Alphabet Inc.’s Google and Constellation Energy are teaming on a clean energy partnership to bring 890 megawatts of nuclear capacity onto the power grid — the latest massive bet by Big Tech to power its artificial intelligence (AI) expansion with carbon-free electricity.

Under the primary 20-year power purchase agreement, Constellation will invest more than $4.3 billion in equipment upgrades and modernizations across 11 nuclear units at six plant locations in Illinois, Pennsylvania, and New Jersey. The physical enhancements — which include state-of-the-art turbines, modernized steam generators, and advanced digital control systems — will significantly boost electrical and thermal efficiency.

The resulting capacity represents entirely new electricity added to the PJM Interconnection grid, the regional transmission network coordinating wholesale power across 13 Mid-Atlantic and Midwest states.

The revenue certainty provided by Google allows Constellation to execute the multibillion-dollar upgrades without saddling everyday utility customers with the additional costs driven by data center energy demands. Beyond the 890-megawatt expansion, the two companies also inked a separate 15-year supply deal for an additional 2,700 megawatts from Constellation’s existing regional fleet. This second agreement ensures that crucial operational assets continue delivering reliable baseload energy directly to the PJM grid.

In tandem with the power contracts, Constellation signed a five-year technology alliance to integrate Google Cloud and Gemini Enterprise software.

Designed to serve as an “AI for energy” blueprint, the software will assist Constellation with AI-driven site selection, generator dispatch optimization, outage management, and critical infrastructure protection.

The economic footprint of the deal is substantial. The project is expected to sustain roughly 4,400 existing high-skilled operational and union positions while creating approximately 7,200 construction jobs during the building phase.

Investors responded swiftly to the announcement. Shares of Constellation Energy surged over 12% in early trading, while Alphabet stock remained virtually flat.

The collaboration highlights a broader push across the technology sector to secure reliable, 24/7 power for energy-intensive AI model training and cloud operations.

While nuclear energy carries a historical stigma, tech majors view it as an essential, zero-emission alternative to carbon-based power sources. Google’s move follows a string of nuclear ventures across the U.S., including investments in Georgia, Iowa, Tennessee, and small modular reactor (SMR) development.

Oracle Corp. is planning to use nuclear energy to power its massive Wisconsin data center project under an agreement that could shift about $300 million in energy costs away from the state’s utility customers.

Google’s deal aligns with aggressive moves by its industry peers. Amazon.com Inc. signed a power purchase agreement with Constellation earlier this year, while Microsoft Corp. contracted with the company in 2024 to reactivate a shuttered unit at Three Mile Island by 2028.

Meta Platforms Inc. has similarly committed to 20-year off-take agreements from Vistra nuclear plants. As hyperscalers race for grid capacity, reactor uprates and compact modular power systems — capable of producing hundreds of megawatts without multi-year construction delays — are rapidly becoming the backbone of Silicon Valley’s infrastructure strategy.