China achieves breakthrough in high-latitude solar thermal power

China's first solar thermal power station in northeast China began operation on Monday in Da'an, Jilin Province, marking a major breakthrough in the application of solar thermal power technology in high-latitude, extremely cold regions.

The 100-megawatt solar thermal power station is expected to provide a replicable model for the development of similar projects in regions with harsh climatic conditions.

Located at high-latitude, the station is the first solar thermal power station in northeast China. Equipped with an eight-hour molten salt thermal energy storage system, it is capable of generating electricity safely and steadily around the clock.

The station generates electricity by using a large field of mirrors to concentrate sunlight onto a central receiver, where solar energy is converted into thermal energy and stored for later power generation.

The mirror field consists of 19,667 high-precision heliostats, covering a total reflective area of about 590,000 square meters. The mirrors continuously track the sun and reflect its rays onto a receiver mounted 210 meters above the ground, where molten salt is heated to 565 degrees Celsius before being stored in a thermal energy storage system.

Due to lower-than-expected heat loss from the storage tanks, the stored thermal energy can be used not only for power generation on the same day but also, depending on weather conditions, on the following day or even later.

To ensure the tower's construction accuracy, the project team adopted an innovative construction method in which friction bears the primary structural load. The 189-meter receiver tower was completed with a vertical deviation of less than 10 millimeters.

"The project is located in an area with extremely harsh natural conditions," said Zhao Xiong, head of the China General Nuclear Power Corporation (CGN) Jixi Solar Thermal Project Company. "Temperatures can fall to minus 37.3 degrees Celsius, wind speeds can reach Force 9, and the site is characterized by saline-alkaline soil, a high groundwater table and heavy clay."

He said CGN has developed key technologies to address challenges posed by harsh winter conditions, including molten salt anti-freezing technology, wind- and snow-resistant heliostat systems, low-temperature pile foundation construction, and advanced waterproofing solutions for large thermal storage tanks. The technologies have been integrated into standardized solutions that can be replicated in regions above the 45th parallel north with similar climatic and geological conditions.

According to Jiang Tonghai, chairman of CGN (Jilin) New Energy Investment Co Ltd, the project is expected to generate about 180 million kilowatt-hours of electricity annually, saving the equivalent of 54,000 metric tonnes of standard coal and reducing carbon dioxide emissions by about 139,000 metric tonnes each year.