production. As part of this work, the Energy & Geoscience Institute (EGI) has developed a web-based Geothermal Economics Calculator (Geothermal Economics Calculator (GEC)) tool that is aimed at helping the industry perform geothermal systems analysis and study the associated impacts of specific geothermal investments or technological improvements on employment, energy and environment. It is well-known in the industry that geothermal power projects will generate positivemore » economic impacts for their host regions. Our aim in the assessment of these impacts includes quantification of the increase in overall economic output due to geothermal projects and of the job creation associated with this increase. Such an estimate of economic impacts of geothermal investments on employment, energy and the environment will also help us understand the contributions that the geothermal industry will have in achieving a sustainable path towards energy production.« less

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.

Downwell pump reliability: Geothermal experience update: Final report

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

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 downwellmore » 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.« less

Geologic controls on supercritical geothermal resources above magmatic intrusions

PubMed Central

Scott, Samuel; Driesner, Thomas; Weis, Philipp

2015-01-01

A new and economically attractive type of geothermal resource was recently discovered in the Krafla volcanic system, Iceland, consisting of supercritical water at 450 °C immediately above a 2-km deep magma body. Although utilizing such supercritical resources could multiply power production from geothermal wells, the abundance, location and size of similar resources are undefined. Here we present the first numerical simulations of supercritical geothermal resource formation, showing that they are an integral part of magma-driven geothermal systems. Potentially exploitable resources form in rocks with a brittle–ductile transition temperature higher than 450 °C, such as basalt. Water temperatures and enthalpies can exceed 400 °C and 3 MJ kg−1, depending on host rock permeability. Conventional high-enthalpy resources result from mixing of ascending supercritical and cooler surrounding water. Our models reproduce the measured thermal conditions of the resource discovered at Krafla. Similar resources may be widespread below conventional high-enthalpy geothermal systems. PMID:26211617

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

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

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

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,more » 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).« less

Geologic controls on supercritical geothermal resources above magmatic intrusions.

PubMed

Scott, Samuel; Driesner, Thomas; Weis, Philipp

2015-07-27

A new and economically attractive type of geothermal resource was recently discovered in the Krafla volcanic system, Iceland, consisting of supercritical water at 450 °C immediately above a 2-km deep magma body. Although utilizing such supercritical resources could multiply power production from geothermal wells, the abundance, location and size of similar resources are undefined. Here we present the first numerical simulations of supercritical geothermal resource formation, showing that they are an integral part of magma-driven geothermal systems. Potentially exploitable resources form in rocks with a brittle-ductile transition temperature higher than 450 °C, such as basalt. Water temperatures and enthalpies can exceed 400 °C and 3 MJ kg(-1), depending on host rock permeability. Conventional high-enthalpy resources result from mixing of ascending supercritical and cooler surrounding water. Our models reproduce the measured thermal conditions of the resource discovered at Krafla. Similar resources may be widespread below conventional high-enthalpy geothermal systems.

Design and optimization of geothermal power generation, heating, and cooling

NASA Astrophysics Data System (ADS)

Kanoglu, Mehmet

Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the

Measurement of Subsidence in the Yangbajain Geothermal Fields from TerraSAR-X

NASA Astrophysics Data System (ADS)

Li, Yongsheng; Zhang, Jingfa; Li, Zhenhong

2016-08-01

Yangbajain contains the largest geothermal energy power station in China. Geothermal explorations in Yangbajain first started in 1976, and two plants were subsequently built in 1981 and 1986. A large amount of geothermal fluids have been extracted since then, leading to considerable surface subsidence around the geothermal fields. In this paper, InSAR time series analysis is applied to map the subsidence of the Yangbajain geothermal fields during the period from December 2011 to November 2012 using 16 senses of TerraSAR-X stripmap SAR images. Due to its high resolution and short repeat cycle, TerraSAR-X provides detailed surface deformation information at the Yangbajain geothermal fields.

WESTERN ENERGY RESOURCES AND THE ENVIRONMENT: GEOTHERMAL ENERGY

EPA Science Inventory

Geothermal energy--from subsurface heat sources created by the underlying geologic configuration of the earth--is addressed, from an environmental research and development perspective. The report covers various geothermal energy systems, which serve as present or potential energy...

Isotopic and noble gas geochemistry in geothermal research

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

Kennedy, B.M.; DePaolo, D.J.

