A unit at the Three Mile Island power plant, the site of the worst nuclear accident in American history, will restart operations to sell power to Microsoft for energy-hungry data centres tapping the boom in artificial intelligence.
Operator Constellation Energy on Friday announced that the 20-year deal would involve the restart of the Unit 1 reactor, “which operated at industry-leading levels of safety and reliability for decades before being shut down for economic reasons exactly five years ago today”.
The Unit 1 reactor was not involved in the partial nuclear meltdown in 1979 at the site in Pennsylvania. Unit 2, which was shut after the incident in 1979, will not be restarted.
The agreement would mark the first-ever restart of a nuclear power plant in the US after being shut down, and shows how utilities are benefiting from a massive surge in demand from data-centre operators as AI applications proliferate.
Constellation, which plans to spend about $1.6 billion to renew the plant, is awaiting permits and expects the facility to come online by 2028. The unit will provide 835 megawatts of energy to Microsoft.
A restart is expected to be challenging, but as power demand spikes, the virtually carbon-free electricity source is seeing renewed support from tech companies.
Major tech executives, including ChatGPT developer OpenAI CEO Sam Altman and Microsoft co-founder Bill Gates, have touted nuclear energy as a solution to the growing power needs of data centres.
Nuclear plants generated about 18.6% of the total electricity in the US last year, according to Energy Information Administration data.
More than a dozen nuclear reactors went dark over the past decade in the face of increasing competition from cheaper natural gas and renewable energy. But growing demand for electricity — from factories, cars and especially from data centres — has spurred interest in nuclear plants that can provide carbon-free power around the clock.
“Policymakers and the market have received a huge wake-up call,” Constellation chief executive officer Joe Dominguez said in an interview. “There’s no version of the future of this country that doesn’t rely on these nuclear assets.”
The nuclear power purchase will aid Microsoft’s plans to run all of its massive global network of data centres on clean energy by 2025, said Bobby Hollis, Microsoft’s vice-president for energy. The energy will be used to fuel data-centre expansion in areas like Chicago, Virginia, Pennsylvania and Ohio.
While the additional nuclear power will help Microsoft’s climate goals, it does not address the most intractable issue – emissions from concrete, steel and chips used in the data centres, Hollis said.
“This is not a simple piece, but it’s easier than figuring out how to decarbonise the entire supply chain,” he said.