To meet the growing energy demands of its artificial intelligence (AI) data centres, Microsoft has signed a 20 year deal to bring the inactive Three Mile Island nuclear power plant back online, according to a recent power purchase agreement by Constellation Energy, the current owner of the Three Mile Island facility.

If the agreement is approved by regulators, Microsoft will secure exclusive rights to 100% of the plant's output, underscoring the immense power required to fuel its AI-driven future.

The deal, which could see the plant reopening in 2028, hinges on regulatory approvals and would mark the revival of a site that was retired in 2019 due to economic challenges. The plant, which can generate up to 837 megawatts of power, is located next to a unit that was permanently shut down following the infamous 1979 nuclear accident, one of the worst in U.S. history.

Once reopened, the plant will be renamed the Crane Clean Energy Center, in honour of the late Chris Crane, former CEO of Exelon, the parent company of Constellation. The 20-year agreement between Microsoft and Constellation represents the software giant's first-ever deal of this scale for nuclear energy.

As Microsoft expands its data centres in Chicago, Virginia, Pennsylvania, and Ohio, the need for clean energy has become more critical, especially given the company's focus on AI, which has significantly increased its greenhouse gas emissions. The revived nuclear plant will play a key role in Microsoft's pledge to run its data centres entirely on carbon-free energy by 2025, according to a report by Bloomberg.

Constellation plans to invest $1.6 billion in the restoration of the plant. To proceed, the company will need approval from the U.S. Nuclear Regulatory Commission, as well as state and local permits. Additionally, Constellation is seeking to extend the plant's operational licence until at least 2054.