How big is Outer Cape Community Battery?

Outer Cape Community Battery has a reported capacity of 25 MW. Source: EIA Form 860M.

What kind of plant is Outer Cape Community Battery?

Outer Cape Community Battery is a batteries facility in Barnstable County, MA, participating in the ISO-NE market.

Where is Outer Cape Community Battery located?

Outer Cape Community Battery is in Barnstable County, MA, inside the ISO-NE balancing area.

Who operates Outer Cape Community Battery?

Outer Cape Community Battery is operated by Eversource according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

How much electricity does Outer Cape Community Battery generate?

Outer Cape Community Battery reported 715 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.

How does Outer Cape Community Battery compare to other plants?

By capacity, Outer Cape Community Battery ranks #349 of 962 operating plants of the same technology nationally. It ranks #3 of 129 in MA.

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Outer Cape Community Battery

NSTAR Electric Company d/b/a Eversource Energy - Barnstable County - ISONE

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.

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ISO-NE · Asset profile

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Outer Cape Community Battery — 25 MW battery storage, MA · Ask the Grid

Overview

Nameplate capacity: 25 MW
Canonical EIA plant baseline.
Registry anchor: Plant 62604
plant-62604

Structured profile

Technology: Batteries
Operator: NSTAR Electric Company d/b/a Eversource Energy

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Units and generators

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

Performance

Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.

Peer context

Technology capacity: 25 MW
National rank: #349
MA rank: #3

Monthly generation

Download CSV

Latest 12 months

715 MWh

Reported gross generation

Latest report

Apr 2026

EIA-923 monthly filing

2025 net exchange

-60 MWh

Generation less station charging

Grid and market context

Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.

Nearby substations

HIFLD infrastructure inventory

UNKNOWN158611

IN SERVICE · 115 kV

19.3 km

UNKNOWN133429

Commercial, land, and environmental record

Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.

Transactions and agreements

Regulatory Approval

2017

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.

Massachusetts Department of Public Utilities · NSTAR Electric Company d/b/a Eversource Energy

fileservice.eea.comacloud.net

Technical Support Engagement

2018

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.

TRC Companies · NSTAR Electric Company d/b/a Eversource Energy

trccompanies.com

Construction Start (Planned)

Mar 2020

Original municipal project briefing indicated planned start of construction. Schedule explicitly noted as subject to change.

NSTAR Electric Company d/b/a Eversource Energy · Town of Provincetown, Massachusetts

provincetown-ma.gov

Commercial Operation

Sep 2022

TRC Companies reports that the 25 MW / 38 MWh energy-storage-driven microgrid went live and became ready to provide backup power.

NSTAR Electric Company d/b/a Eversource Energy

trccompanies.com

Federal Grant Award Selection

Sep 2024

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.

U.S. Department of Energy · NSTAR Electric Company d/b/a Eversource Energy

ecivis-partners.s3.amazonaws.com

Related parties and identifiers

Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.

Relationship graph

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AssetOwner / operatorOrganization

Parties and identifiers

OrganizationRoleBasis

Timeline and sources

Project milestones and public references behind the asset profile.

Project timeline

2017
2017
DPU approval of Wellfleet/Outer Cape BESS demonstration projectfileservice...
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.
2018

Outer Cape Community Battery

Ask about Outer Cape Community Battery

Outer Cape Community Battery

Ask about Outer Cape Community Battery

Overview

Structured profile

Related assets

59 Federal Rd(CSG)

0 Hammond St CSG

Units and generators

Performance

Peer context

Monthly generation

Grid and market context

Nearby substations

Commercial, land, and environmental record

Transactions and agreements

Related parties and identifiers

Relationship graph

Parties and identifiers

Timeline and sources

Project timeline

Bonny Eagle

Cranberry Point Energy Storage

Wakefield MA BESS 1

Minuteman Energy Storage

Reporting portfolio

Sources

Common questions about Outer Cape Community Battery

How big is Outer Cape Community Battery?

What kind of plant is Outer Cape Community Battery?

Where is Outer Cape Community Battery located?

Who operates Outer Cape Community Battery?

How much electricity does Outer Cape Community Battery generate?

How does Outer Cape Community Battery compare to other plants?