Funding from Amazon, which operates more data centers than any other company in the country, is helping drive an expansion of the energy source that supplies more of Maryland's electricity than any other. The two reactors at the Calvert Cliffs nuclear facility in Calvert County have powered a notable share of Maryland's electricity grid and have operated continuously since they came online during the mid-1970s.
Spanning half a century of operation, the plant is lined up for the most extensive round of infrastructure work in its history, with reactor modifications expected to add around 10 percent to generating capacity — a push tied partly to the growing electricity demand associated with artificial intelligence. Upgrading the nuclear facility is projected to carry a price tag in the region of $3 billion.
Pricing details went undisclosed by both parties, though each noted the arrangement was underpinned by a long-term purchase commitment. Under a 20-year power purchase arrangement, Constellation's fleet of generation assets across its Baltimore headquarters will supply electricity to Amazon.
Two months prior to this deal, Amazon had withdrawn a proposal to establish a data center at the Calvert Cliffs facility after local residents opposed the plan — opposition that carried enough weight at the ballot box to remove three county commissioners who had backed data center expansion in the area.
Plans call for Calvert Cliffs to undergo an uprating process over the next four to six years, a technical adjustment that would allow its reactors to push additional electricity onto the regional grid. Upgrades to equipment and other targeted adjustments stand to lift reactor performance noticeably.
According to a news release, the arrangement would give Constellation the financial predictability needed to pursue licence renewals for the existing plants while also developing additional clean energy generation at the same location. Constellation had previously weighed plans for new reactor construction at the site, and the deal with Amazon opens a pathway toward deploying smaller, next-generation reactor designs there. In a statement, the company's chairman, president, and chief executive Joe Dominguez described the arrangement as laying groundwork for continued operation of Calvert Cliffs over the long term, along with potential investment in both the plant itself and in advanced nuclear technologies.
Growing electricity demand — with AI computing among the contributing factors — has returned nuclear power to active consideration among utility executives and legislators who point to its ability to operate around the clock without generating carbon output. Nuclear power generation at national scale falls under Constellation's portfolio, which holds more reactors than any other operator in the country, while the company also ranks as the Baltimore area's largest publicly traded enterprise.
Two separate long-term energy agreements have taken shape for Constellation, with one covering a 20-year supply arrangement tied to Microsoft's data center operations that involves bringing the Three Mile Island facility in Pennsylvania back online, and another pairing the company with Meta for electricity drawn from a nuclear plant in Illinois. The company has directed a portion of its effort toward reaching a net-zero emissions position across all operations by 2040, with Calvert Cliffs serving as one node in a broader portfolio of carbon-free energy procurement spanning multiple countries.
Funding directed toward nuclear facilities and related technology has reached the hundreds of millions of dollars range over recent years, and a separate arrangement locks in power purchases from a Pennsylvania reactor situated beside one of the company's data centers. Cross-party backing has lifted nuclear power onto a more prominent place in the policy agenda.
Before any fleet expansion decision was reached, Constellation moved to renew the operating authorisations on its existing reactors — the two Calvert Cliffs units hold licences running out in 2034 and 2036 respectively — and to increase the output capacity of those facilities. Barrón, who held the role of chief strategy and growth officer at the time, told a broadcast news outlet that any discussion of uprates would depend on securing a customer base whose demand for that output would offset the cost of the investment — a condition Constellation ultimately met through its agreement with Amazon.
