PG&E's 256-Megapack battery on Monterey Bay
Elkhorn is PG&E's 182.5 MW / 730 MWh four-hour battery at Moss Landing, built with 256 Tesla Megapacks. EIA listed the generator as out of service in June 2026; an April 2026 CPUC proposed decision said it had been offline since June 2, 2025, with no definitive return date reported by PG&E as of February 27, 2026.
Answers use this researched asset profile with live CAISO data. Ask about ownership, equipment, project history, or current grid context.
Live CAISO public data · answers can be wrong, verify against source data or the ISO.
Four-hour EIA basis.
PG&E exact-asset fire report.
Project footprint.
Illustrative BESS equipment layout for comparing sites. Not an as-built site map.
Similar plants ranked by technology, capacity, and distance.
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| ELKHO | 182.5 MW 182.5 MW summer | Batteries Electricity used for energy storage · BA | Apr 2022 | Operating |
Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.
Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.
Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.
Project milestones and public references behind the asset profile.
EIA-860 lists generator ELKHO with this operating date.
EIA-923 reports gross generation and net grid exchange for storage plants. Gross generation is shown as a discharge proxy; it is not a cycle count or conventional capacity factor.
| Largest reported plants | Capacity | State | |
|---|---|---|---|
| Diablo Canyon | 2,323 MW | CA | |
| Helms Pumped Storage | 1,053 MW | CA | |
| Colusa Generating Station | 712.4 MW | CA | |
| Gateway Generating Station | 619.7 MW | CA | |
| James B Black | 168.6 MW | CA | |
| Humboldt Bay | 167 MW | CA | |
| Poe | 142.8 MW | CA | |
| Pit 5 | 141.6 MW | CA |
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
View full reporting portfolioAnswered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
Elkhorn Battery Energy Storage System has a reported capacity of 182.5 MW and an energy capacity of 730 MWh. Source: EIA Form 860M.
Elkhorn Battery Energy Storage System is a Lithium-ion battery storage facility in Monterey County, CA, participating in the CAISO market.
Elkhorn Battery Energy Storage System is in Monterey County, CA, inside the CAISO balancing area.
Elkhorn Battery Energy Storage System is operated by Pacific Gas & Electric Co. according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
Elkhorn Battery Energy Storage System reported 637 MWh over the twelve months to 2026-04. For a storage plant this is reported gross generation — a discharge proxy, not a cycle count or a conventional capacity factor.
By capacity, Elkhorn Battery Energy Storage System ranks #74 of 962 operating plants of the same technology nationally. It ranks #18 of 248 in CA.
Plants within 25 km, nearest first, regardless of technology. Proximity is straight-line distance between mapped plant coordinates; it does not by itself establish a shared point of interconnection.