Yunnan Baoshan Tengchong Atami Scenic Area is rich in geothermal resources. Visual China.
Located in Haikou City, Hainan Province, Qiongbei Deep Geothermal (Hot Dry Rock) Fushen Thermal 1 Scientific Exploration Well, which is drilled to a depth of 5,000 meters, is the deepest geothermal exploration well in China.
Courtesy of Sinopec Petroleum Engineering Technology Research Institute.
During the Spring Festival holiday, Tengchong Atami Scenic Area in Baoshan City, Yunnan Province attracts many tourists who come to "soak in the hot springs", which is one of the areas with the most abundant geothermal resources in China's medium and high temperatures, and is known as a popular tourist destination for hot spring viewing and bathing.
When it comes to geothermal energy, hot springs are the first thing that comes to mind. In fact, hot springs are just one of the many ways to use geothermal energy. Liu Sen, a practitioner who has been engaged in geothermal energy development for a long time, told a reporter from China City Daily that China is rich in geothermal resources, and there are many high-quality geothermal resources such as Tengchong, so it is a pity to only stay in the hot spring development.
As a member of clean energy, geothermal energy not only has large reserves and high stability, but also produces almost no pollutants in the process of use, which is in line with the concept of green and low-carbon development.
China is rich in geothermal resources
Geothermal energy is the natural heat energy extracted from the earth's crust, which comes from the lava in the earth's interior and exists in the form of heat. "Generally speaking, the interior of the earth is like a large boiler that is constantly burning, and when the geological conditions are mature, thermal energy will be gathered in the form of hot steam, hot water and hot dry rock, and it will become geothermal energy when it reaches the conditions for development and utilization. Liu Shaomin, vice president of the Beijing Institute of Geology and Mineral Exploration, said.
Because the interior of the earth has been constantly releasing heat, therefore, geothermal energy is inexhaustible, is a recyclable clean energy, but also one of the main forces for the future energy structure adjustment and development of clean energy.
China is rich in geothermal resources, accounting for about 1 6 of the world's geothermal resources, and has great potential for development and utilization. At present, China's installed capacity of direct geothermal energy utilization and geothermal energy utilization rank first in the world. Wang Guiling, deputy chief geologist of the Institute of Hydrogeology and Environmental Geology of the Chinese Academy of Geological Sciences and director of the Technology Innovation Center for Geothermal and Hot Dry Rock Exploration and Development of the Ministry of Natural Resources, said.
According to the results of the survey of China's geothermal resources organized by the China Geological Survey of the former Ministry of Land and Resources in 2017, the total amount of geothermal energy in China is equivalent to about 1.25 trillion tons of standard coal, and the annual exploitable amount is equivalent to 186.5 billion tons. Among them, the hot dry rock resources that are difficult to mine and do not have the conditions for large-scale mining are currently available, and the resource reserves are as high as 856 trillion tons of standard coal. According to the data of the 2023 annual work conference of the National Geothermal Energy Center, the annual recoverable resources of shallow geothermal energy in 336 major cities across the country are equivalent to 700 million tons of standard coal, and the annual recoverable resources of medium and deep geothermal energy are equivalent to more than 1.8 billion tons of standard coal.
Geothermal energy can be used in various forms
In recent years, with the continuous advancement of China's ecological civilization construction, the intensity of air pollution control and clean heating in the north has been continuously enhanced, and the scale of geothermal energy development and utilization has continued to expand.
In June 2022, the "14th Five-Year Plan for Renewable Energy Development" jointly issued by the National Energy Administration and nine other departments clearly stated that the large-scale development of geothermal energy should be actively promoted, and the scale of non-electric utilization such as geothermal heating will reach more than 60 million tons of standard coal by 2025. According to the report released by the 2023 World Geothermal Congress, by the end of 2021, China's geothermal heating (cooling) capacity reached 13300 million square meters, the annual utilization capacity of the hot spring is 6,665 megawatts.
A reporter from China City Daily combed and found that now, Beijing, Shandong, Hebei, Henan and other provinces are actively deploying geothermal energy heating (cooling) projects.
The development of geothermal industry is not only of great significance for adjusting the energy structure, saving energy and reducing emissions, and improving the environment, but also conducive to cultivating emerging industries and driving the development of related equipment manufacturing and engineering technology businesses. Ma Yongsheng, Honorary Director of the Organizing Committee of the 2023 World Geothermal Congress and Chairman of Sinopec, said that Sinopec's geothermal heating capacity is expected to exceed 100 million square meters in 2023, and the service area will increase to more than 60 cities in more than 10 provinces.
According to the report released by the 2023 World Geothermal Congress, by the end of 2021, the annual utilization capacity of geothermal agriculture in China was 1,108 megawatts, and the use of geothermal energy for aquaculture has spread to more than 20 provinces, forming a certain scale.
In the view of industry insiders, the development and utilization of geothermal resources in China has formed a basic pattern of power generation in southwest and south China, heating and breeding in north and northeast China, and health care in East China, central China and northwest China. In the future, geothermal clean heating in the northern region, geothermal heating (cooling) in the middle and lower reaches of the Yangtze River, and geothermal power generation in the Qinghai-Tibet Plateau and its surroundings will still be hot spots for industrial development.
