Planned
Microsoft Three Mile Island Energy Supply
Pennsylvania — Londonderry Township , Dauphin County
Mega-Project
$1.6B
Investment
835 MW
Power Capacity
2
Sponsors
Sponsors & Partners
Constellation Energy
Microsoft
Project Timeline
Announced
2024-09-20
Construction Start
2025
Expected Completion
2028
Current canonical record
Nuclear power plant restart to supply 835MW to Microsoft data centers in four states. Not a data center itself but critical power infrastructure.
20-year power purchase agreement. Microsoft takes 100% of plant output. Expected to create 3,400 jobs and add 800+ MW carbon-free electricity to PJM grid. Pending NRC approval by 2027. Unit closed in 2019 due to unprofitability.
Record provenance
This page is generated from the reviewed project database snapshot. The record was last reviewed on 2026-06-15. Blank fields mean the value was not publicly disclosed or could not be reconciled safely; they do not mean zero.