The agreement will support more than $3 billion in investment at Maryland's Calvert Cliffs nuclear plant, including 190 MW of new capacity expected online between 2030 and 2032.

  • Amazon will buy 690 MW of power under the deal, including the new capacity.
  • Constellation says the revenue certainty supports relicensing the plant for another 20 years.
  • Retail sentiment on Stocktwits flips to 'bullish' from 'bearish' as message volume jumps 311%.

Shares of Constellation Energy Corp. (CEG) rose 2.7% in overnight trading late Wednesday after the company announced a 20-year power purchase agreement with Amazon.com Inc. (AMZN) that will add 190 megawatts (MW) of nuclear capacity at Calvert Cliffs, Maryland. 

The financial terms of the transaction were not disclosed. 

The Calvert Cliffs Clean Energy Center is Maryland's only nuclear plant and its largest source of clean energy.

CEG, AMZN: Deal Contours

The deal will enable more than $3 billion in infrastructure investment in Maryland, including improvements across the entire 1,790 MW plant and about 190 MW of new, emissions-free capacity expected to come online between 2030 and 2032, the company said.

The agreement covers 690 MW of power, including the 190 MW uprate, and includes a related retail supply agreement to support Amazon's operations in the PJM market, which spans 13 states and Washington, D.C.

The deal will not disrupt current energy supply to the PJM regional grid, Constellation said. 

What's In It For CEG And Amazon?

Amazon's long-term commitment is expected to give Constellation the revenue certainty to relicense the plant for another 20 years and move forward with developing new clean energy plants at the site. The deal will also help Amazon manage energy costs for its facilities across the region.

The agreement follows Constellation's earlier power deals with Microsoft and Meta Platforms as tech companies seek reliable, carbon-free power for data centers.

“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 of Constellation Energy, said in the statement. 

“Amazon is committed to investing in carbon-free energy to strengthen the grid and benefit the communities where we operate," Kerry Person, vice president of AWS Global Operations and Data Center Delivery, said. 

"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.”

CEG, AMZN Stocks: Retail Stance

On Stocktwits, retail sentiment around CEG stock jumped from ‘bearish’ to ‘bullish’ territory over 24 hours as message volumes surged 311% in the same time, as per platform data.

Meanwhile, retail sentiment around AMZN stock was ‘bearish’ at the time of writing amid ‘normal’ message volumes. 

One user said, “$CEG They got the power, and it is going to be in high demand.”

CEG stock is down more than 30% in 2026. Meanwhile, AMZN stock is up 10% in the same time. 

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