Google has signed a pair of long-term electricity agreements with Constellation Energy covering 3,590 megawatts in the PJM power market, giving one of the world’s largest technology companies a much larger block of committed power as artificial-intelligence infrastructure strains the U.S. grid. The centerpiece is a 20-year agreement that will support 890 MW of additional nuclear generation, backed by more than $4.3 billion of investment from Constellation.
The announcement sent Constellation shares up 12.3% Tuesday to $300.40, after the stock traded as high as $309.80 during the session. The reaction reflected more than the size of the Google agreement: it offered another indication that large technology companies are willing to make decades-long commitments that can finance expansions of existing nuclear plants rather than wait for entirely new generating facilities to be built.
The 3.59-GW headline figure, however, requires an important distinction. Only 890 MW is new generating capacity. Google separately agreed to a 15-year energy supply arrangement covering another 2,700 MW from Constellation’s existing generation portfolio in PJM, providing long-term commercial support for plants that are already operating rather than adding another 2.7 GW to the grid.
Constellation will pursue the 890-MW expansion through upgrades at 11 nuclear units across six sites in Illinois, Pennsylvania and New Jersey. The company plans to improve equipment and plant efficiency to produce more electricity from reactors that are already operating, with the first incremental capacity expected to become available in 2028.
That structure gives Constellation a path to monetize the value of its nuclear fleet without relying exclusively on the much longer timelines associated with constructing new reactors. For Google, it creates additional firm electricity supply inside PJM, the 13-state regional power market where rapid data-center development has intensified competition for generation and transmission capacity.
A Long-Term Customer Funds More Nuclear Output
The agreement provides Constellation with something increasingly valuable in the power market: a large customer willing to commit for decades while the generator deploys billions of dollars into its existing fleet.
Constellation said the nuclear upgrades represent more than $4.3 billion of investment and are expected to add roughly the output of a large nuclear reactor without constructing a new plant from the ground up. The companies did not disclose the electricity price Google will pay, the expected return on Constellation’s investment or the full revenue value of the agreements, leaving a major piece of the financial calculation unavailable to investors.
That omission limits how precisely the deal can be translated into future earnings. A 20-year customer commitment reduces uncertainty around financing the upgrades, while the separate 15-year supply contract improves revenue visibility for existing generation, but the ultimate value to shareholders will depend on pricing, capital costs, operating performance and the timing of each uprate.
The approach is becoming increasingly important to Constellation’s growth strategy. Less than a week earlier, the company announced a 20-year agreement with Amazon involving 690 MW at Maryland’s Calvert Cliffs nuclear plant, including approximately 190 MW of new generating capacity. That project is expected to support more than $3 billion of infrastructure investment, with the additional output scheduled to arrive between 2030 and 2032.
Taken together, the Google and Amazon agreements show how hyperscaler demand can support capital spending at nuclear plants that were built decades before the AI boom. Instead of purchasing only the output that already exists, large technology customers are increasingly helping create the economics necessary for plant uprates, relicensing and other investments that can add capacity to constrained regional grids.
Google’s agreement expands that model considerably. The company said its support for nuclear uprates and plant restarts has now enabled more than 1.5 GW of additional nuclear capacity in the United States, as it attempts to match data-center expansion with new sources of dependable electricity.
PJM’s Power Constraint Is Becoming a Business Issue
The location of the agreement matters. PJM serves one of the country’s largest concentrations of data centers, but electricity demand has grown faster than additions to available generation in portions of the region. Capacity prices have risen sharply as the system attempts to ensure sufficient resources are available during periods of peak demand.
The resulting power shortage is no longer only a utility-sector concern. Access to electricity is becoming a constraint on where and how quickly technology companies can deploy new computing infrastructure, creating an incentive for companies such as Google to participate directly in the financing of new generation.
The Google arrangement also includes provisions allowing demand to be reduced during periods of grid stress. Constellation and Google said the agreement incorporates load-shaping and demand-response capabilities, giving the system some ability to curtail noncritical consumption when electricity supply is particularly tight. The companies positioned the structure as a way for large new power users to help finance incremental generation rather than pushing the entire cost of accommodating their growth onto other customers.
Google and Constellation also established a broader framework to evaluate future generation, energy storage and demand-response projects across the U.S., initially emphasizing PJM. That framework should not be treated as committed future capacity or contracted revenue, but it creates a pathway for the relationship to expand if additional projects meet the companies’ economic and regulatory requirements.
Constellation Gains More Leverage From Existing Assets
For Constellation, the larger investment case is becoming less dependent on simply selling electricity into wholesale markets and more connected to extracting additional value from scarce, continuously available generation.
Nuclear plants are particularly attractive to hyperscalers because they can operate around the clock and do not depend on weather conditions. Existing sites also have transmission connections and operating infrastructure that can make capacity expansions through uprates faster than developing large new generation projects from scratch.
Tuesday’s stock reaction suggests investors assigned substantial value to that opportunity. Constellation closed at $300.40, up $32.78 for the session, with trading volume around four times the previous day’s level. The company’s shares nevertheless remain exposed to the execution risk inherent in turning these agreements into higher earnings, especially because the first new Google-supported capacity is not expected before 2028.
The undisclosed contract pricing is therefore one of the most important numbers investors still do not have. More than $4.3 billion of planned investment establishes the scale of Constellation’s commitment, but without knowing the contracted electricity prices and expected economics of the uprates, the full return on that capital cannot yet be determined.
What is becoming clearer is the role Constellation could occupy in the build-out of U.S. AI infrastructure. Its nuclear plants were once valued primarily as existing power assets exposed to regional electricity markets. Long-term agreements with Google, Amazon and other large technology customers increasingly give those same plants another source of value: scarce, dependable electricity that hyperscalers are willing to help finance years in advance.
The next test will be execution. Constellation expects the first capacity from the Google-backed uprates in 2028, with additional projects following afterward. Meeting those timelines and demonstrating attractive returns on the more than $4.3 billion being invested will determine whether Tuesday’s agreement becomes primarily a powerful validation of nuclear demand or a material new source of earnings growth for the company.