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Amazon and Constellation sign 20-year deal adding 190 MW of nuclear capacity at Calvert Cliffs
Constellation and Amazon announced a 20-year agreement on September 30 backing more than $3 billion in Calvert Cliffs investment and about 190 MW of new capacity between 2030 and 2032.
By Greener Numbers Editorial Team · Published October 5, 2026 · Updated 10/5/2026
Constellation and Amazon announced a 20-year power purchase agreement on September 30, 2026 that will support more than $3 billion in infrastructure investment at the Calvert Cliffs Clean Energy Center in Lusby, Maryland. Constellation's release is the primary source, and Utility Dive covered it on October 5.
What the companies say the deal does: - The investment includes improvements across the whole 1,790-megawatt plant, which is Maryland's only nuclear plant and its largest source of clean energy. - It adds about 190 megawatts of new generating capacity, expected to come online between 2030 and 2032. - The 20-year agreement covers 690 megawatts of power for Amazon, including the 190 megawatt uprate. - Amazon and Constellation also entered a related retail supply agreement to support Amazon operations in the 13-state PJM market. - The revenue certainty from the agreement is meant to let Constellation relicense the plant for another two decades.
The grid detail: Utility Dive reports that, per Constellation, all the electricity generated at Calvert Cliffs will flow to the PJM grid as usual. PJM is the grid operator for all or parts of 13 states and the District of Columbia.
Scale, per Constellation's figures as relayed by Utility Dive: the plant generates roughly 80% of Maryland's clean energy, enough to power about 1.3 million homes.
Why it matters for ratepayers: this is a data-center-era deal in which a large buyer pays for new capacity on the shared grid. Neither source gives a price, so what it means for Maryland electric bills is not stated. This brief reports the companies' announcement only.
Official source: constellationenergy.com ↗