China Connects First 100-Megawatt Compressed CO2 Storage Facility to Grid

China connected its first 100-megawatt-level compressed carbon dioxide energy storage facility to the grid on October 2 in Mulei County, Xinjiang. Built by state-owned power generator China Huadian, the facility operates as a closed-loop system that shifts carbon dioxide between gas and liquid states to store and discharge electricity. State media reports the installation can store 290 million kilowatt-hours during low-demand periods and supply 180 million to 200 million kilowatt-hours annually during peak hours, providing over six hours of continuous discharge capacity.

The commissioning marks China's first grid-connected commercial deployment of 100-megawatt-scale compressed carbon dioxide storage, demonstrating an alternative long-duration energy storage pathway that bypasses the geographic and water resource constraints of pumped hydro and underground salt caverns.

China connected its first 100-megawatt-level compressed carbon dioxide energy storage project to the power grid on October 2 in Mulei County, Xinjiang, according to state media reports. Developed by state-owned China Huadian Corporation, the facility is designed as a closed-loop system that relies on gas-liquid phase shifts to store and dispatch electricity. State broadcaster CCTV reported that the plant operates by drawing off-peak power to compress gaseous carbon dioxide at ambient temperature, capturing the resulting heat in thermal storage units before cooling the compressed gas into a high-density liquid state. During periods of high power demand, the liquid carbon dioxide is revaporized and reheated using the stored thermal energy. The expanding high-pressure, high-temperature gas drives a turbine to generate clean power, cycling the gas back into low-pressure storage for the next charging phase. The plant configuration includes five gas storage units, 141 liquid storage units, and 97 thermal storage modules. Chinese state outlets noted that because the installation utilizes above-ground modular vessels, it avoids dependence on specific subsurface geological formations such as underground salt caverns or natural aquifers. Operational metrics published by state media indicate minor variations in expected annual discharge. Reports cite the system's capacity to absorb 290 million kilowatt-hours of off-peak electricity annually, with CCTV citing an annual release of 180 million kilowatt-hours and project head Ma Guojiang stating annual output will reach approximately 200 million kilowatt-hours. The facility is designed to deliver continuous generation for over six hours with minute-level response times. According to Ma, the system achieves the highest generation efficiency among domestic carbon dioxide power generation units, while offsetting 50,000 metric tons of standard coal consumption and cutting carbon dioxide emissions by roughly 170,000 metric tons per year. State reports emphasized that the design and core manufacturing technologies were developed domestically.