Overview
Over the National Day holiday, two grid-flexibility breakthroughs landed: on Oct 2, China’s first 100 MW-class compressed carbon-dioxide energy storage project in Xinjiang’s Mulei was connected to the grid, able to store about 290 GWh/year and release about 180 GWh of clean power with over 6 hours of continuous generation. Around the same time, Zhejiang’s market-based virtual power plant (VPP) valley-filling response hit a record—50 operators and 2,542 aggregated users participated, with a peak response load of 3.5952 GW, of which 1,359 behind-the-meter storage units contributed 1.0641 GW.
Background & Interpretation
1. Industry and Policy Context
High renewable penetration makes grid-regulation resources scarce; “source-grid-load-storage” integration and power-market reform are the backbone of the new power system. Long-duration storage “banks the power” while demand response “shifts the load”—their synergy is key to absorbing high renewable shares. Rules such as Zhejiang’s trial 2.0 implementation细则 provide the institutional base for VPPs.
2. Core Drivers and Underlying Mechanism
Compressed-CO₂ storage uses CO₂ as a sealed working fluid in a gas-liquid two-phase cycle with turbine efficiency above 90%, opening a large-capacity zero-carbon storage path—storing 290 GWh in off-peak hours and releasing 180 GWh at peaks. For VPPs, new rules let storage’s “charge-at-noon, discharge-at-peak” value be metered and settled independently rather than cancelled by production cuts, sharply raising behind-the-meter participation.
3. Market Structure and Value-Chain Impact
Zhejiang has connected 65 VPP operators and 9,852 secondary users with over 3.6 GW of dispatchable capacity; resources now span industrial load, behind-the-meter storage, EV charging, commercial buildings and data centers. New storage and VPPs are shifting from holiday-only actions to routine grid regulation, spawning aggregators, EMS and metering-settlement ecosystems.
Implications & Outlook
Long-duration storage (CO₂, molten salt, pumped hydro) and demand response will scale as spot and ancillary-service markets mature. Behind-the-meter storage economics improve, likely moving from policy-driven to market-driven, with distributed aggregation becoming a major flexible resource.
Takeaways for Industry Participants
- Industrial users can monetize idle capacity by joining VPP responses;
- Storage firms must design market-settlable business models around grid rules;
- Grid companies should accelerate market mechanisms, metering and settlement.
This column compiles industry information and shares technical perspectives; it does not constitute investment advice.