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At least 1,027 records · Page 57
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Geothermal-Enabled Zero Energy Electric Community: An Integrated System Design Study

In northern climates, developing a zero-energy community is increasingly costly. Building loads are higher, thanks to the colder weather, and solar PV is both less effective, due to lower solar incidence, and misalignment with the buildings' energy needs (summer production, winter demands). We present a novel application for geothermal energy production in support of a zero-energy community, combining appropriate energy efficiency (demand design), geothermal production (supply design), and asset dispatch as an integrated technoeconomic package. This poster presents the process used to explore this system integration challenge, initial results, and discusses some of the technical opportunities for increasing the community-scale adoption of geothermal as an electric and thermal resource. Results indicate that under certain conditions, community-scale geothermal resources are quite competitive with today's grid tariffs and with PV, showing an LCOE within $0.01/kWh before consideration of important grid modernization factors such as resiliency and reliability.

15 GEOTHERMAL ENERGY↗
DOE OSTI2022

Numerical modeling and parametric study of a dual purpose underground thermal battery

We report integrating thermal energy storage with building energy systems can enable flexible building electric demands at buildings to help mitigate the mismatch between electricity supply and demand. A novel building heating and cooling system that integrates a dual-source heat pump with hybrid thermal storage named dual-purpose underground thermal battery (DPUTB) has been developed for reshaping building electric demands. The proposed DPUTB integrated geothermal heat pump system is an original innovation that enables Grid-interactive Energy Efficient buildings. This paper focuses on the study of the novel DPUTB. The DPUTB works as both a thermal storage tank (an inner tank) and a ground heat exchanger (an outer tank separated from the inner tank by the insulation material). High fidelity and computationally effective models are needed to predict the performance of the novel DPUTB. This study has developed a simplified dynamic model for the DPUTB according to heat transfer and energy conservation principles and validated it by using experimental data obtained from testing a small-scale DPUTB apparatus. A parametric study was conducted to identify a design that can achieve the target thermal storage performance of load shift and energy efficiency. The parametric study results show that the inner tank shell thermal conductivity and the phase change material's melting point are the two most influencing factors on the performance of the DPUTB. One single full-size DPUTB with the identified design could provide 1-ton cooling (3.51 kW) with the supply temperature lower than 11 °C for 4 hours in summer after being fully charged in 8 hours. The inner tank filled with phase change material is for cooling thermal storage as a latent tank in the design. However, its capacity can be as high as 60 MJ as a sensible water tank for heating storage in winter. In the future study, the DPUTB model will be incorporated into the dual-source heat pump system for evaluating the overall system performance of demand side management in the long term.

25 ENERGY STORAGE↗
DOE OSTI2019

Geothermal-Enabled Zero Energy Electric Community -- An Integrated System Design Study: Preprint

In northern climates, developing a zero-energy community is increasingly costly. Building loads are higher, thanks to the colder weather, and solar PV is both less effective, due to lower solar incidence, and misalignment with the buildings' energy needs (summer production, winter demands). We present a novel application for geothermal energy production in support of a zero-energy community, combining appropriate energy efficiency (demand design), geothermal production (supply design), and asset dispatch as an integrated technoeconomic package. This paper presents the process used to explore this system integration challenge, initial results, and discusses some of the technical opportunities for increasing the community-scale adoption of geothermal as an electric and thermal resource. Results indicate that under certain conditions, community-scale geothermal resources are quite competitive with today's grid tariffs and with PV, showing an LCOE within $0.01/kWh before consideration of important grid modernization factors such as resiliency and reliability.