1997-12-31

The objective of this program is to provide, through isotopic analyses of fluids, fluid inclusions, and rocks and minerals coupled with improved methods for geochemical data analysis, needed information regarding sources of geothermal heat and fluids, the spatial distribution of fluid types, subsurface flow, water-rock reaction paths and rates, and the temporal evolution of geothermal systems. Isotopic studies of geothermal fluids have previously been limited to the light stable isotopes of H, C, and O. However, other isotopic systems such as the noble gases (He, Ne, Ar, Kr and Xe) and reactive elements (e.g. B, N, S, Sr and Pb)more » are complementary and may even be more important in some geothermal systems. The chemistry and isotopic composition of a fluid moving through the crust will change in space and time in response to varying chemical and physical parameters or by mixing with additional fluids. The chemically inert noble gases often see through these variations, making them excellent tracers for heat and fluid sources. Whereas, the isotopic compositions of reactive elements are useful tools in characterizing water-rock interaction and modeling the movement of fluids through a geothermal reservoir.« less

New geothermal heat extraction process to deliver clean power generation

ScienceCinema

McGrail, Pete

2017-12-27

A new method for capturing significantly more heat from low-temperature geothermal resources holds promise for generating virtually pollution-free electrical energy. Scientists at the Department of Energys Pacific Northwest National Laboratory will determine if their innovative approach can safely and economically extract and convert heat from vast untapped geothermal resources. The goal is to enable power generation from low-temperature geothermal resources at an economical cost. In addition to being a clean energy source without any greenhouse gas emissions, geothermal is also a steady and dependable source of power.

Hydrogeological, Hydrogeochemical and Isotope Geochemical Features of the Geothermal Waters in Seferihisar and Environs, Western Anatolia, Turkey

NASA Astrophysics Data System (ADS)

Özgür, Nevzat; Aras Pala, Ebru; Degirmenci, Saliha

2017-12-01

The study area of Seferihisar is located within the Izmir-Ankara suture in the NW of the Menderes Massif in western Anatolia, Turkey. The Paleozoic metamorphic rocks of the Menderes Massif form the basement rocks in the area which are overlain by 760 m thick Izmir-flysch series consisting of metamorphic rocks, limestones and ultrabasic rocks tectonically. The Pliocene Bahçecik formation which consists of an alternation of conglomerates, sandstones, claystones, lignite and limestones and shows a thickness of 300 m overlies the (İzmir) flysch series discordantly. This is overlain by 430 m thick Yeniköy formation composed of conglomerates, sandstones, claystones and clayey limestones discordantly. The Miocene volcanic rocks of Cumaovası overlie the Yeniköy formation concordantly which are overlain by alluvium and travertine deposits. Geothermal waters which are observed in the localities of Tuzla, Cumalı, Doğanbey and Karakoç are associated with NE-SW trending faults in the area. The geothermal waters in the area are considered as Na-Cl or Na-Cl-HCO3 type waters. The geothermal waters of Seferihisar and environs are identified to be Na+K>Ca>Mg dominant cations and Cl>HCO3>SO4 dominant anions. According to the diagram of Na/100-K/100-√Mg, a certainly part of the thermal waters can be considered as equilibrated thermal waters during some waters are of immature waters. According to the results of geochemical thermometers, the reservoir temperatures of thermal waters range from 150 to 240°C. The δ2H values of thermal waters are between -13,3 to -31,9, while δ18O values range from -2,55 to -5,70. The tritium contents of thermal waters are between 13 to 64±10 TU.

Optimization of Well Configuration for a Sedimentary Enhanced Geothermal Reservoir

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

Zhou, Mengnan; Cho, JaeKyoung; Zerpa, Luis E.

The extraction of geothermal energy in the form of hot water from sedimentary rock formations could expand the current geothermal energy resources toward new regions. From previous work, we observed that sedimentary geothermal reservoirs with relatively low permeability would require the application of enhancement techniques (e.g., well hydraulic stimulation) to achieve commercial production/injection rates. In this paper we extend our previous work to develop a methodology to determine the optimum well configuration that maximizes the hydraulic performance of the geothermal system. The geothermal systems considered consist of one vertical well doublet system with hydraulic fractures, and three horizontal well configurationsmore » with open-hole completion, longitudinal fractures and transverse fractures, respectively. A commercial thermal reservoir simulation is used to evaluate the geothermal reservoir performance using as design parameters the well spacing and the length of the horizontal wells. The results obtained from the numerical simulations are used to build a response surface model based on the multiple linear regression method. The optimum configuration of the sedimentary geothermal systems is obtained from the analysis of the response surface model. The proposed methodology is applied to a case study based on a reservoir model of the Lyons sandstone formation, located in the Wattenberg field, Denver-Julesburg basin, Colorado.« less

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.

NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency

Science.gov Websites

. Geothermal power plants like The Geysers produce energy by collecting steam from underground reservoirs and NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency For more information world's largest producer of geothermal power has improved its power production efficiency thanks to a new

Liquid-vapor relations for the system NaCl-H2O: summary of the P-T- x surface from 300° to 500°C

USGS Publications Warehouse

Bischoff, J.L.; Pitzer, Kenneth S.

1989-01-01

Experimental data on the vapor-liquid equilibrium relations for the system NaCl-H2O were compiled and compared in order to provide an improved estimate of the P-T-x surface between 300° to 500°C, a range for which the system changes from subcritical to critical behavior. Data for the three-phase curve (halite + liquid + vapor) and the NaCl-H2O critical curve were evaluated, and the best fits for these extrema then were used to guide selection of best fit for isothermal plots for the vapor-liquid region in-between. Smoothing was carried out in an iterative procedure by replotting the best-fit data as isobars and then as isopleths, until an internally consistent set of data was obtained. The results are presented in table form that will have application to theoretical modelling and to the understanding of two-phase behavior in saline geothermal systems.

The Significance of Acid Alteration in the Los Humeros High-Temperature Geothermal Field, Puebla, Mexico.

NASA Astrophysics Data System (ADS)

Elders, W. A.; Izquierdo, G.

2014-12-01

The Los Humeros geothermal field is a high-enthalpy hydrothermal system with more than 40 drilled deep wells, mostly producing high steam fractions at > 300oC. However, although it has a large resource potential, low permeability and corrosive acid fluids have hampered development so that it currently has an installed electrical generating capacity of only 40 MWe. The widespread production of low pH fluids from the reservoir is inconsistent with the marked absence in the reservoir rocks of hydrothermal minerals typical of acid alteration. Instead the hydrothermal alteration observed is typical of that due to neutral to alkaline pH waters reacting with the volcanic rocks of the production zones. Thus it appears that since the reservoir has recently suffered a marked drop in fluid pressure and is in process of transitioning from being water-dominated to being vapor-dominated. However sparse examples of acid leaching are observed locally at depths of about 2 km in the form of bleached, intensely silicified zones, in low permeability and very hot (>350oC) parts of reservoir. Although these leached rocks retain their primary volcanic and pyroclastic textures, they are altered almost entirely to microcrystalline quartz, with some relict pseudomorphs of plagioclase phenocrysts and traces of earlier-formed hydrothermal chlorite and pyrite. These acid-altered zones are usually only some tens of meters thick and deeper rocks lack such silicification. The acid fluids responsible for their formation could either be magmatic volatiles, or could be formed during production (e.g. reaction of water and salts forming hydrogen chloride by hydrolysis at high temperatures). The very high boron content of the fluids produced by the Los Humeros wells suggests that their ultimate source is most likely magmatic gases. However, these acid gases did not react widely with the rocks. We suggest that the silicified zones are forming locally where colder descending waters are encountering

Monitoring Geothermal Features in Yellowstone National Park with ATLAS Multispectral Imagery

NASA Technical Reports Server (NTRS)

