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Renewable energy technologies for greenhouses in semi-arid climates
Published in Jochen Bundschuh, Guangnan Chen, D. Chandrasekharam, Janusz Piechocki, Geothermal, Wind and Solar Energy Applications in Agriculture and Aquaculture, 2017
Francisco Javier Cabrera, Jorge Antonio Sánchez-Molina, Guillermo Zaragoza, Manuel Pérez-García, Francisco Rodríguez-Díaz
The latter scheme type, also called enhanced geothermal system (EGS), allows the exploitation of geothermal energy in locations other than hydrothermal reservoirs, such as using the subsoil for thermal storage or as a thermal source for electric heat pumps coupled to the ground (for heating and cooling), either directly or by way of water circulation wells. This type of application takes advantage of the thermal stability of underground layers (depending on the composition of the ground, a few meters down, the temperature is constant and the external annual thermal wave is cancelled) and the use of efficient systems, such as heat pumps for heat generation, which offer good results, reducing consumption from air-conditioning (Milenić et al., 2010; Ozgener and Hepbasli, 2005).
Modeling Thermohydraulic Process in Enhanced Geothermal System Based on Two-Equation Thermal Model for Porous Media
Published in Yasser Mahmoudi, Kamel Hooman, Kambiz Vafai, Convective Heat Transfer in Porous Media, 2019
Wenbo Huang, Wenjiong Cao, Guoling Wei, Yunlong Jin, Fangming Jiang
Enhanced geothermal system (EGS) represents an advanced geothermal energy utilization technology whereas the idea itself is simple: for low-permeability rocks, a series of rock-fracturing procedures, such as hydraulic stimulation to create an artificially fractured reservoir, is performed. By circulating water through the stimulated region, heat can be continuously extracted from the rock, just like a natural hydrothermal system. Figure 11.1 illustrates the EGS concept and schematically shows its basic underground and earth-surface components. Heat transmission fluids are injected into the heat reservoir, and after being heated up by the hot rocks, they are extracted out for earth-surface power-generation and/or thermal utilizations.
Renewable Futures
Published in Michael Frank Hordeski, Alternative Fuels—The Future of Hydrogen, 2020
The technology called Enhanced Geothermal Systems (EGS) involves drilling wells deep into the rock and pumping water to create fractures, a process known as hydroshearing. Cold water is then pumped into the reservoir and steam drawn out. This is similar to the hydraulic fracturing used to free natural gas from shale, but the fractures are smaller and no chemicals are used. There is still some concern about earthquakes, and the small reservoirs created may not be large enough for a commercial power plant. There are two small plants in France and Germany. One in downtown Basel, Switzerland, was shut down after earthquake complaints. A similar project in Australia has had drilling problems.
A 3-D numerical simulation-based heat production performance research for enhanced geothermal system with two horizontal wells and rectangular multiparallel fractures
Published in Numerical Heat Transfer, Part B: Fundamentals, 2022
Peng Li, Jun Zheng, Bin Dou, Hong Tian, Hengwei Liu, Peng Xiao, Jinlong Chen
Hot dry rock (HDR) refers to a high temperature rock mass buried in the depth of 3–10 km underground with a temperature higher than 180 °C and very low permeability [1–3]. As a clean and renewable energy source, it is the most potential part of geothermal energy [4]. Enhanced geothermal system (EGS) is an engineered system which drills and performs hydraulic fracturing in hot dry rock formation to increase the permeability and construct a circulation loop between the injection well and the production well to mine geothermal energy [5,6]. As an efficient and economically way to exploit high temperature geothermal energy, EGS shows enormous potential for power production and has been widely used to extract heat from HDR [7–10].
Geothermal energy for sustainable water resources management
Published in International Journal of Green Energy, 2020
D. Chandrasekharam, A. Lashin, Nassir Al Arifi, Abdulaziz M. Al-Bassam, Varun Chandrasekhar
The total available heat in the upper part of earth’s crust is around 540 × 107 EJ. This heat energy is continuously renewed by the heat received from various sources. One such source is the heat generated by the decay of radioactive elements like uranium (U), thorium (Th) and potassium (K) (Rybach 1976) There three elements are abundant in the crust, especially in granites and related rocks. Technology to generate fracture network in such granites and extract this heat through a circulating media like water or carbon dioxide (Mohan et al. 2015) is known as enhanced geothermal systems or engineered geothermal system (EGS). While hydrothermal systems are site specific, EGS can be commissioned anywhere on the earth. This is the future energy the world is exploring. This energy is clean and GHG emissions are least compared to any other energy sources. The heat generated by granites due to decay of radioactive elements is given in Table 4. Extensive exploration and in some cases, exploitation work have been carried out by a large number of countries in Europe (Genter et al. 2010; Hurter and Haenel 2002), USA (Cladouhos et al. 2012) and Saudi Arabia (Chandrasekharam et al. 2015b). The future of EGS for providing clean energy and to eliminate the demand and supply of electricity to the world has been detailed in a report published by the Massachusetts Institute of Technology (MIT 2006). The method to extract energy from granites is to create system of fracture network in the granites through hydro-fracturing and connect these fractures by two bore wells, one used for injecting circulating fluids and the second for extracting the heated steam. The viability of this technology has been demonstrated at Sluotz (Genter et al. 2010) and several countries have implemented this EGS method of extracting heat from granites.
Experiments on the thermally enhanced permeability of tight rocks: A potential thermal stimulation method for Enhanced Geothermal Systems
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Junrong Liu, Zhe Wang, Weixin Shi, Xianfeng Tan
Enhanced Geothermal Systems (EGS) is considered as the most effective way to exploit hot dry rock resources. At present, most of the hot dry rocks are mainly granite. Many reservoir stimulation tests have shown that it is almost impossible to create new fissures in hard granite by high-pressure water injection (Xu et al. 2012; Wang et al. 2015). However, numerous heat treatment experiments on granite show positive results that a good fracture network could be developed in granite and its permeability could be improved significantly after high temperature heating treatment.