scholarly journals Introduction to this special section: Geothermal energy

2020 ◽  
Vol 39 (12) ◽  
pp. 855-856
Author(s):  
J. O. Kaven ◽  
D. C. Templeton ◽  
Arpita P. Bathija
Keyword(s):  
Geothermal Energy ◽  
Special Section ◽  
Renewable Resource ◽  
The United States ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Elevated Pressures ◽  
Generation Capacity ◽  
Direct Use

Geothermal energy is a global renewable resource that has the potential to provide a significant portion of baseload energy in many regions. In the United States, it has the potential to provide 8.5% of the electric generation capacity by the middle of the century. In general, geothermal systems require heat, permeability, and water to be viable for energy generation. However, with current technologies, only heat is strictly necessary in a native system. Engineered geothermal systems (EGS) introduce water into the subsurface at elevated pressures and reduced temperatures and enhance permeability through hydraulic and/or shear fracturing. Additionally, although moderate- to high-temperature resources currently dominate geothermal energy production, low-temperature resources have been utilized for direct-use cases. When well balanced and maintained, geothermal resources can produce significant amounts of heat and achieve long-term sustainability on the order of an estimated tens to hundreds of years.

scholarly journals Geothermal Energy R&D: An Overview of the U.S. Department of Energy’s Geothermal Technologies Office

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Susan G. Hamm ◽  
Arlene Anderson ◽  
Douglas Blankenship ◽  
Lauren W. Boyd ◽  
Elizabeth A. Brown ◽  
...  
Keyword(s):  
United States ◽  
Geothermal Energy ◽  
The United States ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Future Directions ◽  
Electricity Grid ◽  
Strategic Goals ◽  
The U.S

Abstract Geothermal energy can provide answers to many of America’s essential energy questions. The United States has tremendous geothermal resources, as illustrated by the results of the DOE GeoVision analysis, but technical and non-technical barriers have historically stood in the way of widespread deployment of geothermal energy. The U.S. Department of Energy’s Geothermal Technologies Office within the Office of Energy Efficiency and Renewable Energy has invested more than $470 million in research and development (R&D) since 2015 to meet its three strategic goals: (1) unlock the potential of enhanced geothermal systems, (2) advance technologies to increase geothermal energy on the U.S. electricity grid, and (3) support R&D to expand geothermal energy opportunities throughout the United States. This paper describes many of those R&D initiatives and outlines future directions in geothermal research.

scholarly journals The EGS Collab Project: An intermediate-scale field test to address enhanced geothermal system challenges

2020 ◽  
Vol 205 ◽  
pp. 01002
Author(s):  
Kneafsey Timothy ◽  
Keyword(s):  
Geothermal Energy ◽  
Crystalline Rock ◽  
Hydrothermal Systems ◽  
Heat Transfer Fluid ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Intermediate Scale ◽  
Term Extraction

Three components are typically needed to extract geothermal energy from the subsurface: 1. hot rock, 2. a heat transfer fluid, and 3. flow pathways contacting the fluid and the rock. These naturally occur in many locations resulting in hydrothermal systems, however there are enormous regions containing hot rock that do not naturally have adequate fluid, and/or appropriate fluid permeability to allow hot fluid extraction. Some type of engineering or enhancement of these systems would be required to extract the energy. These enormous regions provide the possibility of long-term extraction of significant quantities of energy. Enhanced (or engineered) Geothermal Systems (EGS) are engineered reservoirs created to extract economical amounts of heat from low permeability and/or porosity geothermal resources. There are technological challenges that must be addressed in order to extract the heat. These include proper stimulation, effective monitoring, reservoir control, and reservoir sustainability. The US DOE Geothermal Technologies Office and geothermal agencies from other countries have supported field tests over a range of scales and conditions. A current US field project, the EGS Collab Project, is working nearly a mile deep in crystalline rock at the Sanford Underground Research Facility (SURF) to study rock stimulation under EGS stress conditions. We are creating intermediate-scale (tens of meters) test beds via hydraulic stimulation and are circulating chilled water to model the injection of cooler water into a hot rock which would occur in an EGS, gathering high resolution data to constrain and validate thermal-hydrological-mechanical-chemical (THMC) modeling approaches. These validated approaches would then be used in the DOE’s flagship EGS field laboratory, Frontier Observatory for Research in Geothermal Energy (FORGE) underway in Milford, Utah and in commercial EGS. In the EGS Collab project, numerous stimulations have been performed, characterized, and simulated and long-term flow tests have been completed.

