# Constellation Energy advances plans for 2027 Three Mile Island restart > Source: > Published: 2026-06-02 22:00:43+00:00 # Constellation Energy advances plans for 2027 Three Mile Island restart A $1.6 billion bet on nuclear power, backed by Microsoft and a billion-dollar DOE loan, inches closer to reality despite grid upgrade headaches. The most infamous address in American nuclear history is getting a second act. Constellation Energy has cleared a key regulatory hurdle in its push to restart the former Three Mile Island Unit 1 reactor, now officially renamed the Christopher M. Crane Clean Energy Center, with an operational target set for the second half of 2027. The project, estimated at $1.6 billion, is anchored by a 20-year power purchase agreement with Microsoft signed on September 20, 2024. Microsoft plans to use the full 835 MW capacity to feed its expanding fleet of AI data centers. ## Regulatory wins and grid headaches On June 2, 2026, Constellation secured approval to transfer electricity capacity rights from the retiring Eddystone Generating Station, a fossil fuel plant. That approval is a meaningful piece of the puzzle, helping the company meet its aggressive timeline without waiting for entirely new grid capacity to come online. PJM, the regional grid operator covering much of the mid-Atlantic and Midwest, has reportedly faced delays in completing the grid upgrades needed to integrate the reactor’s output. Those delays could, in a worst-case scenario, push the restart all the way to 2031. On March 31, 2026, the company filed a request with the Federal Energy Regulatory Commission to expedite grid interconnection through PJM. The capacity transfer from Eddystone is part of that same strategy. The Nuclear Regulatory Commission approved the facility’s name change to the Christopher M. Crane Clean Energy Center in May 2025. Crane was Constellation’s former CEO who passed away in 2024. ## The money behind the megawatts The Department of Energy committed a $1 billion loan to the project, first disclosed in November 2025, with the initial advance expected by Q1 2026. The Microsoft PPA provides the demand-side certainty that makes the entire financial structure work. With 835 MW locked in for two decades, Constellation has the kind of revenue visibility that most power generators can only dream about. Before its shutdown in September 2019, Unit 1 achieved a 96.3% capacity factor in its final operational year. Wind farms typically operate in the 25-35% range. Solar hovers around 20-25%. It’s worth noting that Unit 1 is entirely separate from Unit 2, which suffered the partial meltdown in 1979. Unit 1 operated safely for decades after that incident and was shut down purely for economic reasons when natural gas prices made it unprofitable. ## What this means for investors The risk side of the ledger is equally clear. Grid upgrade delays through PJM remain the most tangible threat to the timeline. A four-year slip to 2031 would dramatically change the economics, potentially requiring renegotiation of the Microsoft deal or additional capital. Energy traders should watch PJM’s interconnection queue closely. The speed at which grid upgrades proceed will be the single best leading indicator of whether 2027 holds or slips. Constellation’s ability to secure further waivers and capacity transfers will also matter, particularly if additional fossil plants in the PJM footprint approach retirement and free up grid capacity that can be redirected. **Disclosure:** This article was edited by Editorial Team. For more information on how we create and review content, see our [Editorial Policy](https://cryptobriefing.com/editorial-policy/).