An aerial photo shows the Jinta multi-energy complementary 100,000-kilowatt molten salt tower solar thermal power station in Jiuquan, Gansu province, on Dec 2, 2024. CAO HONGZU/FOR CHINA DAILY

In the vast, barren Gobi Desert of northwestern China, over 25,000 heliostats arranged in concentric circles span a total reflective area of 770,000 square meters, equivalent to 108 standard football fields.

Located in Jiuquan, Gansu province, this super project is the Jinta multi-energy complementary 100,000-kilowatt molten salt tower solar thermal power station. It is the largest tower-type solar thermal plant among China's first batch of demonstration power station projects in deserts, Gobi and barren lands commissioned this year.

Gansu, in China's inland northwest, boasts some of the country's highest potential for wind and solar energy development. With 197,000 square kilometers of unused land, 46.3 percent of its total area, the province is among the country's most favorable regions for new energy projects.

Since the start of the 14th Five-Year Plan (2021-25) period, China has accelerated renewable energy development in barren areas, transforming once-inaccessible deserts into "green power treasure troves".

At noon, the heliostats at the Jinta station automatically adjust to track the sun, focusing beams onto a central heat absorption tower. Here, molten salt is heated to over 550 C, stored in tanks, and later used to generate steam for electricity.

"The station has been connected to the grid since this June and is expected to produce 1.45 billion kilowatt-hours of clean electricity annually, equivalent to saving 480,000 (metric) tons of standard coal," said Huang Lushan, deputy manager of the project.

Solar thermal power, which uses molten salt or other mediums to store and convert solar energy, offers both peak shaving and energy storage capabilities, enabling a 24/7 clean power supply. According to a 2024 blue book on China's solar thermal power industry, this technology has gained prominence globally since its commercialization in the 1980s.

Gansu currently has an installed solar thermal capacity of 620,000 kW, supported by a range of implemented systems.

Another super project, the Yumen 100,000-kW molten salt linear Fresnel solar thermal power station, applies principles developed by 18th-century French physicist Augustin-Jean Fresnel. Its ground-level primary mirrors reflect sunlight to elevated secondary mirrors, concentrating heat onto tubes to warm molten salt.

"Compared to other solar thermal technologies, the Fresnel system has the benefits of lower construction difficulty, easier maintenance, and higher safety," said Zhu Yi, production and operation manager of the station. Integrated with existing photovoltaic, wind and storage projects, it can generate 1.7 billion kWh yearly, powering 3.5 million households.

Data from the National Energy Administration show that solar power, including thermal, added 240 million kW of capacity in the first three quarters of this year.

Government policies and market forces are spurring industry growth, with breakthroughs in key materials and core equipment.

"We independently developed the heliostat and mirror field control system, solving challenges like long-distance precision tracking and large-scale array management," Huang said. Optimizations in heat storage and molten salt pumps have also boosted efficiency and cut costs.

This growth is revitalizing traditional sectors like special glass, steel and salt production, while fostering smart control industries.

At a thermal technology company in Yumen, Gansu, production lines were humming with activity. "This is ultra-clear float glass, a core component for solar thermal power. For a long time, it was imported, but we broke the technical barrier and built the province's first production line, now dominating the domestic market," said Huo Fu, executive deputy general manager of the company.

Xinhua