Re-opened Three Mile Island will power AI data centers under new deal

Enlarge / The Three Mile Island Nuclear Plant is seen in the early morning hours March 28, 2011, in Middletown, Penn. (credit: Jeff Fusco/Getty Images)

Microsoft and Constellation Energy have announced a deal that would re-open Pennsylvania’s shuttered Three Mile Island nuclear plant. The agreement would let Microsoft purchase the entirety of the plant’s roughly 835 megawatts of energy generation—enough to power approximately 800,000 homes—for a span of 20 years starting in 2028, pending regulatory approval.

The actual electricity from the Three Mile Island plant—which would be renamed Crane Clean Energy Center—wouldn’t be earmarked for any specific use and would go to local interconnections rather than directly to Microsoft facilities. But the deal comes as Microsoft and large swaths of the tech industry seek new energy sources for data centers that power everything from generative AI models to cloud computing and streaming services.

A new nuclear dawn?

Pennsylvania’s Three Mile Island plant rose to infamy in 1979 when a partial meltdown in Unit 2 helped ignite panic over nuclear safety across the country. The new Microsoft deal would re-open the adjacent Unit 1, which was shuttered in 2019 “due to poor economics,” according to Constellation. If and when the plant reaches its planned 2028 re-opening, it would be among the first wave of shuttered nuclear plants being put back into service.