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 100MW CSP unit. These are spread over about 4,490 acres at the southern foothills of the Tianshan Mountains. The project cost about $480m.
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 800,000 sq m 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.
At night, only the 100MW CSP unit generates electricity, not the full 1GW plant. Rather than running the whole facility overnight, the thermal storage system supplies electricity during the evening when the solar panels stop producing power.
CTG said its linear Fresnel design boosts heat conversion efficiency by up to 10% compared to standard Fresnel systems. The 46-loop layout lets parts of the facility be maintained without stopping operations. A central control system manages both the PV and CSP sections, maintaining frequency regulation accuracy of about 0.02 hertz and responding in less than a second.
Commercial milestone follows months of grid operation
While commercial trial operations started on July 1, the plant has actually been supplying electricity for several months. It was first connected to the grid on September 18, 2025, and has been running ever since.
According to CTG, the facility has already delivered 6.54 million kilowatt-hours of electricity to the regional grid. When running at full capacity, it is expected to generate 2.07 terawatt-hours of electricity each year, enough to power about 830,000 homes. The company also estimates the project could cut annual carbon dioxide emissions by about 1.63 million metric tonnes and raise renewable energy use in Xinjiang to more than 95%.
The Hami project is now the world’s largest hybrid CSP and PV power plant, overtaking Dubai’s 950MW Noor Energy 1.
China sees molten salt as a long-duration storage option
CTG believes thermal energy storage serves a different purpose than lithium batteries, especially for providing electricity for longer periods after sunset.
“Lithium batteries are designed for short-duration peak shaving, while PV systems only produce power during daylight hours. CSP thermal storage stands apart with its large capacity, long discharge cycles, and zero operational emissions,” says Niu Jianle, project director of the CTG Hami project. He called the grid connection “a landmark leap, bringing the technology out of laboratory research and into large-scale commercial rollout”.
CSP projects have usually been more expensive per kilowatt-hour than solar farms with batteries, and lithium battery prices continue to fall. The long-term economics of Hami will depend on whether its thermal storage can deliver reliable evening electricity at a competitive price over time.
China is already planning further expansion. CTG intends to increase the Hami energy base to 3GW in a second phase. At the same time, China Energy Engineering Corp has begun construction of another nearby hybrid project. This new facility will combine 1.3GW of PV capacity with 150MW of CSP, making a 1.5GW plant that will be even larger than Hami when finished.