Impact of enhanced geothermal systems on US energy supply in the twenty-first century

2007 ◽  
Vol 365 (1853) ◽  
pp. 1057-1094 ◽  
Author(s):  
Jefferson W Tester ◽  
Brian J Anderson ◽  
Anthony S Batchelor ◽  
David D Blackwell ◽  
Ronald DiPippo ◽  
...  
Keyword(s):  
Primary Energy ◽  
Economic Feasibility ◽  
Enhanced Geothermal Systems ◽  
Economic Modelling ◽  
Geothermal Systems ◽  
Resource Base ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Capital Costs ◽  
The Usa

Recent national focus on the value of increasing US supplies of indigenous renewable energy underscores the need for re-evaluating all alternatives, particularly those that are large and well distributed nationally. A panel was assembled in September 2005 to evaluate the technical and economic feasibility of geothermal becoming a major supplier of primary energy for US base-load generation capacity by 2050. Primary energy produced from both conventional hydrothermal and enhanced (or engineered) geothermal systems (EGS) was considered on a national scale. This paper summarizes the work of the panel which appears in complete form in a 2006 MIT report, ‘The future of geothermal energy’ parts 1 and 2. In the analysis, a comprehensive national assessment of US geothermal resources, evaluation of drilling and reservoir technologies and economic modelling was carried out. The methodologies employed to estimate geologic heat flow for a range of geothermal resources were utilized to provide detailed quantitative projections of the EGS resource base for the USA. Thirty years of field testing worldwide was evaluated to identify the remaining technology needs with respect to drilling and completing wells, stimulating EGS reservoirs and converting geothermal heat to electricity in surface power and energy recovery systems. Economic modelling was used to develop long-term projections of EGS in the USA for supplying electricity and thermal energy. Sensitivities to capital costs for drilling, stimulation and power plant construction, and financial factors, learning curve estimates, and uncertainties and risks were considered.

scholarly journals Geothermal Sustainability or Heat Mining?

2021 ◽  
Vol 4 (1) ◽  
pp. 15-25
Author(s):  
Ladislaus Rybach
Keyword(s):  
Heat Flow ◽  
Heat Pumps ◽  
Mineral Deposit ◽  
Sustainable Production ◽  
Production Level ◽  
Heat Extraction ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Geothermal Heat ◽  
Geothermal Resources

Heat mining” is, in fact a complete deceptive misnomer. When a mineral deposit (e.g. copper) is mined and the ore has been taken out, it will be gone forever. Not so with geothermal resources: The heat and the fluid are coming back! Namely, the heat and fluid extraction create heat sinks and hydraulic minima; around these, strong temperature and pressure gradients develop. Along the gradients, natural inflow of heat and fluid arises to replenish the deficits. The inflow from the surroundings can be strong: around borehole heat exchangers, heat flow densities of several W/m2 result, whereas terrestrial heat flow amounts only to about 50 – 100 mW/m2. The regeneration of geothermal resources after production, in other words, extraction of fluid and/or heat) is a process that runs over different timescales, depending on the kind and size of the utilization system, the production rate, and the resource characteristics. The resource renewal depends directly on the heat/fluid backflow rate. Heat, respectively fluid production from geothermal resources can be accomplished with different withdrawal rates. Although forced production is more attractive financially (with quick payback), it can nevertheless degrade the resource permanently. The longevity of the resource (and thus the sustainability of production) can be ensured by moderate production rates. The sustainable geothermal production level depends on the utilization technology as well as on the local geologic conditions. The stipulation of the sustainable production level requires specific clarifications, especially by numerical modelling, based on long-term production strategies. In general, resource regeneration proceeds asymptotically: strong at the beginning and slowing down subsequently, reaching the original conditions only after infinite time. However, regeneration to 95 % can be achieved much earlier, e.g. within the lifetime of the extraction/production system. In other words, geothermal resources may under certain circumstances may be considered as having potential regrowth, like biomass. Concerning the requirements for such sustainable production, it is convenient to consider four resource types and utilization schemes. These may be treated by numerical model simulations that consider heat extraction by geothermal heat pumps, hydrothermal aquifer, used by a doublet system for space heating, high enthalpy two-phase reservoir, tapped to generate electricity, and enhanced Geothermal Systems (EGS).

scholarly journals The GRETA project: the contribution of near-surface geothermal energy for the energetic self-sufficiency of Alpine regions

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Alessandro Casasso ◽  
Bruno Piga ◽  
Rajandrea Sethi ◽  
Joerg Prestor ◽  
Simona Pestotnik ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Primary Energy ◽  
Economic Activities ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Near Surface ◽  
Alpine Regions ◽  
Heating And Cooling ◽  
Geothermal Heat Pump ◽  
Alpine Space