Shallow Geothermal Resources Assessment of the Brussels Region: Exploration, 3D Geological Model, Geothermal Potential Mapping and Challenges Related

2020 ◽  
Author(s):  
Estelle Petitclerc ◽  
Pierre Gerard ◽  
Xavier Devleeschouwer ◽  
Bertrand François ◽  
Marijke Huysmans ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Public Awareness ◽  
Design Tool ◽  
Geological Model ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Development Fund ◽  
3D Geological Model ◽  
Geothermal Potential ◽  
Geothermal Parameters

<p>In 2015, a legal framework was implemented in the Brussels-Capital Region (BCR) where passive construction has been mandatory with an obliged heat demand not exceeding 15 kW<sub>h</sub>/m<sup>2</sup>. Since 2015, the interest in installing shallow geothermal systems has significantly increased. However, limited knowledge of ground conditions, lack of public awareness and the urban nature of the Brussels area restrict the development of shallow geothermal systems despite the high potential of this technique in the RBC. The BRUGEO project aims to facilitate accessibility and the efficient use of shallow geothermal energy in the BCR specifically for commercial and residential sectors. Thanks to Brussels ERDF (European Regional Development Fund) funding a consortium of all major actors in geothermal energy were brought together (ULB, Brussels Environment, BBRI, VUB, and GSB). During the  four years project (2016-2020), specific actions promoting the geothermal potential were addressed: 1- Collect existing data related to the knowledge on Brussels subsurface (geological, hydrogeological, and geothermal data) and consolidate them in a single database; 2- Conduct new laboratory and field tests in order to complete geological analyses and to assess geothermal parameters; 3- Map the geothermal potential for open and closed systems. The Geological Survey of Belgium (GSB) has created, during the last 7 years, a GIS based 2D-3D geological model of the BCR underground. 9266 drillings and geotechnical data collected in and around the BCR have been used to create the Brustrati3D model generating interpolated top and base surfaces for 19 geological layers representing the whole lithostratigraphic sequence from Quaternary to the Paleozoic basement. An important exploration phase was included in the first two years of the BRUGEO project to acquire new data improving the geological and hydrogeological knowledge of BCR. Several in-situ parameters are measured by e.g. new piezometers implementation and monitoring, pumping tests, cores sampling, logging and enhanced thermal response tests (eTRT). These measurements are implemented as far as possible on future private projects by a win-win approach. The idea is to be grafted on existing projects to increase the data acquisition and to avoid purely exploratory drilling that are expensive and not used later for any geothermal exploitation. So far, the BRUGEO consortium has also conducted three exploration drillings to assess the lithology, the structure, the groundwater flows, and geophysical properties of the Cambrian basement (Brabant Massif). In parallel, laboratory measurements are achieved to characterize the determinant thermal parameters of the Brussels underground. From all the subsurface data collected, the BRUGEO consortium aims at mapping the geothermal potential of the BCR. This web-based mapping, accessible to design offices, installers of geothermal systems, citizens, public and private stakeholders or regional and municipalities administrations, will make it easier to foster the use of geothermal energy. The web portal will consist of an interactive decision support and a design tool based on maps built thanks to the geoscientific 3D models and geothermal parameters assessed during BRUGEO. The results are expected to be published online in March 2020.</p>

scholarly journals Geothermal Power Project’s Manageable Risks in Hungary

2021 ◽  
Author(s):  
Aniko Toth ◽  
Peter Szucs ◽  
David K. Fenerty
Keyword(s):  
Geothermal Energy ◽  
Energy Production ◽  
Time Budget ◽  
Geothermal Resources ◽  
Geothermal Reservoirs ◽  
Energy Projects ◽  
Tremendous Amount ◽  
Term Energy ◽  
Project Objectives

Abstract There are many compelling arguments for using geothermal energy in Hungary. One of the most important is that the country could thereby exploit its abundant, relatively untapped network of geothermal reservoirs. These are considerably warmer and closer to the surface than in most of Europe. In the foreseeable future, Hungary’s geothermal resources can satisfy the conditions required for efficient energy production. The tremendous amount of energy stored in our geothermal reservoirs could satisfy much of the country’s long-term energy demand.Every geothermal project is designed to fulfill its project objectives by meeting time, budget, technical, and legal/regulatory provisions. Geothermal development is necessarily exposed to risks of varying degrees throughout its development, something which distinguishes geothermal from other kinds of renewable-energy projects. These risks most often concern the availability, amount, suitability, sustainability and use-potential of the geothermal resource, but may also include market, financing, commercial and macro-economic risks.

scholarly journals Review of the Low-Enthalpy Lower Cretaceous Geothermal Energy Resources in Poland as an Environmentally Friendly Source of Heat for Urban District Heating Systems

