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Groton Submarine Base

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

CoverageDetailed public record
Named organizations7
System facts18
Sources reviewed8
Evidence reviewed2026-07-20

The operating islandable microgrid at Naval Submarine Base New London in Groton, Connecticut now combines a 10.75 MW natural-gas combined-heat-and-power plant with first-call access to a 7.4 MW FuelCell Energy fuel-cell park, plus cybersecure controls, fast load shedding, upgraded distribution, steam, lighting, and base-wide energy management. Its directly documented firm resources total 18.15 MW, so the recovered 13 MW rating is obsolete.

Research status
Operating. The FuelCell Energy project entered commercial operation on December 16, 2022; the Navy held its comprehensive microgrid ribbon cutting in October 2024; and DOE/NAVFAC recognized first-year performance in 2025. NORESCO says the ESPC has exceeded its annual savings guarantee in every year of performance and has 18 years of ongoing O&M/repair/replacement services. A 2026 FuelCell Energy SEC filing continued to list the Groton project in its operating portfolio.
Historical classification
CHP
Reported capacity
13,000 kW
Coordinates
41.38844, -72.08600
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 Groton Submarine Base?

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

Organization

Connecticut Municipal Electric Energy Cooperative (CMEEC)

Purchaser of normal-operation fuel-cell electricity and public-power partner; the Navy has first right to the fuel-cell output during a base outage. [2][8]

Organization

FuelCell Energy, Inc.

Fuel-cell technology supplier and owner/operator of the 7.4 MW generating portfolio through its project entity. [7][8][2]

Organization

Groton Utilities and State of Connecticut

Local utility/community and state partners cited by the Navy in bringing the base-resilience project to operation. [2]

Organization

Naval Facilities Engineering Systems Command Mid-Atlantic

Navy project-delivery, technical, contracting, and energy-program organization for the financed microgrid and ESPC work. [4][5]

Organization

NORESCO

Energy service company responsible for the CHP, cybersecure microgrid, energy-management controls, infrastructure upgrades, and long-term performance/O&M under the ESPC. [6][5][2]

Organization

U.S. Navy / Naval Submarine Base New London

Installation owner and microgrid beneficiary/operator; the system supports base-wide loads, waterfront operations, training facilities, shore power, and moored submarines. [2][3][4]

Organization

US Department of Defence

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

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
1500 [1]
Combined heat and power plant
10.75 MW electrical capacity from two new generators, with high-efficiency boilers and steam heat for mission-critical waterfront and training facilities [2][6][5]
Fuel-cell park
7.4 MW nameplate; FuelCell Energy said it would operate at approximately 6 MW during its first year after December 2022 commercial operation [7][2]
Total documented on-site generation available to microgrid
18.15 MW nameplate across 10.75 MW CHP and 7.4 MW fuel cells; the fuel-cell output normally serves the public grid and becomes first-call base supply during outages [2][4]
First-year reported savings
$8 million, 162,800 MBtu net energy reduction, and 3.6 million gallons of water conserved [3][4]
Reported annual emissions reductions
48,084 metric tons CO2, 7 metric tons sulfur oxides, and 33 metric tons nitrogen oxides [5][4]
ESPC economics
NORESCO's 2025 fact sheet describes a $90.1 million ESPC with more than $183.8 million guaranteed savings; its 2020 groundbreaking release described a broader 21-year, $169.3 million contract. The different published scopes are retained rather than reconciled without contract documents. [5][6]
Resilience coverage
NORESCO states that the CHP and microgrid support 100% of base power requirements during grid outages; DOE says the system now powers the entire base, including moored submarines [5][3]

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

Fuel-cell generation

FuelCell Energy

7.4 MW natural-gas fuel-cell portfolio on leased base land. Public project sources reviewed do not give a definitive commercial platform/model designation, so none is inferred. [7][8][2]

02

Combined heat and power

Model not publicly disclosed

Two new natural-gas generators totaling 10.75 MW plus high-efficiency boilers and steam distribution. NORESCO and Navy sources do not identify generator/engine manufacturer or model. [2][5]

03

Microgrid and energy-management controls

NORESCO

Cybersecure base-wide controls provide automated data collection, precise peak-demand management, utility separation, fast load shedding, islanding, and dispatch of on-site resources. A product/model name is not disclosed. [2][4][5]

04

Electrical and thermal infrastructure

Model not publicly disclosed

The ESPC also upgraded electrical infrastructure, steam distribution, LED lighting, and base-wide building/energy controls. No as-built BESS is identified in the current project sources. [6][5]

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.

  • Grid relationship

    In normal operation the fuel-cell park sells to the public grid through CMEEC. During a base interruption, the Navy has first right to its 7.4 MW output, and the microgrid combines that resource with the 10.75 MW CHP after separating from the utility. [2][8]

  • Mission scope

    The islanded system supports submarine maintenance, training systems, base-wide communications, mission-critical waterfront facilities, shore power, and moored submarines, rather than only a small subset of buildings. [3][4][2]

  • Implementation chronology

    The Navy/NORESCO CHP expansion broke ground in June 2020 with late-2022 operation expected. FuelCell Energy reached COD in December 2022. The Navy celebrated completion of the comprehensive microgrid in October 2024, reflecting phased completion rather than a single commissioning date. [6][7][2]

  • Verified performance

    DOE and NAVFAC report $8 million first-year savings and quantified energy/water reductions. NORESCO's 2025 fact sheet adds that annual savings guarantees have been exceeded every performance year and supplies emissions reductions; these are federal/contractor reports, not raw interval-meter data. [3][4][5]

  • Current update

    FuelCell Energy's April 2026 Form 10-Q continued to describe the Groton Station project as part of its operating portfolio with CMEEC as purchaser and Navy resilience access, providing current regulatory evidence that the fuel-cell asset remained in service. [8]

  • Evidence boundary

    No current primary source identifies a battery-storage installation, individual CHP-engine models, fuel-cell platform model, island duration under a specified outage/load case, or measured annual renewable share. The system is predominantly natural-gas generation plus efficiency/control measures, not a renewable-storage microgrid. [5][2]

Provenance

8 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]
  3. [3]
    2024 Federal Energy and Water Management Awards Winners

    U.S. Department of Energy · Primary source

  4. [4]
    SUBASE New London Energy Team Honored with 2024 Federal Energy and Water Management Award

    Naval Facilities Engineering Systems Command Atlantic · Primary source

  5. [5]
  6. [6]
  7. [7]
  8. [8]
    FuelCell Energy Form 10-Q for the quarter ended April 30, 2026

    U.S. Securities and Exchange Commission / FuelCell Energy · Primary source

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