Constellation Energy and Microsoft finalized a 20-year power purchase agreement under which Constellation will supply all energy, capacity, and clean energy attributes from its nuclear generation to power Microsoft’s data centers. The deal ensures Microsoft’s data center operations receive carbon-free energy while supporting Constellation’s nuclear fleet restart plans. Microsoft’s data center expansion in the U.S. requires reliable, clean baseload power, which nuclear energy uniquely provides. Constellation must secure Federal Energy Regulatory Commission waivers to restart the nuclear unit and deliver power, potentially as early as next year. The agreement aligns with Microsoft’s 2030 carbon-negative goal and Constellation’s strategy to monetize its nuclear assets through long-term offtake contracts.