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1302 ◽  
Author(s):  
Leszek Pająk ◽  
Barbara Tomaszewska ◽  
Wiesław Bujakowski ◽  
Bogusław Bielec ◽  
Marta Dendys
Keyword(s):  
Lower Cretaceous ◽  
Geothermal Energy ◽  
Public Awareness ◽  
District Heating ◽  
Thermal Waters ◽  
Geothermal Systems ◽  
Urban District ◽  
Geothermal Resources ◽  
Heating Systems ◽  
District Heating Systems

The paper presents a review of the geological and hydrogeological data of the Lower Cretaceous aquifer in the Polish Lowlands and discusses the possibilities for the utilisation of geothermal water resources in existing and new district heating systems. Based on experience related to the use of thermal waters in existing geothermal systems, and using data from the literature, assessments have been made of the energy and environmental effects of the application of low-enthalpy geothermal resources from the Lower Cretaceous aquifer as a source of heat for urban district heating systems. The authors concluded that the implementation of such solutions could result in the production of approximately 4 PJ of geothermal energy annually. To date, these resources have only been developed in three locations—Mszczonów, Uniejów and Poddębice—with the total amount of energy generated annually reaching 100 TJ/year. Similar district heating networks in 120 nearby localities have been also identified. Here, specified geological and hydrogeological conditions enable the extraction of heat from the investigated Lower Cretaceous aquifer, with the aim of using this for heating purposes. To achieve this goal, multiple measures are required, including the following: raising public awareness through appropriate education programmes aimed at the youngest school children; systemic, efficient energy management measures at the central, regional and local levels, and providing financial support and ensuring regulations and laws aimed at improving the development of geothermal resources.

scholarly journals Nested Shallow Geothermal Systems

2020 ◽  
Vol 12 (12) ◽  
pp. 5152 ◽  
Author(s):  
Alejandro García-Gil ◽  
Miguel Mejías Moreno ◽  
Eduardo Garrido Schneider ◽  
Miguel Ángel Marazuela ◽  
Corinna Abesser ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Energy Demand ◽  
Data Sets ◽  
Thermal Plume ◽  
Geothermal Systems ◽  
Groundwater Heat Pump ◽  
Energy Governance ◽  
Shallow Geothermal Energy ◽  
Nested System

The long-term sustainability of shallow geothermal systems in dense urbanized areas can be potentially compromised by the existence of thermal interfaces. Thermal interferences between systems have to be avoided to prevent the loss of system performance. Nevertheless, in this work we provide evidence of a positive feedback from thermal interferences in certain controlled situations. Two real groundwater heat pump systems were investigated using real exploitation data sets to estimate the thermal energy demand bias and, by extrapolation, to assess the nature of thermal interferences between the systems. To do that, thermal interferences were modelled by means of a calibrated and validated 3D city-scale numerical model reproducing groundwater flow and heat transport. Results obtained showed a 39% (522 MWh·yr−1) energy imbalance towards cooling for one of the systems, which generated a hot thermal plume towards the downgradient and second system investigated. The nested system in the hot thermal plume only used groundwater for heating, thus establishing a positive symbiotic relationship between them. Considering the energy balance of both systems together, a reduced 9% imbalance was found, hence ensuring the long-term sustainability and renewability of the shallow geothermal resource exploited. The nested geothermal systems described illustrate the possibilities of a new management strategy in shallow geothermal energy governance.

scholarly journals Current trends in the development of geothermal resources

Georesursy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 113-122
Author(s):  
Alexander N. Shulyupin ◽  
Natalia N. Varlamova
Keyword(s):  
Geothermal Energy ◽  
Technology Development ◽  
Local Heat ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Current Trends ◽  
Geothermal Fields ◽  
The World ◽  
Development Processes

Based on the analysis of publications in world publications, as well as a generalization of the experience of developing domestic geothermal fields, current trends in the development of geothermal resources are shown. The key trend is considered to be the transition from subsidized to commercial projects, which increases the relevance of research in areas that have a significant impact on the economic efficiency of resource development processes, primarily in the direction of geothermal technologies. In terms of subsidized projects that set research goals, the most relevant are works in the direction of EGS (Enhanced Geothermal Systems). Moreover, there is a tendency towards the creation of international interdisciplinary collaborative research teams. It is noted that the current level of technology development allows producing geothermal energy for use in local heat supply systems practically anywhere in the world. However, given the concentration of power per unit area, the basis of modern geothermal energy is still the direction associated with the rise of deep fluids to the surface in areas characterized by the presence of ascending flows of hot juvenile fluids. It is indicated that Russia is lagging behind the world level of progress in the development of geothermal resources, including in terms of current research and development directions, and measures are proposed to overcome this lag.

