Constellation Energy

Constellation Energy Corporation is a Baltimore-based American energy company serving residential, commercial, industrial, public-sector, utility, municipal, cooperative, and wholesale customers. Its activities include electricity supply and marketing, natural-gas marketing, renewable-energy procurement, energy-management services, power-generation operations, and technical services for nuclear facilities. The company serves approximately two million customers across the continental United States. The present company emerged in 2022, when Exelon separated its competitive generation and energy-supply operations from its regulated utility businesses. This structure should be distinguished from the earlier Constellation Energy Group, which was created in 1999 as a holding company by Baltimore Gas and Electric. The earlier business became one of the largest U.S. electricity producers and operated more than 35 generating plants in 11 states before Exelon acquired it in 2012. Baltimore Gas and Electric remained within Exelon Utilities, while the competitive supply business was rebranded as Constellation, an Exelon company. Constellation’s current identity is strongly associated with nuclear power. It operates a large fleet of nuclear stations in Illinois, Maryland, New York, Pennsylvania, and other states, with more than 19,000 megawatts of nuclear capacity cited in company and reference descriptions. Its nuclear portfolio includes Calvert Cliffs, Braidwood, Byron, Clinton, Dresden, Ginna, FitzPatrick, LaSalle, Limerick, Nine Mile Point, Peach Bottom, Quad Cities, and other facilities, including minority interests in Salem and South Texas. In 2024, Microsoft entered an agreement with Constellation connected with restarting the undamaged Unit 1 reactor at the Three Mile Island site, subject to regulatory and project requirements. The company also owns or operates natural-gas, oil-fired, hydroelectric, wind, and solar assets. Its hydroelectric portfolio includes Conowingo Dam and the Muddy Run pumped-storage facility. Its wind business has included 27 projects in ten states totaling nearly 1,400 megawatts, while its solar portfolio has included projects in California, Maryland, Arizona, New Jersey, and Texas. Constellation’s CORe offering combines renewable-energy purchases and environmental attributes with physical electricity supply for corporate and institutional customers. Natural gas remains another important commercial activity. Constellation markets, transports, stores, prices, hedges, and manages physical gas supplies, and reference material describes annual volumes of roughly 730 billion cubic feet. The company has expanded its retail and commercial customer base through acquisitions including StarTex Power, MXenergy, Integrys Energy Services, ConEdison Solutions’ retail business, and other gas-marketing operations. It also operates specialized generation-maintenance and laboratory businesses, including Constellation Generation Solutions and Constellation PowerLabs, and has used Constellation Technology Ventures to invest in emerging energy technologies. Constellation positions itself around reliable power, decarbonization, energy resilience, and customized supply arrangements. Its nuclear fleet provides firm, low-carbon generation, while its renewable products and energy-efficiency services address customers seeking lower-emissions electricity. At the same time, its ownership and marketing of fossil-fuel generation and natural gas expose it to the broader commercial, environmental, and regulatory issues affecting the U.S. power sector.