Spruce, Joseph; Berglund, Judith

2000-01-01

The National Park Service (NPS) must produce an Environmental Impact Statement for each proposed development in the vicinity of known geothermal resource areas (KGRAs) in Yellowstone National Park. In addition, the NPS monitors indicator KGRAs for environmental quality and is still in the process of mapping many geothermal areas. The NPS currently maps geothermal features with field survey techniques. High resolution aerial multispectral remote sensing in the visible, NIR, SWIR, and thermal spectral regions could enable YNP geothermal features to be mapped more quickly and in greater detail In response, Yellowstone Ecosystems Studies, in partnership with NASA's Commercial Remote Sensing Program, is conducting a study on the use of Airborne Terrestrial Applications Sensor (ATLAS) multispectral data for monitoring geothermal features in the Upper Geyser Basin. ATLAS data were acquired at 2.5 meter resolution on August 17, 2000. These data were processed into land cover classifications and relative temperature maps. For sufficiently large features, the ATLAS data can map geothermal areas in terms of geyser pools and hot springs, plus multiple categories of geothermal runoff that are apparently indicative of temperature gradients and microbial matting communities. In addition, the ATLAS maps clearly identify geyserite areas. The thermal bands contributed to classification success and to the computation of relative temperature. With masking techniques, one can assess the influence of geothermal features on the Firehole River. Preliminary results appear to confirm ATLAS data utility for mapping and monitoring geothermal features. Future work will include classification refinement and additional validation.

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

Laboratory Simulation of the Geothermal Heating Effects on Ocean Overturning Circulation

NASA Astrophysics Data System (ADS)

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

2016-12-01

A large-scale circulation subject to an additional heat flux from the bottom is investigated laboratorially, motivated by understanding the geothermal heating effects on ocean circulation. Despite its idealization, our experiment suggests that the leading order effect of geothermal heating is to significantly enhance the abyssal overturning, which is in agreement with the findings in ocean circulation models. Our results also suggest that geothermal heating could not influence the poleward heat transport due to the strong stratification in the thermocline. It is revealed that the ratio of geothermal-flux-induced turbulent dissipation to the dissipation due to other energies is the key determining the dynamical importance of geothermal heating. This quantity explains why the impact of geothermal heating is sensitive to the deep stratification and the diapycnal mixing, in addition to the amount of geothermal flux. Moreover, this dissipation ratio may be used to understand results from different studies in a consistent way. This work is supported by the Hong Kong Research Grants Council under Grant No. CUHK1430115 and by the CUHK Research Committee through a Direct Grant (Project No. 3132740).

Magmatic-like fluid source of the Chingshui geothermal field, NE Taiwan evidenced by carbonate clumped-isotope paleothermometry

NASA Astrophysics Data System (ADS)

Lu, Yi-Chia; Song, Sheng-Rong; Wang, Pei-Ling; Wu, Chung-Che; Mii, Horng-Sheng; MacDonald, John; Shen, Chuan-Chou; John, Cédric M.

2017-11-01

The Chingshui geothermal field, a moderate-temperature and water-dominated hydrothermal system, was the site of the first geothermal power plant in Taiwan. Many geological, geophysical and geochemical studies using more than 21 drilled wells have been performed since the 1960s. However, there are still controversies regarding the heat and fluid sources due to the tectonically complicated geological setting. To clarify the heat and fluid sources, we analyzed clumped isotopes with carbon and oxygen isotopic compositions of calcite scaling in geothermal wells and veins on outcrops and calculated the δ18O values of the source fluids. Two populations of δ18O values were calculated: -5.8 ± 0.8‰ VSMOW from scaling in the well and -1.0 ± 1.6‰ to 10.0 ± 1.3‰ VSMOW from outcropping calcite veins, indicative of meteoric and magmatic fluid sources, respectively. Meanwhile, two hydrothermal reservoirs at different depths have been identified by magnetotelluric (MT) imaging with micro-seismicity underneath this area. As a result, we propose a two-reservoir model: the shallow reservoir provides fluids from meteoric water for the scaling sampled from wells, whereas the deep reservoir provides magmatic fluids from deep marble decarbonization recorded in outcropping calcite veins.

Nevada Renewable Energy Training Project: Geothermal Power Plant Operators

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

Jim, Nichols

2014-04-29

The purpose of this project was to develop and institute a training program for certified geothermal power plant operators (GPO). An advisory board consisting of subject matter experts from the geothermal energy industry and academia identified the critical skill sets required for this profession. A 34-credit Certificate of Achievement (COA), Geothermal Power Plant Operator, was developed using eight existing courses and developing five new courses. Approval from the Nevada System of Higher Education Board of Regents was obtained. A 2,400 sq. ft. geothermal/fluid mechanics laboratory and a 3,000 sq. ft. outdoor demonstration laboratory were constructed for hands-on training. Students alsomore » participated in field trips to geothermal power plants in the region. The majority of students were able to complete the program in 2-3 semesters, depending on their level of math proficiency. Additionally the COA allowed students to continue to an Associate of Applied Science (AAS), Energy Technologies with an emphasis in Geothermal Energy (26 additional credits), if they desired. The COA and AAS are stackable degrees, which provide students with an ongoing career pathway. Articulation agreements with other NSHE institutions provide students with additional opportunities to pursue a Bachelor of Applied Science in Management or Instrumentation. Job placement for COA graduates has been excellent.« less

