Current situation and future trend of geothermal energy development and utilization in China

Development of hydrothermal geothermal energy

Hydrothermal geothermal energy utilization is the main force of geothermal industry in China. The development and utilization of hydrothermal geothermal heating in China has a history of thousands of years. After the reform and opening up, especially in recent years, the development and utilization of hydrothermal geothermal heating have made great progress in scale, depth and breadth. In the past decade, China's direct utilization of hydrothermal geothermal energy has grown at an average annual rate of 10%, ranking first in the world for many years in a row. The direct utilization of geothermal energy in China is mainly heating, followed by health care, breeding and so on. According to incomplete statistics, as of the end of 2017, the national hydrothermal geothermal heating construction area exceeded 150 million square meters, of which Shandong, Hebei and Henan have enjoyed rapid growth.

China's geothermal power generation began in the 1970s, and in December 1970, the first medium-low temperature geothermal power generator set was successfully generated in Dengwu, Fengshun County, Guangdong Province. At present, the total installed capacity of geothermal power generation in China has been 53.45MW, the current operating capacity is 46.46MW, the suspended capacity is 5.79MW, and the dismantled capacity is 1.2MW.

Exploration and development of geothermal energy resources in dry hot rock

Dry hot rock geothermal energy is an important field of geothermal energy development in the future. After 20 to 40 years of exploration and research, the United States, Germany, France, Japan and other countries have made important progress in the exploration and evaluation of dry hot rock geothermal energy, heat storage transformation and power generation experiments, and accumulated certain experience. In 2012, the Ministry of Science and Technology established the National High-tech Research and Development Program (863 Program), which started the special research on hot and dry rock in China. Since 2013, the China Geological Survey and Qinghai Province have jointly promoted dry-hot rock geothermal energy exploration in key areas of Qinghai Province. In 2017, a 236-℃ dry-hot rock mass was drilled at a depth of 3,705 meters in Gonghe Basin, Qinghai Province, marking the first discovery of high-temperature dry-hot rock geothermal energy resources in sedimentary basins in China.

Development and utilization mode

The exploitation and utilization of geothermal resources can be divided into two aspects: power generation and direct utilization. High temperature geothermal resources are mainly used for power generation; Moderate and low temperature geothermal resources are mainly used directly. For shallow geothermal energy below 25 ° C, ground source heat pumps can be used for heating and cooling.

Shallow geothermal heating and cooling. Since 2015, the total annual utilization rate of shallow geothermal has ranked first in the world. In 2017, the installed capacity of ground source heat pump reached 20,000 MW, and the annual use of shallow geothermal energy and standard coal was 19 million tons. In China, the utilization of shallow geothermal energy develops rapidly, the application area is large, the utilization development degree is different in different regions, the coverage is wide, and the system types are diverse.

Direct utilization of medium and low temperature geothermal energy. The direct utilization of medium and low temperature geothermal in China is mainly in geothermal heating, medical care, hot springs, bathing and tourism, aquaculture, agricultural greenhouse planting and irrigation, industrial production, mineral water production, etc., and gradually developed geothermal resource cascade utilization technology, underground aquifer energy storage technology.

Develop and utilize 60 ~ 100℃ medium and low temperature geothermal water, hot tail water and shallow geothermal energy. Some areas with hot springs, especially in the north, are using geothermal heating to varying degrees, and good results have been achieved. The use of geothermal district heating in Tianjin has become a model in China, which is driving the development of geothermal district heating in northern China. The use of geothermal water heating, with its advantages of cleanliness, minimal air pollution, low operating costs, and high comprehensive utilization of resources, coupled with heat pump technology, has been generally valued in areas where there is a shortage of conventional energy and conditions to develop geothermal resources, and has received obvious economic and social benefits, and its development prospects are broad.

Geothermal fluid has a high temperature, contains special chemical and gas components, a small amount of bioactive ions and radioactive substances, and has obvious medical and health care effects on the function regulation of various human systems and organs. In the spa sanatoriums, the use of geothermal energy can be used for hydrotherapy, gas therapy and mud therapy. With the development of economy and the improvement of people's living standards, a number of "hot spring resorts" or "medical rehabilitation centers" integrating medical treatment, bathing, health care, entertainment and tourism have been established in many areas throughout the country.