World’s largest hybrid solar plant stores energy in molten salt to supply power at night

China Three Gorges Corporation (CTG) has begun commercial trial operations at what it claims is the world’s largest hybrid solar power plant in Xinjiang, northwest China. Announced on July 1, this 1-gigawatt (GW) facility uses both traditional solar panels and concentrated solar power (CSP) technology. This setup allows the plant to continue generating electricity for up to eight hours after sunset without using lithium batteries. Located in the Gobi Desert near Hami, the project uses molten salt to store heat from the sun during the day. This stored heat is then converted into electricity, allowing the plant to continue producing power into the evening when demand remains high.

Hybrid system combines solar panels with thermal storage
The Hami complex consists of 900 megawatts (MW) of photovoltaic (PV) solar panels and a 100 MW CSP unit. These are spread over about 4,490 acres (1,817 hectares) at the southern foothills of the Tianshan Mountains. The project cost 3.53 billion yuan, or about $480 million.

During the day, the PV array sends electricity straight to the grid. Meanwhile, the CSP section gathers solar energy with 260,000 tracking mirrors that cover about 8.6 million square feet (800,000 square meters) of reflective surface.

The mirrors focus sunlight to heat molten salt up to 1,022°F (550°C). This heat is stored and later used to make steam, which powers a turbine after sunset.