Environmental aspects of the geothermal energy utilisation in Poland

NASA Astrophysics Data System (ADS)

Sowiżdżał, Anna; Tomaszewska, Barbara; Drabik, Anna

2017-11-01

Geothermal energy is considered as a strategic and sustainable source of renewable energy that can be effectively managed in several economic sectors. In Poland, despite the abundant potential of such resources, its share in the energy mix of renewable energy sources remains insubstantial. The utilisation of geothermal resources in Poland is related to the hydrogeothermal resources, however, numerous researches related to petrogeothermal energy resources are being performed. The utilisation of each type of energy, including geothermal, has an impact on the natural environment. In case of the effective development of geothermal energy resources, many environmental benefits are pointed out. The primary one is the extraction of clean, green energy that is characterised by the zero-emission rate of pollutants into the atmosphere, what considering the current environmental pollution in many Polish cities remains the extremely important issue. On the other hand, the utilisation of geothermal energy might influence the natural environment negatively. Beginning from the phase of drilling, which strongly interferes with the local landscape or acoustic climate, to the stage of energy exploitation. It should be noted that the efficient and sustainable use of geothermal energy resources is closely linked with the current law regulations at national and European level.

Transported Low-Temperature Geothermal Energy for Thermal End Uses Final Report

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

Yang, Zhiyao; Liu, Xiaobing; Gluesenkamp, Kyle R

2016-10-01

The use of geothermal energy is an emerging area for improving the nation’s energy resiliency. Conventionally, geothermal energy applications have focused on power generation using high temperature hydrothermal resources or enhanced geothermal systems. However, many low temperature (below 150°C/300°F) geothermal resources are also available but have not been fully utilized. For example, it is estimated that 25 billion barrels of geothermal fluid (mostly water and some dissolved solids) at 176°F to 302°F (80°C to 150°C) is coproduced annually at oil and gas wells in the United States (DOE 2015). The heat contained in coproduced geothermal fluid (also referred as “coproducedmore » water”) is typically wasted because the fluid is reinjected back into the ground without extracting the heat.« less

Status of geothermal direct use in Poland

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

Bujakowski, W.

1997-12-31

Geothermal Energy uses the natural heat of the Earth. It is a local energy source, competitive, renewable and acceptable from the ecological and social points of view, which is used either for the electricity production, or for direct application such as a district heating. A great number of operating geothermal installations are found in Europe. European Community energy programs foresee in the coming years a great reduction of conventional fuel consumption, due to the risks that dependency on imported fuels implies and to the future environmental problems, which a mass exploitation of these fuels can lead to. Thus, EC energymore » policy is aimed at a drastic reduction of oil consumption and at diversification of primary energy sources. This paper will present the results from the exploration and evaluation of geothermal water resources in Poland. Herewith, a short description of performed projects, examples of designed geothermal water utilization, some economical, sociological, ecological and political aspects of present out and future projects will be presented.« less

Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

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

Grant, M.A.; Truesdell, A.H.; Manon, A.

1981-01-01

Chemical and physical data suggest that the relatively shallow western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapor. Local boiling occurs near most wells in response to pressure decreases, but no general vapor zone hasmore » formed.« less

Monitoring environmental and related performance parameters for a Rankine-cycle turbine electric generator utilizing geothermal energy at the Gila Hot Springs, New Mexico

NASA Astrophysics Data System (ADS)

Starkey, A. H.; Icerman, L.

1984-08-01

The environmental effects associated with the operation of a privately owned Rankine-cycle turbogenerator unit using low temperature geothermal resources in the form of free-flowing hot springs to produce electricity in a remote, rural area were studied. The following conclusions pertain to the operation of the turbogenerator system: (1) the heat exchanger could not provide sufficient freon vapor at the required pressures to provide adequate thermal input to the turbine; (2) conversion or redesign of the condenser and return pump to function adequately represents a problem of unknown difficulty; (3) all pressure and heat transfer tests indicated that a custom designed heat exchanger built on-site would provide adequate vapor at pressures high enough to power a 10-kW (sub e) or perhaps larger generator; and (4) automated control systems are needed for the hot and cold water supplies and the freon return pump.

