Commonwealth Edison

Commonwealth Edison, often called ComEd, is the biggest electric company in Illinois. It mainly provides electricity to Chicago and many parts of Northern Illinois. Its service area reaches from Iroquois County in the south to the Wisconsin border in the north, and from the Iowa border in the west to the border with Indiana in the east. For over 100 years, ComEd has been the main provider of electricity for people living in Northern Illinois.

Today, ComEd is part of the Exelon Corporation, a big company based in Chicago that provides electricity and gas. ComEd serves more than 3.8 million customers in Northern Illinois. In 2023, the company made more than $7 billion in revenue.

As of 2015, ComEd connects with several other power companies, including We Energies, ITC Midwest, Ameren, American Electric Power, Northern Indiana Public Service, and MidAmerican Energy Company. These connections help make sure electricity can flow to many places.

History

Founding

The story of Commonwealth Edison began with the Isolated Lighting Company, started in 1881 by George H. Bliss. This company sold small generators and lighting systems made by Thomas Edison. Soon after, it became part of the Western Edison Light Company, which aimed to create a central electric system in Chicago. In 1882, Western Edison installed the first home lighting in Chicago for a stockholder named John W. Doane.

Chicago Edison

In 1887, three men received permission from Chicago to provide electricity in the downtown area. They formed the Chicago Edison Company, which took over Western Edison's work. The company opened its first power station in 1888 on West Adams Street, serving a small area with direct current electricity until it closed around 1915.

The Samuel Insull Era

By 1892, Chicago Edison needed new leadership. Samuel Insull, who had worked with Thomas Edison, became the company’s president. He believed that one regulated company serving a specific area was better than many small competitors. Insull grew the company by buying others and building a large power plant on Harrison Street in 1894. This plant became very important and was expanded several times.

In 1907, Chicago Edison merged with another company to form Commonwealth Edison. Later, it bought more companies and became the main electricity provider in Chicago. Insull also started a company to bring electricity to rural areas outside Chicago.

Central Illinois Electric and Gas Company

In 1967, Commonwealth Edison bought Central Illinois Electric and Gas Company, which served the Rockford area and parts of Lincoln, Illinois.

ComEd Transmission

ComEd runs transmission lines at different voltages, including 765kV, 345kV, 138kV, and 69kV. It connects with several other energy companies.

ComEd Metering

ComEd uses meters made by Aclara. The meters have different colors like brown, rust, pink, beige, yellow, and green for various purposes.

Deregulation and divestiture

In the late 1990s, ideas about electricity changed. Instead of one company controlling everything, many thought customers would benefit from choosing their electricity supplier. Illinois passed a law in 1997 allowing customers to pick different suppliers and lowering electricity prices. Commonwealth Edison sold its power plants in 2000 and 2003 to focus on delivering electricity.

The 2007 Rate Case

In 2006, as old price rules ended, Commonwealth Edison wanted to raise electricity rates. This caused big debates. ComEd planned to increase delivery costs by 22% and let customers choose their electricity supplier through a reverse auction. This would make bills go up by about 33%. Many people were upset, and there were talks to keep old prices longer. ComEd said this would hurt them. In the end, the new rates started on January 2, 2007, but customers could choose to pay the increase later with interest.

Corruption scandal

In 2020, ComEd agreed to pay $200 million after an investigation into unfair business deals. Several former leaders were charged with trying to unfairly influence a state leader. In 2023, four former ComEd employees were found guilty of bribery and falsifying records. They were sentenced to prison in 2025, but in 2026, two of them were allowed out of prison and will have new trials. The other two had already finished their sentences.

Smart Grid

In 2016, ComEd spent $2.6 billion to improve the electric system in Illinois. This project, called the Smart Grid, aimed to make the electric lines better and install smart meters in homes and businesses. These smart meters use wireless technology to share information about electricity use, making the system stronger and more modern.

The project began in Chicago in late 2016 and finished in 2019. In 2018, Illinois regulators allowed ComEd to start a 10-year project to create a small electric grid on the South Side of Chicago, connecting to a microgrid at the Illinois Institute of Technology.