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Ameren Illinois Co
Ameren Illinois Co is the regulated electric and natural gas utility operating in central and southern Illinois, serving 1.2 million customers.
Ameren Illinois Co
Ameren Illinois Co is a subsidiary of Ameren Corporation (NYSE: AEE), a utility holding company formed in 1997 through the merger of Union Electric Company and CIPSCO Inc. The company's operations are divided into two main segments: electric transmission and distribution, and natural gas distribution. It owns approximately 5,000 miles of transmission lines and 46,000 miles of distribution lines, along with several natural gas storage fields. The company has been investing heavily in grid modernization and renewable energy integration. In 2023, Ameren Illinois filed a multi-year grid investment plan with the Illinois Commerce Commission, proposing $3.1 billion in capital spending through 2027 for grid hardening, technology upgrades, and electric vehicle infrastructure. The plan includes deploying advanced metering infrastructure and automated grid switches. Ameren Illinois employs about 3,200 people across its service territory. The company operates from headquarters in Peoria, Illinois, with major offices in Collinsville and Decatur, and maintains customer service centers in Springfield and Mount Vernon. In May 2024, Ameren announced a partnership with the University of Illinois to research grid modernization and energy equity. What distinguishes Ameren Illinois from its regional peers is its vertically integrated structure within a parent company that also owns a regulated natural gas distribution utility in Missouri. This structure gives it some insulation from market volatility while requiring careful regulatory navigation across multiple state commissions.
General information
Firm type
other
Year founded
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AUM
Undisclosed
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Frequently asked questions
What is Ameren Illinois Co's regulatory structure?
Ameren Illinois Co is subject to regulation by the Illinois Commerce Commission, which sets its rates and approves its capital investment plans. The company operates under a cost-of-service model, meaning profits are derived from allowed returns on invested capital. The ICC also oversees reliability standards and consumer protections.
How does Ameren Illinois Co generate its electricity?
The company owns a mix of generation assets including natural gas-fired and coal-fired plants, though it has been reducing coal capacity. It also purchases power from third-party and independent power producers. As of 2024, about 10% of its supply came from renewable sources like solar and wind, with plans to reach 25% by 2030.
What is the relationship between Ameren Illinois Co and Ameren Corporation?
Ameren Illinois Co is a wholly owned subsidiary of Ameren Corporation (NYSE: AEE), which also owns Union Electric Company (d/b/a Ameren Missouri) and several unregulated businesses. The parent company provides shared services like finance, legal, and IT, while each utility maintains its own regulatory filings and local management.
Is Ameren Illinois Co focused on renewable energy?
While primarily a distribution utility, Ameren Illinois is investing in renewable energy through its transmission network to support customer-owned solar and community solar projects. The company also offers energy efficiency programs and has installed over 500 electric vehicle charging stations in its service territory.
How large is Ameren Illinois Co's service territory?
The utility serves approximately 1.2 million electric and natural gas customers across a 43,000-square-mile area in central and southern Illinois. That territory includes about 600 communities, with major population centers such as Peoria, Champaign-Urbana, Decatur, and Carbondale.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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