The unit is one nuclear megawatt-hour. The fleet made 182.7 TWh in 2025 at a 94.7% capacity factor. Fuel costs about $5 per MWh, and the rest of the cost base is largely fixed.
Each MWh earns three things: an energy price set mostly by gas plants (PJM West averaged $50.19 around the clock in 2025), a capacity payment (now at PJM's ~$325–333/MW-day cap), and, when prices are low, a federal tax credit that tops receipts up toward ~$45.
Revenue net of purchased power and fuel came to about $40 per MWh of load served. Because costs do not move with price, every $1/MWh on nuclear output is worth roughly $0.43 per share after tax, before hedges.
| Item | Summary |
|---|---|
| What it is | The largest US nuclear operator (~22 GW, 25 units at 14 sites) and the largest competitive retail supplier to businesses. Calpine, which closed January 7, 2026, added ~23 GW of mostly gas generation for ~55 GW in total. |
| Industry | Merchant generation and retail supply in restructured US power markets, with ~70% of pre-Calpine resources in PJM. |
| How it makes money | It produces megawatt-hours at a low, fixed cost and sells them into energy and capacity markets, through its retail book, or under long-term contracts. |
| What protects it | Nuclear capacity no one can rebuild quickly, licences running into the 2040s–2050s, top-tier operations, and investment-grade scale to sign 20-year contracts. |
| Earnings drivers | PJM capacity prices, gas-linked energy prices, contracted share of output, and Calpine accretion in 2026. |
| Watch | Political limits on PJM prices, pace and pricing of new contracts, and debt reduction after Calpine. |
| Cycle exposure | Medium–high: energy prices move earnings, with a partial federal floor through 2032. |
In the restructured parts of the US, including the Mid-Atlantic, Illinois, New York, New England and Texas, independent generators keep the lights on. They sell into wholesale markets run by grid operators and to customers who choose their supplier. Constellation, spun out of Exelon on February 1, 2022, is the largest of them by nuclear capacity. It serves two needs from one fleet: grid operators' need for firm supply every hour, and large buyers' wish for carbon-free power at a known price.
Tracing one MWh.
Retail is the hedge, not the profit centre. The company served ~147 TWh of retail load, mainly commercial and industrial (C&I), plus ~57 TWh of wholesale load in 2025. It claims over 32% of the direct C&I market, with 77% renewal on power contracts. The book lets it sell its generation forward at a margin over wholesale cost. Headline revenue ($25.5B in 2025) includes this pass-through, so the company measures segments on revenue net of purchased power and fuel (RNF).
| Segment RNF, $M | 2023 | 2024 | 2025 | Share 2025 | 1H 2026 |
|---|---|---|---|---|---|
| Mid-Atlantic (eastern PJM) | 2,924 | 3,080 | 3,411 | 32% | 1,800 |
| Midwest (ComEd / MISO) | 3,255 | 3,202 | 3,702 | 35% | 1,831 |
| New York | 1,251 | 1,453 | 1,600 | 15% | 798 |
| ERCOT | 582 | 1,047 | 1,137 | 11% | 493 |
| Other Power Regions | 1,240 | 1,268 | 819 | 8% | 554 |
| Calpine (from Jan 7, 2026) | — | — | — | — | 2,153 |
| Total segments | 9,252 | 10,050 | 10,669 | 100% | 7,629 |
From 2021 to 2025 owned capacity was nearly flat, at 32,400 MW and then 31,676 MW. The mix moved toward nuclear and away from gas. Calpine reverses that. It adds 21 GW of gas, the 730 MW Geysers geothermal complex, ~800 MW of batteries and ~62 TWh a year of retail load, mostly in Texas, California and the Northeast.
Restructured power has four layers: generators, non-profit grid operators, regulated wires utilities and retailers. Only generators carry real price exposure. Nuclear plants gain the most when prices rise, because their costs are fixed while prices are usually set by the marginal gas plant. PJM's annual price tracked Henry Hub gas with a correlation of about 0.88 over 2005–2025 (inferred from Market Monitor and EIA data).
The market is regional. PJM, ERCOT, NYISO, ISO-NE and CAISO run separate markets with different rules, and ERCOT has no capacity market. Constellation's weight is in PJM, whose capacity auction has cleared at its administrative cap three times running.
Constellation holds about two-thirds of the merchant nuclear fleet. EIA counts 96 reactors and ~98.4 GW of US nuclear, about 18% of US generation in 2025. Constellation's ~22 GW is about 22% of that. Most other reactors belong to regulated utilities and earn a regulated return. Of the roughly one-third that sells at market, Constellation owns about two-thirds (inferred). Merchant peers are far smaller in nuclear: Vistra has 6.4 GW, Talen 2.2 GW, PSEG ~3.7 GW, and NRG none.
Barriers that bind:
Barrier that doesn't: retail. The company itself calls retail entry barriers low.
