World’s first: China integrates 50MW sCO2 plant with 100MW molten salt storage

Keep aside lithium-ion battery banks for a moment. China is banking on molten-salt storage and super-pressurized gas to keep its power grid stable as demand rises.

Construction is reportedly underway on the Ruitan demonstration project at Shandong’s Bajiao power station.

It is said to be the world’s first utility-scale facility combining supercritical carbon dioxide power generation with molten salt thermal energy storage.

The facility is expected to be operational next year. It integrates a 50-megawatt supercritical carbon dioxide power generation unit with a 100-megawatt, 400 megawatt-hour molten salt energy storage system.

Power grids are volatile, fickle things. When factories power down at midnight, standard coal plants waste vast amounts of energy just to stay spun up.

The Ruitan facility operates like a thermal vault. During periods of low demand, the facility converts surplus power from coal units into stored heat using molten salt. When peak demand strikes, this stored heat powers a supercritical carbon dioxide unit to generate efficient electricity and maintain grid stability.

sCO2 units are water-free, more compact, highly efficient, lower in carbon emissions, and can adjust load four times faster than coal units.

China’s next big energy bet

Compared to standard power plants that boil water into steam to drive turbines, supercritical systems use carbon dioxide pressurized into a dense state with both gas and liquid properties.

This fluid directly powers turbines inside a closed-loop system that requires zero water and runs with higher efficiency and lower carbon emissions. Interestingly, the technology offers four times the load-adjustment speed of conventional coal units and can draw heat from diverse sources like solar, geothermal, or industrial waste.

The timing could not be better. While lithium-ion batteries dominate short-duration storage and mobile electronics, they degrade rapidly over an 8- to 10-year lifespan. On the other hand, molten salt tanks store energy reliably for over 30 years with virtually no capacity loss. Over several decades, that longevity slashes capital expenditure for long-duration grid storage.

China is moving fast to establish a lead in the space.

Guizhou province recently saw commercial operations launch at Chaotan One — the world’s first CO2 plant — which captures industrial waste heat from a local steel facility. Meanwhile, the China National Nuclear Corporation plans to roll out its own combined nuclear and molten-salt sCO2 system by 2028, and solar developers in Tibet are deploying molten-salt tanks at the 50-megawatt Dangxiong plant to store daytime solar energy.

Higher efficiency & lower emissions

The technology isn’t just a Chinese phenomenon. Projects like Europe’s SOLARSCO2OL are integrating similar loops into concentrated solar plants. Aerospace and nuclear researchers worldwide eye closed-loop sCO2 systems for next-generation reactors and spacecraft propulsion.

Unlike chemical batteries suited for mobile devices, molten salt systems store excess energy as heat in large liquid salt tanks. Operators can use this thermal energy directly or convert it back into electricity.

As a result, the Ruitan facility would give energy companies a practical way to meet strict decarbonization goals without tearing down existing infrastructure. Power producers can convert obsolete coal facilities into adaptable, water-free clean energy centers.

These converted plants store massive amounts of thermal energy for weeks, stabilize power grids during demand spikes, and extend the operating life of valuable industrial sites for decades.