The Alpine regions are deeply involved in the challenge set by climate change, which is a threat for their environment and for important economic activities such as tourism. The heating and cooling of buildings account for a major share of the total primary energy consumption in Europe, and hence the energy policies should focus on this sector to achieve the greenhouse gas reduction targets set by international agreements. Geothermal heat pump is one of the least carbon-intensive technologies for the heating and cooling of buildings. It exploits the heat stored within the ground, a local renewable energy source which is widely available across the Alpine territory. Nevertheless, it has been little considered by European policies and cooperation projects. GRETA (near-surface Geothermal REsources in the Territory of the Alpine space) is a cooperation project funded by the EU INTERREG-Alpine Space program, aiming at demonstrating the potential of shallow geothermal energy and to foster its integration into energy planning instruments. It started in December 2015 and will last three years, involving 12 partners from Italy, France, Switzerland, Germany, Austria, and Slovenia. In this paper, the project is presented, along with the results of the first year of work.

scholarly journals Longevity of Enhanced Geothermal Systems with Brine Circulation in Hydraulically Fractured Hydrocarbon Wells

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 63
Author(s):  
Zuo ◽  
Weijermars
Keyword(s):  
Limit State ◽  
Extraction Process ◽  
Heat Extraction ◽  
Working Fluid ◽  
Heat Equations ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Geothermal Heat ◽  
Horizontal Fracture ◽  
Rock Temperature

A simple, semi-analytical heat extraction model is presented for hydraulically fractured dry reservoirs containing two subparallel horizontal wells, connected by a horizontal fracture channel, using injected brine as the working fluid. Heat equations are used to quantify the heat conduction between fracture walls and circulating brine. The brine temperature profiles are calculated for different combinations of fracture widths, working fluid circulation rates, and initial fracture wall temperatures. The longevity of the geothermal heat extraction process is assessed for a range of working fluid injection rates. Importantly, dry geothermal reservoirs will not recharge heat by the geothermal flux on the time scale of any commercial heat extraction project. A production plan is proposed, with periodic brine circulation maintained in a diurnal schedule with 8 h active production alternating with 16 h of pump switched off. A quasi-steady state is achieved after both the brine temperature and rock temperature converge to a limit state allowing fracture-wall reheating by conduction from the rock interior in the diurnal production schedule. The results of this study could serve as a fast tool for assisting the planning phase of geothermal reservoir design as well as for operational monitoring and management.

scholarly journals Assessing the prospective resource base for enhanced geothermal systems in Europe

2014 ◽  
Vol 2 (1) ◽  
pp. 55-71 ◽  
Author(s):  
J. Limberger ◽  
P. Calcagno ◽  
A. Manzella ◽  
E. Trumpy ◽  
T. Boxem ◽  
...  
Keyword(s):  
Grid Cell ◽  
Enhanced Geothermal Systems ◽  
Conductive Heat ◽  
Cost Models ◽  
Temperature Model ◽  
Geothermal Systems ◽  
Resource Base ◽  
Model Calculations ◽  
Technical Potential ◽  
Subsurface Temperatures

<p><strong>Abstract.</strong> In this study the resource base for EGS (enhanced geothermal systems) in Europe was quantified and economically constrained, applying a discounted cash-flow model to different techno-economic scenarios for future EGS in 2020, 2030, and 2050. Temperature is a critical parameter that controls the amount of thermal energy available in the subsurface. Therefore, the first step in assessing the European resource base for EGS is the construction of a subsurface temperature model of onshore Europe. Subsurface temperatures were computed to a depth of 10 km below ground level for a regular 3-D hexahedral grid with a horizontal resolution of 10 km and a vertical resolution of 250 m. Vertical conductive heat transport was considered as the main heat transfer mechanism. Surface temperature and basal heat flow were used as boundary conditions for the top and bottom of the model, respectively. If publicly available, the most recent and comprehensive regional temperature models, based on data from wells, were incorporated. <br><br> With the modeled subsurface temperatures and future technical and economic scenarios, the technical potential and minimum levelized cost of energy (LCOE) were calculated for each grid cell of the temperature model. Calculations for a typical EGS scenario yield costs of EUR 215 MWh<sup>−1</sup> in 2020, EUR 127 MWh<sup>−1</sup> in 2030, and EUR 70 MWh<sup>−1</sup> in 2050. Cutoff values of EUR 200 MWh<sup>−1</sup> in 2020, EUR 150 MWh<sup>−1</sup> in 2030, and EUR 100 MWh<sup>−1</sup> in 2050 are imposed to the calculated LCOE values in each grid cell to limit the technical potential, resulting in an economic potential for Europe of 19 GW<sub>e</sub> in 2020, 22 GW<sub>e</sub> in 2030, and 522 GW<sub>e</sub> in 2050. The results of our approach do not only provide an indication of prospective areas for future EGS in Europe, but also show a more realistic cost determined and depth-dependent distribution of the technical potential by applying different well cost models for 2020, 2030, and 2050.</p>

