Google buys 3.6 gigawatts from Constellation, but only a quarter is new nuclear

Google has signed up for a vast block of electricity from Constellation Energy, the largest nuclear operator in the United States, and the part that matters most is the smallest. Only about a quarter of that power will come from reactors that cannot produce it yet. Constellation will rebuild turbines, steam generators and control systems at existing units so they generate more, and Google will buy the extra output for two decades. The rest comes from plants already running.

That split matters to anyone who pays an electricity bill across the more than a dozen states served by PJM Interconnection, the largest grid in the country. Data centers account for almost all of the demand growth PJM expects this decade, and the price it pays to guarantee enough supply has risen more than elevenfold in two years. Those costs land on household bills. Every megawatt a tech company adds to the grid, rather than takes from it, is one that families no longer have to bid against.

In all, Google is contracting 3,590 megawatts, and the new nuclear slice is 890 of them, drawn from upgrades at 11 units on six sites: Braidwood, Byron, LaSalle and Quad Cities in Illinois, Limerick in Pennsylvania and Salem in New Jersey, where Constellation owns 43%. Constellation says it will invest more than $4.3 billion, and Google compares the result to adding an entirely new large reactor. Its argument is speed. “The fastest new megawatt is often the one that can be provided by existing infrastructure,” Amanda Peterson Corio, who leads Google’s data-center energy work, wrote on the company’s blog. Google says its uprate and restart deals now exceed 1.5 gigawatts, including the revival of NextEra’s Duane Arnold plant in Iowa. Microsoft made a similar bet on restarting Three Mile Island in Pennsylvania.

The timing follows a warning from the grid itself. PJM has asked federal regulators to approve a rule under which new data centers of 50 megawatts or more either bring their own supply or accept that they can be cut off during emergencies, ahead of homes. Both companies present the agreement as a working model of that rule and of the White House’s Ratepayer Protection Pledge, which says AI growth should not raise other customers’ bills. Constellation’s shares jumped more than 12% on the announcement, because a 20-year buyer for nuclear output is the kind of revenue power companies rarely get.

The headline figure still flatters the deal. The 2,700 megawatts in the second contract, which runs 15 years, are not tied to any plant and add no capacity; they lock in output that already exists and give Constellation revenue certainty rather than giving the grid more supply. Even the new nuclear arrives slowly, and each uprate needs a licence amendment from the Nuclear Regulatory Commission. Consumer advocates also doubt the states are ready to police the bring-your-own-power model. “No state that I know of yet is completely prepared,” Clara Summers of the Citizens Utility Board told Canary Media.

Constellation says the program sustains about 4,400 existing jobs and creates roughly 7,200 temporary construction jobs. The company also gets a five-year expansion of its Google Cloud contract, with Gemini Enterprise tools used for site selection, permitting and outage management. “Preserving and expanding the output of the existing nuclear fleet and developing new clean generation is critical to meeting our nation’s growing energy needs,” said Joe Dominguez, Constellation’s chief executive. The effects stay inside PJM’s footprint, which stretches from New Jersey to Illinois. Customers on other American grids, in Europe or in Asia see no change in what they pay.

The calendar is the weak point. The first uprate is due by 2028 and the full program by the end of 2032, while PJM’s curtailment regime could start as early as June 2027. The rule, filed with the Federal Energy Regulatory Commission on August 13, still needs approval. Until those reactors deliver, Google’s newest nuclear power is a promise with a cooling tower attached.

Tags: Google, AI infrastructure, data centers, Constellation Energy, nuclear power, PJM Interconnection