An aerial view of the world's first dual-tower solar thermal plant in northwest China's Gansu Province. /China Three Gorges Corporation
A Chinese power company is pioneering world-first technology by combining two endothermic towers to achieve a significant efficiency boost.
China Media Group (CMG) released a video on Tuesday showing the impressive project near Guazhou County in Gansu Province. The two towers are each 200 meters tall with nearly 30,000 mirrors installed on the ground. The mirrors form two vast, overlapping circles that focus sunlight onto each tower.
Like a traditional coal plant, the concentrated sunlight heats water to generate electricity. Unlike other thermal power plants, this design can produce power at night. Molten salt stored within the towers acts like a thermal battery, retaining extra heat collected during the daytime and releasing it to keep the generators running continuously.
The mirrors are made of special materials, whose reflection efficiency can reach a staggering 94 percent.
A sample of the molten salt used in the plant. /CMG
China's foray into solar thermal power began in 2016, but this new project takes it a step further with its dual-tower design. "The mirrors in the overlapping area can be utilized by either tower," explains plant project manager Wen Jianghong. "This configuration is expected to enhance efficiency by 24 percent."
The CMG video shows the mirrors' remarkable ability to track the sun's movement. They concentrate the sun's rays on the eastern tower in the morning and automatically adjust westward in the afternoon.
According to the CMG report, the innovative design isn't limited to the two towers. It has the potential to involve multiple towers for even greater efficiency gains. The plant is expected to be operational by the end of 2024.
The plant is part of a clean energy complex with solar, thermal and wind power plants that will work together to generate over 1.8 billion kilowatt-hours of electricity each year and save 1.53 million tonnes of carbon emission.