# Ameren **Source:** https://geo.sig.ai/brands/ameren **Vertical:** Energy & Utilities **Subcategory:** Enterprise **Tier:** Leader **Website:** ameren.com **Last Updated:** 2026-04-14 ## Summary St. Louis MO regulated utility (NYSE: AEE) ~$8.2B revenue; 2.4M electric + 900K gas customers in MO/IL, 250MW solar project near Callaway Nuclear (2028), formula rate in Illinois competing with Evergy. ## Company Overview Ameren Corporation is a St. Louis, Missouri-based regulated electric and natural gas utility holding company — publicly traded on the New York Stock Exchange (NYSE: AEE) as an S&P 500 Utilities component — serving approximately 2.4 million electric customers and 900,000 natural gas customers in Missouri and Illinois through two primary regulated subsidiaries: AmerenMissouri (electric and gas in Missouri, including the Callaway Nuclear Power Station — Missouri's only commercial nuclear plant) and AmerenIllinois (electric and gas distribution across central and southern Illinois), through approximately 9,000 employees. In fiscal year 2024, Ameren reported revenue of approximately $8.2 billion, with continued capital investment in transmission upgrades, distribution modernization, and renewable energy additions. Ameren Missouri's clean energy transition includes the announced Reform Renewable Energy Center — a 250-megawatt solar facility near the Callaway Nuclear site, with construction beginning in 2026 and expected to power 44,000 homes by 2028, creating 300 construction jobs. CEO Martin Lyons, who succeeded Warner Baxter in 2022, has maintained Ameren's steady capital investment trajectory targeting 6-8% annual EPS growth through infrastructure modernization and renewable energy additions in both states. The company's transmission infrastructure — spanning MISO (Midcontinent Independent System Operator) in Missouri and PJM Interconnection in Illinois — positions Ameren to benefit from grid investment programs enabling renewable energy integration across the Midwest. Ameren's regulated utility model earns its allowed return on equity on an expanding rate base driven by two complementary investment programs: AmerenMissouri's clean energy transition (replacing retiring coal capacity with solar, wind, and battery storage while upgrading transmission for renewable integration) and AmerenIllinois's formula rate mechanism (Illinois law automatically adjusts rates annually to reflect actual capital investment, eliminating the regulatory lag that makes multi-year rate cases a drag on utility earnings). The AmerenIllinois formula rate creates a particularly efficient capital recovery mechanism — utilities in most states file rate cases every 3-5 years and must wait for commission approval before recovering capital costs, while AmerenIllinois's formula rate adjusts annually with a regulatory formula that accounts for actual capital additions, depreciation, and allowed return, enabling faster and more predictable earnings per dollar invested. The Callaway Nuclear Power Station (1,200 MW capacity) provides low-carbon baseload generation that supports reliability through Missouri's peak summer and winter demand periods. In 2025, Ameren competes in regulated electric and gas utility service in Missouri and Illinois against Evergy (NYSE: EVRG, Kansas and Missouri electric, $2.9B revenue, border service overlap in Missouri), Spire Inc. (NYSE: SR, Missouri natural gas distribution), and Ameren's own transmission investments competing for MISO transmission project awards. Ameren's Missouri service territory does not face direct electric utility competition (regulated monopoly territory), but competes for large industrial customer attraction with utilities in neighboring states — data center developers, manufacturing companies, and distribution centers choosing Missouri vs. Kansas, Iowa, or Indiana locations compare utility rate competitiveness, reliability, and renewable energy availability. The 2025 strategy focuses on executing the AmerenMissouri clean energy plan (solar additions replacing coal retirements), deploying AmerenIllinois distribution capital under the formula rate framework, and advancing transmission projects within MISO to support the broader Midwest renewable energy buildout. ## Frequently Asked Questions ### What is Ameren Corporation? Ameren Corporation is a Fortune 500 energy holding company headquartered in St. Louis, Missouri, that provides electric and natural gas services to approximately 2.5 million electric customers and more than 900,000 natural gas customers across 64,000 square miles in Missouri and Illinois through its subsidiaries Ameren Missouri and Ameren Illinois. ### When was Ameren founded? Ameren Corporation was founded on December 31, 1997, through a $1.3 billion merger of Union Electric Company and Central Illinois Public Service Company. However, the company's heritage extends back to 1902 when its predecessor companies first began operations. ### Where is Ameren based and what areas does it serve? Ameren is headquartered in St. Louis, Missouri. The company serves customers across Missouri and Illinois, with Ameren Missouri being the largest electric power provider in Missouri and Ameren Illinois serving 1.2 million electric customers and 816,000 natural gas customers in central and southern Illinois. ### What are Ameren's main products and services? Ameren provides electric generation, transmission, and distribution services, as well as natural gas distribution. The company operates approximately 10,000 megawatts of generating capacity including nuclear, fossil fuel, and renewable energy sources, along with over 8,000 miles of transmission infrastructure. ### How many employees does Ameren have? Ameren employs more than 9,000 professionals across its operations in Missouri and Illinois who work to power the quality of life for millions of customers throughout the region. ### What is Ameren's revenue? Ameren reported revenue of $7.32 billion in 2024, with growth of 1.54% year-over-year. In the last twelve months, revenue reached $8.64 billion, up 23.25% year-over-year. ### What makes Ameren different from other utility companies? Ameren distinguishes itself through its commitment to clean energy transition with a goal of net-zero carbon emissions by 2045, its operation of the Callaway Nuclear Generating Station, and its leadership in renewable energy investments including the largest-ever solar investment approved in 2024. ### Who are Ameren's main competitors? Ameren competes with other major Midwest utilities including Exelon, Duke Energy, Evergy, and other regional electric and gas providers serving Missouri and Illinois markets. ### What is Ameren's clean energy strategy? Ameren has committed to achieving net-zero carbon emissions by 2045. The company is investing heavily in renewable energy, with approximately 400 megawatts of solar capacity approved in 2024 and additional projects including the 250-megawatt Reform Renewable Energy Center planned for 2028. ### How can I contact Ameren? Customers can contact Ameren through www.ameren.com for online services, or reach Ameren Missouri and Ameren Illinois through their respective customer service numbers. The corporate headquarters is located at One Ameren Plaza in St. Louis, Missouri. ### Is Ameren hiring? Yes, Ameren regularly hires for positions across operations, engineering, customer service, and corporate functions. The company has been recognized as a Great Place to Work® and ranks #10 on the Best Utilities Companies to Work For in America list. ### What are Ameren's recent achievements and future plans? Recent achievements include securing approval for the largest-ever solar investment of 400 megawatts, winning $1.3 billion in transmission infrastructure projects from MISO, and completing multiple solar facilities. Future plans include continued renewable energy expansion, grid modernization investments, and achieving net-zero emissions by 2045. ## Tags b2b, b2c, energy, infrastructure, public --- *Data from geo.sig.ai Brand Intelligence Database. Updated 2026-04-14.*