What a rival could not reproduce. First, the fleet itself: licensed, depreciated, connected to the tightest market, and impossible to build or buy at scale. Second, operations: a 94.7% capacity factor, with outages of 22 days against an industry 33–38. One point of fleet capacity factor is ~1.9 TWh, about $95M a year at $50/MWh (inferred). Third, a BBB+/Baa1 balance sheet that can carry 20-year obligations and the collateral hedging requires.
| Company claim | Outside evidence |
|---|---|
| Largest US carbon-free producer | Supported for nuclear. 183 TWh ≈ 23% of US nuclear output and ~10% of all US carbon-free generation. |
| ~4 points above industry capacity factor | Partially supported. 94.6% vs the US fleet's 92% in 2024, a ~2.6-point gap. |
| Nuclear capacity is scarce | Supported. No large reactor under construction; restartable units essentially used up. |
| Data centers create a durable premium | Partially supported. 15–20-year PPAs exist across peers. But PJM trimmed its near-term load forecast, policy is steering new load toward new build, and contract prices are undisclosed. |
| The 45U credit is a downside floor | Partially supported. No protection below ~$26/MWh of receipts, and it expires after 2032. |
Who wins here, and does CEG fit? The winner is the owner of the largest, lowest-cost, longest-lived firm fleet in the tightest market, with the credit to sign long contracts and the regulatory skill to shape market rules. Constellation fits better than any peer. Its own complaint started the FERC proceeding behind the December 2025 co-location order. The caveat is that size makes it the natural target of price caps and antitrust remedies: the DOJ required divestitures before Calpine could close. Peers have also signed hyperscaler nuclear deals (Talen–Amazon for 1,920 MW, Vistra–Meta for 2,176 MW), so Constellation is the largest seller, not the only one.
Volume hardly grows. Nuclear output was 175 TWh in 2021 and 183 TWh in 2025, mostly because of the South Texas stake. Growth comes from price, contract mix and acquisitions. Adjusted EPS went from $6.28 (2023) to $8.67 (2024) and $9.39 (2025), with diluted shares down only from 324M to 314M. In 2025, tax-credit revenue fell from $2,080M to $320M as prices rose above the phase-out, yet adjusted earnings still grew. Market revenue replaced the subsidy.
| 1H 2026 vs 1H 2025 | Reported | Calpine | Ex-Calpine |
|---|---|---|---|
| Operating revenues | +44.5% | $4,541M | +3.4% (segments) |
| Segment RNF | +48.6% | $2,153M | +6.6% |
| FY2026 EPS guide midpoint vs FY2025 | +28% | ~$2.00/share | ~+6.5% (inferred) |
The price went from $28.92/MW-day (2024/25) to $269.92, then $329, $333 and $325, and Constellation clears 17,500–18,875 MW. Management put the effect at ~+$1.25/share for 2026 from the 2025/26 auction and ~+$1.50/share for 2027 from 2026/27. Part comes back through tax-credit phase-out and Illinois CMC refunds.
Adds ~$2/share in 2026 and $2.15B of segment RNF in the first half. It also takes the company into Texas and California gas, geothermal and batteries.
Microsoft (20 years from the Crane restart), Meta (20 years for Clinton from June 2027), a 10-year $840M GSA contract, and ~920 MW of new 2026 nuclear PPAs averaging 18.5 years, including Walmart. About 30% of clean baseload output is now under long-term agreements. Prices are disclosed only as a $20–50/MWh "value" range.
The Crane restart (~835 MW, ~$1.6B, targeted 2H 2027), Byron/Braidwood uprates (~160 MW, ~$800M), and +30 MW each at Clinton and Dresden. A further ~900 MW uprate pipeline adds to EPS only from 2030.
PJM West prices rose ~49% in 2025 as Henry Hub gas went from $2.19 to $3.52.
About $2.2B repurchased between March and July 2026, with $2.8B of authorisation remaining.
Management targets base EPS growth above 20% a year through 2029 including Calpine, then a "rolling 10%+". The target has been raised twice, from at least 10% to at least 13% and then to the current figure. No filing reconciles results against the earlier targets.
Against ~$40/MWh of net revenue sits a fixed cash cost base of roughly $30 per owned MWh: O&M excluding decommissioning accretion, plus taxes other than income (inferred, including retail and gas-fleet costs). Depreciation is low at $985M, because the plants are old and largely written down. Decommissioning is pre-funded, with $19.4B of trust assets at end-2025 against a $12.9B obligation. About $5.3B of the trust is owed back to ratepayers.
Cash flow needs care. A receivables-sale facility made GAAP operating cash flow negative from 2021 to 2024, so 2025's $4.2B is the first clean year. The company's preferred measure, free cash flow before growth, is disclosed only as forecasts: $8.4B for 2026–27 and $11.5–13B for 2028–29.
| $M unless noted | FY2022 | FY2023 | FY2024 | FY2025 |
|---|---|---|---|---|
| Operating revenues | 24,440 | 24,918 | 23,568 | 25,533 |
| Revenue net of purchased power & fuel | 6,978 | 8,917 | 12,149 | 10,852 |
| of which nuclear tax credit (45U) | — | — | 2,080 | 320 |
| Adjusted operating EPS ($) | ≈4.06 | 6.28 | 8.67 | 9.39 |
| Capex incl. nuclear fuel | 1,689 | 2,422 | 2,565 | 2,949 |
| Total debt (year-end) | 5,768 | 9,261 | 8,412 | 8,992 |
Capex roughly doubles to $5.7B in 2026 and $4.7B in 2027. That includes $3.9B of growth spending (Crane, uprates, co-location, licences), and ~29% is nuclear fuel, partly inventory built against Russian supply risk.