Geothermal power generation has a promising future
In addition to geothermal heating (cooling), in the eyes of many industry insiders, geothermal power generation also has great room for development.
The development and utilization of geothermal energy is promising. According to Du Li, president of the New Energy Research Institute of Sinopec New Star Petroleum Co., Ltd., compared with natural gas, biomass, coal, etc., medium and deep geothermal energy heating has obvious economic advantages in the development and utilization of high-quality resource areas, and the operating cost is low. At the same time, geothermal energy is a local energy source, and it is an important form of energy for heating in addition to natural gas and coal.
At present, the development and utilization of geothermal energy can be roughly divided into two types: direct utilization and geothermal power generation. For shallow geothermal resources, as well as medium and low temperature hydrothermal geothermal resources, direct utilization is usually the mainstay, such as ground source heat pumps, geothermal heating, hot spring health care, agricultural breeding, etc. For high-temperature hydrothermal geothermal resources, geothermal power generation is a more valuable way to utilize. In Liu Sen's view, compared with clean energy such as wind, hydropower, and photovoltaics, geothermal power generation is very little affected by the weather, and the biggest advantage is stability.
During the interview, the reporter of China City Daily learned that whether it is direct utilization or geothermal power generation, for hydrothermal geothermal resources, the core of its utilization technology is "heat without water consumption", that is, the geothermal water containing heat is extracted from the mining well, and the heat exchanger is used to absorb the heat in the water, and then the cold water that has lost heat is re-injected back into the aquifer through the recharge well. After a period of time, the underground heat source will reheat the cold water and wait for it to be mined again.
In the whole process, the underground heat source acts as a boiler, and the geothermal energy is recycled by continuously heating the groundwater. This method of geothermal resource extraction requires 100% recharge of the extracted geothermal water to achieve a 'balance between production and irrigation' and ensure the sustainable use of geothermal resources, and some geothermal power generation technologies directly use geothermal steam to generate electricity, which is lower than almost zero groundwater extraction. Liu Sen said.
There are many challenges to be overcome in the development of the industry
Although the industry generally believes that geothermal power generation has great advantages in terms of stability and power generation capacity, the reality is that the development of geothermal power generation is far from that of wind and solar power generation.
Due to the high investment threshold of geothermal power generation and the difficulty of engineering design and installation, there are still many challenges to be overcome in how to achieve the sustainable development and commercial application of geothermal energy.
In addition, although China's geothermal energy resources are abundant, they are unevenly distributed, and it is difficult to develop, so strict environmental assessment and social risk assessment are required.
At present, in the most suitable areas for geothermal power generation in China, hydropower and solar power generation are the main forces, and the power is sufficient, which compresses the demand for geothermal power generation to a certain extent, resulting in a lack of enthusiasm for geothermal power generation in the local government. According to Pang Zhonghe, director of the Geothermal Resources Research Center of the Institute of Geology and Geophysics of the Chinese Academy of Sciences, the construction cost of geothermal power generation is high, and the maintenance and operating costs are relatively low in long-term operation. More importantly, under the "dual carbon" goal, geothermal energy resources, as one of the five "non-carbon" energy sources, have their utilization value, and need to be given the same attention as wind, solar, and water energy sources. Through policy guidance and support, commercial application should be carried out as soon as possible, large-scale development should be formed, and the green and low-carbon transformation and high-quality development of China's related industries should be further promoted.
In order for geothermal resources to play a better role in the construction of a new power system, it is not enough to pay attention to ideology, and policy support is the key to solving the problem. "China's geothermal power generation needs to reduce costs, and without policy support, it cannot compete with other energy sources. After more than 10 years of policy subsidies, the cost of power generation has decreased year by year, and finally achieved grid parity. Pang Zhonghe said.
In addition to policy support, geothermal energy technology research and development and equipment manufacturing must also be strengthened. Taking low-temperature waste heat power generation technology as an example, the current standards and industry standards are not perfect, there is a lack of unified standard system and technical specifications, there are differences in the technical performance of equipment from different manufacturers, and it is difficult to compare and evaluate product quality, which increases the difficulty and risk of procurement and selection, and is not conducive to the development of healthy competition in the industry.
It is worth noting that in August 2023, Sinopec successfully drilled China's deepest geothermal scientific exploration well in Haikou City, Hainan Province, Fushen Thermal 1 Well, which has a drilling design depth of 5,000 meters, which is the deepest geothermal exploration well in China at present, and will lead China's deep geothermal resource exploration and development technology to the forefront of the world.
Zhang Dawei, Dean of the Institute of Urban Underground Space and Energy and the Institute of Geothermal Energy Science and Technology (Dali) of the Chinese University of Hong Kong (Shenzhen), suggested that the survey should be carried out first, and the geothermal energy survey should be carried out across the country to find out the resource base and formulate a development plan. At the same time, carry out scientific research theories and technical research, research and development of major key technologies required for geothermal energy utilization, especially technical equipment, and pilot demonstrations can also be carried out through the construction of demonstration projects to promote industrial development.
China City Daily reporter Kang Kejia.