Geothermal Resource Reporting Metric (GRRM) Developed for the U.S. Department of Energy's Geothermal Technologies Office

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

Young, Katherine R.; Wall, Anna M.; Dobson, Patrick F.

This paper reviews a methodology being developed for reporting geothermal resources and project progress. The goal is to provide the U.S. Department of Energy's (DOE) Geothermal Technologies Office (GTO) with a consistent and comprehensible means of evaluating the impacts of its funding programs. This framework will allow the GTO to assess the effectiveness of research, development, and deployment (RD&D) funding, prioritize funding requests, and demonstrate the value of RD&D programs to the U.S. Congress and the public. Standards and reporting codes used in other countries and energy sectors provide guidance to develop the relevant geothermal methodology, but industry feedback andmore » our analysis suggest that the existing models have drawbacks that should be addressed. In order to formulate a comprehensive metric for use by the GTO, we analyzed existing resource assessments and reporting methodologies for the geothermal, mining, and oil and gas industries, and sought input from industry, investors, academia, national labs, and other government agencies. Using this background research as a guide, we describe a methodology for evaluating and reporting on GTO funding according to resource grade (geological, technical and socio-economic) and project progress. This methodology would allow GTO to target funding, measure impact by monitoring the progression of projects, or assess geological potential of targeted areas for development.« less

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.

The missing link between submarine volcano and promising geothermal potential in Jinshan, Northern Taiwan

NASA Astrophysics Data System (ADS)

Wang, S. C.; Hutchings, L.; Chang, C. C.; Lee, C. S.

2017-12-01

The Tatun volcanic group (TVG) and the Keelung submarine volcano (KSV) are active volcanoes and surrounding three nuclear plant sites in north Taiwan. The famous Jinshan-Wanli hot springs locates between TVG and KSV, moreover, the geochemical anomalies of acidic boiling springs on the seacoast infer that the origin is from magmatic fluids, sea water and meteoric water mixture, strongly implying that mantle fluids ascends into the shallow crust. The evidence for a magma chamber, submarine volcano, and boiling springs have a close spatial relationship. Based on UNECE specifications to Geothermal Energy Resources (2016), the Jinshan-Wanli geothermal area could be classified as Known Geothermal Energy Source for geothermal direct use and Potential Geothermal Energy Source for conventional geothermal system. High resolution reservoir exploration and modeling in Jinshan-Wanli geothermal area is developing for drilling risk mitigation. The geothermal team of National Taiwan Ocean University and local experts are cooperating for further exploration drilling and geothermal source evaluation. Keywords: geothermal resource evaluation, Jinshan-Wanli geothermal area, submarine volcano

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,…

Koenraad Beckers: A Love of Science Benefits Geothermal Research | News |

Science.gov Websites

for this avid biker. The reason, though, is unusual. Passionate about geothermal energy research, he forms of geothermal energy are gaining traction in Europe, China, and elsewhere, Koenraad says support ," he says-as well as a good way to keep tabs on geothermal energy

2014 Low-Temperature and Coproduced Geothermal Resources Fact Sheet

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

Tim Reinhardt, Program Manager

2014-09-01

As a growing sector of geothermal energy development, the Low-Temperature Program supports innovative technologies that enable electricity production and cascaded uses from geothermal resources below 300° Fahrenheit.

A comparison of economic evaluation models as applied to geothermal energy technology

NASA Technical Reports Server (NTRS)

Ziman, G. M.; Rosenberg, L. S.

1983-01-01

Several cost estimation and financial cash flow models have been applied to a series of geothermal case studies. In order to draw conclusions about relative performance and applicability of these models to geothermal projects, the consistency of results was assessed. The model outputs of principal interest in this study were net present value, internal rate of return, or levelized breakeven price. The models used were VENVAL, a venture analysis model; the Geothermal Probabilistic Cost Model (GPC Model); the Alternative Power Systems Economic Analysis Model (APSEAM); the Geothermal Loan Guarantee Cash Flow Model (GCFM); and the GEOCOST and GEOCITY geothermal models. The case studies to which the models were applied include a geothermal reservoir at Heber, CA; a geothermal eletric power plant to be located at the Heber site; an alcohol fuels production facility to be built at Raft River, ID; and a direct-use, district heating system in Susanville, CA.

