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.

Public Service Enterprise Group Incorporated, through its subsidiaries, operates in electric and gas utility business in the United States. It operates through PSE&G and PSEG Power segments. The PSE&G segment transmits electricity; distributes electricity and natural gas to residential, commercial, and industrial customers; and appliance services and repairs to customers through its service territory, as well as invests in solar generation projects, and energy efficiency and related programs. The PSEG Power segment engages in nuclear generation businesses; and supplies power and natural gas to nuclear power plants and gas storage facilities activities. As of December 31, 2023, it had electric transmission and distribution system of 25,000 circuit miles and 866,600 poles; 56 switching stations with an installed capacity of 39,953 megavolt-amperes (MVA), and 235 substations with an installed capacity of 10,382 MVA; 109 MVA aggregate installed capacity for substations; four electric distribution headquarters and five electric sub-headquarters; 18,000 miles of gas mains, 12 gas distribution headquarters, two sub-headquarters, and one meter shop, as well as 56 natural gas metering and regulating stations; and 158 MegaWatts defined conditions of installed PV solar capacity. Public Service Enterprise Group Incorporated was founded in 1903 and is based in Newark, New Jersey.

WEC Energy Group, Inc., through its subsidiaries, provides regulated natural gas and electricity, and renewable and nonregulated renewable energy services in the United States. It operates through Wisconsin, Illinois, Other States, Electric Transmission, and Non-Utility Energy Infrastructure segments. The company generates and distributes electricity from coal, natural gas, oil, and nuclear, as well as renewable energy resources, including wind, solar, hydroelectric, and biomass; and distributes and transports natural gas. It also owns, maintains, monitors, and operates electric transmission systems; and generates, distributes, and sells steam. As of December 31, 2023, the company operated approximately 35,500 miles of overhead distribution lines and 36,500 miles of underground distribution cables, as well as 430 electric distribution substations and 523,700 line transformers; approximately 46,400 miles of natural gas distribution mains; 1,700 miles of natural gas transmission mains; 2.4 million natural gas lateral services; 490 natural gas distribution and transmission gate stations; and 69.3 billion cubic feet of working gas capacities in underground natural gas storage fields. The company was formerly known as Wisconsin Energy Corporation and changed its name to WEC Energy Group, Inc. in June 2015. WEC Energy Group, Inc. was founded in 1896 and is headquartered in Milwaukee, Wisconsin.

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.

FirstEnergy Corp., through its subsidiaries, generates, transmits, and distributes electricity in the United States. It operates through Regulated Distribution and Regulated Transmission segments. The company owns and operates coal-fired, nuclear, hydroelectric, wind, and solar power generating facilities. It operates 24,080 circuit miles of overhead and underground transmission lines; and electric distribution systems, including 274,518 miles of overhead pole line and underground conduit carrying primary, secondary, and street lighting circuits. The company serves approximately 6 million customers in Ohio, Pennsylvania, West Virginia, Maryland, New Jersey, and New York. FirstEnergy Corp. was incorporated in 1996 and is headquartered in Akron, Ohio.

Alliant Energy Corporation operates as a utility holding company that provides regulated electricity and natural gas services in the United States. It operates in three segments: Utility Electric Operations, Utility Gas Operations, and Utility Other. The company, through its subsidiary, Interstate Power and Light Company (IPL), primarily generates and distributes electricity, and distributes and transports natural gas to retail customers in Iowa; sells electricity to wholesale customers in Minnesota, Illinois, and Iowa; and generates and distributes steam in Cedar Rapids, Iowa. Alliant Energy Corporation, through its other subsidiary, Wisconsin Power and Light Company (WPL), generates and distributes electricity, and distributes and transports natural gas to retail customers in Wisconsin; and sells electricity to wholesale customers in Wisconsin. It serves retail customers in the farming, agriculture, industrial manufacturing, chemical, packaging, and food industries, as well as wholesale customers comprising municipalities and rural electric cooperatives. In addition, the company owns and operates a short-line rail freight service in Iowa; a Mississippi River barge, rail, and truck freight terminal in Illinois; freight brokerage services; wind turbine blade recycling services; and a rail-served warehouse in Iowa. Further, it holds interests in a natural gas-fired electric generating unit near Sheboygan Falls, Wisconsin; and a wind farm located in Oklahoma. The company was formerly known as Interstate Energy Corp. and changed its name to Alliant Energy Corporation in May 1999. Alliant Energy Corporation was incorporated in 1981 and is headquartered in Madison, Wisconsin.

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.