Constellation’s roots lie in Baltimore Gas and Electric, which created Constellation Energy as a holding company in 1999. The new structure enabled the business to participate more broadly in competitive power generation and energy supply while BGE continued as a regulated utility. During the following decade, Constellation expanded its generation, retail-supply, commodities, and energy-services operations across the United States. In 2005, Constellation and Areva formed UniStar Nuclear to promote the European Pressurized Reactor in the U.S. market. A proposed merger with FPL Group, announced in 2005 and valued at more than $11 billion, was canceled in 2006. Constellation later broadened its commercial activities by acquiring uranium trader Nufcor International in 2008 and by developing or purchasing generation assets, including wind and natural-gas facilities. The company experienced severe financial and strategic pressure during the 2008 financial crisis. Reports concerning exposure to Lehman Brothers were followed by a sharp fall in Constellation’s share price and a temporary New York Stock Exchange trading halt. Constellation explored strategic alternatives, accepted and then canceled a proposed transaction with MidAmerican Energy, and ultimately agreed to be acquired by Électricité de France in late 2008. It subsequently sold most of its London-based international commodities business to a Goldman Sachs affiliate in 2009. Constellation continued expanding its power and retail platform in 2010 and 2011. It acquired the Criterion Wind Project and associated turbines in Maryland, purchased two 550-megawatt natural-gas facilities in Texas, acquired StarTex Power and MXenergy, and announced a natural-gas marketing acquisition from ONEOK. It also contracted to build and operate a major rooftop solar installation for a Toys “R” Us distribution center in New Jersey. In 2011, Exelon announced its intention to acquire Constellation, and the transaction closed on March 12, 2012. Following the Exelon transaction, the competitive energy-supply business operated under the Constellation name, while BGE became part of Exelon’s regulated utility organization. Constellation expanded through acquisitions of ETC ProLiance Energy, Integrys Energy Services, and the retail electricity and natural-gas business of ConEdison Solutions. It also developed solar projects for municipalities and school systems, including a large project supporting Tucson Unified School District facilities. The business became an independent publicly traded company again in 2022, when Exelon separated its competitive power-generation and energy-supply activities from its regulated utilities. The reconstituted Constellation retained a substantial nuclear fleet and continued to offer electricity, natural gas, renewable products, energy management, and technical services. Its strategic profile increasingly emphasized nuclear power as a source of firm, low-carbon electricity, alongside wind, solar, hydroelectric, gas, and oil-fired generation. In 2024, Constellation entered an agreement with Microsoft associated with a proposed restart of the undamaged reactor at the Three Mile Island site. The proposal reflected rising demand for dependable electricity from data centers and other large customers. In 2025, the company announced a proposed acquisition of Calpine, a major natural-gas and geothermal generator. The transaction attracted antitrust scrutiny, including a proposed Justice Department remedy requiring power-plant divestitures. Constellation also faced continuing environmental and regulatory issues concerning the Conowingo Dam and a proposed worker-compensation antitrust class action naming multiple nuclear operators. These matters illustrate the regulatory, environmental, labor, and competition risks accompanying its expansion in the U.S. power market.

• 2024

  Microsoft power agreement announced

  [1]Constellation Energyen.wikipedia.org

  Constellation and Microsoft announced an arrangement associated with restarting Three Mile Island Unit 1, subject to regulatory and operating requirements.

• 2022

  Spun off from Exelon

  [1]Constellation Energyen.wikipedia.org

  Constellation became an independent company after Exelon separated its regulated utilities from its competitive generation and energy-supply businesses.

• 2014

  Integrys Energy Services acquisition completed

  [1]Constellation Energyen.wikipedia.org

  Constellation completed the acquisition of Integrys Energy Services, expanding competitive electricity and natural-gas retail operations across 22 states.

• 2012

  Acquired by Exelon

  [1]Constellation Energyen.wikipedia.org

  Exelon completed its acquisition of Constellation. The competitive supply business retained the Constellation name, while BGE moved into Exelon’s regulated utility structure.

• 2010

  Criterion Wind Project acquired

  [1]Constellation Energyen.wikipedia.org

  Constellation completed an agreement involving Maryland’s Criterion Wind Project and 28 wind turbines.

• 2008

  Financial crisis and strategic review

  [1]Constellation Energyen.wikipedia.org

  Lehman-related concerns caused a severe share-price decline and led Constellation to seek strategic alternatives, ultimately resulting in an EDF transaction.

• 2005

  UniStar Nuclear joint venture announced

  Constellation and Areva formed UniStar Nuclear to market the European Pressurized Reactor in the United States.

• 1999

  Constellation Energy holding company created

  [1]Constellation Energyen.wikipedia.org

  Baltimore Gas and Electric created Constellation as a holding company, establishing the corporate platform that later expanded into competitive generation and energy supply.

A large-scale U.S. power producer and energy supplier emphasizing reliable, low-carbon nuclear generation, renewable procurement, and tailored energy-management solutions.

