Constellation, Amazon Sign 20-Year Calvert Cliffs Nuclear PPA
Aerial view of the Calvert Cliffs nuclear plant in Lusby, Maryland, in 2005. Photo Credit: Jbs666, retouched by MutantMonkey, Wikimedia Commons, CC BY-SA 3.0 (cropped)
Key Points
- Constellation and Amazon announced a 20-year agreement on September 30, 2026 for 690 MW from the Calvert Cliffs Clean Energy Center in Maryland.
- The contracted volume includes an uprate of approximately 190 MW, scheduled to come online between 2030 and 2032.
- The companies said the agreement will enable more than $3 billion of infrastructure investment in Maryland, including upgrades across the 1,790 MW plant.
- Calvert Cliffs output will continue to flow to the PJM grid, and a related retail supply agreement covers Amazon operations across PJM’s 13 states.
- Constellation said the contract revenue supports relicensing the plant for another 20 years and progress toward new generation at the site.
Deal Terms
Constellation Energy (Nasdaq: CEG) and Amazon (Nasdaq: AMZN) announced a 20-year power purchase agreement on Wednesday covering 690 MW from the Calvert Cliffs Clean Energy Center in Lusby, Maryland. The volume includes approximately 190 MW of new capacity from an uprate due between 2030 and 2032, which leaves about 500 MW drawn from the plant’s existing output.
Calvert Cliffs is Maryland’s only nuclear plant and has 1,790 MW of capacity. On the figures in the announcement, Amazon’s contract covers roughly a third of the plant’s capacity once the uprate is complete.
The companies said the agreement will enable more than $3 billion of infrastructure investment in Maryland. That figure covers the uprate and equipment improvements across the whole plant. The announcement did not disclose pricing or the start date of deliveries.
| Term | Detail |
|---|---|
| Seller | Constellation Energy (Nasdaq: CEG) |
| Buyer | Amazon (Nasdaq: AMZN) |
| Plant | Calvert Cliffs Clean Energy Center, Lusby, Maryland (1,790 MW) |
| Contract length | 20 years |
| Contracted volume | 690 MW, including the uprate |
| New capacity | Approximately 190 MW, online between 2030 and 2032 |
| Investment enabled | More than $3 billion in Maryland |
| Related agreement | Retail supply for Amazon operations in the 13-state PJM market |
Uprate and Relicensing
The 190 MW uprate is the new generation in the deal. The added capacity is scheduled to come online between 2030 and 2032 and would lift the plant’s capacity by about 11%.
Nuclear Uprate
An uprate raises the licensed output of an operating reactor, typically through improved measurement or upgrades to plant equipment. It adds generating capacity at an existing site without building a new plant, and it requires approval from the Nuclear Regulatory Commission.
Constellation said Amazon’s commitment also gives it the revenue certainty to relicense Calvert Cliffs for another 20 years. It added that the agreement helps it make progress toward developing new clean energy power plants at the site, a step it listed separately from the uprate. The announcement named no specific project, technology or timeline for those plants.
“Amazon’s commitment supports the long-term operation of Calvert Cliffs for generations to come and creates a strong foundation for future investment in both the facility and in advanced nuclear technologies.”
— Joe Dominguez, Chairman, President and Chief Executive Officer, Constellation
Output Stays on the PJM Grid
All electricity generated at Calvert Cliffs will continue to flow to the PJM regional grid, as it does now.
Alongside the power purchase agreement, the two companies entered into a retail supply agreement that serves Amazon operations across the 13-state PJM market. Constellation said the agreement will help Amazon manage its energy costs for its facilities throughout the region.
“This long-term agreement with Constellation sustains the continued operation and expansion of Maryland’s largest source of carbon-free energy, supports hundreds of jobs, and brings significant new generation to the regional grid.”
— Kerry Person, Vice President of AWS Global Operations and Data Center Delivery, Amazon
According to the announcement, Calvert Cliffs produces approximately 80% of Maryland’s clean energy and enough electricity for the equivalent of more than 1.3 million homes. The plant employs more than 800 people and pays about $21 million a year in taxes.
Constellation’s Technology Company Contracts
The Calvert Cliffs agreement follows earlier 20-year nuclear contracts between Constellation and large technology companies. In September 2024, Microsoft agreed to buy power from the restart of the approximately 835 MW unit now named the Crane Clean Energy Center in Pennsylvania. In June 2025, Meta contracted 1,121 MW from the Clinton Clean Energy Center in Illinois, with deliveries from June 2027.
| Buyer | Announced | Plant | Nuclear Capacity | Term |
|---|---|---|---|---|
| Microsoft | September 2024 | Crane, Pennsylvania (restart) | Approximately 835 MW | 20 years |
| Meta | June 2025 | Clinton, Illinois | 1,121 MW, plus a 30 MW uprate | 20 years |
| Amazon | September 2026 | Calvert Cliffs, Maryland | 690 MW, including a 190 MW uprate | 20 years |
Constellation describes itself as the largest nuclear energy company in the United States, with 55 GW of generating capacity across all fuel types as of September 2026. It is also a competitive retail supplier, serving approximately 2.5 million customer accounts.
References
- Constellation Energy, “Constellation and Amazon Announce 20-Year Power Purchase Agreement Adding 190 Megawatts of Nuclear Capacity at Calvert Cliffs,” Press Release, September 30, 2026.
- Constellation Energy, “Constellation, Meta Sign 20-Year Deal for Clean, Reliable Nuclear Energy in Illinois,” Press Release, June 3, 2025.
- Constellation Energy, “Constellation to Launch Crane Clean Energy Center, Restoring Jobs and Carbon-Free Power to The Grid,” Press Release, September 20, 2024.