Where the cash went, 2022–2025: capex $9.6B, buybacks $2.4B (about 17M shares), acquisitions $1.7B (the South Texas stake), dividends $1.5B. Net borrowing was only ~$0.9B. The dividend nearly tripled, from $0.564 to $1.55 per share, with a stated ~10% annual growth policy.
Then Calpine. The price was 50M new shares plus $4.5B cash: $21.8B of consideration plus ~$12.6B of assumed debt, against a stated $26.6B net price (7.9x 2026 EV/EBITDA). The deal created $11.1B of goodwill. Required sales of PJM and Texas plants to LS Power for $5.0B and $0.86B are agreed but had not closed at the latest filing. Debt nearly tripled to ~$24.7B, and management targets its credit metrics by end-2027. Buybacks continued anyway, including 2M shares bought from former Calpine owners in their June 2026 secondary sale.
Incentives reward the same things. The annual bonus is 70% adjusted operating earnings. Long-term awards are 67% free cash flow before growth and 33% relative TSR, with a credit-rating penalty.
Electricity demand barely falls in recessions, so the exposure is to price. Including Calpine, first-half 2026 segment margin came 28% from Calpine, 24% each from Midwest and Mid-Atlantic, 10% from New York, 7% from Other and 6% from ERCOT.
Hedging changed after 2023. Before then the company sold ~90%, 60% and 30% of the next three years forward. Once the tax credit began, it stopped hedging generation that way and stopped disclosing hedge levels. The only current disclosure says a $10/MWh fall in power prices plus a $5/MWh fall in spark spreads would have a "not material" effect on 2026–27 earnings.
The floor, precisely. §45U pays up to $15/MWh and loses $0.80 per $1 of receipts above ~$26. It reaches zero at ~$44.75 (2025 values) and ends after 2032. Between $26 and $45, receipts plus credit hold at roughly $41–45. 2024 proved it: PJM prices averaged $33.74, the company booked $2,080M of credits, and adjusted EPS still rose 38%.
Where the cycle stands. On every price measure the business is near the top of its own range. PJM energy averaged $50.73 in 2025, 50% above 2024 and well above the 2012–2020 average of ~$34, though below the 2008 and 2022 spikes. Capacity is at the cap. The tax credit pays almost nothing ($25M in 1H 2026), and capacity factor sits inside its historical 94–96% band.
Downside mechanism. If gas fell back to $2–2.50, the credit would rebuild nuclear receipts toward ~$41–45, as it did in 2024. The bigger exposure is capacity. A drift from the $325 cap to the ~$175 floor on ~18,900 cleared MW is about $1B a year (inferred). After 2032 the floor is gone.
| Indicator | Why it matters | Where published |
|---|---|---|
| PJM 2029/30 auction (Dec 2026) and the backstop procurement | Largest swing factor; tests whether caps persist | PJM reports; FERC ER26-3380 |
| PJM load-weighted price; Henry Hub | Energy margin on unhedged output | PJM Market Monitor; EIA |
| New long-term contract MW and % contracted | Turns merchant exposure into contracted cash | CEG calls, 10-Q |
| FERC co-location rates (EL25-49) | Whether data centers can contract existing nuclear | FERC eLibrary |
| Nuclear capacity factor, outage days | Each fleet point ≈ 1.9 TWh | CEG 10-Q/10-K |
| Debt vs end-2027 target; Crane restart | Calpine de-levering; main volume project | CEG 10-Q |
What the filings could not answer:
To resolve before forming a thesis:
Sources. CEG Form 10-K FY2021–FY2025; Form 10-Q Q1 2022–Q2 2026 (latest filed August 6, 2026); earnings-call transcripts Q1 2022–Q2 2026 (Q4 2024 and Q4 2025 not available); 8-Ks for PJM auctions, the Microsoft/Crane PPA, the Calpine agreement (January 2025) and closing (January 7, 2026), the DOE Crane loan, and the June 2026 secondary sale (424B4); DEF 14A 2023–2026. The earnings-release 8-Ks in the folder are cover pages only. Industry data: EIA, PJM, PJM Independent Market Monitor (2025 State of the Market), FERC, NRC, LBNL, DOE, 26 USC 45U, and the FY2025 filings and releases of Vistra, NRG and Talen.
After the filings. The LS Power divestitures ($5.0B and $0.86B) were agreed but not closed at the latest 10-Q. Trade press reports a Constellation–Google agreement (October 6, 2026) and a Calvert Cliffs agreement with Amazon (September 2026). Neither appears in the filings reviewed, and neither is reflected above.