World’s second-largest solar power plant goes online

China’s CHN Energy has connected the Mengxi Lanhai solar power plant (SPP) with a capacity of 3 gigawatts (GW) to the grid. During the 14-month construction process, 5.9 million photovoltaic panels worth $1.6 billion in total were installed at the plant. Electricity generated by the SPP will be supplied from the Inner Mongolia Autonomous Region in northern China to provinces on the east coast using ultra-high voltage (UHV) lines.

UHV lines make “clean” electricity available to densely populated cities that do not have enough space for wind and solar generators. The area occupied by the Mengxi Lanhai SPP is 35 times larger than Monaco (70 square kilometers versus 2 square kilometers).

China is already implementing UHV technologies. For instance, Jiangsu Province in eastern China receives electricity via two UHV lines. The first of these lines is 3,324 km long with a voltage of 1,100 kV; it was brought into operation in 2018 and is used to supply power from the Xinjiang Uyghur Autonomous Region in northwestern China, which is home to Midong, the world’s largest solar power plant at 3.5 GW.

The construction of the second UHV line was completed in 2018; the 2,080-km 800-kV transmission line is designed to supply electricity from the southwestern province of Sichuan, which is home to the Baihetan Dam, the world’s second-largest hydroelectric power plant at 16 GW.

Since the Mengxi Lanhai project was implemented on a former coal mining site, the construction area was affected by soil subsidence. This necessitated special engineering solutions, including flexible mounting systems equipped with telescopic racks to ensure that the solar panels are aligned. The condition of the panels will be checked via drones that will be recharged at docking stations, and cleaning will be performed by cleaning robots. As a rule, these robots use a dry cleaning method, which makes it possible to remove dirt by an antistatic microfiber cloth.

China is the world leader in terms of the pace of solar energy development. According to the International Renewable Energy Agency (IRENA), the country was responsible for 63% of newly-launched global photovoltaic capacity in 2023 (199.1 GW out of 345.5 GW). This was caused by, among other things, the high availability of raw materials used in solar panel production. The United States Geological Survey estimates that China accounted for 68% of global silicon production in 2022, also ranking second worldwide in terms of silver production.