LANZHOU, July 20 (Xinhua) -- In Guazhou County of northwest China's Gansu Province, a solar thermal energy storage power station can generate power for 24 hours non-stop.
Its main project has begun commissioning and will be put into operation by the end of this year, according to the China Three Gorges Corporation.
The solar thermal energy storage power station can generate electricity with or without direct sunlight, thanks to the heliostats and the molten salt, while achieving stable all-day power output.
Two adjacent heat-absorbing towers, sharing one turbine generator, are settled in the power station. Beneath the towers, heliostat arrays are installed, covering a lighting area of 800,000 square meters.
Notably, the heliostats can pivot and follow the directions of sunlight, like a sunflower tracking the sun through the course of the day.
Assisted by such function turning sunlight into green energy, the power station attracts the sunlight into the two heat-absorbing towers to power up the turbine generator.
With a very high definition, the heliostats can reach 94 percent reflection efficiency, which reflects more sunlight to the heat-absorbing tower and greatly improves the efficiency of power generation.
At the foot of the heat-absorbing towers, there are two huge storage tanks filled with molten salt in 300 and 500 degrees Celsius respectively. The molten salt in its liquid form can store several times more heat than water.
The solar energy collected by the heat-absorbing towers during the day is stored in the form of heat in this liquid molten salt, achieving a stable and continuous power output for 24 hours.
Once in operation, the power station will serve as the basic regulation power supply, forming a clean energy base in a total installed capacity of 700,000 kilowatts together with the surrounding photovoltaic and wind power. The annual electricity generation will reach 1.8 billion kWh, cutting about 1.53 million tonnes of carbon dioxide emissions.
Since China introduced new energy bases in its vast desert and Gobi areas, the large-scale solar thermal power generation development has also kicked off.
Solar thermal power generation integrates energy storage and power generation, which is one of the effective means for new energy to replace traditional energy safely and reliably, said Hu Wenping, an official of China Electric Power Planning and Engineering Institute.
A solar thermal project is under construction in Haixi Mongolian and Tibetan Autonomous Prefecture of northwest China's Qinghai Province. At present, more than 90 percent of heliostats have been installed and the project is about to be connected to the grid by the end of September this year.
In Hami City of northwest China's Xinjiang Uygur Autonomous Region, the main body of an 1.5 million kilowatts solar thermal energy storage project has been fully started.
According to a blue book on China's solar thermal power industry of 2023, the total installed capacity of the country's solar thermal generating units above megawatt-level reached 588 megawatts, accounting for 7.8 percent of the global cumulative installed capacity of solar thermal power generation. ■