15 GEOTHERMAL ENERGY↗
DOE OSTI2017

Update on Geothermal Direct-Use Installations in the United States

Direct-use of geothermal energy currently has limited penetration in the United States, with an estimated installed capacity of about 500 MWth, supplying on the order of 0.01% of the total annual U.S. heat demand (about 30 EJ). We see higher penetration levels in other countries such as Iceland (about 90%) and Hungary (2.5%). An updated database of geothermal direct-use systems in the U.S. has been compiled and analyzed, building upon the Oregon Institute of Technology (OIT) Geo-Heat Center direct-use database. Types of directuse applications examined include hot springs resorts and pools, aquaculture farms, greenhouses, and district heating systems, among others; power-generating facilities and ground-source heat pumps were excluded. Where possible, the current operation status, open and close dates, well data, and other technical data were obtained for each entry. The database contains 545 installations, of which 407 are open, 108 are closed, and 30 have an unknown status. Spas are the most common type of installation, accounting for 50% of installations by number. Aquaculture installations (46 out of 407 open installations) account for the largest percentage (26%) of installed capacity in operation (129 MWth out of 501 MWth). Historical deployment curves show the installed capacity significantly increased in the 1970s and 1980s mainly due to development of geothermal district heating, aquaculture, and greenhouse systems. Since the 2000s, geothermal direct-use development appears to have slowed, and the number of sites in operation decreased due to closures. Case studies reveal multiple barriers to geothermal direct-use implementation and operation, including 1) existence of an information gap among stakeholders, developers, and the general public, 2) competition from cheap natural gas, and 3) the family-owned, small-scale nature of businesses might result in discontinuation among generations.

15 GEOTHERMAL ENERGY↗
DOE OSTI2016

Multifluid geo-energy systems: Using geologic CO 2 storage for geothermal energy production and grid-scale energy storage in sedimentary basins

We present an approach that uses the huge fluid and thermal storage capacity of the subsurface, together with geologic carbon dioxide (CO 2 ) storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources, as well as excess energy on electric grids. Captured CO 2 is injected into saline aquifers to store pressure, generate artesian flow of brine, and provide a supplemental working fluid for efficient heat extraction and power conversion. Concentric rings of injection and production wells create a hydraulic mound to store pressure, CO 2 , and thermal energy. This energy storage can take excess power from the grid and excess/waste thermal energy, and dispatch that energy when it is demanded and thus enable higher penetration of variable renewable energy technologies (e.g., wind, solar). CO 2 stored in the subsurface functions as a cushion gas to provide enormous pressure-storage capacity and displace large quantities of brine, some of which can be treated for a variety of beneficial uses. Geothermal power and energy-storage applications may generate enough revenues to compensate for CO 2 capture costs. While our approach can use nitrogen (N 2 ), in addition to CO 2 , as a supplemental fluid, and store thermal energy, this study focuses using CO 2 for geothermal energy production and grid-scale energy storage. We conduct a techno-economic assessment to determine the levelized cost of electricity of using this approach to generate geothermal power. We present a reservoir pressure-management strategy that diverts a small portion of the produced brine for beneficial consumptive use to reduce the pumping cost of fluid recirculation, while reducing the risk of seismicity, caprock fracture, and CO 2 leakage.

15 GEOTHERMAL ENERGY↗
DOE OSTI2017

Well Monitoring System For EGS

This grant is a collection of projects designed to move aircraft high temperature electronics technology into the geothermal industry. Randy Normann is the lead. He licensed the HT83SNL00 chip from Sandia National Labs. This chip enables aircraft developed electronics for work within a geothermal well logging tool. However, additional elements are needed to achieve commercially successful logging tools. These elements are offered by a strong list of industrial partners on this grant as: Electrochemical Systems Inc. for HT Rechargeable Batteries, Frequency Management Systems for 300C digital clock, Sandia National Labs for experts in high temperature solder, Honeywell Solid-State Electronics Center for reprogrammable high temperature memory. During the course of this project MagiQ Technologies for high temperature fiber optics.

15 GEOTHERMAL ENERGY↗
DOE OSTI2012

Recovery Act - Geothermal Technologies Program: Ground Source Heat Pumps Final Scientific/Technical Report

A large centralized geothermal heat pump system was installed to provide ice making, space cooling, space heating, process water heating, and domestic hot water heating for an ice arena in Eagan Minnesota. This paper provides information related to the design and construction of the project. Additionally, operating conditions for 12 months after start-up are provided.

