Google has contracted for 3,590 megawatts of electricity from Constellation Energy in the largest U.S. power grid, with new nuclear energy accounting for roughly one-quarter of the supply, the companies announced Tuesday.
As part of the agreement, Constellation will invest more than $4.3 billion in its power fleet by adding capacity at several nuclear reactors across the Midwest and Mid-Atlantic regions.
The deal highlights how major technology companies are competing to secure massive amounts of electricity for artificial intelligence data centers, driving unprecedented power agreements and renewed investment in the U.S. nuclear industry.
Over the past two years, Constellation has announced plans to restart its Three Mile Island nuclear reactor in Pennsylvania to supply Microsoft data centers, while Google reached an agreement to restart NextEra Energy’s nuclear facility in Iowa.
Under the latest agreement, Google signed a 20-year power purchase agreement for 890 megawatts of electricity from several Constellation-owned nuclear plants. The facilities will be upgraded to increase output from existing reactors.
The first upgraded nuclear facility is expected to begin delivering electricity in 2028, according to the companies.
Google also signed a separate 15-year agreement for an additional 2,700 megawatts of power from Constellation within the PJM power grid. The supply is not linked to a specific generation source but provides long-term revenue certainty for Constellation’s operating facilities.
Shares of Constellation rose more than 13% on Tuesday morning following the announcement.
Maryland-based Constellation is the largest nuclear power operator in the U.S. and also owns a significant portfolio of natural gas power plants and geothermal assets following its acquisition of Calpine Corp earlier this year.
“We’re committed to meeting our growth responsibly by actively investing in clean, reliable power that brings new capacity to our nation’s grids,” said Amanda Peterson Corio, Google’s global head of energy and power.
The agreement includes upgrades to 11 nuclear units located in Illinois, Pennsylvania, and New Jersey, all within PJM Interconnection, the largest U.S. electric grid.
Growing electricity demand from data center expansion has contributed to an 11-fold increase in PJM capacity prices since 2024, creating concerns about future power availability.
In response, PJM has proposed requiring data center operators connected to its 13-state grid to either secure their own power supplies or risk temporary disconnection during periods of peak demand.
The Google and Constellation agreement responds to this “bring your own power” proposal by creating a model where large electricity users can support new power generation alongside their expanding operations.
The companies also agreed on a strategic framework that could be replicated across the U.S. to develop additional power generation, battery storage, and demand response programs.
Constellation CEO Joe Dominguez said the partnership provides a model for how technology companies and the energy industry can work together to expand digital infrastructure while investing in national energy systems.
