Amazon's Calvert Cliffs Deal: 690 MW, Including a 190 MW Uprate

Amazon's 20-year power purchase agreement with Constellation for 690 MW from the Calvert Cliffs Clean Energy Center in Lusby, Maryland, now sits beside a conditional federal loan commitment: Constellation said on Oct. 27 that a conditional Department of Energy loan commitment of up to $5 billion would be available for uprates at eight of its plants, Calvert Cliffs among them.

The Amazon agreement, announced on Sept. 30, includes an uprate of about 190 MW that Constellation targets for 2030 to 2032. Constellation says Amazon's commitment will help provide the revenue certainty to relicense the 1,790 MW plant for another 20 years. That matters because the two reactors' current NRC licences expire in 2034 and 2036. For Amazon, the contract is a 20-year agreement for 690 MW that includes the roughly 190 MW uprate, which does not exist yet, plus a related retail supply agreement to support its operations in the 13-state PJM market. Constellation does not say how the 690 MW splits between existing output and the uprate.

The Technology: How a Reactor Uprate Works

Calvert Cliffs has two pressurized-water reactors supplied by Combustion Engineering, each licensed by the Nuclear Regulatory Commission for 2,737 MWt of thermal power. World Nuclear News reports the units were connected to the grid in 1975 and 1976. Constellation gives the plant's electric capacity as 1,790 MW and says it produces about 80% of Maryland's clean energy; it is the state's only nuclear plant.

An uprate raises the output of a reactor that already runs, through changes that, per the NRC, can involve a reactor's instruments, controls and power generation systems, rather than a new unit. The release does not name the work planned at Calvert Cliffs. That is the one idea that makes this project different from Amazon's small modular reactor bets: the reactors, their fuel and the site already exist, so the new megawatts depend on engineering work and NRC approval rather than on a first-of-a-kind build. The 190 MW is a target, and the release does not say how it splits between the two units.

The Deal and the Money Behind Amazon's 690 MW

Constellation describes three pieces. The first is the 20-year agreement, which includes 690 MW of power, the roughly 190 MW uprate among it. The second is a related retail supply agreement to support Amazon operations in PJM. The third is the investment the deal underwrites: more than $3 billion in Maryland, covering improvements across the whole plant and the uprate, according to Constellation. The price and other financial terms were not disclosed, and the release does not say how much of the 690 MW is existing output.

This is a front-of-the-meter arrangement. Constellation said all of Calvert Cliffs' electricity will keep flowing to the PJM regional grid as it does now, and that the agreement helps Amazon manage energy costs for facilities across the region. ESG Dive reported the same structure. Amazon signed; the quote in the release came from Kerry Person, vice president of AWS Global Operations and Data Center Delivery.

The DOE commitment is a separate, conditional layer that Voltgrid covered in DOE Offers Constellation Up to $5B for Nearly 1.1 GW of Nuclear Uprates. For Calvert Cliffs, two points from Constellation's Oct. 27 release matter. The commitment still needs due diligence and definitive financing documents, and it is not a final decision to proceed with any individual uprate. Neither DOE nor Constellation has said how much of the up to $5 billion would go to Calvert Cliffs. Constellation said its recent 20-year agreements with Google and Amazon have incentivized it to invest more than $7 billion to add approximately 1,080 MW of nuclear capacity; that is the company's figure, not a total for Calvert Cliffs.

What the Uprate Needs

The NRC sets a plant's maximum power level in its licence, and the owner can change it only after the NRC approves an application. Constellation has not said when it will file. The 190 MW sits inside the 690 MW Amazon agreement, not on top of it, and Constellation gives the plant's 1,790 MW as today's capacity.

Licensing and Timeline for Calvert Cliffs

The licences come first. The NRC renewed both Calvert Cliffs licences in March 2000, and they now run to July 31, 2034, for Unit 1 and Aug. 13, 2036, for Unit 2, according to the NRC. In November 2024 the NRC granted Constellation exemptions on timing: if it files subsequent licence renewal applications at least three years before those dates, and the NRC accepts them for docketing, the current licences stay in force until the NRC decides. The normal rule asks for five years. Calvert Cliffs does not appear on the NRC's status page for subsequent licence renewal applications, as of the page's Sept. 15 update.

The uprate needs NRC approval of its own. The NRC's list of expected applications shows 12 Constellation uprate applications between the fourth quarter of 2026 and 2030 without naming the plants, as Voltgrid reported according to POWER, so the Calvert Cliffs filing date is not public. Constellation's target is new capacity online between 2030 and 2032, which falls before Unit 1's current licence expiry. The 20-year term would run past Unit 1's 2034 licence expiry, and Constellation says Amazon's commitment helps it seek renewal. The release does not say the contract is conditional on renewal.

What It Means for Amazon and PJM

Calvert Cliffs gives Amazon output from a plant that runs today. Amazon's SMR work is earlier stage, including a 960 MW Xe-100 study with AEP and X-energy in Indiana and an SMR memorandum with Dominion at North Anna. Amazon also already buys from an operating plant: Talen's Susquehanna agreement is for up to 1,920 MW through 2042, per Talen. The uprate would add about 190 MW of new supply to PJM, and Constellation calls uprates one of the fastest and most cost-effective ways to add dependable power. Because all output keeps flowing to the PJM grid, the deal does not connect a data center to the plant. Constellation describes a 20-year agreement for 690 MW and a related retail supply agreement to support Amazon operations in PJM; it does not say how the two connect.

What to Watch Next

Constellation's third-quarter results are expected on Nov. 9, according to an earnings preview (Constellation's own investor page was blocked on this read), and may say more about uprate timing. Next come the Calvert Cliffs uprate application to the NRC and a subsequent licence renewal filing, neither dated, and definitive financing documents for the DOE commitment, which has no date either. The uprate's 2030 to 2032 window is Constellation's target, not a schedule the NRC has set.