Ameren Corporation powers the quality of life for 2.4 million electric customers and more than 900,000 natural gas customers in a 64,000-square-mile area through its Ameren Missouri and Ameren Illinois rate-regulated utility subsidiaries. Ameren Illinois provides electric distribution and transmission service, as well as natural gas distribution service, while Ameren Missouri provides vertically integrated electric service, with generating capacity of over 10,200 megawatts, and natural gas distribution service. Ameren Transmission Company of Illinois develops regional electric transmission projects.

Xcel Energy, Inc. operates as a holding company, which engages in the generation, purchase, transmission, distribution and sale of electricity and natural gas business through its subsidiaries. It operates through the following segments: Regulated Electric Utility, Regulated Natural Gas Utility and All Others. The Regulated Electric Utility segment generates, transmits and distributes electricity primarily in portions of Minnesota, Wisconsin, Michigan, North Dakota, South Dakota, Colorado, Texas and New Mexico. In addition, this segment includes sales for resale and provides wholesale transmission service to various entities in the United States. It also includes commodity trading operations. The Regulated Natural Gas Utility segment transports, stores, and distributes natural gas primarily in portions of Minnesota, Wisconsin, North Dakota, Michigan and Colorado. The All Others segment engages in steam, appliance repair services, nonutility real estate activities, processing solid waste into refuse-derived fuel and investments in rental housing projects that qualify for low-income housing tax credits. The company was founded in 1909 and is headquartered in Minneapolis, MN.

ConEdison Solutions is an energy services company that provides renewable energy, sustainability services, cost-effective energy efficiency solutions, demand response, and energy performance contracting.

Vectren is an energy holding company. Vectren Utility Holdings serves as the intermediate holding company for three operating utilities. The company provides energy delivery services to residential, commercial, and industrial and other contract customers in Indiana and west central Ohio.

Entergy (NYSE:ETR) together with its subsidiaries, engages in the production and distribution of electricity in the United States. It generates electricity through gas/oil, nuclear, coal, hydro, and solar power sources. The company's Utility segment generates, transmits, distributes, and sells electric power in portions of Arkansas, Mississippi, Texas, and Louisiana, including the City of New Orleans; and distributes natural gas. Its Entergy Wholesale Commodities segment engages in the ownership, operation, and decommissioning of nuclear power plants located in the northern United States; sale of electric power to wholesale customers; provision of services to other nuclear power plant owners; and owning interests in non-nuclear power plants that sell electric power to wholesale customers.

CenterPoint Energy (NYSE: CNP) is a domestic energy delivery company that includes electric transmission & distribution, natural gas distribution, and energy services operations. The company serves more than five million metered customers primarily in Arkansas, Louisiana, Minnesota, Mississippi, Oklahoma, and Texas. The company also owns a 55.4 percent limited partner interest in Enable Midstream Partners, a publicly traded master limited partnership it jointly controls with OGE Energy Corp., which owns, operates, and develops natural gas and crude oil infrastructure assets.