How Much Energy Do Military Bases Consume?

Last updated: October 18, 2026

The US Department of Defense is the largest single energy consumer in the US federal government, and its installations alone used nearly 29 terawatt-hours of electricity in a recent fiscal year — a figure that sits in the same order of magnitude as a meaningful slice of the world’s data-centre industry. That scale is why military energy use has become an energy-industry story in its own right: bases are increasingly buying solar, batteries, fuel cells and even microreactors through the same kind of long-term lease and power-purchase structures that utilities and corporate campuses use, often from the same vendors.

How much energy the US military actually uses

According to the Department of Defense’s FY2023 Sustainability Scorecard, compiled from its own Federal Energy Management Program (FEMP) reporting, DoD facilities consumed 28,901,231 MWh of electricity that year — about 56% of all electricity used across the entire US federal government. Facility energy use across all end-uses (electricity, on-site fuel combustion and purchased thermal energy) totalled 173,108 billion Btu across 1.9 billion square feet of floor space.

That figure is facility energy — what bases use to run buildings, runways, hospitals and training ranges. It is separate from operational energy, the fuel consumed in aircraft, ships and vehicles during training and deployment. The Pentagon’s operational energy office reported that DoD consumed more than 73 million barrels of fuel for worldwide operations in FY2022, of which 48% was purchased outside the United States — a reminder that fuel logistics, not just electricity, is a core part of military energy demand. For context on scale: DoD’s facility electricity use is large by federal standards, but independent analysis (New America) notes it still represents only around 1% of total US energy consumption nationwide — the Pentagon dominates federal government energy use without dominating the national energy system.

How the US compares with other militaries

The United Kingdom’s Ministry of Defence publishes comparable figures in its annual report. In FY2024–25, UK MoD facilities used approximately 1.76 terawatt-hours of electricity (1,729.6 GWh non-renewable plus 25.7 GWh renewable) — roughly one-sixteenth of US DoD’s FY2023 total, consistent with the relative size of the two forces. Notably, the UK MoD’s own figures show a trend worth watching: estate energy spending rose from £336.2 million (FY2021–22) to £596.9 million (FY2024–25) even as fuel volumes for aviation, ground vehicles and maritime equipment fell, which the MoD attributes partly to lower operational tempo.

NATO does not publish a consolidated alliance-wide energy consumption figure; it has instead set a goal of a 45% reduction in its own greenhouse gas emissions by 2030 against a 2019 baseline, with net zero targeted for 2050, as part of its Climate Change and Security Impact Assessment.

Why installation energy demand is becoming a bigger issue

US facility efficiency investment has actually been falling — from $1.65 billion in FY2020 to $296 million in FY2023 — even as the legal requirements on installations have tightened. A 2023 statute, 10 U.S.C. § 2920, requires 100% of critical-mission energy loads at every DoD installation to maintain at least 99.9% power availability by the end of FY2030. That resilience mandate, more than any single demand driver, is what has pushed the US military toward the same on-site generation and storage technologies now spreading across the civilian grid: solar-plus-storage microgrids, fuel cells and, increasingly, nuclear microreactors.

How bases are building out power generation and storage

The US Army’s build-out has moved from pilot projects to a defined programme. As of mid-2025, the Army had 32 microgrids operational across 25 installations, with 20 more under construction and 47 in design, according to the Department of Energy’s Federal Energy Management Program.

Two newer programmes, both covered in more detail in our reporting on the Pentagon’s 2026 energy showcase, show where the investment is heading:

These Enhanced Use Lease deals — which, for the Aberdeen Proving Ground, Picatinny Arsenal, Fort Detrick, Letterkenny and Tobyhanna awards, are the same six-installation programme we reported on in September 2026 — are structured so the developer funds 100% of design, construction and operating costs in exchange for a long-term lease. The Army pays no capital cost, and in return the facility must be able to “island” from the grid and sustain the base for at least 14 days during an outage longer than four hours. Earlier examples of the same lease structure are already operating: a 42 MW solar array paired with a 42 MW/168 MWh battery at Joint Base Pearl Harbor-Hickam in Hawaii (Ameresco, for the Navy — one of several defence-adjacent companies now building energy infrastructure), and a $133.5 million solar-storage-and-standby-generation retrofit across Joint Base San Antonio covering roughly 900 buildings.

Where this connects to civilian energy

The technology and financing playbook is identical to what large civilian electricity buyers are doing. The International Energy Agency estimated global data-centre electricity consumption at around 415 terawatt-hours in 2024, projected to more than double to roughly 945 terawatt-hours by 2030 — and some of the same developers now building military microgrids, including Bloom Energy and Ameresco, are simultaneously building fuel-cell and storage capacity for data centres, hospitals and corporate campuses. Both military installations and hyperscale data centres are large, single-site loads that increasingly can’t wait for grid interconnection queues to clear, so both are turning to on-site generation, storage and, in a small but growing number of cases, dedicated nuclear capacity.

FAQ

How much electricity does the US military use?
DoD facilities consumed 28,901,231 MWh of electricity in FY2023, according to the Department of Defense’s own Sustainability Scorecard — more than half of all electricity used across the US federal government.

Is the Department of Defense the largest energy consumer in the US government?
Yes, by a wide margin. DoD accounts for the majority of federal government electricity use, though this still represents only a small fraction — roughly 1% — of total US energy consumption nationwide.

Are military bases switching to solar and battery storage?
Yes, largely through Enhanced Use Lease agreements under 10 U.S.C. § 2667, where private developers finance, build and operate the generation in exchange for a long-term lease, at no upfront cost to the military.

What is driving the push toward on-site power and microgrids?
A 2023 federal statute (10 U.S.C. § 2920) requires 100% of critical-mission loads at every DoD installation to have at least 99.9% power availability by FY2030, pushing installations toward resilient, islandable local generation rather than relying solely on the commercial grid.

Can nuclear microreactors power military bases?
The Army’s Janus Program has selected five vendors to build microreactors at five US installations, with up to $2.2 billion committed through FY2031 and a first operating unit targeted by September 2028.

Related reading: why Rolls-Royce is building small modular reactors for civilian grids using the same nuclear expertise behind naval propulsion, and how China’s grip on critical minerals shapes the supply chains behind both military and civilian power equipment.

Sources

• US Department of Defense, FY2023 Sustainability Scorecard, sustainability.gov
• DOE Federal Energy Management Program (FEMP), FY2023/FY2024 federal energy performance data
• DoD Operational Energy office, FY2022 Annual Energy Performance, Resilience, and Readiness summary
• UK Ministry of Defence, Annual Report and Accounts 2024–25, Annex D
• NATO, Climate Change and Security Impact Assessment, July 2023
• World Nuclear News, “US Army selects five microreactor vendors to power bases,” August 2026
• Power Magazine / soldiersystems.net, Army Strategic Capital Initiatives Tranche II awards, September 2026
• Ameresco and NAVFAC project announcements (Joint Base Pearl Harbor-Hickam, Joint Base San Antonio)
• IEA, Energy and AI report (data centre electricity demand figures)

Illustrative image. Photo: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons — source