Amazon has agreed to buy 690 megawatts of power from Constellation Energy's Calvert Cliffs nuclear plant in Maryland for 20 years, a contract that will help fund a capacity increase and another license extension for the two reactors, World Nuclear News reported Thursday. The companies said the agreement supports about $3 billion of investment at the site.

What Happened

Under the power purchase agreement, Constellation will add about 190 megawatts of new generating capacity at Calvert Cliffs between 2030 and 2032 through an uprate of the existing units. That would lift the site from its current 1,790 megawatts to roughly 1,980 megawatts.

The plant, in Lusby on the Chesapeake Bay, has two pressurized water reactors that connected to the grid in 1975 and 1976. Their operating licenses, already renewed once by the Nuclear Regulatory Commission in 2000, run to 2034 and 2036. Constellation said the long-term revenue from Amazon gives it the certainty needed to pursue a further 20-year renewal for both units.

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A related retail supply agreement will serve Amazon operations across the PJM Interconnection, the grid that covers all or part of 13 states plus Washington, D.C. Constellation also said it would explore developing 2,000 megawatts of next-generation nuclear capacity at Calvert Cliffs, which could roughly double the site's output.

Constellation CEO Joe Dominguez said the deal shows how private investment can strengthen critical energy infrastructure. Kerry Person, AWS vice president of global operations, said Amazon is committed to "carbon-free energy to strengthen the grid" in the communities where it operates.

Why It Matters

Calvert Cliffs is Maryland's only nuclear station. It supplies about 40% of the state's electricity and roughly 80% of its carbon-free power, according to World Nuclear News, and FOX 5 DC reported that it employs more than 800 workers. Keeping it running into the 2050s, if regulators approve, would remove a major uncertainty for the state's power supply at a time when PJM is grappling with rising demand from data centers, many of them in neighboring northern Virginia.

For Amazon, the deal adds firm, around-the-clock supply that does not depend on new construction. Unlike wind or solar contracts, output from existing reactors is available regardless of weather, which is why technology companies have turned to nuclear plants to back AI data center growth.

Investors welcomed the news. Constellation shares rose about 3.9% in premarket trading Thursday, Investing.com reported.

A Growing List of Nuclear Deals

Constellation has become a central supplier to large technology buyers. In 2024 it agreed with Microsoft to restart the shuttered Three Mile Island Unit 1 reactor in Pennsylvania, since renamed the Crane Clean Energy Center, and in 2025 it signed a 20-year agreement with Meta for the output of its Clinton plant in Illinois. Amazon has separately contracted for power from Talen Energy's Susquehanna plant in Pennsylvania and invested in small modular reactor developer X-energy.

What to Watch

The uprate and the license extension both need NRC approval, and the review process for a second renewal typically takes years. Constellation will also have to decide whether to move ahead with new reactors at the site. The companies did not say whether Amazon plans to build data centers near Calvert Cliffs; the retail agreement covers Amazon operations across PJM rather than a specific campus.