Facts about Ameren Illinois

Ameren Illinois Service Area Map 
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Ameren Illinois is a subsidiary of St. Louis-based Ameren Corporation.

Ameren Corporation keeps its Illinois operations separate from its Missouri operations for legal and regulatory reasons. In 1997, Illinois legislation restructured the utility generation and delivery model to make Illinois utilities regulated delivery-only companies. That means Ameren Illinois delivers your power. You are able to purchase electric power from Retail Electric Suppliers (RESs). Otherwise, if you choose not to purchase your power, Ameren Illinois buys power passing through the supply cost, dollar for dollar, to customers with no mark-up. The power is purchased through the state regulated Illinois Power Authority.

Today, Ameren Illinois is based in Collinsville. We are the pipes, wires and people delivering electricity and natural gas to your home and/or business. You can count on our commitment to provide safe, reliable energy every minute of every day.

Ameren Illinois serves 1.2 million electric and 816,000 natural-gas customers in more than 1,200 communities within a 43,700 square-mile territory.

Our complex delivery system includes about 4,500 miles of transmission lines, 45,400 miles of distribution lines, 18,200 miles of natural gas transmission and distribution mains, and 12 underground natural gas storage fields.

A quick history of Ameren Illinois

  • AmerenCIPS was founded in 1902 and in 2010 served nearly 400,000 electric and 190,000 natural gas customers.
  • AmerenCILCO was founded in 1913 and in 2010 provided electricity and natural gas to more than 210,000 customers.
  • AmerenIP was founded in 1923 and in 2010 provided electric service to about 626,000 electric and 421,000 natural-gas customers.
  • Ameren Corporation was created by the December 1997 merger of CIPSCO Incorporated (parent company of Central Illinois Public Service) and Union Electric Company. In 2003, Ameren grew with the acquisition of CILCORP, Inc., parent of Central Illinois Light Company, and operated as AmerenCILCO, and in 2004, Ameren acquired Illinois Power Company - and operated as AmerenIP - from Dynegy Inc.
  • Ameren Illinois was formed October 1, 2010 consolidating AmerenCIPS, AmerenCILCO and AmerenIP. Today the companies are working as one company and continue to deliver safe and reliable power to you.
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