15 GEOTHERMAL ENERGY↗
DOE OSTI2026

Value of Geothermal Energy Storage for Supply-Side and Demand-Side Applications

This report presents the results of a study examining the value potential for geothermal energy storage (GES), a long-duration energy storage resource that stores thermal and/or geomechanical energy in the subsurface. GES could benefit the overall U.S. power system by temporally shifting electricity generation (supply-side) or meeting building heating and cooling load (demand-side). This report analyzes supply-side and demand-side opportunities independently because of differences in applications and models. Currently there is significant uncertainty about the development costs for GES, with only a limited number of demonstration plants for electric energy storage and building heating and cooling storage developments. In this report, we estimate the value of supply-side and demand-side GES to the bulk power system in the contiguous United States. Because of the significant uncertainty about GES development costs, this analysis does not consider GES deployment costs but instead focuses on the value of GES to the U.S. electricity system. The estimated values of GES provide reference points for economically competitive commercial cost targets. Supply-side GES is modeled as part of an enhanced geothermal system (EGS) generation plant in NREL's Regional Energy Deployment System (ReEDS) capacity expansion model (Ho et al. 2021). In contrast to conventional geothermal plants, which generate constant power, EGS plants have unique features that may allow for in-reservoir energy storage for flexible generation. Demand-side GES for heating and cooling, including seasonal hot and cold storage and short-duration heat pump storage, is incorporated into a price-taker model using Cambium electricity marginal cost projections. To establish an upper bound for the value of GES, analysis focused on favorable scenarios for storage with high generation from zero marginal cost, variable renewable energy resources. High penetrations of variable renewable energy generation can increase hourly electricity price variability, which increases the value of temporal energy arbitrage for storage technologies like GES.

15 GEOTHERMAL ENERGY↗
DOE OSTI2018

PoroTomo: Horizontal Distributed Acoustic Sensing (DAS) Measurements During an M 2.3 Explosion

Included here are Distributed Acoustic Sensing (DAS) data collected by the horizontal DAS array at Brady's Hot Springs Geothermal Field. The system recorded this data during an M 2.3 explosion at the Nevada Test Site (NTS), which is located approximately 400km southeast of the field. On December 19, 2018, a Silixa iDAS interrogator continuously acquired data on single-mode fibers, starting approximately two hours prior to the detonation and extending until 15 minutes after the event. This dataset comprises separate SEG-Y files that span the entire recording interval. The measurement fiber was part of the PoroTomo experiment and is horizontally emplaced in alluvial fan gravels at a depth of approximately one meter for a distance of more than 2.5 km in a zig-zag pattern. Exact coordinates of this DAS surface array are provided in the attached GDR dataset below. The iDAS interrogator channel spacing is 1.021 m and gauge length is 10 m. Concurrent Distributed Temperature Sensing (DTS) measurements made with a Silixa XT on the multi-mode fibers aided in calibrating the DAS measurements.

15 GEOTHERMAL ENERGY↗
DOE OSTI2016

Appalachian Basin Play Fairway Analysis Analyses and Results

*This submission updates a 2015 submission for the utilization analysis (https://gdr.openei.org/submissions/623)* The files document the analysis of utilization potential in support of Phase 1 Low Temperature Geothermal Play Fairway Analysis for the Appalachian Basin. This 2016 submission includes data pertinent to the methods and results of an analysis of the Surface Levelized Cost of Heat (SLCOH) for US Census Bureau 'Places' within the study area. The SLCOHis was calculated using a modification of a program called GEOPHIRES, available at http://koenraadbeckers.net/geophires/index.php. In addition to calculating SLCOH, this task also identified many industrial sites that may be prospects for use of a geothermal district heating system, based on their size and industry, rather than on the SLCOH. An industry sorted listing and maps of the sites have been plotted as a layer onto different iterations of maps combining the three geologic risk factors (Thermal Quality, Natural Reservoir Quality, and Risk of Seismicity). In addition, a shapefile of the industrial sites is also included with 7 associated files. Supporting files are also supplied.