• Electricity generation

  Nuclear generation

  Constellation’s core generation platform consists of a large U.S. nuclear fleet, including stations in Illinois, Maryland, New York, Pennsylvania, and other states. The fleet supplies firm electricity and supports the company’s low-carbon positioning. Major facilities include Calvert Cliffs, Braidwood, Byron, Clinton, Dresden, Ginna, FitzPatrick, LaSalle, Limerick, Nine Mile Point, Peach Bottom, and Quad Cities, alongside minority interests in other plants.

• Renewable electricity supply

  CORe

  CORe is Constellation’s off-site renewable-energy offering for commercial and institutional customers. It combines renewable-energy purchases and associated certificates with a physical, load-following electricity supply contract, allowing customers to match procurement goals with their actual electricity consumption.

• Natural gas

  Natural gas marketing

  Constellation supplies and markets natural gas for commercial, industrial, public-sector, and other customers. Its activities include physical trading, transportation, storage, pricing, hedging, and risk management. Reference material describes annual marketed volumes of approximately 730 billion cubic feet.

• Renewable energy

  Renewable generation

  The company’s renewable portfolio includes wind and solar projects spread across multiple U.S. states. Its documented activities include the Criterion Wind Project, large commercial and institutional solar installations, and solar generation assets in locations including Maryland, California, Arizona, New Jersey, and Texas.

• Technical services

  Generation services

  Constellation Generation Solutions provides maintenance and technical services focused particularly on nuclear generation. Constellation PowerLabs operates engineering, calibration, metrology, and testing laboratories serving nuclear facilities, power grids, and critical energy infrastructure.

• 2025

  Conowingo Dam environmental dispute

  Constellation and environmental organizations reached an agreement announced by Maryland officials concerning water-quality, sediment, nutrient, and relicensing issues associated with the Conowingo Dam. The agreement followed years of litigation and regulatory disagreement.

  Source

• 2025

  Nuclear-worker compensation antitrust lawsuit

  Constellation was named among defendants in a proposed federal class action alleging that nuclear operators and consulting firms shared compensation information in ways that suppressed worker pay. The claims were allegations and the litigation remained pending against multiple defendants.

  Source

• 2013

  California market transaction settlement

  FERC approved a settlement involving Constellation Energy Commodities Group over transactions in the California Independent System Operator market. The matter concerned falsely designated transactions submitted to affect bid awards at interties.

  Source

• 2012

  Electricity-market manipulation settlement

  Constellation Energy Commodities Group reached a Federal Energy Regulatory Commission settlement concerning alleged manipulation of ISO New England and New York Independent System Operator markets. The resolution included civil penalties, disgorgement, trading restrictions, and compliance obligations.

  Source

• 2008

  Lehman-related market crisis

  Reports that Constellation had exposure to Lehman Brothers contributed to a dramatic one-day share-price fall and a temporary exchange trading halt. The episode prompted the company to seek strategic alternatives and negotiate possible transactions.

  Source

Read more

• 2018Ocean City solar project

  United States

  Constellation began construction of a 10-megawatt solar array near Ocean City, Maryland. The project was designed to supply roughly one-fifth of the city’s annual electricity use.

  Outcome. Municipal renewable-energy project developed in Maryland.

  Source
• 2018Tucson Unified School District solar program

  United States

  Constellation and Tucson Unified School District completed solar installations across 82 district buildings and facilities. The project was estimated to meet approximately 47 percent of the district’s electricity needs.

  Outcome. Large distributed solar program completed for a public-school system.

  Source
• 2011Toys “R” Us rooftop solar project

  United States

  Constellation contracted to construct and operate a large rooftop solar installation at the Toys “R” Us distribution center in Flanders, New Jersey. At the time, the project was described as the largest rooftop solar array of its kind.

  Outcome. Project developed and operated as a major commercial solar installation.

  Source

• 2025

  Agree to acquire CalpineM&A

  Background

  Constellation sought to expand its generation portfolio with Calpine’s natural-gas and geothermal assets.

