The Army announced Wednesday that its Janus Program selected five nuclear energy companies for $2.2 billion in combined awards to own, build and operate nuclear microreactors at bases in North Carolina, Kentucky, Texas, Georgia and New York.

The announcement follows an executive order President Donald Trump signed that directs the Army to build the first Army-regulated reactor to operate on a military installation by September 2028, Fox News reported. 

Supported by an expected private-sector investment, the Army said it expects to build and operate more than 20 nuclear microreactors across Department of War installations. 

Microreactors are small enough to be mass-produced in a factory and shipped by truck or airplane. They provide reliable electricity without the need for frequent refueling. While roughly a dozen companies are developing designs for them, none have been built yet, the New York Times reported.