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 Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy)

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1237 ◽  
Author(s):  
Marina Iorio ◽  
Alberto Carotenuto ◽  
Alfonso Corniello ◽  
Simona Di Fraia ◽  
Nicola Massarotti ◽  
...  
Keyword(s):  
Public Schools ◽  
Structural Information ◽  
Geothermal Field ◽  
Open Loop ◽  
Carbonate Reservoir ◽  
Geothermal Systems ◽  
Hydrogeological Model ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Heating Plant

In this study, the sustainability of low-temperature geothermal field exploitation in a carbonate reservoir near Mondragone (CE), Southern Italy, is analyzed. The Mondragone geothermal field has been extensively studied through the research project VIGOR (Valutazione del potenzIale Geotermico delle RegiOni della convergenza). From seismic, geo-electric, hydro-chemical and groundwater data, obtained through the experimental campaigns carried out, physiochemical features of the aquifers and characteristics of the reservoir have been determined. Within this project, a well-doublet open-loop district heating plant has been designed to feed two public schools in Mondragone town. The sustainability of this geothermal application is analyzed in this study. A new exploration well (about 300 m deep) is considered to obtain further stratigraphic and structural information about the reservoir. Using the derived hydrogeological model of the area, a numerical analysis of geothermal exploitation was carried out to assess the thermal perturbation of the reservoir and the sustainability of its exploitation. The effect of extraction and reinjection of fluids on the reservoir was evaluated for 60 years of the plant activity. The results are fundamental to develop a sustainable geothermal heat plant and represent a real case study for the exploitation of similar carbonate reservoir geothermal resources.

Fracturing in HDR Geothermal System

2017 ◽  
Vol 20 ◽  
pp. 57-60 ◽  
Author(s):  
A.M. Al-Mukhtar
Keyword(s):  
Initial Crack ◽  
Geothermal System ◽  
Hydraulic Fractures ◽  
Geothermal Systems ◽  
Fluid Circulation ◽  
Fracture Permeability ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Linear Elastic ◽  
Electrical Generation

Geothermal systems have a big draw as a provider for free thermal energy for electrical generation. The resource based on fracture networks that permit fluid circulation, and allow geothermal heat to be extracted. Most geothermal resources occur in rocks that posses lack fracture permeability and fluid circulation. Hence, the fluid will be heated due to the Hot Dry Rock (HDR). The flow is circulated through the cracks, and extracts the heat to the ground. The emphasis of the simulators is on the HDR and on the development of methods that produce the hydraulic fractures. Linear elastic fracture mechanics approach (LEFM) was used to predict the crack propagation for initial crack. Finite element method (FEM) is used to predict the maximum stress areas, hence, determining the crack initiation.

scholarly journals Introduction to the geothermal play and reservoir geology of the Netherlands

2020 ◽  
Vol 99 ◽  
Author(s):  
Harmen F. Mijnlieff
Keyword(s):  
The Netherlands ◽  
Oil And Gas ◽  
Regional Scale ◽  
Upper Jurassic ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Matrix Permeability ◽  
Sedimentary Aquifer

Abstract The Netherlands has ample geothermal resources. During the last decade, development of these resources has picked up fast. In 2007 one geothermal system had been realised; to date (1 January 2019), 24 have been. Total geothermal heat production in 2018 was 3.7 PJ from 18 geothermal systems. The geothermal sources are located in the same reservoirs/aquifers in which the oil and gas accumulations are hosted: Cenozoic, Upper Jurassic – Lower Cretaceous, Triassic and Rotliegend reservoirs. Additionally, the yet unproven hydrocarbon play in the Lower Carboniferous (Dinantian) Limestones delivered geothermal heat in two geothermal systems. This is in contrast to the Upper Cretaceous and Upper Carboniferous with no producing geothermal systems but producing hydrocarbon fields. Similar to hydrocarbon development, developing the geothermal source relies on fluid flow through the reservoir. For geothermal application a transmissivity of 10 Dm is presently thought to be a minimum value for a standard doublet system. Regional mapping of the geothermal plays, with subsequent resource mapping, by TNO discloses the areas with favourable transmissivity within play areas for geothermal development. The website www.ThermoGis.nl provides the tool to evaluate the geothermal plays on a sub-regional scale. The Dutch geothermal source and resource portfolio can be classified using geothermal play classification of, for example, Moeck (2014). An appropriate adjective for play classification for the Dutch situation would be the predominant permeability type: matrix, karst, fracture or fault permeability. The Dutch geothermal play is a matrix-permeability dominated ‘Hot Sedimentary Aquifer’, ‘Hydrothermal’ or ‘Intra-cratonic Conductive’ play. The Dutch ‘Hot Sedimentary Aquifer’ play is subdivided according to the lithostratigraphical annotation of the reservoir. The main geothermal plays are the Delft Sandstone and Slochteren Sandstone plays.

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.

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