Amazon Signs 20-Year Nuclear Power Agreement with Constellation
Constellation to supply 190 MW of nuclear energy from Maryland plant for AWS data centers
Amazon Web Services has secured a 20-year power purchase agreement with Constellation Energy to source 190 megawatts of nuclear electricity from the Calvert Cliffs plant in Maryland. The deal aims to power expanding artificial intelligence infrastructure while offsetting grid emissions.
Key details
Under the terms of the two-decade agreement, Constellation Energy will supply Amazon Web Services (AWS) with 190 megawatts (MW) of zero-carbon nuclear electricity generated by the Calvert Cliffs Nuclear Power Plant in Lusby, Maryland. The power purchase agreement (PPA) will support the continuous energy demands of AWS data center facilities across the mid-Atlantic region as compute workloads for generative AI model training and inference continue to scale rapidly.
The transaction represents one of the largest corporate nuclear power commitments in Maryland to date, matching dedicated nuclear capacity directly to hyperscale data center operations. Constellation confirmed that the contract involves energy produced directly by the 1,828 MW two-unit facility, providing firm, round-the-clock baseload power necessary to maintain high data center uptime without relying on fossil-fuel peaker plants during periods of peak grid stress.
Why this matters
AI data centers require uninterrupted baseload power operating at high capacity factors, making intermittent renewable sources like solar and wind insufficient on their own without massive energy storage systems. By contracting 190 MW of firm nuclear generation, Amazon avoids increasing regional carbon intensity or adding to grid congestion in the PJM Interconnection territory, where surging data center electricity demand has raised wholesale capacity costs and sparked regulatory scrutiny.
Context
Hyperscalers are increasingly turning to nuclear energy to meet aggressive corporate net-zero targets while expanding energy-intensive AI compute infrastructure. Similar agreements—such as Microsoft's deal to restart a reactor at Three Mile Island and Oracle's plans for SMR-powered campuses—highlight how tech companies are competing for direct access to nuclear generation as traditional power grids face tightening reserve margins and long interconnection queues.
Risks and open questions
While long-term nuclear PPAs secure clean baseload electricity, questions remain regarding grid transmission congestion within PJM and whether co-located or dedicated power arrangements shift grid maintenance costs onto residential ratepayers. Furthermore, regional regulators and consumer advocacy groups continue to examine whether large-scale corporate off-take agreements limit the volume of zero-carbon power available to public utilities working toward state-mandated decarbonization goals.
What happens next
Constellation and Amazon will begin power delivery under the PPA terms as AWS expands its regional compute clusters. State energy regulators, PJM grid operators, and local policymakers are expected to monitor the operational impact on regional power prices and grid stability as more hyperscale operators pursue long-term nuclear agreements across the eastern United States.
Source: Data Center Dynamics Published on AI Usage Global, author: AUG Bot
