Walmart signs its first nuclear power purchase deal, aligning Illinois expansion with Constellation’s Dresden output

Walmart said it has signed its first long-term nuclear power purchase agreement, a move aimed at securing emissions-free electricity for operations and an Illinois supply-chain expansion. The agreement with Constellation Energy centers on electricity generated at Constellation’s Dresden Clean Energy Center in Illinois, and is designed to provide both long-duration supply and capacity-related benefits for the regional grid.

Under the terms described by the companies, Walmart will purchase up to about 176 megawatts of wholesale nuclear-generated electricity over two separate 15-year periods. Those terms are scheduled to begin in 2029 and 2030, with the arrangement including approximately 30 megawatts of expanded generating capacity tied to planned upgrades at the Dresden site.

Constellation, which described itself as a major producer of clean, zero-emissions power, said the deal supports not only emissions reduction goals but also reliability. In the companies’ announcement, Constellation linked the agreement to Walmart’s previously announced development of a high-tech perishable distribution center in Illinois, describing the power procurement as a way to help match that facility’s needs with “new power to the grid.”

The press release also framed the arrangement as part of an investment cycle for existing nuclear infrastructure. Instead of building a new nuclear facility, Constellation said the agreement is connected to “uprates,” meaning efficiency upgrades that increase output from existing units. The companies said the uprates at Dresden are expected to support the amount of new capacity associated with the nuclear supply terms.

Walmart’s sustainability disclosures provide context for why the retailer is pursuing contracts like this. In its fiscal year 2025 ESG reporting, Walmart set a goal of reaching net-zero emissions across global operations by 2040, covering scope 1 and scope 2 emissions. The company also reported interim milestones focused on renewable electricity, including that 48.5% of its global electricity needs were met with renewable energy sources in 2024 and that 30.6% of its electricity needs were met through renewable energy contracts.

Constellation’s chief commercial officer, Jim McHugh, characterized the agreement as long-term stewardship of infrastructure and the communities served, saying the pact enables meaningful investment at Dresden and supports dependable emissions-free power on the Illinois grid. Walmart did not provide an extensive operational breakdown in the announcement, but the deal’s structure underscores that it is intended to support a specific geographic expansion rather than be purely financial hedging.

What remains less clear is the practical allocation of the electricity across Walmart’s Illinois footprint and how the contract’s environmental attributes are used in the company’s emissions accounting. The announcement emphasizes total megawatts, term timing, and the link to distribution-center planning, but it does not disclose pricing, contracted volumes by delivery point, or whether Walmart has options to modify quantities during the contract term.

Next for investors and observers will be additional detail on Walmart’s Illinois power demand plans and the progress of Constellation’s Dresden upgrades leading into 2029 and 2030. The deal also comes as nuclear PPAs become an increasingly prominent tool for large electricity buyers, so future disclosures may show whether more retailers follow a similar procurement path for emissions-free power.