World's 1st supercritical CO₂ waste heat plant fully online in China

The second unit of the "Carbon One" supercritical carbon dioxide waste heat power project has been connected to the grid at the Shougang Shuicheng steel plant in Liupanshui City, southwest China's Guizhou Province on Saturday, according to Science and Technology Daily. This completes the world's first commercial-scale demonstration of supercritical CO₂ waste heat power generation.

Built by the China National Nuclear Corporation (CNNC) Nuclear Power Institute, Jigang International and Shougang Shuicheng, the project now has a combined capacity of 30 megawatts across two 15 MW units – making it the world's largest and most advanced supercritical CO₂ power facility.

The first unit entered commercial operation on December 20, 2025, and has run stably for more than five months, with all performance indicators meeting or exceeding design specifications, CNNC said.

The second unit's successful grid connection, following intensive commissioning, proves the technology is commercially viable, CNNC added.

Unlike conventional steam turbines, supercritical CO₂ power cycles use CO₂ in a supercritical state – where it behaves as both liquid and gas – as the working fluid. This delivers higher thermal efficiency, particularly for waste heat recovery in heavy industries such as steelmaking, where exhaust heat is repurposed instead of being released into the atmosphere.

The technology was developed by the Nuclear Power Institute, which adapted expertise from nuclear power systems where supercritical CO₂ has been studied as a potential working fluid for next-generation reactors.