Representative image: Technicians maintain a steam turbine in China.Getty Images
The China National Nuclear Corporation (CNNC) claimed the world’s first commercial supercritical carbon dioxide power generator has been connected to the grid.
CNNC says that the system uses carbon dioxide in place of steam to transfer heat. It has been placed in a steel production plant in the Guizhou province of China. The power generator has been connected to the grid, and it will supply electricity generated from the plant’s waste heat.
According to reports, the two 15 megawatt units are thought to be at least 50 percent more efficient in making electricity from waste heat than the steam power systems that are in use around the world.
The breakthrough in clean energy systems promises a new future even for nuclear technology.
Carbon dioxide power generator’s application in nuclear energy
The 15 MW system built by China could be scaled up in the future to meet utility-relevant sizes and start replacing steam variants in nuclear as well as other settings.
A report by SCMP on China’s achievement mentions that the compact power generators can be used to make power from mobile nuclear reactors, spacecraft, and solar plants.
The supercritical carbon dioxide power generator works by keeping CO2 in such a state that it acquires the properties of a gas and a liquid. It is achieved by keeping the gas above a critical pressure and temperature.
Compressor loop of US STEP pilot project.
The generator installed at the steel production plant will use the high-temperature (over 1,292 degrees Fahrenheit) waste heat from the sintering process.
According to the SCMP report, while the efficiency of steam power plants is at 40 percent in high-temperature sources, the supercritical CO2 power generator’s efficiency can reach above 50 percent.
Moreover, China’s Institute of Mechanics says that since supercritical carbon dioxide is denser than steam, the power generators can be more compact and used in much smaller spaces.
A similar system is being tested in the US
It should be noted that China’s system claims to be the world’s first commercial carbon dioxide power generator to be connected to the grid.
In 2023, a 10 MW supercritical carbon dioxide was declared ‘mechanically complete’ at the pilot plant in Texas by project partners SwRI, GTI Energy, GE Vernova, and the US Department of Energy. It was called the Supercritical Transformational Electric Power (STEP) demo pilot plant.
The first phase of testing for the STEP plant had been completed in September 2024. The pilot plant had reached full operational speed at 932 degrees Fahrenheit (500 degrees Celsius) and generated four megawatts of electricity.
In the final testing phase, the project aims to reach 10 MW of electricity production while operating at 1,319 degrees Fahrenheit (715 degrees Celsius).
The Nuclear Power Institute of China had been working on the supercritical carbon dioxide power generator for over a decade.
Other such systems are also being tested across the world, and it could revolutionize clean energy. The small systems can also be used in ships and spacecraft.
