Commonwealth Edison
| Company type | Subsidiary |
|---|---|
| Industry | Electric utility |
| Founded | 1881 |
| Founder | George H. Bliss |
| Headquarters | Chicago , United States |
Area served | Northern Illinois, including Chicago |
Key people | Joe Dominguez (CEO), Terence Donnelly (President and COO) |
| Products | Electricity distribution and transmission |
| Owner | Exelon Corporation |
| Parent | Exelon Corporation |
Commonwealth Edison, commonly known as ComEd, stands as the largest electricity utility in Illinois and serves as the main power supplier for Chicago along with much of Northern Illinois. Its coverage spans from Iroquois County in the south up to the Wisconsin state line in the north, stretching eastward to Indiana and westward to the Iowa border. For more than one hundred years, ComEd has been the principal electric distribution company within Northern Illinois. Operating as a subsidiary of Chicago-headquartered Exelon Corporation, one of the country’s leading electric and gas utility holding firms, ComEd caters to over 3.8 million customers throughout Northern Illinois and reported revenues surpassing $7 billion in 2023.
Since 2015, ComEd has established interconnections with several major regional utilities such as We Energies, ITC Midwest, Ameren, American Electric Power, Northern Indiana Public Service, and MidAmerican Energy Company.
Founding
The beginnings of Commonwealth Edison date back to early 1881 with the establishment of the Isolated Lighting Company by George H. Bliss. This entity functioned as a subsidiary under Thomas Edison's enterprise, focused on marketing small-scale Edison-patented generators and lighting solutions designed for individual buildings or nearby clusters. In 1882, Western Edison Light Company—a group of Chicago investors—took over Isolated Lighting’s role as Edison's representative in Chicago and developed a centralized electric system. That same year, Western Edison installed Chicago’s first incandescent lighting in the residence of stockholder John W. Doane, which was illuminated for the first time on November 10.
Chicago Edison
In March 1887, John M. Clark (then president of Western Edison), Robert Todd Lincoln, and John B. Drake obtained a franchise from the city of Chicago to supply electricity downtown, leading to the creation of the Chicago Edison Company. On July 2, 1887, it assumed control over Western Edison’s operations. The company’s initial central generating station, designed by chief engineer Frederick Sargent, began operation in August 1888 at 139 (later renumbered 120) West Adams Street. This facility served a specific area using an Edison-patented direct current system until its decommissioning around 1914–1915.
The Samuel Insull Era
By 1892, Chicago Edison had reached its full generating capacity of 3,200 kilowatts amid growth stimulated by the upcoming 1893 Columbian Exposition. After President E. T. Watkins resigned, the board sought new leadership. Samuel Insull—previously an associate of Thomas Edison and second vice-president at General Electric—was elected president on May 26, 1892.
Facing nearly thirty competing electric companies in Chicago, Insull rejected the popular belief in competition and instead championed a regulated monopoly approach—securing exclusive operating rights in return for state regulation over service quality and pricing. Although state regulation was only instituted in 1914, Insull quickly consolidated competitors; by 1895, Chicago Edison had established a complete monopoly within its service area.
He spearheaded construction of an expanded power plant on Harrison Street, west of the Chicago River, which doubled capacity to 6,400 kilowatts upon its August 1894 opening—the largest plant in the United States at that time. Insull expected that economies of scale would reduce costs. This new facility replaced the overburdened Adams Street Station and expanded further to reach 16,200 kilowatts by 1903.
In 1907, Chicago Edison merged with Commonwealth Electric to create Commonwealth Edison Company (ComEd). Six years later, it acquired Cosmopolitan Electric Company—an independent operator—becoming Chicago’s exclusive electricity provider.
Insull also founded Public Service Company of Northern Illinois, promoting electrification efforts beyond Chicago into rural areas. Both Public Service and ComEd were subsidiaries under Insull’s Middle West Utilities Company until its collapse during the Great Depression. In the 1920s, Insull pioneered transmission companies—a concept later restricted by Public Utility Commissions and legislation such as the Public Utilities Company Holding Act of 1935 but partially revived through recent deregulation initiatives.
In 1994, ComEd restructured into a holding company named Unicom Corporation, with ComEd as its principal subsidiary. Subsequently, in 2000, UniCom merged with Philadelphia-based PECO Energy to form Exelon.
Central Illinois Electric and Gas Company
In 1967, Commonwealth Edison expanded its reach by acquiring Central Illinois Electric and Gas Company, a utility based in Rockford that provided services to the greater Rockford region as well as Lincoln, Illinois.
ComEd Transmission
Commonwealth Edison manages transmission networks operating at voltages of 765kV, 345kV, 138kV, and 69kV, with 34.5kV commonly utilized for sub-transmission purposes. The company maintains significant interconnections with utilities such as MidAmerican Energy, AEP, ATC, Ameren, and NIPSCO.
ComEd Metering
The electric meters employed by ComEd are produced by Aclara. These meters feature seals in various colors—Brown (primarily used by Metering staff), Light Brown (Rust), Pink (Rose), Beige, Yellow, and Green—each color designated for distinct operational functions.