15 GEOTHERMAL ENERGY↗
DOE OSTI2022

Basin and Range Investigation for Developing Geothermal Energy: Exploration Data

This data package includes exploration material from the Basin & Range Investigation for Developing Geothermal Energy [in Hidden Systems] project (BRIDGE), which is part of a broader initiative to advance the exploration of hidden geothermal resources in the Basin & Range Province of the western U.S. Data modalities include a helicopter-borne time-domain electromagnetic survey, magnetotellurics, 2-meter temperature measurements, ground-based gravity and legacy aeromagnetic surveys, geochemistry, geologic mapping, LiDAR analysis, 3D models, associated geospatial data, and a bibliography of existing data and references utilized in prospect characterization and conceptual modeling. Key files are in CSV, Geosoft, and Geotools formats. Please refer to READMEs for dataset-specific information. Where applicable, acquisition data and inversion models for a particular prospect or area of interest are organized separately. This BRIDGE data package is the product of a collaboration led by Sandia National Laboratories with partners from Geologica Geothermal Group, Inc., the U.S. Navy Geothermal Program Office, and consultants Steven Sewell (Australis Geoscience Ltd) and William Cumming (Cumming Geoscience). The project's areas of interest (AOIs) are based off priority areas of interest in the southwestern portion of the Nevada Play Fairway map, distribution across tectonic provinces, accessibility, and the project team's extensive experience in the region. AOIs cover about a dozen basins that include unexplored prospects, partially explored prospects, and some developed analogue resources that provide validation cases. Many unexplored and partially explored prospects are on U.S. Department of Defense (DoD) land, though adjacent lands are included as well.

15 GEOTHERMAL ENERGY↗
DOE OSTI2013

Business Case Analysis of Real Green Building Systems, LLC Technologies

Real Green Building Systems, LLC offers environmentally friendly home designs with five synergistic systems: plumbing-based fire protection, solar thermal heating and domestic hot water, solar electricity, and recycled water. This home design fits with the green construction movement in the United States that has developed to the point where 20 percent of all newly built homes last year were “green,” with an overall $25B market value. The market is expected to grow to between 29% and 38% of new U.S. homes by 2016. Generally, materials and construction costs are somewhat higher (five to ten percent) for green homes, but some localities offer rebates form the state or utility to help offset this. Structural features that are typical include tightly insulated walls to prevent air escape, insulated foundations, and windows designed to capture heat. Other add-on systems include solar or geothermal heating or cooling, and solar electric. A mechanical air exchange system may be needed to ensure good air quality given the tight nature of the house. A green home is desirable to buyers who are looking to save utility bills or reduce dependence on the grid. Often buyers are at or nearing retirement, and such a home can reduce volatility of energy costs long term. Owners may need education on the systems to feel comfortable with the relatively novel active technologies. Passive systems such as thick walls with better insulation need no maintenance or training, and can be quiet, medically safer, and more comfortable. The resale value of a green home appears to be somewhat higher than conventional homes. California data suggest a premium of about nine percent on green home sales prices. One of the key differences in RGBS homes is the fully insulated, fire-protected multi-purpose room instead of a garage. A “garage” in normal houses is not suitable for uses other than storage and parking vehicles. But RGBS designs this area to be conditioned floor space, equivalent to the rest of the home with the only difference being an overhead door. In fact, most home owners do not use a garage to store their car—a recent study showed that about 75 percent of garages are used for other purposes. This is explicitly recognized in the RGBS design, with the conditioned space made fully functional for all uses. A key benefit of this is also that the space can be counted as living space for appraisal purposes, which leads to a lower cost per square foot for the home in addition to increased functionality.

14 SOLAR ENERGY↗
DOE OSTI2013

Air-Cooled Condensers for Next Generation Geothermal Power Plants (Final Report)

