Google has signed a 20-year agreement with Constellation Energy to secure 890 megawatts of additional nuclear power for its growing AI and data-center operations.

The deal will fund upgrades at 11 existing nuclear reactors across Illinois, Pennsylvania and New Jersey, with Constellation investing more than $4.3 billion to increase their output.

The first upgraded facility is expected to begin supplying electricity in 2028, with the projects collectively adding capacity roughly equivalent to a new nuclear reactor.

Google and Constellation also agreed to a separate 15-year arrangement covering another 2,700 megawatts of electricity from Constellation’s generation fleet in the PJM market, Yahoo Finance has reported.

The agreement highlights how rapidly growing AI electricity demand is pushing major technology companies toward nuclear power and prompting new investment in the U.S. electric grid.