Union Electric 

Operating under the trade name Ameren Missouri, the Union Electric Company is a utility provider in Missouri, responsible for the regulated generation, transmission, and distribution of electricity. Its power generation relies on a diverse range of sources, including coal, nuclear energy, natural gas, hydroelectric facilities, methane gas, and solar installations. In addition to its electricity business, the company is also involved in the regulated distribution of natural gas. It supplies electric services to 1.2 million customers and natural gas to 100,000 customers across a sprawling 24,000 square-mile service area located in central and eastern Missouri. Founded in 1881, the company maintains its principal offices in St. Louis, Missouri, and operates as a subsidiary of Ameren Corporation.