Constellation Energy
Largest US nuclear operator; restarting Three Mile Island for Microsoft
Constellation is the largest US operator of nuclear plants and became the face of the AI-nuclear boom by signing a 20-year PPA with Microsoft to restart Three Mile Island Unit 1 (rebranded the Crane Clean Energy Center), targeting ~2027-2028. It is also acquiring Calpine to expand its generation fleet. Constellation's existing ~22 GW nuclear fleet makes it the go-to counterparty for hyperscalers seeking firm carbon-free power without waiting for new-build reactors.
Position
Largest US nuclear operator
Marquee deal
Microsoft PPA to restart Three Mile Island Unit 1
TMI restart target
~2027-2028 (Crane Clean Energy Center)
Expansion
~$26-27B Calpine acquisition
How it fits the stack
Constellation Energy with what it depends on (above) and what it feeds (below). The figure renders as a crawlable diagram and upgrades to an interactive 3D graph as it scrolls into view.
Constellation Energy in the AI stack. Constellation Energy with its immediate upstream dependencies (top) and downstream dependents (bottom) in the AI value chain. Hover a node in 3D, or read the full relationships below.
Graph data (text) — 5 entities, 4 relationships
- Constellation Energy —uses→ Nuclear Power (incl. SMRs)
- Microsoft Azure —powers→ Constellation Energy
- Constellation Energy —partners with→ Microsoft
- Constellation Energy —competes with→ Vistra Corp
Depends on ↑ · 1