Constellation’s Clean Energy Centers Achieve Near-Perfect Summer Reliability with $7B Investment
During a summer marked by extended heatwaves and record-breaking humidity, Constellation’s emissions-free clean energy centers demonstrated their resilience and reliability, operating at near-full capacity. These results underscore the role of nuclear power as one of the most dependable and cost-effective sources of electricity on the grid, especially during periods of rising demand and increasingly unpredictable weather patterns. Constellation’s 21 nuclear reactors, spread across 12 sites from the Midwest to the Mid-Atlantic and Northeast, collectively achieved an outstanding 98.8% operational rate during June, July, and August. This level of performance ensured continuous electricity supply for the equivalent of 16 million homes and businesses, keeping lights on and air conditioners running during one of the hottest summers on record. The company’s ongoing investments in these nuclear plants not only maintain but also enhance the immense value they provide to society through reliable, affordable, and emissions-free energy.
“Constellation has reinvested billions of dollars to upgrade and enhance our U.S. nuclear fleet with state-of-the-art equipment and controls, and that investment is paying huge dividends for families and businesses in the PJM, NYISO, and MISO service territories,” said Joe Dominguez, Constellation President and CEO. “Like the well-known phrase about the postal service, neither snow nor rain nor heat or gloom of night will keep our team from powering America 24 hours a day, 365 days a year. That is our promise; that is our commitment.”
Capacity factors, a key metric in the nuclear industry, measure the reliability and operational efficiency of reactors. Constellation has consistently led the nation in capacity factors for more than a decade, producing approximately 4% more electricity than the industry average—equivalent to the output of an additional reactor. Impressively, every one of Constellation’s 21 nuclear reactors now operates at a higher capacity factor than when it first came online, reflecting continuous improvements in performance and operational excellence.
Reliable energy is critical in supporting the growing demands of the data economy, onshoring of manufacturing, and the electrification of transportation. Recognizing this, Constellation is actively investing in modern equipment and advanced technologies to increase the output of its existing nuclear plants. The company is also focused on restarting the Crane Clean Energy Center in Pennsylvania, which, combined with these other initiatives, could provide up to 2,000 megawatts of additional clean and reliable baseload capacity to the electric grid.
Preparation and maintenance are central to the high performance of Constellation’s nuclear fleet. In anticipation of extreme summer heat, technical experts at the company’s nuclear facilities carried out tens of thousands of preventive maintenance tasks during spring refueling and maintenance outages. These activities are designed to ensure that reactors can operate continuously and without interruption, even under the most severe weather conditions. Each year, Constellation undertakes targeted technology upgrades and installs new and enhanced equipment, further ensuring that its plants can meet peak demand periods. Unlike other energy sources, a typical nuclear plant can operate continuously for up to two years without refueling, regardless of external weather conditions. As the summer season concluded, preparations for the fall maintenance period began, positioning the fleet to meet increasing electricity demand during the colder months.
Constellation’s clean energy centers are strategically located across the Mid-Atlantic, Northeast, and Midwest, reflecting a broad footprint that strengthens the resilience of regional power grids. In the Mid-Atlantic and Northeast, these facilities include Calvert Cliffs in Calvert County, Maryland; Pennsylvania’s Limerick and Peach Bottom plants in Montgomery and York counties; and New York’s Fitzpatrick and Nine Mile Point plants in Oswego County, along with Ginna in Wayne County. The company’s Illinois-based plants include Braidwood in Will County, Byron in Ogle County, Clinton in DeWitt County, Dresden in Grundy County, LaSalle in LaSalle County, and Quad Cities in Rock Island County. Collectively, these facilities form a backbone of clean, reliable, and resilient energy, supporting millions of households, businesses, and critical infrastructure across multiple states.
The performance of Constellation’s nuclear fleet over the summer is a testament to decades of strategic investment, rigorous maintenance, and operational excellence. Over the past ten years alone, the company has invested more than $7 billion in its nuclear plants, a commitment that has consistently delivered value to customers and communities alike. These investments have included upgrades to core systems, implementation of advanced monitoring and control technologies, and replacement of aging infrastructure with modern, state-of-the-art equipment. By continually improving the reliability and efficiency of its nuclear fleet, Constellation ensures that communities receive uninterrupted electricity, even under the most challenging conditions.
Moreover, nuclear energy’s role extends beyond immediate electricity supply. By producing large amounts of carbon-free energy, Constellation’s plants contribute significantly to the reduction of greenhouse gas emissions, supporting broader environmental and climate goals. The ability of nuclear plants to provide consistent, 24/7 power also complements renewable energy sources like solar and wind, which are variable by nature. This makes nuclear power a critical component of a balanced, low-carbon energy mix capable of meeting modern energy demands while addressing climate change.
As Constellation continues to innovate and invest in its nuclear portfolio, it not only strengthens grid reliability but also reinforces energy security for millions of Americans. The summer performance of its clean energy centers demonstrates that nuclear power remains a cornerstone of the U.S. energy system, providing affordable, reliable, and emissions-free electricity that families, businesses, and communities can depend on, regardless of extreme weather or rising demand. With ongoing investments, technological upgrades, and strategic expansions, Constellation is well-positioned to continue delivering high-performance, low-carbon energy for decades to come.
