Constellation + Calpine
Constellation Energy Corporation (post-Calpine merger)
Last updated: 2026-05-19
As of 2026-01-07, Constellation + Calpine reported 55.0 GW of total power generation capacity globally.
Largest U.S. IPP after the January 2026 Calpine acquisition. Combines the country's largest nuclear fleet with extensive gas and geothermal assets, anchored by long-term data-center PPAs.
Key figures
Headline capacity
Op55.0 GW
Geography
North America
All catalogued metrics
Every metric carries a basis, an as-of date, sources and confidence. Click a source to open it in a new tab.
| Metric | Technology | Value | Basis | As of | Sources | Confidence |
|---|---|---|---|---|---|---|
| Total capacity | All technologies | 55.0 GW | Op | 2026-01-07 | Constellation Energy | High confidence |
Ownership
- Type
- public company
- Listed
- Yes
- Ticker
- CEG
Notable projects
Crane Clean Energy Center restart
United States · Nuclear
Freestone Energy Center / Thad Hill
United States · Gas — CyrusOne 380+380 MW PPAs.
Recent corporate actions
m and a · 2026-01-07
Constellation completed acquisition of Calpine
Methodology notes
- Capacity reflects post-merger pro-forma platform; low/zero-carbon tilt driven by nuclear baseload.
Sources
All sources used for this profile. Confidence labels reflect source reliability and disclosure freshness.
- Constellation completes Calpine transaction
Constellation Energy · 2026-01-07 · Press release
Primary source
Frequently asked questions
How much renewable capacity does Constellation + Calpine have?▾
As of 2026-01-07, Constellation + Calpine reported 55.0 GW of total power generation capacity globally.
What technologies does Constellation + Calpine operate?▾
Constellation + Calpine operates Nuclear, Gas, Geothermal, Solar PV.
Is Constellation + Calpine an IPP?▾
Yes. Constellation + Calpine is classified as an IPP in IPPData's taxonomy, alongside the categories asset_owner.
What is the difference between Constellation + Calpine's installed capacity and pipeline?▾
IPPData separates Constellation + Calpine's operational capacity from secured, under-construction and pipeline figures, marked with basis codes (Op, Att, Sec, Port). See the capacity table for the full breakdown.
What sources does IPPData use for Constellation + Calpine?▾
IPPData uses 1 catalogued sources for Constellation + Calpine, including Constellation Energy. See the full source list at the bottom of this page.
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