Microsoft has just signed a deal to restart the decommissioned Three Mile Island nuclear power plant. If regulators approve, the software maker will receive exclusive rights to 100 percent of the production for its AI data centers.

Constellation, the owner of the Three Mile Island power plant, today announced that it has entered into a power purchase agreement with Microsoft that, subject to regulatory approval, will enable the site to restart in 2028.

The reactor Microsoft plans to use to get its energy was shut down in 2019 for economic reasons and is located next to a facility that was shut down in 1979 after the worst U.S. nuclear accident in history. The power plant Constellation plans to restart can generate 837 megawatts of energy, enough to power more than 800,000 homes – highlighting the enormous power demand for data centers and Microsoft’s AI ambitions.

Microsoft has committed to buying power from the plant — which will be renamed the Crane Clean Energy Center in honor of the late Chris Crane, former CEO of Exelon — for 20 years, the first deal of its kind for the software giant.

As Microsoft focuses on AI, the company’s greenhouse gas emissions are also increasing, jeopardizing its ambitious climate goals. Bloomberg reported that this nuclear power plant would help Microsoft run its data centers on clean energy by 2025 and power data center expansions in Chicago, Virginia, Pennsylvania and Ohio.

“This agreement is an important milestone in Microsoft’s efforts to decarbonize the grid and support our goal of becoming carbon negative,” said Bobby Hollis, Vice President of Energy at Microsoft. “Microsoft continues to work with utilities to develop carbon-free energy sources that help meet grid capacity and reliability requirements.”

Microsoft has recently started relying on next-generation nuclear reactors to power its data center and AI plans. The company has been looking for someone to implement a small modular reactor (SMR) plan since last year. Microsoft co-founder Bill Gates is also “firmly convinced that nuclear energy can help us solve the climate problem.”

Constellation will invest $1.6 billion to restart the plant. To bring the site back online, the company needs approval from the Nuclear Regulatory Commission, as well as permits from state and local authorities. Constellation is also seeking a license extension to extend the plant’s operation until at least 2054.