China Three Gorges Corporation (CTG) has put the world’s largest solar PV-plus-concentrated-solar hybrid into commercial trial operation in the Gobi Desert — and its headline trick is delivering power after sunset without a single lithium battery.
The 1-gigawatt Hami project in Xinjiang stores the sun’s energy as heat in molten salt, letting it keep generating for up to eight hours after dark.
How the plant works
The Hami complex pairs 900 MW of standard solar panels with a 100 MW concentrated solar power (CSP) unit built on 1,817 hectares of desert at the southern foot of the Tianshan mountains. Total investment was CNY 3.53 billion, or about $480 million.
During the day, the PV array feeds the grid at full load. The CSP unit does something different: 260,000 tracking mirrors covering 800,000 square meters of collector surface focus sunlight to heat molten salt to 550°C (1,022°F). That heat is stored, then used to produce steam and spin a turbine once the sun goes down.
It’s important to be precise about what that means. The 8-hour after-dark output comes from the 100 MW CSP unit, not the full gigawatt — this is a dispatchable evening block, not 1 GW running through the night. But it’s the part of the plant that solves solar’s biggest problem, and it does it with thermal storage rather than batteries.
CTG uses a linear Fresnel design, which the company says improves heat-conversion efficiency by up to 10% over conventional Fresnel systems, and a 46-loop layout that keeps the plant running during maintenance. A centralized controller splits output between the PV and thermal sides with frequency-regulation accuracy of around 0.02 Hz and sub-second response.
Not exactly new — but now commercial
The “commercial trial operation” milestone landed on July 1, but the plant itself isn’t a fresh discovery. It was first connected to the grid on September 18, 2025, and has run on continuous load ever since, supplying 6.54 million kWh to the regional grid so far, according to CTG.
At full capacity, CTG projects the complex will generate 2.07 TWh of electricity a year — enough for roughly 830,000 households — while cutting about 1.63 million tons of CO2 annually and lifting renewable-utilization rates in Xinjiang above 95%.
The project unseats the 950 MW Noor Energy 1 plant at Dubai’s Mohammed bin Rashid Al Maktoum Solar Park as the world’s largest CSP-PV hybrid.
China has been on a tear across every solar format. We’ve covered its 3 GW Gobi Desert solar farm, the world’s first 1 GW offshore solar farm, and the fact that China installed more solar in the first half of 2025 than the rest of the world combined. Molten-salt thermal storage is the next front.
Salt vs. lithium
The pitch for CSP thermal storage is that it targets a different job than batteries.
“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.”
The catch is cost. CSP has historically been more expensive per kWh than PV-plus-battery, and lithium prices keep falling. The real test for Hami isn’t whether it works — it’s whether it can deliver those eight hours cheaply enough over years of operation to beat batteries that get cheaper every quarter.
China is betting it can. CTG plans to expand the Hami base to 3 GW in a second phase, and China Energy Engineering Corp has already broken ground on a separate 1.5 GW hybrid nearby — 1.3 GW of PV paired with 150 MW of CSP — that would top Hami as soon as it comes online.
Electrek’s Take
The genuinely interesting thing here isn’t “world’s largest” — that title changes hands every few months in China. It’s that China is industrializing molten-salt storage at utility scale while most of the world treats CSP as a dead end.
The skeptical read is warranted. CSP’s levelized cost has lost badly to PV-plus-lithium over the past decade, and a 100 MW dispatchable block bolted onto 900 MW of panels is a demonstration, not a template that automatically pencils out everywhere. The “no batteries” framing is also doing some work — after sunset, this is a 100 MW plant, not a 1 GW one.
I don’t know if there’s a real future in this as battery costs continue to come down and longevity continues to increase. I think ultimately, batteries are the solution to the intermittent nature of renewables. It’s a cool project nonetheless. And worth exploring.
If you’re weighing how to lock in low, stable electricity costs at home, rooftop solar is the most direct way to do it. With electricity rates climbing nearly 10% last year, home solar protects you against future rate increases. And with lease and PPA options, you can go solar with zero upfront cost and start saving immediately. If you want to find the best deal, check out EnergySage. It’s a free service with hundreds of pre-vetted installers competing for your business, so you save 20 to 30% compared to going it alone. No sales calls until you pick an installer. Get your free quotes here.
FTC: We use income earning auto affiliate links. More.