Microsoft and Constellation Energy have entered into a 20-year power purchase agreement (PPA) that will enable the restart of the Three Mile Island Unit 1 nuclear reactor in Pennsylvania, adding approximately 835 MW of carbon-free energy to the PJM grid, which serves 13 states. Under this agreement, Microsoft will source energy from the revived plant to support its efforts to match the energy consumption of its data centers with carbon-free electricity. This move aligns with Microsoft’s broader goal to become carbon negative by 2030 and meet its “100/100/0” clean energy target—ensuring that 100% of its electricity use, 100% of the time, is met with zero-carbon energy by the end of the decade.
This agreement highlights Microsoft’s need to address the rising emissions tied to its rapidly expanding data center footprint, driven largely by demand for AI computing power. Despite its goal to reduce Scope 3 emissions by over 50% from 2020 levels by 2030, Microsoft recently reported a 30% increase in these emissions between 2020 and 2023. To counter this, Microsoft has launched projects to identify ways to address the challenges of Scope 3 releases. Bobby Hollis, vice president of Microsoft Energy, emphasized the importance of the agreement as help de-clutter the power grid, which is critical to the company’s sustainability goals. For its part, Constellation Energy sees this contract as an important step in reviving one of the safest and most reliable nuclear facilities, which was closed in 2019 for financial reasons. Restarting Unit 1 requires regulatory approval and a comprehensive safety review, with operations expected to resume in 2028. The facility will be named the Crane Clean Energy Center (CCEC) after Former CEO of Constellation Chris Crane. Constellation President and CEO Joe Dominguez emphasized the critical role nuclear power plays in providing reliable, carbon-free energy to businesses such as data centers that are critical to technological progress and economic competitiveness. Noting that the building was a model of safety and reliability before the closure, Dominguez expressed hope that operations will resume with a new mission as an economic driver for Pennsylvania.