Development status and prospect analysis of tower solar thermal power generation technology in China

4.1 Advantages of China's development of tower solar thermal power generation

China is very rich in solar energy resources, the Qinghai-Tibet Plateau, Xinjiang, Inner Mongolia, Gansu and other places are high radiation areas of solar energy, of which about 800,000 square kilometers of desert areas are the most abundant solar energy resources, the development of tower solar thermal power generation project has obvious environmental advantages.

According to the calculation of the thermal power conversion efficiency of 35%, the more than 800,000 square kilometers of desert, only 1/8 of the area, can produce enough electricity to meet China's electricity consumption for 1 year. Therefore, the development of solar power generation in our country is very feasible and necessary, and has very important strategic significance for alleviating the situation of energy shortage and environmental deterioration in our country.

In April 2014, the National Energy Administration held the "solar thermal power generation demonstration project technical requirements and application report outline consultation discussion", to determine the demonstration project using trough and tower heat collection methods, considering the project scale and efficiency and other characteristics, demonstration projects in accordance with the single capacity of 50MW and above grade construction, and put forward requirements for different solar technology heat storage capacity.

At present, the National Energy Administration has basically determined the schedule of the development of China's solar thermal power generation industry, that is, first through the model price policy to support the completion of a number of commercial demonstration projects, after entering the large-scale development and construction stage.

"Large capacity, high parameter, continuous power generation" is the trend of solar thermal power generation in the future. Ivanpah and Crescent Dune have verified the feasibility of large-scale development of tower power plants with engineering examples, and the overall efficiency of tower power plants is much higher than that of trough power plants, especially in the environment of large temperature difference between day and night in western China.

4.2 Problems in the development of tower solar thermal power generation in China

From the overall development stage, China's tower solar thermal power generation technology is still in the initial stage of demonstration projects, in the solar thermal power generation materials and equipment, China and foreign gap of about 5 years, in the power station integration, service, and the gap with foreign countries.

Only 1MW Badaling Yanqing Power Station and 10MW Delingha Power Station have been completed [5]. At present, there is no other clear policy to promote the industrialization and marketization of solar thermal power generation, and the policy environment for solar thermal power generation urgently needs to be improved.

China's development of tower solar thermal power generation still lacks some key technologies such as heliostat coating material, heat absorption tube and coating material on the heat absorber, heat absorption equipment, high temperature molten salt pump and other manufacturing technologies. These technologies are classified and difficult to introduce.

In addition, the overall system design capability and integration technology of the tower power station, the simulation and control technology of the solar thermal power station system have just started, lack of power station construction and operation experience and ability, and most foreign technologies are in the demonstration stage.

The applicability of foreign technology to our special climate conditions still needs to be verified. Due to the high altitude, strong wind, sand and other climatic characteristics in China's "three North" areas and the Qinghai-Tibet Plateau, the distribution of DNI is also very different, and it is difficult for Spanish or American technologies to be directly applied in China, so it is necessary to adjust foreign technologies accordingly or conduct independent research and development.

Tower solar thermal power generation is a typical capital and technology intensive, its economy and competitiveness still need to be improved. At present, the cost of tower power generation is still relatively high, in addition to the need for continuous progress in technology, but also the need for key equipment localization to reduce costs.

5. Conclusion

Accelerate the introduction of electricity price policy or electricity price guidance opinions, according to the distribution of light resources in China, the establishment of local solar thermal power station construction standards, such as installed capacity and energy storage time, is not limited to electricity prices, should include land use, grid access, loan concessions and other supportive policies or opinions. The policy of solar thermal power generation should focus on how to cultivate industrialization and reduce the cost of power generation.