Aerial photo of heliostats of molten-salt solar thermal power plant in Gansu(1/4)

Aerial photo taken on Oct. 23, 2019 shows heliostats of a molten-salt solar thermal power plant in Dunhuang, northwest China's Gansu Province. (Xinhua/Ma Ning)

Workers clean heliostats for a molten-salt solar thermal power plant in Dunhuang, northwest China's Gansu Province. (Xinhua/Ma Ning)

Workers clean heliostats for a molten-salt solar thermal power plant in Dunhuang, northwest China's Gansu Province. (Xinhua/Ma Ning)

Workers clean heliostats for a molten-salt solar thermal power plant in Dunhuang, northwest China's Gansu Province. (Xinhua/Ma Ning)