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Oct. 2, 2026Northwest China, Sep 30, The Huadian 100MW/1000MWh compressed CO₂ energy storage station, with technology, core equipment and system integration by Exax Energy, completed grid commissioning successfully on the first attempt.
It is the world’s first 100 MW-class compressed CO₂ energy storage project and the largest publicly disclosed CO₂ storage facility to date, marking CO₂ long-duration energy storage entering the era of GW-scale grid-connected operation.
Long-Duration Energy Storage (LDES) has become critical infrastructure for high-penetration renewable power systems, with IEA, BNEF and other institutions closely tracking its scaled rollout. This project offers a replicable pathway for large-scale LDES deployment without geological constraints.
Project Profile
• Location: Northwest China
• Capacity: 100MW/1000MWh, 10-hour discharging
• Technology: Compressed CO₂ energy storage
• Core components: 5 gaseous storage domes, 141 liquid storage units, 97 thermal storage units
• Design lifespan: ≥30 years
• Cycling capability: Over 20,000 frequent start-stop cycles
• Response time: <20 minutes from startup to full load
• O&M: One-click startup, unattended intelligent operation; automatic drone remote inspection. All data feeds to the central control center for rapid assessment and closed-loop control.
• Environmental benefits: Stores 290 GWh of off-peak green power annually and discharges 180 GWh during peak hours, with ~200 GWh estimated annual generation. It saves 50,000 tons of standard coal and cuts CO₂ emissions by ~170,000 tons per year.
Global merits of CO₂ energy storage
Compared with lithium-ion batteries, compressed CO₂ storage excels in long-duration, large-scale and frequent-cycling applications. Unlike pumped hydro storage, it requires no special geological conditions and can operate in harsh environments including Gobi deserts, arid, windy and sandy regions.
As a closed-cycle working fluid, CO₂ enables the system to run at moderate pressure and temperature with outstanding safety and longevity. The technology can be integrated with CCUS to unlock carbon-negative and circular carbon value, supporting decarbonization across industry and power systems.
Rolling out the China Solution: From demonstration to global collaboration
Exax Energy delivers the full value chain, covering system design, core equipment development, engineering integration and commissioning. This project creates a replicable model for LDES to move from demos to large-scale commercialization.
For markets across the Middle East, Europe, the Americas and Asia-Pacific, Exax Energy stands ready to advance Belt and Road green energy cooperation through technology licensing, core equipment supply, system integration, joint development and local O&M, accelerating worldwide adoption of CO₂ long-duration energy storage.
