The Coupled Effects of Dryness and Non‐condensable Gas Content of Geothermal Fluid on the Power Generation Potential of an Enhanced Geothermal System

Abstract

The geothermal energy has developed rapidly, due to its inherent advantages of stability, renewability and its huge reserves (Deng et al., 2019). The applications of geothermal energy include space heating and cooling, greenhouse heating, aquaculture, bathing, thermal city networks and industrial uses (Chong et al., 2021). According to the depth of the geothermal energy, high temperature (> 160°C) and medium temperature (90-160°C) can be employed for power generation, while low temperature (< 90°C) is usually used by heat pumps for district heating. Hot dry rock (HDR) is a form of granite with a high temperature underground. In order to utilize the geothermal energy of HDR, an enhanced geothermal system (EGS) has been developed to extract thermal energy. Based on the forecast power generation capacity, the estimated potential electricity generated by HDR ranges between 117.5 EJ/year (down to 3 km depth) and 1108.6 EJ/year (down to 10 km depth) (Ambriz-Dí az et al., 2021). In China, the conventional hydro-geothermal resources are equivalent to 1.25 trillion tons of standard coal, with the annually exploitable resources being equivalent to 1.9 billion tons of standard coal. The distribution of geothermal resources (China basemap after the China National Bureau of Surveying and Mapping Geographical Information) is shown in Fig. 1 .From the perspective of indicating how EGS has developed globally, in 2010 there were 10715 MW of power generated in 24 countries, with the expectation that it would expected to provide 67246 GWh electricity. The United States has had the highest rate of geothermal electricity production