Dept of Energy gets all the energy headlines. But the Dept of War has been quietly building out energy investments, and it's putting small nuclear reactors, geothermal wells, and new power plants on military bases. Quick summary on what this market looks like and who is winning -- Starting with the problem: military bases run on the civilian power grid, and their backup power is mostly diesel. The Pentagon wants bases that keep running if the grid goes down, and its missile defense systems need a lot of power. So it's bringing in private companies to build power on base land, with utilities as partners. This all picked up speed in May 2025, when an executive order put the Army in charge of nuclear power for the whole military and set a deadline: an Army-regulated reactor running on a domestic base by Sept 30, 2028. A second order created a Dept of Energy program to speed up testing of new reactors, and the July 2025 budget bill added $125M for small, portable reactors. The way the Army is doing it is unusual. Companies design, build, own, and run the reactors on Army land. The Army pays in installments as each company hits milestones, and the Army oversees the safety of its own projects. In this case, a military customer lets a startup prove its reactor works, so it can later sell to others. The $$ flowing towards this is interesting. The Army launched a program called Janus in October 2025. On Aug 26, 2026 it picked 5 companies for 5 bases, with up to $2.2B in govt $$ through 2031 and 20+ reactors expected. The Air Force ran its own version and picked 3 companies in April. And here are the winners so far: 3 names appear in both the Army & Air Force programs, which makes them the early leaders: Antares, Radiant, and Westinghouse. In June, Antares became the first company in the DOE reactor test program to get a test reactor to criticality, the point where a reactor sustains a nuclear reaction. Federal contract records show a Janus agreement worth up to $435.6M, with $58.5M funded so far, and a separate Air Force agreement with $11.4M funded so far. Its reactors are planned for Fort Bragg and Joint Base San Antonio. Radiant is planned for Fort Benning in the Army program and Buckley Space Force Base in the Air Force program. Federal records show $22.6M funded so far on its Air Force agreement. The company has announced a Janus agreement, but its value doesn’t appear in federal records yet. Westinghouse is planned for Fort Drum and Malmstrom Air Force Base. On Aug 24, a test of its eVinci reactor design reached criticality at a Nevada test site. Federal records show $10.6M funded so far on its Air Force agreement and its Army agreement value hasn't been disclosed. The other two Army picks matter too. BWXT, at Fort Campbell, is already building the Pentagon's earlier prototype reactor and is the only one of the 5 Army picks that makes its own fuel. General Atomics, at Fort Hood, uses a different fuel design than the rest. Oklo has a planned reactor at Eielson Air Force Base in Alaska. Fuel is where this gets fascinating. These reactors need special fuel that very few companies can make, and Army officials say supplying more than 20 reactors will likely exceed what the U.S. can currently produce. That gives an edge to whoever locks in supply early. BWXT makes its own, and in August Radiant and Antares both signed long-term fuel deals with Standard Nuclear. Reactors are only part of it. On Sept 18 the Army conditionally awarded land leases at 6 installations to 3 developers, Ameresco, Indelible-Bloom, and Frontier Power, to build power plants that sell to the grid and back up the base. The Army pays nothing to build them. And since 2023 the Navy, Army, and Air Force have been exploring geothermal power, using heat from underground, at bases in 6 states with companies like Fervo, GreenFire, and Sage. Pulled all together, the Dept of War is acting as the first customer, landlord + test site for a new energy industry, and interesting to see the small group of companies already holding the base sites & first contracts.