Microsoft’s AI is using so much energy it could put the infamous nuclear power plant back into operation

The site of the worst nuclear accident in US history could be brought back into service in 2028 to power Microsoft’s data center, including artificial intelligence.

Under a purchase agreement between Microsoft and Constellation Energy, a nuclear reactor at Three Mile Island in Pennsylvania that went offline five years ago would be reactivated. The reactor, called Unit 1, is located near Unit 2, which was made famous by a partial meltdown in 1979 in an incident that dampened enthusiasm for nuclear power in the US for decades.

Pending approval from the Nuclear Regulatory Commission, the plant would resume operations in 2028 and, under a 20-year agreement, supply power exclusively to Microsoft. Constellation said in a news release that it hopes to extend operations there until at least 2054 and that the reactor would generate an additional 800 megawatts of electricity and add 3,400 jobs to the economy.

A Microsoft representative pointed out a company blog post on the progress of the company’s energy and sustainability initiatives.

Constellation says the Unit 1 reactor was shut down in 2019 for economic reasons and previously generated 837 megawatts, enough to power more than 800,000 homes. The facility will be named the Crane Clean Energy Center in honor of former CEO of Constellation parent company Exelon, Chris Crane, who died in 2022.

Microsoft says it is using the carbon-free energy to help achieve its environmental goals.

“This agreement is a significant milestone in Microsoft’s efforts to help decarbonize the grid in support of our commitment to becoming carbon negative,” Bobby Hollis, Microsoft’s vice president of energy, said in the press release. “Microsoft continues to work with energy providers to develop carbon-free energy sources to help meet the grid’s capacity and reliability needs.”

The release doesn’t specifically mention AI, but Microsoft’s new efforts in this area have put its 2030 carbon emissions goals in jeopardy, and the agreement could be one way Microsoft addresses those energy needs. The latest sustainability report showed a 30% jump in carbon emissions from 2020 to 2023.

The companies have not disclosed financial terms of the energy deal.