19 MW / 200 MWh CO2 battery at Coronado Generating Station (decommissioned coal plant) in St. Johns, Arizona, with Google and SRP. Ten-hour storage for Arizona grid.
Announced June 2026; under development on decommissioned site.
Checked 10 Oct0 updates this week
Grid power (ideally from solar or wind) drives compressors that squeeze CO2 into high-pressure tanks at colder temperatures for storage.
Compressed CO2 is stored in tanks on site. Unlike lithium-ion, CO2 degrades extremely slowly and the system is not limited to underground caverns.
When grid demand peaks, high-pressure CO2 expands through turbines connected to a generator, producing electricity. The cycle is reversible.
| Spec | Arizona CO2 Battery (Google / SRP) |
|---|---|
| Power capacity | 19 MWR (reported) |
| Energy storage | 200 MWhR (reported) |
| Discharge duration | ~8–10 hoursR (reported) |
| Site | Coronado Generating Station, ArizonaR (reported) |
| Estimated homes powered per hour | ~4,275R (reported) |
R reported by the company
Energy Dome
CO2 battery long-duration energy storage, grid storage
Energy Dome develops long-duration energy storage using compressed CO2. It compresses CO2 with renewable power, stores it in tanks, and expands through turbines to generate electricity on demand. Unlike lithium-ion, it avoids lithium and rare minerals.
