- Company name
- Constellation Energy
- Sector
- Power generation (nuclear & clean energy)
- About
- Constellation Energy owns and operates the largest fleet of nuclear power plants in the United States. In January 2026, it completed a $26.6 billion acquisition of Calpine, adding natural gas and geothermal power plants to its fleet. The combined company now generates electricity from about 55 gigawatts of capacity. Constellation sells this electricity through long-term contracts and in wholesale power markets.
- Thesis
- Constellation runs the largest US nuclear fleet. But the market still doubts the pace of its biggest growth project. Grid operator PJM warned in 2026 that Crane Clean Energy Center, the restarted Three Mile Island reactor, might not connect to the grid until 2031. That is four years later than the original 2027 target. A delay this long would push back revenue from the 20-year power deal tied to that plant with Microsoft. New York's one-year pause on new large data centers adds a second worry. Other states could slow new long-term power contracts with data center customers too. For the gap to close, Crane's remaining federal and grid-connection steps need to clear on a credible schedule. Constellation also needs to keep signing new deals that show growth does not depend on Crane alone. These include its September 2026 agreements with Toyota and Amazon, and its purchase of the RISEC gas plant from Shell. Federal reviewers advanced Crane's environmental review in late September 2026, a sign the restart process keeps moving. No firm reconnection date has been set yet. The next update comes at Q3 2026 earnings, expected around November 9, 2026, with further grid-connection milestones expected through 2027. Because full resolution of the Crane timeline could still take until 2031, part of this discount may persist for years even as near-term contract wins narrow it.
- Risks
- Grid operator PJM warned in 2026 that the Crane Clean Energy Center, the former Three Mile Island reactor, might not connect to the grid until 2031 instead of 2027. A further delay could push back revenue from the 20-year power deal with Microsoft at this site.
In July 2026, New York state ordered a one-year pause on new large data centers, over concerns about ratepayer costs from new transmission lines. Other states could follow, which would slow new long-term power contracts with data center customers.
The Calpine acquisition added about $12.7 billion in assumed debt, and required Constellation to sell several power plants to satisfy antitrust regulators. Integrating a much larger and more diverse fleet raises execution risk for the company's growth targets.
Constellation is adding a new gas plant, RISEC, bought from Shell for about $715 million, on top of integrating Calpine and restarting the Crane nuclear plant. Running three large projects at once adds to management's execution load.
- Recent events
- 2026-09-30: FERC put a five-month hold on PJM's reliability backstop procurement filing. FERC said the proposed cost split needs a paper hearing first. Constellation shares fell about 4% to 5% that day.
2026-09-30: Constellation signed a 20-year power purchase agreement with Amazon for 690 megawatts from the Calvert Cliffs plant in Maryland. The deal funds over $3 billion of investment, including a 190-megawatt uprate planned for 2030 to 2032.
2026-09-25: Federal reviewers advanced the environmental review needed to reauthorize the Crane Clean Energy Center, moving the restart process forward, though no firm reconnection date has been set yet.
2026-09-21: Constellation signed a 15-year renewable energy agreement with Toyota.
2026-09-10: Constellation agreed to buy RISEC, a 609-megawatt natural gas plant in Rhode Island, from Shell for about $715 million, or about $580 million after expected first-year tax benefits.
2026-08-06: Constellation reported Q2 2026 results. Adjusted operating earnings per share were $2.55, up from $1.91 a year earlier. The company raised its full-year 2026 guidance to $11.50-$12.50 per share.
2026-01-09: Constellation completed its $26.6 billion acquisition of Calpine, creating the largest electricity producer in the United States, with about 55 gigawatts of combined generating capacity.