Geology, carbon emission reduction potential, and development progress of hot dry rock in China

The available heat content (stored heat energy) of hot dry rock (HDR) at a depth of 1–10 km in the global land crust is estimated to be 5.06 × 108 EJ, attracting considerable global attention. This paper presents a comprehensive analysis of the geological framework, HDR resource potential, exploration advancements, and the development of enhanced geothermal systems (EGSs) in China. HDR resources are extensively distributed across China. Within the depth range of 3–10 km, China’s estimated potential approximates 2.29 × 107 EJ, with a theoretical power generation capacity of approximately 1.67 × 1016 kWh. Replacing coal power with HDR can help to achieve a net emission reduction of 1.34 × 1016 kg CO2 (approximately 1.34 × 1013 t), representing an emission reduction efficiency of 94.4%. Based on a development cycle of 100 years, the average annual emission reduction reaches 1.34 × 1010 t CO2, equivalent to 117% of China’s annual carbon emissions in 2022. Furthermore, in the context of global warming, the development and utilization of HDR, which is feasible in virtually any region worldwide, offers significant potential to support global carbon reduction efforts. China has made substantial progress in HDR exploration in recent years. This paper systematically classifies China’s HDR resources into four genetic types—highly radioactive heat-producing, sedimentary basin, active volcanic, and intensely tectonic zones—and offers detailed exploration insights for each category. Each classification exhibits distinct geological and tectonic characteristics that influence heat source mechanisms and resource distribution. Furthermore, this paper documents significant advances in EGS construction, particularly in the Gonghe Basin on the northeastern margin of the Qianghai-Xizang Plateau and the Matouying uplift in the North China Basin, where successful reservoir stimulation, microseismic monitoring, and experimental power generation have been achieved. Despite these developments, challenges persist, including technical adaptability under complex geological conditions and the economic viability of large-scale HDR development. This paper suggests that future initiatives should emphasize resource exploration, technological research, and policy support to foster sustainable HDR resource development in China, thereby contributing to the global energy transition and environmental sustainability.