This report summarizes the efforts performed under the ARRA project “Air-Cooled Condensers in Next Generation Conversion Systems”. This project examined technologies that provide near-term improvements to the performance of binary power plants utilizing air-cooled condensers. The motivation for pursuing these improvements is to reduce the power generation costs for enhanced geothermal system (EGS) resources. The study is based on two premises. • Water will not be readily available, and there will be no consumptive use of it in the surface energy conversion system. • The EGS resources utilized for power production will be at greater depths, requiring expensive wells to access the heat. In addition, these resources will have costs associated with the creation of the subsurface reservoir where heat that powers the energy conversion system is extracted. The costs associated with the well field development and EGS reservoir creation provide the impetus for using more efficient energy conversion systems, as well as conversion systems that have higher efficiencies at ‘off-design’ conditions. In identifying the more efficient conversion systems, this work focused on: • Existing technologies with the potential to increase conversion efficiency. These are commercially available technologies that are not typically used in plants operating on hydrothermal resources, • Design strategies to increase plant output during operation at higher ambient temperatures, as well as at ‘off-design’ conditions (operation at resource and ambient temperatures other than those for which the plant was designed), • The feasibility of using mixed working fluids in binary plants using air-cooled condensers. Mixtures have been shown to have the potential to increase binary plant performance by 10% to 20%. This project was originally proposed to also evaluate the use of air-cooled condensers in flash-steam geothermal plants. However, reduced funding subsequent to starting work resulted in elimination of that task.

15 GEOTHERMAL ENERGY↗
DOE OSTI2013

Air-Cooled Condensers for Next Generation Geothermal Power Plants (Final Report)

This report summarizes the efforts performed under the ARRA project “Air-Cooled Condensers in Next Generation Conversion Systems”. This project examined technologies that provide near-term improvements to the performance of binary power plants utilizing air-cooled condensers. The motivation for pursuing these improvements is to reduce the power generation costs for enhanced geothermal system (EGS) resources. The study is based on two premises. • Water will not be readily available, and there will be no consumptive use of it in the surface energy conversion system. • The EGS resources utilized for power production will be at greater depths, requiring expensive wells to access the heat. In addition, these resources will have costs associated with the creation of the subsurface reservoir where heat that powers the energy conversion system is extracted The costs associated with the well field development and EGS reservoir creation provide the impetus for using more efficient energy conversion systems, as well as conversion systems that have higher efficiencies at ‘off-design’ conditions. In identifying the more efficient conversion systems, this work focused on: • Existing technologies with the potential to increase conversion efficiency. These are commercially available technologies that are not typically used in plants operating on hydrothermal resources • Design strategies to increase plant output during operation at higher ambient temperatures, as wells as at ‘off-design’ conditions (operation at resource and ambient temperatures other than those for which the plant was designed) • The feasibility of using mixed working fluids in binary plants using air-cooled condensers. Mixtures have been shown to have the potential to increase binary plant performance by 10% to 20%.

15 GEOTHERMAL ENERGY↗
DOE OSTI2022

Exploring for Superhot Geothermal Targets in Magmatic Settings: Developing a Methodology

This paper presents preliminary results from a subset of work carried out as part of a multinational research project entitled DErisking Exploration for multiple geothermal Plays in magmatic ENvironments (DEEPEN). One objective of DEEPEN is to develop a customized approach to exploration for superhot geothermal plays in magmatic systems. This paper summarizes key geologic components, risk factors, and exploration methods for geothermal plays in magmatic settings based on a review and comparative analysis of international training sites. As part of a Play Fairway Analysis (PFA) approach to exploring for multiple play types in a single magmatic system, training data were compiled and weights assigned to various evidence layers. Two different approaches for weighting exploration datasets are described in this paper - one based on expert opinions and the other using statistical learning. Weights produced by both approaches will be input into a 3D PFA workflow that combines multiple exploration datasets to generate 3D geothermal favorability models, which will be applied to two international demonstration sites.

GEOTHERMAL ENERGY↗
DOE OSTI2014

Geothermal Water Use: Life Cycle Water Consumption, Water Resource Assessment, and Water Policy Framework

This report examines life cycle water consumption for various geothermal technologies to better understand factors that affect water consumption across the life cycle (e.g., power plant cooling, belowground fluid losses) and to assess the potential water challenges that future geothermal power generation projects may face. Previous reports in this series quantified the life cycle freshwater requirements of geothermal power-generating systems, explored operational and environmental concerns related to the geochemical composition of geothermal fluids, and assessed future water demand by geothermal power plants according to growth projections for the industry. This report seeks to extend those analyses by including EGS flash, both as part of the life cycle analysis and water resource assessment. A regional water resource assessment based upon the life cycle results is also presented. Finally, the legal framework of water with respect to geothermal resources in the states with active geothermal development is also analyzed.

15 GEOTHERMAL ENERGY↗