China has connected its first 100-MW-class compressed carbon dioxide energy storage plant to the grid in Mori Kazakh Autonomous County, Xinjiang. The facility compresses CO2 into liquid during off-peak hours, then expands it to drive turbines when demand rises. It is designed to move about 180 million kWh of power to peak periods each year and avoid around 170,000 tons of CO2 emissions annually, according to the project team. Unlike pumped hydro or compressed air storage, the closed loop system does not depend on mountains or underground caverns. That makes it easier to site near wind and solar farms or load centers. The project is meant to absorb surplus renewable generation and reduce curtailment in the regional grid. The storage field is still new, so the main open questions are real-world round trip efficiency, operating costs, and how the technology scales beyond 100 MW.
