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Portsmouth Naval Base Microgrid Testing

Current status, energy mix, organizations, suppliers, equipment, controls, reported specifications, and project updates—with source-level citations.

CoverageDetailed public record
Named organizations7
System facts22
Sources reviewed11
Evidence reviewed2026-07-20

This project is at Portsmouth Naval Shipyard in Kittery, Maine—not Norfolk Naval Shipyard in Portsmouth, Virginia. Its documented architecture has two generations: an ESTCP-era microgrid that integrated an existing 10.4 MW natural-gas CHP plant, emergency diesel generation, GE controls/Fast Load Shed, and a 500 kW/580 kWh Saft battery; and a US$58 million 2020 energy-savings expansion that added a 7.5 MW CHP plant, expanded controls/distribution redundancy, and announced a larger battery configuration. Public sources conflict on whether the expanded battery is 1 MW/2 MWh or a 1.5 MW/2.5 MWh engineering scope, so only the original 500/580 installation is treated as unambiguously commissioned at exact rating.

Research status
The original microgrid completed two live base-wide outage simulations and successfully maintained critical loads. Ameresco's current portfolio page continues to list shipyard CHP, emergency generation, microgrid controls, Fast Load Shed, and a 1 MW/2 MWh BESS. A February 2026 Town of Kittery climate-planning packet also describes the shipyard's natural-gas cogeneration, microgrid Fast Load Shed, and power-plant BESS as available capabilities. The broader expansion is therefore operational/currently referenced, although a public commissioning report reconciling all battery and generation nameplates has not been found.
Historical classification
CHP
Reported capacity
See component specifications
Coordinates
43.08035, -70.73991
Evidence note: “Every company” cannot be proven from public material alone. This page lists every organization found in the recovered record and reviewed sources, preserves unknown roles, and explicitly marks undisclosed controller or equipment details.
Report missing evidenceResearch methodology

Project delivery

Who was involved in Portsmouth Naval Base Microgrid Testing?

7 publicly identified organizations. Where a recovered source named a participant without explaining its work, the role remains explicitly unspecified.

Organization

Ameresco

ESPC developer, system integrator, CHP/BESS/microgrid contractor, and long-term operations-and-maintenance provider. [3][4][8]

Organization

GE

Publicly named participant; role not specified in the recovered record [1]

Organization

GE Grid Solutions

Supplier/integrator of the original microgrid supervisory controls and Fast Load Shed logic. [4][7]

Organization

Saft

Supplier of the original 500 kW/580 kWh lithium-ion battery. [7]

Organization

U.S. Department of Defense Environmental Security Technology Certification Program (ESTCP)

Funder/validation sponsor of the original microgrid controls and battery demonstration. [5][6]

Organization

United States Navy / Portsmouth Naval Shipyard

Federal installation owner, host, mission-load operator, and energy-savings customer. [3][5]

Organization

Waldron Engineering & Construction

Engineering participant on the later CHP/BESS expansion; its project page provides a larger battery design figure that conflicts with Ameresco's current rating. [10]

System evidence

Energy mix, capacity, and specifications

Values can describe different project phases, generation sources, storage systems, or other components. Source citations are attached to each figure so discrepancies remain visible.

KW Gas/Diesel
14000 [1]
Storage
500 kW/580kWh Battery Energy Storage System (BESS) [1]
Original CHP plant
10.4 MW from two 5.2 MW Solar Taurus 60 natural-gas turbines, with two 70,000 lb/hour heat-recovery steam generators and two 70,000 lb/hour package boilers; some summaries round the plant to 10 MW. [8][7]
Emergency diesel
Ameresco's detailed project sheet identifies 2 x 2 MW emergency diesel generators (4 MW total). The ESTCP page describes 2 x 1.5 MW, likely an earlier boundary/design figure; the discrepancy is preserved. [8][5]
Original battery
500 kW/580 kWh Saft lithium-ion, about 1.16 hours at rated power, providing immediate bridge/ramp support while CHP or emergency units respond. [4][7][8]
Expansion CHP
The 2020 ESPC announced a new 7.5 MW CHP plant in addition to existing generation. Public announcements sometimes call the pre-existing site CHP fleet '14 MW,' which does not reconcile cleanly with the detailed 10.4 MW two-turbine plant and may use a broader site boundary. [9][3]
Expanded battery conflict
The 2020 award and Ameresco's current page use 1 MW/2 MWh; Waldron describes 1.5 MW/2.5 MWh. These may be design versus final scope, but no public as-built acceptance document was found. They must not be summed with each other; whether the 500/580 unit was replaced or incorporated is also not public. [9][3][10]
Energy mix
Normal supply is utility electricity plus natural-gas CHP and recovered heat/steam; diesel is emergency generation and the battery is storage, not a fuel source. No installed renewable generator or current annual MWh/fuel split is documented in the cited sources. [3][8]
Expansion economics
US$58 million ESPC award, with approximately US$175 million in guaranteed/expected savings over a 22-year performance period. These are contract projections rather than independently audited realized savings to date. [9]

