Constellation Energy (NASDAQ: CEG) and Google, a subsidiary of Alphabet Inc. (NASDAQ: GOOGL),signed a 20-year power purchase agreement to add 890 megawatts of nuclear capacity to the PJM Interconnection grid as the companies work to meet growing electricity demand.

The agreement supports upgrades at 11 existing Constellation nuclear units in Illinois, Pennsylvania and New Jersey.

Upgrades to raise output at 11 nuclear units

The agreement will enable investments in new equipment and technology at 11 Constellation-owned nuclear units across six sites in Illinois, Pennsylvania and New Jersey. The upgrades, called uprates, modernize turbines, steam generators, and digital control systems at operating plants to increase thermal and electrical efficiency. Companies expect the first uprate by 2028. 

The companies said Tuesday that uprates add capacity from existing nuclear facilities rather than through new plant construction, potentially avoiding some of the longer development and interconnection timelines associated with new generation. They said the 890 megawatts is equivalent to the output of several small modular reactors or one large conventional reactor.

Constellation to invest more than $4.3 billion across six sites

Constellation will invest more than $4.3 billion in upgrades across six nuclear sites. The company said the agreement helps sustain about 4,400 existing jobs and will create about 7,200 construction jobs during the building period.

Joe Dominguez, Constellation's chairman, president and CEO, said preserving and expanding the output of the existing nuclear fleet is critical to meeting energy needs while keeping costs affordable for homes and businesses. He said the collaboration could provide a model for private investment in energy infrastructure as electricity demand grows.

Agreement to include demand response during grid stress

The commercial agreement includes load-shaping and demand-response capabilities to curtail non-critical power use during high-stress grid events. The companies said the demand flexibility measures are intended to help manage power consumption during periods of grid stress. 

Google, Constellation add 15-year supply deal

Google and Constellation also entered into a 15-year energy supply agreement for an additional 2,700 megawatts from Constellation's PJM fleet. The companies said the agreement allows Constellation's operating plants to keep delivering energy and capacity to the PJM market while remaining economically viable.

Together, the two agreements cover 3,590 MW, but only the 890 MW covered by the 20-year agreement represents new nuclear capacity from the planned uprates. The companies have not disclosed the financial terms of either agreement. 

Constellation to use Gemini Enterprise in operations

Constellation selected Google Cloud and Gemini Enterprise under an expanded five-year technology alliance. It will build Gemini Enterprise agentic workflows into its core operations as part of an "AI for energy" blueprint. The companies said the blueprint will support capacity delivery, asset dispatch and protection of critical infrastructure. They said the aim is to use AI to reduce the cost of new infrastructure, improve performance and ensure enough power is generated to meet rising demand in communities Constellation serves.

For new capacity, Constellation will use AI for site selection, power flow modeling, permitting and interconnection planning. For plant operations, it will use AI for asset health monitoring, outage and turnaround management, and scenario optimization. For security, it will use Google Cloud's defense-grade platforms for operational technology networks, including systems that are air-gapped and connect to the bulk electric system.

The companies said the broader objective is to use AI to reduce infrastructure costs, improve plant performance and help meet rising electricity demand. 

Companies link deal to PJM proposal, federal program

The companies said the agreement responds to PJM's "Bring Your Own Power" proposal and is intended to provide a model for large power consumers to add supply alongside growing operations without state or federal mandates. They said it also advances the goals of the federal UPRISE program, which encourages public-private efforts to maximize clean electricity output from existing U.S. nuclear infrastructure.

Google aims to add capacity in PJM without passing costs to residential customers, in line with the White House Ratepayer Protection Pledge. Amanda Peterson Corio, Google's global head of energy and power, said the agreement will strengthen the PJM grid, which serves 67 million people, while protecting energy affordability and supporting local union jobs.

Constellation operates 55 gigawatts of capacity

Constellation has 55 gigawatts of generating capacity across its portfolio of nuclear, natural gas, oil, geothermal, hydro, wind and solar facilities. 

The Google agreement adds to a series of deals between large technology companies and power producers seeking additional electricity for data centers and other growing loads.

Constellation, Google agree on framework for new projects

Google and Constellation agreed on a framework to evaluate new clean generation, storage and demand-response projects across the United States. The companies said the framework is intended to support Google's growth by identifying potential projects, commercial structures, and policy pathways. It prioritizes near-term efforts in PJM. 

The companies have not disclosed any projects under the framework.