Amazon signs a 20-year nuclear power deal to expand Calvert Cliffs

Amazon is committing to two decades of electricity purchases to support an expansion of Maryland’s Calvert Cliffs nuclear plant. The September 30 agreement with Constellation gives the operator a long-term customer for output from an existing facility, helping underpin investment in additional generating capacity.

The 690 MW agreement includes a planned 190 MW increase expected to come online between 2030 and 2032. The remaining 500 MW is existing capacity. Megawatts measure power, so the contract’s headline figure should not be read as 690 MW of new generation arriving immediately.

What the long-term commitment pays for

Constellation says the agreement will enable more than $3 billion in Maryland infrastructure investment, including improvements across the plant. That is the company’s estimate of investment supported by the deal, not a disclosed electricity-contract price or a statement that Amazon will directly fund the entire amount.

The operator lists Calvert Cliffs’ current output capacity at up to 1,790 MW. The proposed 190 MW increase would add roughly 11% to that total. A committed buyer makes future revenue easier to plan around, supporting the case for the upgrades, but the extra capacity still has to be delivered.

The plant stays connected to the regional grid

All of Calvert Cliffs’ electricity will continue flowing into PJM’s regional grid, Amazon says. PJM serves 13 states and the District of Columbia. A related retail supply agreement will support Amazon facilities across that region, rather than creating a private connection that takes the entire plant off the shared grid.

Data centers need electricity for both their computing equipment and the cooling systems that remove its heat. The agreement covers Amazon facilities in the region, however, without disclosing what share of the electricity will specifically serve AI workloads.

Securing supply and adding generation are separate steps, a distinction that also matters in the debate over who pays for the grid as data centers expand in New York. Calvert Cliffs’ extra capacity is expected between 2030 and 2032. The announcement does not guarantee lower household electricity bills.

A power contract is not a license extension

Constellation intends to use the revenue certainty to support another 20 years of plant operation. Its current licensing information lists authorization through 2034 for one reactor and 2036 for the other. The commercial deal does not itself renew those licenses. Amazon and Constellation are also exploring further nuclear units at the site, without announcing a construction date or presenting those units as approved projects.