It can not only generate electricity normally when there is sunlight, but also store excess solar energy with the help of molten salt to achieve 24-hour stable and uninterrupted power output. This solar thermal energy storage power station located in Guazhou, Gansu Province, has two adjacent heat absorption towers, sharing a steam turbine generator. Nearly 30,000 heliostats are installed under the towers, with a lighting area of ​​800,000 square meters. The power station uses these mirrors that track the rotation of the sun to collect sunlight into the heat absorption tower to heat the molten salt, thereby driving the steam turbine to generate electricity.

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Wen Jianghong, Project Manager of Guazhou CSP Energy Storage Project of China Three Gorges Corporation: The project adopts a dual-tower dual-mirror field design. The heliostat located in the middle area of ​​the two mirror fields can serve any heat-absorbing tower, which can improve the optical efficiency by about 24% under the same boundary conditions. It is equipped with a 6-hour molten salt heat storage system, which has the characteristics of long heat storage time, fast response speed, stable output power, and better peak-shaving performance. After it is put into operation at the end of this year, the CSP energy storage power station will serve as the basic regulating power source, and will form a multi-energy complementary clean energy base with a total installed capacity of 700,000 kilowatts with the surrounding photovoltaic and wind power, and will bundle and deliver a steady stream of green electricity. The annual power generation will reach 1.8 billion kWh, and carbon dioxide emissions will be reduced by about 1.53 million tons. Visit the world’s first “dual-tower one-machine” CSP energy storage power station. As the world’s first “dual-tower one-machine” CSP energy storage power station, what are its characteristics and differences?

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Each set of mirrors here can rotate freely, just like a sunflower, chasing the sun’s trajectory throughout the day, thereby converting more sunlight into green electricity. The mirrors are very high-definition. According to the staff, they are made of ultra-white glass made of special materials, with a reflection efficiency of up to 94%, thereby reflecting more sunlight onto the heat-absorbing tower and greatly improving the power generation efficiency.
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Inside the towering heat absorption tower, there are two huge storage tanks filled with molten salt, which has a boiling point of 600°C. The boiling point of water is 100°C, so liquid molten salt can store several times more heat than water. The solar energy collected by the heat absorption tower during the day will be stored in the liquid molten salt in the form of heat energy, achieving 24-hour stable and uninterrupted power output.

From the renderings, we can see the full picture of the solar thermal energy storage power station. It consists of two huge circular arrays. In the center of each array, there will be a heat absorption tower about 200 meters high. These two huge arrays are like two concave mirrors, reflecting all the sunlight to the heat absorption tower in the center. There is also a part of the two circular arrays that overlap, and the mirror surface of this part is very particular. It can rotate freely. In the morning, when the sunlight on the east array is better, the mirror will turn around and reflect more sunlight to the east tower; in the afternoon, when the sunlight on the west array is better, it will turn back and reflect the sunlight to the west tower. Compared with the traditional single-tower solar thermal power station, this double-tower or even multi-tower design is not limited by installed capacity. At the same time, its power generation efficiency, power generation and storage capacity will be greatly improved.

Solar thermal power generation has ushered in large-scale development. With the large-scale construction of new energy bases in deserts, Gobi and desert areas in my country, the large-scale development of solar thermal power generation has also begun. In Haixi Prefecture, Qinghai Province, the solar thermal projects of Golmud Haixi Base and Qingyu DC Phase II are under construction. At present, the number of heliostats installed exceeds 90%, and it is expected to be connected to the grid for power generation by the end of September this year. In Xinjiang, China Energy Construction Hami 50,000-kilowatt solar thermal demonstration project has gradually completed the technical transformation of key equipment, and the main project of the world’s largest single-phase 1.5 million-kilowatt Hami solar thermal energy storage project has been fully launched. By the end of 2023, there will be 11 solar thermal power stations connected to the grid in my country, with an installed capacity of 570 megawatts.

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