Four oil-fired units plus the separately interconnected Casco Bay battery
William F. Wyman is a hybrid EIA plant in Yarmouth, Maine: four petroleum-fired units total 846.0 MW nameplate and the separate Casco Bay battery adds 16.7 MW gross.
Answers use this researched asset profile with live ISO-NE data. Ask about ownership, equipment, project history, or current grid context.
Live ISO-NE public data · answers can be wrong, verify against source data or the ISO.
846.0 MW petroleum generation plus 16.7 MW battery storage.
16.2 MW net summer and winter.
Similar plants ranked by technology, capacity, and distance.
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| 1 | 50 MW 50.1 MW summer | Petroleum Liquids Residual Fuel Oil · ST | Jan 1957 | Operating |
| 2 | 50 MW 47.8 MW summer | Petroleum Liquids Residual Fuel Oil · ST | Jan 1958 | Operating |
| 3 | 113.6 MW 110.9 MW summer | Petroleum Liquids Residual Fuel Oil · ST | Jan 1965 | Operating |
| 4 | 632.4 MW 602.1 MW summer | Petroleum Liquids Residual Fuel Oil · ST | Jan 1978 | Operating |
| BESS | 16.7 MW 16.2 MW summer | Batteries Electricity used for energy storage · BA | Dec 2016 | Operating |
Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.
Monthly generation is reported through EIA-923. Capacity factor uses the current EIA nameplate capacity and is shown only for complete calendar years.
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.
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
Project milestones and public references behind the asset profile.
EIA-860 lists generator 1 with this operating date.
EIA-860 lists generator 2 with this operating date.
EIA-860 lists generator 3 with this operating date.
EIA-860 lists generator 4 with this operating date.
Answered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
William F Wyman Hybrid has a reported capacity of 862.7 MW. Source: EIA Form 860M.
William F Wyman Hybrid is a Petroleum-fired steam generation plus battery storage facility in Cumberland County, ME, participating in the ISO-NE market.
William F Wyman Hybrid is in Cumberland County, ME, inside the ISO-NE balancing area.
William F Wyman Hybrid is operated by FPL Energy Wyman LLC according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
William F Wyman Hybrid reported 338.6 GWh over the twelve months to 2026-04. Figures are net generation as filed to EIA-923.
William F Wyman Hybrid on the Central Maine Power system.
By capacity, William F Wyman Hybrid ranks #3 of 705 operating plants of the same technology nationally. It ranks #1 of 3 in ME.
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.