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Fort Hunter Liggett

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

CoverageDetailed public record
Named organizations6
System facts18
Sources reviewed12
Evidence reviewed2026-07-20

Fort Hunter Liggett's installation microgrid is a multi-phase U.S. Army Reserve resilience project that integrates legacy solar, new photovoltaic generation, battery storage, distribution automation, and supervisory controls. The final Ameresco scope added 3.75 MW of PV and a 2.5 MW/5 MWh battery to earlier arrays, rather than the 5 MW PV and 3 MWh storage described in preliminary plans. The Army activated the renewables-only, fully islandable system in September 2024 and says it can sustain prioritized loads for up to 14 days during a grid outage.

Research status
Operational. Construction broke ground in May 2021 and the Army held the activation ribbon cutting on September 19, 2024. The Army Reserve's 2024 annual report calls the $21.8 million system completed and says it can meet about 90% of installation energy needs; the Army separately describes annual net-zero capability and up to 14 days of outage support. These metrics describe different boundaries and should not be read as proof that every load is continuously off-grid. A December 2024 Army cyber-resilience exercise assessed the commissioned system, while the Army said further battery expansion and upgrades to older solar arrays remain possible future work.
Historical classification
Military
Reported capacity
2,000 kW
Coordinates
36.00861, -121.23694
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 Fort Hunter Liggett?

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

Organization

Ameresco

Prime contractor and system integrator for the 3.75 MW PV, 5 MWh battery, microgrid controls, and distribution upgrades. [5][7][10]

Organization

Lawrence Berkeley National Laboratory

Developed and field-tested an earlier supervisory optimization controller for the preexisting 2 MW PV/1 MWh storage microgrid phase. [3]

Organization

Tri-Technic

Project lead and implementation partner for the earlier California-funded PV-and-storage supervisory-controller demonstration. [3]

Organization

U.S. Army Corps of Engineers, Sacramento District

Contracting and project-delivery organization that awarded the microgrid construction contract in April 2019. [5][10]

Organization

U.S. Army Garrison Fort Hunter Liggett

Installation owner and operator; its Directorate of Public Works developed the phased energy-resilience program and operates the completed microgrid. [4][8][10]

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 Solar
8000 [1]
Storage
8000 kWh [1]
New photovoltaic capacity in final Ameresco scope
3.75 MW, integrated with smaller preexisting arrays; an April 2019 award announcement described a preliminary 5 MW addition, so 5 MW should not be treated as the final as-built increment [5][7][9]
Battery energy-storage system in final scope
2.5 MW / 5 MWh. Earlier Army planning described 3 MWh, and a 2015 controller demonstration used an existing 1 MWh system; those are different phases rather than interchangeable as-built figures. [2][3][7][9]
Installation solar portfolio context
The Army's 2019 award history described a multi-phase 8 MW solar program: an initial phase had installed 3 MW of PV plus 1 MWh of storage, followed by the later microgrid phase. Public sources reviewed do not provide one reconciled post-commissioning nameplate total for every surviving array. [4][7]
Resilience duration
Army-reported ability to support the installation for up to 14 days during a utility outage by islanding and prioritizing loads; this is not a claim of 14 days at unrestricted full-installation load [10]
Renewable-energy share before final commissioning
21.97% of installation electricity in FY2020 and 23.2% in FY2021, before the final microgrid was activated [6][9]
Project value
$21.6 million contract award in 2019; the Army Reserve's completed-project account rounds total value to $21.8 million [5][11]

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

Solar photovoltaic generation

Model not publicly disclosed

Ameresco installed 3.75 MW of new PV and integrated it with legacy arrays. Module and inverter manufacturers and models were not disclosed in the reviewed public sources. [7][9]

02

Battery energy storage

Model not publicly disclosed

The completed expansion uses a 2.5 MW/5 MWh battery system. Public Army and contractor sources reviewed do not identify cell chemistry, battery manufacturer, or power-conversion model. [7][9][10]

03

Microgrid controls and distribution automation

Model not publicly disclosed

The project added a microgrid control system, automated medium-voltage switches, and distribution-system upgrades so prioritized loads and generation can be isolated and coordinated. Specific control-platform and switchgear models were not published. [7][10]

04

Earlier supervisory controller

Lawrence Berkeley National Laboratory / Tri-Technic

The earlier demonstration coupled Siemens SCADA with Berkeley Lab's Operations DER-CAM optimizer for forecasting, day-ahead battery scheduling, 15-minute reoptimization, and one-minute balancing. It should not be assumed to be the same controller used in the 2024 Ameresco build. [3]

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.

  • Island operation

    The 2024 system is described by the Army as fully islandable and powered only by renewable generation and storage when isolated. Its controller prioritizes loads and manages power distribution during an outage. [10][11]

  • Net-zero boundary

    The 2021 Army account explained that annual net-zero energy does not mean continuous physical independence: seasonal solar surpluses and deficits still require imports and exports, battery capacity is insufficient to store every surplus kilowatt-hour, and PG&E export constraints affect dispatch. The later 90% independent-needs and 14-day resilience statements use still different operating boundaries. [8][11][10]

  • Phased capacity record

    Public descriptions changed as the design matured: FY2016 planning called for 5 MW PV plus 3 MWh storage; the April 2019 award still said 5 MW; the 2021 contractor and 2022 federal award descriptions give the more specific final addition of 3.75 MW PV and 2.5 MW/5 MWh storage. [2][5][7][9]

  • Earlier optimization demonstration

    In July 2015, Berkeley Lab and Tri-Technic deployed a controller against a then-existing 2 MW PV/1 MWh storage system. It forecast load and PV, optimized a day-ahead battery schedule, reoptimized every 15 minutes, and balanced at one-minute intervals. The final report called for further performance collection, so it is evidence of deployment, not a long-term savings result. [3]

  • Cyber resilience

    In December 2024, an Army Reserve 'Hack the Army Microgrid' exercise brought 11 vetted researchers to assess battery storage, solar integration controllers, radio-frequency exposure, and network monitoring. The Army presented the event as a model for cyber commissioning and resilience testing, not as evidence of a known compromise. [12]

  • Open evidence gaps

    No independently audited post-activation energy production, outage event, battery round-trip efficiency, state-of-health, renewable fraction, or realized annual savings through July 2026 was located. The Army also identified future battery expansion and older-array upgrades as possible next phases. [10]

Provenance

12 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 2020-11-30

  2. [2]
  3. [3]
    Supervisory Controller for PV and Storage Microgrids

    Lawrence Berkeley National Laboratory / California Energy Commission · Primary source

  4. [4]
  5. [5]
    Corps awards $21.6M contract for Fort Hunter Liggett microgrid

    U.S. Army Corps of Engineers, Sacramento District · Primary source

  6. [6]
  7. [7]
  8. [8]
  9. [9]
    2022 Federal Energy and Water Management Awards Winners

    U.S. Department of Energy · Primary source

  10. [10]
  11. [11]
    2024 U.S. Army Reserve Annual Report

    U.S. Army Reserve · Primary source

  12. [12]
    U.S. Army Reserve establishing energy microgrid cyber resilience protocols

    U.S. Army Reserve Innovation Command · Primary source

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