Outer Cape Community Battery
NSTAR Electric Company d/b/a Eversource EnergyBarnstable County
The Outer Cape Community Battery is a 25 MW / 38 MWh utility-owned lithium-ion battery energy storage system and distribution-level microgrid located at the Provincetown Transfer Station in Provincetown, Massachusetts. The system avoids the need to construct a second 13-mile distribution line through the environmentally sensitive Cape Cod National Seashore and serves approximately 11,000 customers connected via a single distribution line.
Mapped infrastructure geometry associated with this asset.
EIA plant 62604 · Inventory for Aug 2026.
| Generator | Technology | Status | Power (MW) | Energy (MWh) |
|---|---|---|---|---|
| OCESS | Batteries | Operating | 25 | 38 |
Similar plants ranked by technology, capacity, and distance.
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| OCESS | 25 MW 25 MW summer | Batteries Electricity used for energy storage · BA | Dec 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.
Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.
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.
The Massachusetts Department of Public Utilities approved two battery-storage demonstration projects in Eversource's base distribution rate case (D.P.U. 17-05). The Wellfleet/Outer Cape project was initially approved with a phase-one budget of $40 million.
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.
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
TRC Companies began providing technical advisory services to Eversource, including site selection and evaluation, environmental permitting and hearing support, geotechnical investigation, engineering and contracting support, building and site design, and system-study evaluations.
Original municipal project briefing indicated planned start of construction. Schedule explicitly noted as subject to change.
TRC Companies reports that the 25 MW / 38 MWh energy-storage-driven microgrid went live and became ready to provide backup power.
EIA-860 lists generator OCESS with this operating date.
NSTAR Electric Company d/b/a Eversource Energy was selected for award negotiations under the U.S. Department of Energy's Distributed Energy Systems Demonstrations program for the Outer Cape Microgrid Optimization (OCMO) project. Federal cost share: up to $19.5 million. Scope: distributed energy resource management system (DERMS) to coordinate customer-owned distributed energy resources (solar, smart thermostats, batteries) with the existing 24.9 MW Eversource-owned battery.
ecivis-partners.s3.amazonaws.comecivis-partners.s3.amazonaws.compublic_sourceAnswered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
Outer Cape Community Battery reports 25 MW battery storage of operating nameplate capacity. These technology ratings do not establish a common export limit. Source: EIA Aug 2026.
Outer Cape Community Battery is a batteries facility in Barnstable County, MA, participating in the ISO-NE market.
Outer Cape Community Battery is in Barnstable County, MA, inside the ISO-NE balancing area.
Outer Cape Community Battery is operated by Eversource according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
Outer Cape Community Battery reported 796 MWh over the twelve months to 2026-07. For a storage plant this is reported gross generation — a discharge proxy, not a cycle count or a conventional capacity factor.
By capacity, Outer Cape Community Battery ranks #396 of 1,061 operating plants of the same technology nationally. It ranks #3 of 131 in MA.