Controls and hardware

Equipment and controller details

Manufacturer and model are shown only when a source names them. Generic descriptions are not converted into guessed product assignments.

01

CHP gas turbines

Solar Turbines — Taurus 60

Two 5.2 MW units in the original 10.4 MW CHP plant, each paired with heat recovery. [8][7]

02

Original battery energy storage

Saft

500 kW/580 kWh lithium-ion system; exact Saft product model is not identified in the cited public project material. [7]

03

Microgrid controls

GE Grid Solutions

Supervisory microgrid controller integrated with Ameresco's Fast Load Shed system for islanding, critical-load prioritization, generation dispatch, and reconnection. [4][7]

04

Steam production

Model not publicly disclosed

Two 70,000 lb/hour heat-recovery steam generators plus two 70,000 lb/hour package boilers in the documented original plant. [8]

Technical record

Architecture, performance, and project updates

Concise technical facts, milestones, operating results, and later developments. Dated notes distinguish historical design claims from current evidence.

  • General

    Ameresco announced May 3rd, 2016 that its Federal Solutions Group successfully demonstrated GE’s microgrid control system at Portsmouth Naval Shipyard in Kittery, Maine. [1]

  • General

    The project shows how the DOD is increasingly looking at energy storage to reduce dependence on diesel generators. [1]

  • Storage

    500 kW / 125 kWh BESS [1]

  • Generation

    10MW Combined Heat and Power (CHP) plant [1]

  • Validated islanding

    Two live tests simulated a base-wide utility outage. The controls shed nonessential loads and maintained mission-critical loads with on-site generation and storage, validating transition and island operation rather than merely a desktop study. [4][5]

  • Fast Load Shed

    Automated load prioritization balances the island when grid supply is lost or generation changes, avoiding the need to keep all emergency diesel units preemptively running and enabling smoother CHP-supported islanding. [7][6]

  • Battery role

    The battery supplies instantaneous transition/bridging power and frequency/ramp support while slower combustion units start or adjust; ESTCP also evaluated grid-connected ancillary-service value. [5][7]

  • Current evidence

    A 2026 Kittery municipal climate packet refers to the shipyard's cogeneration, Microgrid Fast Load Shed, and power-plant BESS as current resilience capabilities. It is corroborative public evidence, not a Navy performance test or detailed asset register. [11]

  • Identity and phase warning

    All figures here concern Portsmouth Naval Shipyard in Kittery, Maine. The original ESTCP demonstration and 2020 ESPC expansion are related but distinct phases, and public battery ratings should not be added without an as-built single-line diagram. [5][9]

Provenance

11 sources

Primary owner, government, university, supplier, and engineering sources are preferred. Archived references preserve claims whose original pages moved or disappeared.

  1. [1]
    Recovered Microgrid Projects record

    Internet Archive · Archived source · captured 2021-01-17

  2. [2]
    Ameresco

    ameresco.com · Archived source · captured 2021-01-17

  3. [3]
    Portsmouth Naval Shipyard

    Ameresco · Primary source

  4. [4]
  5. [5]
    Microgrid Controls and Energy Storage Demonstration at Portsmouth Naval Shipyard

    U.S. Department of Defense SERDP-ESTCP · Primary source

  6. [6]
    Successful Technology Transition: Portsmouth Naval Shipyard Microgrid

    U.S. Department of Defense SERDP-ESTCP · Primary source

  7. [7]
  8. [8]
  9. [9]
    U.S. Navy Awards Ameresco $58M and Invests in Infrastructure Redundancy for Mission-Critical Loads

    National Technology Alliance / Ameresco release · Secondary research

  10. [10]
    Portsmouth Naval Shipyard

    Waldron Engineering & Construction · Primary source

  11. [11]
    Town of Kittery Agenda Packet, February 12, 2026

    Town of Kittery, Maine · Primary source

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