scholarly journals Economic and fault stability analysis of geothermal field development in direct-use hydrothermal reservoirs

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Caroline Zaal ◽  
Alexandros Daniilidis ◽  
Femke C. Vossepoel
Keyword(s):  
Large Scale ◽  
Net Present Value ◽  
Spatial Density ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Field Development ◽  
Fault Stability ◽  
Economic Output ◽  
Fault Permeability ◽  
Direct Use

AbstractThe installed capacity of geothermal systems for direct use of heat is increasing worldwide. As their number and density is increasing, the their interaction with subsurface faults becomes more important as they could lead to safety risks from induced seismicity. Assessment and management of such risks is essential for the further development and extension of geothermal energy for heating. At the same time, the economic output of geothermal systems can be marginal and is hence often supported by subsidy schemes. A combined assessment of fault stability and economic output could help operators to balance economic and safety aspects, but this is currently not common practice. In this study we present a methodology to assess field development plans based on fault stability and Net Present Value (NPV) using reservoir simulations of a fluvial, heterogeneous sandstone representative of the majority of direct-use Dutch geothermal systems. We find that the highest friction coefficient leading to exceedance of the Mohr–Coulomb failure criteria in this sandstone is 0.17; such values could be encountered in clay-rich fault gouges. Similar or lower fault permeability compared to the reservoir results in no changes and an increase respectively of both NPV and fault stability with larger Fault-to-Well Distance (FWD). Fault permeability higher than the reservoir permeability results in a minor increase in NPV with smaller FWD. Our results demonstrate that a combined analysis of thermal, hydraulic, mechanical and economic assessment supports a responsible and viable development of geothermal resources at a large scale. The importance of a high spatial density of supporting stress data will be essential for a better understanding and quantification of economic and fault stability effects of geothermal operations.

Speech-Language Pathology in the Peace Corps: Necessity and Sustainability

2012 ◽  
Vol 2 (1) ◽  
pp. 11-18
Author(s):  
Melissa A. Pierce
Keyword(s):  
United States ◽  
Special Education ◽  
Peace Corps ◽  
People With Disabilities ◽  
Communication Disorders ◽  
The United States ◽  
Speech Language Pathology ◽  
Speech Language Pathologists ◽  
Language Pathology

In countries other than the United States, the study and practice of speech-language pathology is little known or nonexistent. Recognition of professionals in the field is minimal. Speech-language pathologists in countries where speech-language pathology is a widely recognized and respected profession often seek to share their expertise in places where little support is available for individuals with communication disorders. The Peace Corps offers a unique, long-term volunteer opportunity to people with a variety of backgrounds, including speech-language pathologists. Though Peace Corps programs do not specifically focus on speech-language pathology, many are easily adapted to the profession because they support populations of people with disabilities. This article describes how the needs of local children with communication disorders are readily addressed by a Special Education Peace Corps volunteer.

Multidisciplinary Evidence to Treat Bilingual Individuals with Aphasia

2008 ◽  
Vol 15 (3) ◽  
pp. 66-72 ◽  
Author(s):  
José G. Centeno
Keyword(s):  
Stroke Rehabilitation ◽  
Culturally Diverse ◽  
Treatment Strategies ◽  
The United States ◽  
Intervention Strategies ◽  
Steady Increase ◽  
Clinical Procedures ◽  
Bilingual Speakers ◽  
Aphasic Clients

Abstract The steady increase in linguistic and cultural diversity in the country, including the number of bilingual speakers, has been predicted to continue. Minorities are expected to be the majority by 2042. Strokes, the third leading cause of death and the leading cause of long-term disability in the U.S., are quite prevalent in racial and ethnic minorities, so population estimates underscore the imperative need to develop valid clinical procedures to serve the predicted increase in linguistically and culturally diverse bilingual adults with aphasia in post-stroke rehabilitation. Bilingualism is a complex phenomenon that interconnects culture, cognition, and language; thus, as aphasia is a social phenomenon, treatment of bilingual aphasic persons would benefit from conceptual frameworks that exploit the culture-cognition-language interaction in ways that maximize both linguistic and communicative improvement leading to social re-adaptation. This paper discusses a multidisciplinary evidence-based approach to develop ecologically-valid treatment strategies for bilingual aphasic individuals. Content aims to spark practitioners' interest to explore conceptually broad intervention strategies beyond strictly linguistic domains that would facilitate linguistic gains, communicative interactions, and social functioning. This paper largely emphasizes Spanish-English individuals in the United States. Practitioners, however, are advised to adapt the proposed principles to the unique backgrounds of other bilingual aphasic clients.

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