Xcel Energy Inc., through its subsidiaries, engages in the generation, purchasing, transmission, distribution, and sale of electricity. It operates through Regulated Electric Utility, Regulated Natural Gas Utility, and All Other segments. The company generates electricity through wind, nuclear, hydroelectric, biomass, and solar energy sources, as well as coal, natural gas, oil, wood, and refuse-derived fuels. It also purchases, transports, distributes, and sells natural gas to retail customers, as well as transports customer-owned natural gas. In addition, the company develops and leases natural gas pipelines, and storage and compression facilities; and invests in rental housing projects and nonregulated assets, as well as procures equipment for the construction of renewable generation facilities. It serves residential, commercial, and industrial customers in the portions of Colorado, Michigan, Minnesota, New Mexico, North Dakota, South Dakota, Texas, and Wisconsin. The company was incorporated in 1909 and is headquartered in Minneapolis, Minnesota.

Entergy Corporation, together with its subsidiaries, engages in the production and retail distribution of electricity in the United States. It generates, transmits, distributes, and sells electric power in portions of Arkansas, Louisiana, Mississippi, and Texas, including the City of New Orleans; and distributes natural gas. It also engages in the ownership of interests in non-nuclear power plants that sell electric power to wholesale customers, as well as provides decommissioning services to other nuclear power plant owners. It generates electricity through gas, nuclear, coal, hydro, and solar power sources. The company sells energy to retail power providers, utilities, electric power co-operatives, power trading organizations, and other power generation companies. The company's power plants have approximately 24,000 megawatts of electric generating capacity. It delivers electricity to 3 million utility customers in Arkansas, Louisiana, Mississippi, and Texas. Entergy Corporation was founded in 1913 and is headquartered in New Orleans, Louisiana.

DTE Energy Company engages in the utility operations. The company's Electric segment generates, purchases, distributes, and sells electricity to various residential, commercial, and industrial customers in southeastern Michigan. It generates electricity through coal-fired plants, hydroelectric pumped storage, and nuclear plants, as well as wind and solar assets. This segment owns and operates distribution substations and line transformers. The company's Gas segment purchases, stores, transports, distributes, and sells natural gas to various residential, commercial, and industrial customers throughout Michigan; and sells storage and transportation capacity. Its DTE Vantage segment offers metallurgical and petroleum coke to steel and other industries; and power generation, steam production, chilled water production, and wastewater treatment services, as well as air supplies compressed air to industrial customers. Its Energy Trading segment engages in power, natural gas, and environmental marketing and trading; structured transactions; and the optimization of contracted natural gas pipeline transportation and storage positions. The company was founded in 1849 and is based in Detroit, Michigan.

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.

Consumers Energy Company operates as an electric and gas utility in Michigan. It is involved in the generation, purchase, transmission, distribution, and sale of electricity through coal, wind, gas, renewable energy, oil, and nuclear sources. The company also engages in the purchase, transmission, storage, distribution, and sale of natural gas. It serves residential, commercial, and diversified industrial customers. Consumers Energy Company was formerly known as Consumers Power Company and changed its name to Consumers Energy Company in 1997. The company was founded in 1886 and is based in Jackson, Michigan. Consumers Energy Company operates as a subsidiary of CMS Energy Corporation.

Black Hills Corporation, through its subsidiaries, operates as an electric and natural gas utility company in the United States. The company operates in two segments: Electric Utilities and Gas Utilities. The Electric Utilities segment generates, transmits, and distributes electricity to approximately 222,000 electric utility customers in Colorado, Montana, South Dakota, and Wyoming; and owns and operates 1,394 megawatts of generation capacity and 9,106 miles of electric transmission and distribution lines. The Gas Utilities segment distributes natural gas to approximately 1,116,000 natural gas utility customers in Arkansas, Colorado, Iowa, Kansas, Nebraska, and Wyoming; owns and operates 4,663 miles of intrastate gas transmission pipelines; 42,514 miles of gas distribution mains and service lines; seven natural gas storage sites; and approximately 50,000 horsepower of compression and 516 miles of gathering lines. It also constructs and maintains customer owned gas infrastructure facilities for gas transportation customers; and provides appliance repair services to residential utility customers, as well as electrical system construction services to large industrial customers. In addition, the company produces electric power through wind, natural gas, and coal-fired generating plants; and coal at its coal mine located near Gillette, Wyoming. Black Hills Corporation was incorporated in 1941 and is headquartered in Rapid City, South Dakota.

MGE Energy, Inc., through its subsidiaries, operates as a public utility holding company primarily in the United States. It operates through Regulated Electric Utility Operations; Regulated Gas Utility Operations; Nonregulated Energy Operations; Transmission Investments; and All Other segments. The company generates, purchases, and distributes electricity and natural gas in Wisconsin and Iowa; owns and leases electric generating capacity; and plans, constructs, operates, maintains, and expands transmission facilities to provide transmission power services. It generates electricity from coal-fired, gas-fired, and renewable energy sources. As of December 31, 2023, the company owned and operated 835 miles of overhead electric distribution lines; 1,330 miles of underground electric distribution cables; 49 substations with an installed capacity of 1.2 million kVA; and gas facilities, including 3,066 miles of distribution mains, as well as supplied electric service to approximately 163,000 customers. MGE Energy, Inc. founded in 2001 and is headquartered in Madison, Wisconsin.