Corrosion engineering in the utilization of the Raft River geothermal resource

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

Miller, R.L.

1976-08-01

The economic impact of corrosion and the particular problems of corrosion in the utilization of geothermal energy resources are noted. Corrosion is defined and the parameters that control corrosion in geothermal systems are discussed. A general background of corrosion is presented in the context of the various forms of corrosion, in relation to the Raft River geothermal system. A basic reference for mechanical design engineers involved in the design of geothermal energy recovery systems is provided.

Geothermal Potential for China, Poland and Turkey with/Financing Workbook

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

Keller, J G

This collection of documents presents the results of assessments of the geothermal power potential in three countries: China, Poland, and Turkey. Also included is a Geothermal Financing Workbook, which is intended to provide a comprehensive package of information on financing, financing plans, financial analysis, and financial sources for smaller geothermal resource developers. All three countries are facing ever increasing demands for power in the coming decades, but each has some barriers to fully developing existing resources. For Poland and Turkey, it is important that legislation specific to geothermal resource development be enacted. For China, a crucial step is to developmore » more detailed and accurate estimates of resource potential. All three countries could benefit from the expertise of U.S. geothermal companies, and this collection of material provides crucial information for those interested companies.« less

New Mexico statewide geothermal energy program. Final technical report

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

Icerman, L.; Parker, S.K.

1988-04-01

This report summarizes the results of geothermal energy resource assessment work conducted by the New Mexico Statewide Geothermal Energy Program during the period September 7, 1984, through February 29, 1988, under the sponsorship of the US Dept. of Energy and the State of New Mexico Research and Development Institute. The research program was administered by the New Mexico Research and Development Institute and was conducted by professional staff members at New Mexico State University and Lightning Dock Geothermal, Inc. The report is divided into four chapters, which correspond to the principal tasks delineated in the above grant. This work extendsmore » the knowledge of the geothermal energy resource base in southern New Mexico with the potential for commercial applications.« less

GEOTHERMAL ENVIRONMENTAL IMPACT ASSESSMENT: SUBSURFACE ENVIRONMENTAL ASSESSMENT FOR FOUR GEOTHERMAL SYSTEMS

EPA Science Inventory

This is the second in a series of reports concerning the environmental assessments of effluent extraction, energy conversion, and waste disposal in geothermal systems. This study involves the subsurface environmental impact of the Imperial Valley and The Geysers, California; Klam...

The annual cycle of stratospheric water vapor in a general circulation model

NASA Technical Reports Server (NTRS)

Mote, Philip W.

1995-01-01

The application of general circulation models (GCM's) to stratospheric chemistry and transport both permits and requires a thorough investigation of stratospheric water vapor. The National Center for Atmospheric Research has redesigned its GCM, the Community Climate Model (CCM2), to enable studies of the chemistry and transport of tracers including water vapor; the importance of water vapor to the climate and chemistry of the stratosphere requires that it be better understood in the atmosphere and well represented in the model. In this study, methane is carried as a tracer and converted to water; this simple chemistry provides an adequate representation of the upper stratospheric water vapor source. The cold temperature bias in the winter polar stratosphere, which the CCM2 shares with other GCM's, produces excessive dehydration in the southern hemisphere, but this dry bias can be ameliorated by setting a minimum vapor pressure. The CCM2's water vapor distribution and seasonality compare favorably with observations in many respects, though seasonal variations including the upper stratospheric semiannual oscillation are generally too small. Southern polar dehydration affects midlatitude water vapor mixing ratios by a few tenths of a part per million, mostly after the demise of the vortex. The annual cycle of water vapor in the tropical and northern midlatitude lower stratosphere is dominated by drying at the tropical tropopause. Water vapor has a longer adjustment time than methane and had not reached equilibrium at the end of the 9 years simulated here.

