The Southern Company, through its subsidiaries, engages in the generation, transmission, and distribution of electricity. The company also develops, constructs, acquires, owns, and manages power generation assets, including renewable energy projects and sells electricity in the wholesale market; and distributes natural gas in Illinois, Georgia, Virginia, and Tennessee, as well as provides gas marketing services, gas distribution operations, and gas pipeline investments operations. In addition, it owns and operates nuclear, coal, hydro, cogeneration, solar, wind, battery storage, and fuel cell facilities. Further, the constructs, operates, and maintains approximately 77,900 miles of natural gas pipelines and 14 storage facilities with total capacity of 157 Bcf to provide natural gas to residential, commercial, and industrial customers. The company serves approximately 8.9 million electric and gas utility customers. Further, it develops distributed energy and resilience solutions; deploys microgrids for commercial, industrial, governmental, and utility customers; and offers digital wireless communications and fiber optics services. The Southern Company was incorporated in 1945 and is headquartered in Atlanta, Georgia.

Ameren Corporation, together with its subsidiaries, operates as a public utility holding company in the United States. The company operates through four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. It engages in the rate-regulated electric generation, transmission, and distribution activities; and rate-regulated natural gas distribution business. In addition, the company generates electricity through coal, nuclear, and natural gas, as well as renewable sources, such as hydroelectric, wind, methane gas, and solar. It serves residential, commercial, and industrial customers. The company was founded in 1881 and is headquartered in Saint Louis, Missouri.

CenterPoint Energy, Inc. operates as a public utility holding company in the United States. The company operates through two segments, Electric and Natural Gas. The Electric segment includes electric transmission and distribution services to electric customers and electric generation assets, as well as optimizes assets in the wholesale power market. The Natural Gas segment engages in the intrastate natural gas sales, and natural gas transportation and distribution for residential, commercial, industrial and institutional customers in Indiana, Louisiana, Minnesota, Mississippi, Ohio, and Texas; permanent pipeline connections through interconnects with various interstate and intrastate pipeline companies; and provides maintenance and repair services of home appliances to customers in Minnesota and home repair protection plans to natural gas customers in Indiana, Mississippi, Ohio, and Texas through a third party. It serves approximately 2,534,730 metered customers; owned 348 substations with transformer capacity of 79,719 megavolt amperes; and owned and operated 217 miles of intrastate pipeline in Louisiana and Texas. The company was founded in 1866 and is headquartered in Houston, Texas.

NRG Energy, Inc., together with its subsidiaries, operates as an energy and home services company in the United States and Canada. It operates through Texas; East; West/Services/Other; Vivint Smart Home; and Corporate Activities segments. The company produces and sells electricity generated using coal, oil, solar, and battery storage; natural gas; and a cloud-based home platform, including hardware, software, sales, installation, customer service, technical support, and professional monitoring solutions. It offers retail electricity and energy management, line and surge protection products, HVAC installation, repair and maintenance, home protection products, carbon offsets, back-up power stations, portable power, portable solar, and portable lighting; retail services comprising demand response, commodity sales, energy efficiency, and energy management solutions; and system power, distributed generation, renewable and low-carbon products, carbon management and specialty services, backup generation, storage and distributed solar, and energy advisory services. In addition, the company trades in power, natural gas, and related commodities; environmental products; weather products; and financial products, including forwards, futures, options, and swaps. It offers its products and services under the NRG, Reliant, Direct Energy, Green Mountain Energy, and Vivint. It serves residential, commercial, government, industrial, and wholesale customers. NRG Energy, Inc. was founded in 1989 and is headquartered in Houston, Texas.

Evergy, Inc., together with its subsidiaries, engages in the generation, transmission, distribution, and sale of electricity in the United States. The company generates electricity through coal, landfill gas, uranium, and natural gas and oil sources, as well as solar, wind, other renewable sources. It serves residences, commercial firms, industrials, municipalities, and other electric utilities. The company was incorporated in 2017 and is headquartered in Kansas City, Missouri.

Talen Energy Corporation, an independent power producer and infrastructure company, produces and sells electricity, capacity, and ancillary services into wholesale power markets in the United States. The company operates nuclear, fossil, solar, and coal power plants. It is also developing battery storage projects. The company owns and operates approximately 10.7 GW of power infrastructure. Talen Energy Corporation is headquartered in Houston, Texas.

OGE Energy Corp., together with its subsidiaries, operates as an energy services provider in the United States. The company generates, transmits, distributes, and sells electric energy. In addition, it provides retail electric service to approximately 896,000 customers, which covers a service area of approximately 30,000 square miles in Oklahoma and western Arkansas; and owns and operates coal-fired, natural gas-fired, wind-powered, and solar-powered generating assets. OGE Energy Corp. was founded in 1902 and is headquartered in Oklahoma City, Oklahoma.

Entergy Texas, Inc. generates, transmits, and distributes electric power through coal to residential, commercial, industrial, and government sectors in Texas. The company was founded in 1998 and is headquartered in The Woodlands, Texas. Entergy Texas, Inc. operates as a subsidiary of Entergy Corporation.