# Exelon West Medway II LLC

ISO-NE asset profile · https://askthegrid.com/assets/facilities/exelon-west-medway-ii-llc

## Current generation inventory

EIA plant 59882 · Inventory reporting month: 2026-08.

- natural gas: 263.6 MW operating nameplate
- Capacity basis: operating_generator_nameplate_mw
- Source inventory: [EIA-860M workbook (preliminary)](https://www.eia.gov/electricity/data/eia860m/xls/august_generator2026.xlsx)
- Inventory retrieved: 2026-10-10T02:12:40.665346+00:00
- Filed coordinate (longitude, latitude): -71.4447, 42.137218
- OSM extract: 2026-10-08T20:21:06Z
- OSM mapped edit: 2026-09-07 21:59:51+00:00
- Map prepared: 2026-10-10T02:28:24.190698+00:00

Battery power (MW) and stored energy (MWh) are separate measures. Shared physical-site membership does not establish electrical connectivity, settlement or a common export limit.

## Reviewed overview

Exelon West Medway II LLC is a 263.6 MW natural gas fired combustion turbine plant in Norfolk County. West Medway Generating Station II is a two-unit, 192 MW simple-cycle, dual-fuel peaking station in West Medway, Massachusetts, owned and operated by West Medway II, a wholly owned Constellation subsidiary. Exelon won state siting approval for the expansion in August 2017, using two GE LMS100 turbines. The plant entered commercial operation in 2019, burns primarily natural gas with ultra-low sulfur diesel as backup for up to 30 days a year, and reaches full power in 10 minutes.

## Reviewed metrics

- **Nameplate capacity:** 263.6 MW — Canonical EIA plant baseline.
- **Registry anchor:** Plant 59882 — plant-59882

## Facts

- **Technology:** Natural Gas Fired Combustion Turbine
- **Operator:** Constellation

## Related parties

- **Owner / operator / parent company:** Constellation — owner ([source](https://www.constellationenergy.com))
- **Owner / operator:** West Medway II — owner
- **Equipment supplier:** General Electric — equipment_supplier ([source](https://www.ge.com))
- **Construction contractor:** Gemma Power — construction_contractor

## Sources

- [stateelectriccorp.com](https://stateelectriccorp.com/portfolio/medway-power-plant-200mw-peaking-station) — stateelectriccorp.com · public_source — Source retained for exact-record publication review.
- [constellationenergy.com](https://www.constellationenergy.com/about/locations/west-medway-generating-station-ii.html) — constellationenergy.com · public_source — Source retained for exact-record publication review.
- [powermag.com](https://www.powermag.com/exelon-set-to-expand-massachusetts-peaking-plant/) — powermag.com · public_source — Source retained for exact-record publication review.

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Canonical page: https://askthegrid.com/assets/facilities/exelon-west-medway-ii-llc
Website: [Constellation](https://www.constellationenergy.com)

Source: Ask the Grid — https://askthegrid.com/