Amazon has signed a 20-year deal to buy power from the Calvert Cliffs nuclear plant in Lusby. Constellation Energy says the agreement will pay for more than $3 billion in upgrades, add about 190 megawatts of generating capacity and give the company the financial footing to keep Maryland’s only nuclear plant running for another two decades.
The announcement came Sept. 30, less than two months after Amazon Web Services withdrew its plan for a data center campus on Constellation land beside the plant. Calvert County’s own leaders say they learned about the new deal when everyone else did.
“I want to be clear: I, like many of you here in Calvert County, learned about this announcement today,” Commissioner Mike Hart said in a statement. “When a project of this significance involves a facility in our own backyard, our residents deserve transparency, clear communication and timely information.”
Hart said he is working to get the facts and noted that “this announcement is about an energy agreement.” Calvert County Government said in a separate statement that staff are reviewing the announcement and have asked Constellation for more information about potential effects on the county and its residents. The county said it will share updates as details become available.
What the deal does
Under the agreement announced by Constellation and Amazon, Amazon will buy 690 megawatts of the plant’s output for 20 years. That figure includes the 190 megawatts of new capacity Constellation plans to add through an uprate, a package of equipment and operating improvements that lets existing reactors produce more power. The new capacity is expected to come online between 2030 and 2032. It would raise the plant’s capacity from 1,790 megawatts to about 1,980, enough additional power for roughly 147,000 homes, according to Maryland Matters. Financial terms were not disclosed.
The companies also signed a related retail supply agreement to serve Amazon operations across the 13-state PJM Interconnection grid, which includes Maryland.
The deal is not a data center, and no power is being diverted. Constellation says every megawatt Calvert Cliffs produces will keep flowing into the PJM regional grid as it does today. What Amazon gets is a long-term, fixed arrangement that helps it manage power costs at its facilities across the region. What Constellation gets is guaranteed revenue that makes a multibillion-dollar investment in an aging plant worth the risk.
“Without an agreement like this, and the certainty it provides, you have to make projections about future power prices. And one thing we know about future power prices is: We’re always wrong,” David Dardis, Constellation’s senior executive vice president, told Maryland Matters. He called the deal “a home run for Maryland.”
Joe Dominguez, Constellation’s chairman, president and CEO, said in the release that the agreement “demonstrates how private investment can strengthen critical energy infrastructure.” He said 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.”
Kerry Person, Amazon Web Services’ vice president of global operations and data center delivery, said the agreement “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.”
Investors reacted quickly. Constellation shares rose as much as 5% in after-hours trading Wednesday, Investing.com reported.
A clock on the reactors
Calvert Cliffs’ two reactors went into service in 1975 and 1977. In 2000 the plant became the first in the nation to have its operating licenses renewed by the Nuclear Regulatory Commission. Those renewed licenses run out on July 31, 2034, for Unit 1 and Aug. 13, 2036, for Unit 2.
Constellation says Amazon’s commitment provides “the revenue certainty to relicense the plant for another 20 years.” That would carry the reactors into the mid-2050s. In late 2024 the NRC granted Constellation an exemption that lets it file those second renewal applications as late as three years before each license expires: by July 31, 2031, for Unit 1 and Aug. 13, 2033, for Unit 2. The exemption keeps the plant running while the NRC reviews them. The power uprate will also need NRC approval.
Constellation laid the groundwork for this deal well before Amazon came to the table. In February 2025 it announced a roughly $100 million round of electrical and equipment upgrades aimed at “a potential renewal of the plant’s operating licenses and a future increase in power output.” In November 2025 it offered Maryland a menu of options that included the same 190-megawatt uprate, the 20-year license extensions and up to 2,000 megawatts of new advanced nuclear at the site. Dominguez said then that the company needed “clear direction and enabling legislation” from state policymakers.
Constellation now says Amazon’s money will help it move toward developing new clean energy plants at the site, and Maryland Matters reported that the company plans to evaluate small modular reactors at Calvert Cliffs. The site has been here before. From 2007 to 2015, the UniStar Nuclear Energy venture pursued a third reactor at Calvert Cliffs, a project estimated at $9.6 billion. It collapsed after federal loan-guarantee talks failed and federal regulators found the venture ineligible because of its foreign ownership.
The state is also building its own path to new nuclear. The Next Generation Energy Act of 2025 created a framework for the Maryland Public Service Commission to procure nuclear power, and the commission expects to finalize regulations by July 1, 2027. The Amazon deal is privately financed and is not part of that process.
A sore spot in Calvert County
The deal lands in a county where the words “Amazon” and “Calvert Cliffs” have become politically charged.
This spring, Amazon Web Services proposed the Calvert Technology Center: eight data center buildings totaling about 2.46 million square feet on roughly 2,000 acres of Constellation land next to the plant, needing around 500 megawatts of power. At the time, a Constellation spokesperson told The Banner that the campus would connect to the PJM grid and enter into a power-purchase agreement with Constellation.
Residents pushed back hard. Three incumbent commissioners who had opposed a pause on data center development lost their seats in the June primary. Amazon withdrew its application in early August, and a spokesperson said the decision was driven by “development timelines, operational requirements,” not politics. On Aug. 18, commissioners unanimously approved a six-month moratorium on new data center site plans.
The outgoing board has since directed staff to pursue a two-year extension of that moratorium, to remove data centers as a permitted use, and to consider reversing a 2025 rezoning that turned about 800 acres of Constellation forest and farmland near the plant into heavy industrial land. During that discussion, one commissioner warned that reversing the rezoning could complicate Constellation’s separate plans to expand generation at the plant. The new board, sworn in Dec. 15, will make the final decisions.
Constellation says this deal is a different animal. Dardis told Maryland Matters the company is still open to a data center or another large customer at Calvert Cliffs, but that “nothing is in the works.” “We’re open to considering those sorts of arrangements,” he said, “but we would only do so in partnership with Calvert County and other important stakeholders.”
What it means locally
Calvert Cliffs is Calvert County’s economic anchor and one of the most important power plants in Maryland. It supplied 38% of the state’s electricity generation in 2025 and about 80% of its clean energy. Maryland still uses about five times more energy than it produces, relying heavily on power imported through PJM. Constellation says the plant employs more than 800 people, brings in more than 2,000 skilled tradespeople during refueling outages, and pays about $21 million a year in taxes that support schools, roads and other public services.
The questions now coming from residents and county officials are the ones the announcement doesn’t answer:
- How much construction work and how many permanent jobs the $3 billion will bring to Calvert.
- Whether a larger plant will pay more in local taxes.
- How the upgrades will affect traffic and the community during construction.
- What Constellation’s plans for new reactors mean for the land around the plant.
The county says it is waiting on answers from Constellation and will share them as they come in. The Chronicle has also asked Constellation for comment and will update this story.
