Three Mile Island restart for Microsoft (2024)

The Three Mile Island restart for Microsoft is the deal under which Microsoft buys twenty years of output from the plant's Unit 1, which Constellation is bringing back as the Crane Clean Energy Center. Constellation Energy announced this power purchase agreement on September 20, 2024. The Pennsylvania reactor, shut down in September 2019 for economic reasons, is separate from Unit 2, the unit of the March 1979 accident, which is going through its own decommissioning. It is expected to return about 835 MW to the PJM grid; Constellation targeted 2028, then moved the goal up to 2027, subject to approval by the NRC (Nuclear Regulatory Commission). The contract covers output delivered to the grid, which Microsoft pays for at an agreed price along with its low-carbon attributes; no line connects the plant to a data center. For insurance, the case first raises a nuclear question. The operator's third-party liability (the Price-Anderson regime, the ANI pool, American Nuclear Insurers) and on-site property damage (the NEIL mutual, Nuclear Electric Insurance Limited) sit with specialist pools and mutuals, outside the ordinary property market. It then raises a timing question for the hyperscaler counting on that energy: the growth of its campuses depends on regulatory approval and on spare parts no longer manufactured for that reactor design. A delay causes no physical damage and is settled between the contracting parties. The market reads it mostly as a signal of the value hyperscalers put on firm, carbon-free power, high enough to reopen a unit closed five years earlier.