China's First Commercial Supercritical CO2 Closed-Loop Geothermal Project Turns the Earth into a Rechargeable Battery

China's First Commercial Supercritical CO2 Closed-Loop Geothermal Project Turns the Earth into a Rechargeable Battery

In May 2026, engineers from China Huaneng Group in Zhengzhou drilled a 2,500-meter well and pumped supercritical carbon dioxide into the ground instead of water. The CO2 goes down cold and comes back hot, extracting heat from the rock. It is China's first commissioned supercritical CO2 closed-loop geothermal demonstration project, and it removes the old constraint of geothermal, which needs natural underground hot water.Traditional hydrothermal …