Amazon signs 20-year PPA with Constellation for Calvert Cliffs expansion

Amazon has signed a 20-year power purchase agreement with Constellation Energy covering the Calvert Cliffs Clean Energy Center, the 1.78GW plant in Lusby, Calvert County that remains Maryland's only operating reactor. Announced this week, the 690MW agreement supports more than $3 billion of infrastructure investment, according to the two companies — improvements across the plant and roughly 190MW of new generating capacity due online between 2030 and 2032. A related retail supply agreement covers Amazon's operations across the 13-state PJM market.

For Constellation, a 20-year contract at an already-operating asset is worth more than the megawatts it covers. Joe Dominguez, the company's chairman, president and chief executive, said the agreement "demonstrates how private investment can strengthen critical energy infrastructure," and that Amazon's commitment supports the plant's long-term operation while creating "a strong foundation for future investment in both the facility and in advanced nuclear technologies." The announcement names no advanced-nuclear project, so that foundation has no disclosed project behind it.

Kerry Person, Amazon's vice president of AWS global operations and data center delivery, described Calvert Cliffs as the state's largest source of carbon-free energy, in the company's characterization, and said Amazon is "committed to investing in carbon-free energy to strengthen the grid and benefit the communities where we operate." The retail agreement, the quieter half of the package, gives Amazon a route to supply its buildings across PJM even as it contracts for generation at the same time.

A creditworthy buyer taking 690MW for two decades gives Calvert Cliffs a revenue stream long enough to amortize capital against, which is what makes $3 billion a commitment to an operating asset rather than a bet on merchant power prices. The same mechanism has kept firm, dispatchable, carbon-free generation drawing capital all year while merchant renewables announce capacity without buyers. What sets this deal apart from the hyperscaler's smaller arrangements is the term and the size of the commitment.

The announcement attributes the investment to the agreement without saying who provides it, on what terms, or whether Constellation leans on its own balance sheet against the contracted cash flow. The offtake is in place before the new capacity is built, which is how firm generation now gets financed. The 190MW arrives at a plant already sited and already operating, on a schedule running from 2030 to 2032 — an inference from the dates rather than a stated plan, and the kind of timeline a greenfield reactor would struggle to match.

Amazon's own portfolio shows the range it is willing to sign. In late September it took a 36MW Shetland wind PPA with Statkraft for 2030 delivery, and in August it contracted 199MW of Swedish wind at Fagerasen; both are smaller, earlier-stage arrangements, and the Shetland deal carried no disclosed price or contract length. Calvert Cliffs sits at the other end of that range — an operating reactor, a named expansion, a 20-year term — and even with no disclosed power price, its $3 billion of supported investment gives the market a number to scale against.

Until August, Amazon planned a large data center campus on the plant's doorstep; documents cited in the coverage suggest it had been targeting more than 2.46 million square feet across eight buildings, around 500MW of load, before it pulled out. The power agreement outlasted the withdrawal, which is the advantage of an offtake over a co-located campus: the PPA does not require Amazon to hold the land, win the local approvals or build beside the reactor. Its Maryland footprint has shifted accordingly, with a campus under development at TPG's Quantum Frederick Park in Adamstown, just over the border from Virginia's Loudoun County, and an office and data center site outside Baltimore bought recently in a sale-leaseback with asset manager T. Rowe.

The withdrawal left the rest of Amazon's Maryland plans in place, and not all of them are moving smoothly. The company has also been pursuing a cable landing station for its Fastnet cable, which is to connect the US to Ireland and land in Ocean City, and the coverage describes that plan as facing difficulties, with local moratoriums against data centers in effect. Consent has become a pre-construction currency, and the projects that clear cleanest are the ones that do not need a local fight; an offtake at a plant that already exists and already operates is one of them.

The wider market has run a version of this trade with a different allocation of risk. A $1.9 billion Department of Energy loan in September turned Google's PPA for the Duane Arnold restart into infrastructure, with federal credit absorbing part of the technology and construction risk. Amazon's agreement takes the private-capital route: the coverage does not mention federal support, the reactor is already running, and the capital rests on a corporate offtake and on Constellation's ability to deliver the new capacity on schedule. Whether 190MW at Calvert Cliffs is a one-off or a template for uprates elsewhere in the existing US fleet will be answered by the next announcement.