Amazon signs 20-year nuclear power deal to unlock $3 billion Maryland plant upgrade

Amazon and Constellation Energy announced a 20-year power purchase agreement on Tuesday that will unlock more than $3 billion in infrastructure investment at the Calvert Cliffs Clean Energy Center, Maryland's only nuclear plant. Under the deal, Amazon will purchase 690 megawatts of power from the facility, including a 190-megawatt capacity expansion expected to come online between 2030 and 2032.

The agreement is the latest in a string of direct power deals between hyperscale cloud providers and nuclear operators, a pattern driven almost entirely by the electricity demands of AI data centers. Training and running large AI models at scale requires power in quantities that are straining regional grids, and tech companies have increasingly concluded that the fastest way to secure reliable, carbon-free supply is to fund the life extension and capacity expansion of existing nuclear plants directly, rather than wait for new generation capacity to come online through conventional utility planning.

For Constellation, the revenue certainty from a two-decade contract is what makes the investment case work: it allows the company to relicense Calvert Cliffs for another 20 years of operation and justifies the capital spending on plant upgrades that extend well beyond the current license period. Calvert Cliffs currently supplies roughly 80% of Maryland's clean electricity from its two reactors, enough to power more than 1.3 million homes, and supports over 800 jobs while contributing an estimated $21 million annually in state and local taxes.

“This agreement demonstrates how private investment can strengthen critical energy infrastructure,” said Constellation CEO Joe Dominguez. “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.” AWS vice president Kerry Person framed the deal in similar terms, saying it “sustains the continued operation and expansion of Maryland's largest source of carbon-free energy.”

Constellation Energy shares rose as much as 5% in after-hours trading following the announcement. The deal adds to a growing list of nuclear power agreements tied directly to AI infrastructure buildout, following similar moves by other hyperscalers to secure long-term, emissions-free electricity at a time when AI compute demand is outpacing the near-term supply of new grid capacity.