An analysis of potential contribution by geothermal development to carbon neutrality: country update on technology and market in China

Abstract

China is rich in geothermal resources of continental nature, mostly low-medium temperature geothermal waters in sedimentary basins at economic depth ranges. China has achieved scalable geothermal development in the past two decades, and fast growth especially in the past ten years. All types of geothermal resources are being utilized including heat from surface water and waste water. Various technologies are being applied especially the doublets in carbonate (karst) geothermal reservoirs at intermediate depth ranges. The deep borehole heat exchanger (DBHE) is being increasingly applied with local innovations to achieve better efficiency. Xiongxian district heating and Nanjing Jiangbei New City air-conditioning are most successful business examples for intermediate hydrothermal resources and surface water geothermal resources utilization, respectively. Both shallow geothermal utilization and intermediate geothermal resources utilization have grown exponentially in China in the past 30 years or so. Emerging technologies such as intermediate depth heat storage, geothermal heat pipe, etc, are promising in enhancing both hydrothermal and petro-thermal resources, respectively. The current share of geothermal energy among the five carbon-free energies. Planned increase towards 2025 is 2.1 billion square meters of heated area, and 4.2 billion square meters by 2035, which are official targets set by National Energy Administration of China. With a huge domestic market demand and due to stable nature of geothermal energy, it is expected to grow faster in the future. We predict a long-term share of geothermal energy to be higher than 10% towards carbon neutrality in year 2060.