  Action taken

  The company announced a proposed cash-and-stock acquisition of Calpine, described as $16.4 billion excluding assumed debt and approximately $26.6 billion including debt.

  Aftermath

  The proposed transaction became subject to state and federal regulatory review and antitrust remedies, including proposed plant divestitures.

  Announced transaction value. $16.4 billion excluding assumed debt; approximately $26.6 billion including debt (2025 announcement)

  Source

• 2024

  Pursue Three Mile Island Unit 1 restart arrangementProduct launch

  Background

  Demand from large electricity users, including data-center operators, increased interest in dependable low-carbon generation.

  Action taken

  Constellation entered an agreement with Microsoft associated with restarting the undamaged reactor at the Three Mile Island site.

  Aftermath

  The proposal placed renewed attention on existing nuclear plants as sources of firm power, while remaining subject to regulatory, technical, and commercial conditions.

  Source

• 2022

  Separate competitive generation from regulated utilitiesStrategy

  Background

  Exelon reorganized after determining that its regulated utility businesses and competitive generation and supply operations required distinct corporate structures.

  Action taken

  Exelon spun off the competitive generation and energy-supply activities as the independent Constellation Energy Corporation.

  Aftermath

  Constellation returned as a publicly traded company focused on generation, wholesale and retail energy supply, nuclear operations, renewables, and energy services.

  Source

• 2012

  Accept Exelon acquisitionM&A

  Background

  Constellation had expanded into generation, retail supply, and energy services, while the power industry was undergoing consolidation and financial pressure.

  Action taken

  Constellation completed its acquisition by Exelon. Its competitive supply operations continued under the Constellation brand, while Baltimore Gas and Electric became part of Exelon Utilities.

  Aftermath

  The transaction removed Constellation as an independent public company until the competitive generation and supply business was spun off again in 2022.

  Source

• 2026.10.28

  Reported2026.10.28

  Constellation Energy to receive $5 billion in government loans[3]Constellation Energy 将获得 50 亿美元政府贷款techcrunch.com

  The Trump administration is providing Constellation Energy with $5 billion in government loans to expand nuclear generating capacity at eight power plants by 1.1 gigawatts.

• 2026.10.27

  Reported2026.10.28

  Constellation secures conditional DOE loan commitment[4]Constellation获得美国能源部有条件贷款承诺oilprice.com

  Constellation Energy secured a conditional loan commitment of up to $5 billion from the U.S. Department of Energy to support nuclear upgrades and modernization projects at eight existing facilities. The commitment remains subject to due diligence, final financing agreements, and other conditions.

• 2026.10.06

  Reported2026.10.06

  Google enters 3.6-GW power deal with Constellation Energy[5]谷歌与星座能源(Constellation Energy)达成3.6吉瓦电力协议cnbc.com

  Google contracted for 3,590 megawatts of power from Constellation Energy in the PJM grid, the largest US power grid, with new nuclear energy accounting for about a quarter of the supply. The arrangement includes a 20-year power purchase agreement for 890 megawatts from multiple Constellation-owned nuclear plants that would be upgraded to produce more electricity, with first deliveries expected in 2028, plus a long-term supply agreement for an additional 2,700 megawatts not tied to a specific generation source. The deal enables more than $4.3 billion of new investment by Constellation, including capacity additions at 11 nuclear units in Illinois, Pennsylvania and New Jersey, and the companies said it is in response to PJM's "bring your own power" proposal.

Read more

1. 1Constellation Energyen.wikipedia.org
2. 2Constellation Energy corporate websiteconstellation.com
3. 3Constellation Energy 将获得 50 亿美元政府贷款techcrunch.com
4. 4Constellation获得美国能源部有条件贷款承诺oilprice.com
5. 5谷歌与星座能源(Constellation Energy)达成3.6吉瓦电力协议cnbc.com
6. 6Stocks making the biggest moves premarket: Constellation Energy, Option Care Health, Lennar, P&G and morecnbc.com