Numerical and experimental design of coaxial shallow geothermal energy systems

NASA Astrophysics Data System (ADS)

Raghavan, Niranjan

Geothermal Energy has emerged as one of the front runners in the energy race because of its performance efficiency, abundance and production competitiveness. Today, geothermal energy is used in many regions of the world as a sustainable solution for decreasing dependence on fossil fuels and reducing health hazards. However, projects related to geothermal energy have not received their deserved recognition due to lack of computational tools associated with them and economic misconceptions related to their installation and functioning. This research focuses on numerical and experimental system design analysis of vertical shallow geothermal energy systems. The driving force is the temperature difference between a finite depth beneath the earth and its surface stimulates continuous exchange of thermal energy from sub-surface to the surface (a geothermal gradient is set up). This heat gradient is captured by the circulating refrigerant and thus, tapping the geothermal energy from shallow depths. Traditionally, U-bend systems, which consist of two one-inch pipes with a U-bend connector at the bottom, have been widely used in geothermal applications. Alternative systems include coaxial pipes (pipe-in-pipe) that are the main focus of this research. It has been studied that coaxial pipes have significantly higher thermal performance characteristics than U-bend pipes, with comparative production and installation costs. This makes them a viable design upgrade to the traditional piping systems. Analytical and numerical heat transfer analysis of the coaxial system is carried out with the help of ABAQUS software. It is tested by varying independent parameters such as materials, soil conditions and effect of thermal contact conductance on heat transfer characteristics. With the above information, this research aims at formulating a preliminary theoretical design setup for an experimental study to quantify and compare the heat transfer characteristics of U-bend and coaxial

Hawaii's geothermal program

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

Zorpette, G.

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, growersmore » 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.« less

Rock geochemistry related to mineralization processes in geothermal areas

NASA Astrophysics Data System (ADS)

Kausar, A. Al; Indarto, S.; Setiawan, I.

2018-02-01

Abundant geothermal systems in Indonesia suggest high heat and mass transfer associated with recent or paleovolcanic arcs. In the active geothermal system, the upflow of mixed fluid between late stage hydrothermal and meteoric water might contain mass of minerals associated with epithermal mineralisation process as exemplified at Lihir gold mine in Papua New Guinea. In Indonesia, there is a lack of study related to the precious metals occurrence within active geothermal area. Therefore, in this paper, we investigate the possibility of mineralization process in active geothermal area of Guci, Central Java by using geochemical analysis. There are a lot of conducted geochemical analysis of water, soil and gas by mapping the temperature, pH, Hg and CO2 distribution, and estimating subsurface temperature based on geothermometry approach. Then we also apply rock geochemistry to find minerals that indicate the presence of mineralization. The result from selected geothermal area shows the presence of pyrite and chalcopyrite minerals on the laharic breccias at Kali Putih, Sudikampir. Mineralization is formed within host rock and the veins are associated with gold polymetallic mineralization.

Microbial Community Biofabrics in a Geothermal Mine Adit▿ †

PubMed Central

Spear, John R.; Barton, Hazel A.; Robertson, Charles E.; Francis, Christopher A.; Pace, Norman R.

2007-01-01

Speleothems such as stalactites and stalagmites are usually considered to be mineralogical in composition and origin; however, microorganisms have been implicated in the development of some speleothems. We have identified and characterized the biological and mineralogical composition of mat-like biofabrics in two novel kinds of speleothems from a 50°C geothermal mine adit near Glenwood Springs, CO. One type of structure consists of 2- to 3-cm-long, 3- to 4-mm-wide, leather-like, hollow, soda straw stalactites. Light and electron microscopy indicated that the stalactites are composed of a mineralized biofabric with several cell morphotypes in a laminated form, with gypsum and sulfur as the dominant mineral components. A small-subunit rRNA gene phylogenetic community analysis along the stalactite length yielded a diverse gradient of organisms, with a relatively simple suite of main constituents: Thermus spp., crenarchaeotes, Chloroflexi, and Gammaproteobacteria. PCR analysis also detected putative crenarchaeal ammonia monooxygenase subunit A (amoA) genes in this community, the majority related to sequences from other geothermal systems. The second type of speleothem, dumpling-like rafts floating on a 50°C pool on the floor of the adit, showed a mat-like fabric of evidently living organisms on the outside of the dumpling, with a multimineral, amorphous, gypsum-based internal composition. These two novel types of biofabrics are examples of the complex roles that microbes can play in mineralization, weathering, and deposition processes in karst environments. PMID:17693567