Deregulation and divestiture
By the mid-1990s, the U.S. utility industry transitioned from monopolistic regional control toward competitive market structures. The Federal Energy Regulatory Commission’s Order 888 facilitated open access to national transmission grids, leaving states to determine their own implementation strategies.
In response, Illinois enacted the Electric Service Customer Choice and Rate Relief Law of 1997, mandating utilities such as Commonwealth Edison to permit customers to purchase electricity from alternative suppliers. This legislation reduced residential rates by 15%, followed by an additional 5% cut in 2001, froze rates for a decade, and required competitive energy procurement thereafter.
To comply and eliminate conflicts of interest, Commonwealth Edison divested its generation assets: coal-fired plants were sold to Midwest Generation in 2000 and nuclear facilities transferred to Exelon Nuclear in 2003. Although generation and distribution were legally separated, the holding company maintained control over management and profits of both segments. Long-term power purchase agreements enabled ComEd to acquire electricity below market prices throughout the rate freeze period.
The 2007 Rate Case
As the rate freeze concluded in 2006, Commonwealth Edison confronted a fully competitive market alongside the expiration of its power purchase contracts with former generating plant owners. The proposed rate adjustments sought a substantial increase in residential electricity costs, igniting intense public debate regarding deregulation.
The proposal featured two main components: delivery charges—covering electricity transportation—were set to rise by approximately 22%, while electricity prices would be established via a reverse auction, securing fixed rates from selected suppliers for a predetermined term. Together, these changes resulted in roughly a 33% increase on average residential bills.
The significant rate hike provoked widespread criticism, with opponents arguing that deregulation had failed consumers. The Illinois General Assembly considered extending the existing rate freeze to devise an improved strategy. ComEd cautioned that prolonging the freeze risked insolvency due to its inability to procure power at frozen prices.
In January 2007, investigative reporting by the Chicago Tribune uncovered ComEd’s financial support for Consumers Organized for Reliable Electricity (CORE), an organization opposing a statewide rate freeze. This group utilized astroturfing methods to sway public opinion and influence legislators. Illinois Lieutenant Governor Pat Quinn pressured CORE to clearly disclose ComEd’s backing in its advertisements. While the Illinois Commerce Commission rejected a related petition, CORE agreed to enhance transparency.
Ultimately, the General Assembly chose not to extend the freeze, allowing ComEd’s new rate structure to commence on January 2, 2007. Due to concerns about the reverse auction’s integrity, the Illinois Power Agency was established to oversee energy procurement for utilities within Illinois.
To mitigate customer burden from the 22% increase in delivery charges, ComEd introduced an option allowing payment deferrals with interest rates exceeding 3% applied on deferred balances.
In September 2011, ComEd appointed Anne Pramaggiore as its first female CEO. Following her promotion within parent company Exelon, Joe Dominguez succeeded her as CEO while Terence Donnelly was elevated to president while continuing his role as COO.
Corruption scandal
On July 17, 2020, ComEd consented to a $200 million settlement following an extensive federal inquiry into unlawful lobbying activities, political corruption, and preferential contract arrangements that effectively established the company’s dominant position in the regional electricity market. Subsequently, on September 4, 2020, Fidel Marquez, a former ComEd Vice-President, became the initial executive to face criminal charges tied to this controversy.
2023 ComEd Four convictions
On May 2, 2023, four individuals—former ComEd CEO Anne Pramaggiore, ex-lobbyist Mike McClain, retired executive John Hooker, and former City Club of Chicago president and consultant Jay Doherty—collectively known as the "ComEd Four," were convicted on nine counts each. These charges included conspiracy to commit bribery and falsification of corporate records. Their convictions stemmed from schemes aimed at improperly influencing Michael Madigan, the former Speaker of the Illinois House.
Smart Grid
In 2016, ComEd committed $2.6 billion toward upgrading Illinois’ electrical infrastructure through its "Smart Grid" program. This initiative involved enhancing power lines and deploying smart meters intended to replace obsolete equipment and eliminate the need for manual meter reading. Despite resistance from the Attorney General and consumer advocacy groups, ComEd successfully advocated for legislation mandating wireless smart meter installation for all customers in Illinois. The company invested roughly $16 million to overturn Governor Quinn’s veto; later legislation endorsed by Governor Rauner further restricted customers’ ability to opt out.
In partnership with another leading Illinois utility, ComEd has installed more than three million smart meters capable of wirelessly transmitting electricity consumption data. According to the company, this technology has helped avert approximately 7.6 million power outages and produced societal savings totaling $1.4 billion. The deployment of smart meters, overseen by Aclara Smart Grid Solutions, began in Chicago in late 2016 and was completed across ComEd’s western service area by 2019.
On February 28, 2018, Illinois utility regulators authorized a decade-long electric microgrid pilot project on Chicago’s South Side. The Bronzeville Community Microgrid Project will integrate with a microgrid at the Illinois Institute of Technology, creating one of the country’s earliest utility-scale microgrid clusters.
See also
External links
- Commonwealth Edison official website