Chinese state-owned clean energy group, China Three Gorges Corporation (CTG) has commenced commercial trial operations at its “world’s largest” hybrid solar power plant in Xinjiang, northwest China.
This 1-gigawatt (GW) facility uses both traditional solar panels and concentrated solar power (CSP) technology, and would 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. The stored heat is then converted into electricity, allowing the plant to continue producing power into the evening when demand remains high.
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 metres) 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 100 MW CSP unit generates electricity, not the full 1 GW 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 percent 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 under a second.
While commercial trial operations started on July 1, the plant has actually been supplying electricity for several months with first connection 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 around 1.63 million metric tons and raise renewable energy use in Xinjiang to over 95 percent. The Hami project is now the world’s largest hybrid CSP and PV power plant, overtaking Dubai’s 950 MW Noor Energy 1.
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,” said 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, as CTG intends to increase the Hami energy base to 3 GW 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 1.3 GW of PV capacity with 150 MW of CSP, making a 1.5 GW plant that will be even larger than Hami when finished.
