Google has contracted about 3,590 megawatts of electricity from Constellation Energy in PJM Interconnection (the largest US power grid, covering 13 states), with roughly a quarter coming from upgrades to existing nuclear reactors in Illinois, Pennsylvania and New Jersey. Constellation will invest over $4.3 billion in its fleet under the deal, with the first upgraded output due in 2028, and its shares jumped more than 13% on Tuesday. The agreement answers PJM's proposal that data centres bring their own power amid soaring demand and capacity prices, and underscores how big tech is driving a revival of US nuclear power.