Solar thermal power generation has a good opportunity to scale

Recently, the National Energy Administration issued the "Notice on Matters related to Promoting the Large-scale development of solar thermal power generation" proposed that, combined with the construction of new energy bases in desert, Gobi and desert areas, a number of solar thermal power generation projects will be launched as soon as possible. Strive to "14th Five-Year Plan" period, the national solar thermal power generation annual new construction scale reached about 3 million kilowatts. This means that the large-scale development of solar thermal power generation in our country is prologue.

Compared with common photovoltaic power plants, solar thermal power generation is not well known. Photovoltaic power generation is based on the principle of photovoltaic effect, the use of solar cells to directly convert solar energy into electrical energy, and photothermal power generation is to convert solar energy into heat energy, through the thermal conversion process of power generation system. Its principle is basically the same as thermal power generation, and the back-end technical equipment is exactly the same, the difference is that the former uses solar energy to collect heat, the latter is the use of burning coal, natural gas and other heat. After the solar thermal generator set is configured with the heat storage system, it can achieve 24 hours continuous and stable power generation.

This kind of renewable energy with high stability is of great significance to the construction of new power system. Photovoltaic power generation and wind power generation are subject to meteorological conditions and have the characteristics of intermittency, volatility and randomness, which poses challenges to the security and reliability of power supply system. As the proportion of large-scale new energy units in China continues to increase, the proportion of coal electricity continues to decrease, and the western region's wind power and photovoltaic rely on coal power bundle delivery mode will not be sustainable. Some UHV transmission channels, due to the lack of regulating power supply, the transmission power of the channel is far from the design value, and the wind power and photovoltaic power emitted can not be sent out, and the phenomenon of abandoning wind and abandoning light is serious, resulting in a waste of resources.

Photothermal power generation has dual functions of peak power supply and energy storage. After the solar thermal generator set is configured with the heat storage function, the heat is not all used when it is generated, but a part of the heat is stored by heating molten salt, which is stored in a special insulated storage tank until it is needed. The heat stored in the molten salt can generate electricity for several hours, and in theory even for several days. With this special ability, the solar thermal power station can realize the adjustment and support of new energy with new energy, and provide better long-term peak load capacity and moment of inertia for the power system, which is an effective means of safe and reliable replacement of traditional energy with new energy. The General Institute of Electric Power Planning and Design took Xinjiang power grid as an example to simulate the peaking effect of solar thermal power generation, and found that if the construction of solar thermal generating units of different sizes of 1 million kW to 5 million kW, the abandoned wind and light power can be reduced by 10.2% to 37.6%.

At the same time, the long industrial chain of solar thermal power generation can digest and improve traditional industries such as special glass, steel, cement, molten salt, and can also drive the development of new materials, intelligent control and other emerging industries. The large-scale development and utilization of solar thermal power generation will become a new growth point of China's new energy industry.

In order to promote the industrialization of China's solar thermal power generation technology, the National Energy Administration launched the first batch of 20 solar thermal power generation demonstration projects in 2016, with a total installed capacity of 1.349 million kilowatts, opening the commercialization process of China's solar thermal power generation. Through the first batch of demonstration projects, it has driven the independent innovation of relevant enterprises, broken through a number of core technologies, and formed a complete industrial chain. At present, the localization rate of equipment exceeds 90%, laying a solid foundation for the large-scale development of subsequent solar thermal power generation technology. By the end of 2022, China has 9 grid-connected solar thermal power generation demonstration projects, with a total capacity of 550,000 kilowatts. Compared with the target of "annual new construction scale of about 3 million kilowatts", the scale of solar thermal power generation is expected to usher in rapid growth.

However, in actual development, the scale of solar thermal power generation has been far behind photovoltaic power generation. At present, the main factor restricting the sustainable development of solar thermal power generation in China is the lack of continuity of relevant policies, for example, in 2016, after the National Development and Reform Commission approved the benchmark online demonstration price of solar thermal power generation, enterprise construction enthusiasm is high; The "Several Opinions on Promoting the Healthy Development of Non-Water Renewable Energy Power Generation" issued at the beginning of 2020 clearly states that new solar thermal projects are no longer included in the scope of central financial subsidies, and the good development momentum of solar thermal power generation has been significantly affected. The unclear policy leads to the lack of market development space for solar thermal power generation in China at present, and the cost can not be continuously reduced through large-scale application, and the solar thermal power generation industry in its initial stage is difficult. At the same time, the current financing environment, land policies, and tax policies cannot provide strong support for the healthy development of solar thermal power generation.