American Electric Power Company, Inc., an electric public utility holding company, engages in the generation, transmission, and distribution of electricity for sale to retail and wholesale customers in the United States. It operates through Vertically Integrated Utilities, Transmission and Distribution Utilities, AEP Transmission Holdco, and Generation & Marketing segments. The company generates electricity using coal and lignite, natural gas, renewable, nuclear, hydro, solar, wind, and other energy sources. It also supplies and markets electric power at wholesale to other electric utility companies, rural electric cooperatives, municipalities, and other market participants. American Electric Power Company, Inc. was incorporated in 1906 and is headquartered in Columbus, Ohio.

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.

PG&E Corporation, through its subsidiary, Pacific Gas and Electric Company, engages in the sale and delivery of electricity and natural gas to customers in northern and central California, the United States. It generates electricity using nuclear, hydroelectric, fossil fuel-fired, fuel cell, and photovoltaic sources. The company owns and operates interconnected transmission lines; electric transmission substations, distribution lines, transmission switching substations, and distribution substations; and natural gas transmission, storage, and distribution system consisting of distribution pipelines, backbone and local transmission pipelines, and various storage facilities. It serves residential, commercial, industrial, and agricultural customers, as well as natural gas-fired electric generation facilities. PG&E Corporation was incorporated in 1905 and is based in Oakland, California.

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.

Korea Electric Power Corporation, an integrated electric utility company, engages in the generation, transmission, and distribution of electricity in South Korea and internationally. The company operates through Transmission and Distribution, Nuclear Power Generation, Thermal Power Generation, and Others segments. It generates power from nuclear, coal, oil, liquefied natural gas, internal combustion, combined-cycle, integrated gasification combined cycle, hydro, wind, solar, fuel cell, biogas, and other sources. As of December 31, 2023, the company had a total of 794 generation units, including nuclear, thermal, hydroelectric, and internal combustion units with an installed generation capacity of 83,235 megawatts; transmission system consisted of 35,596 circuit kilometers of lines of 765 kilovolts and others, including high-voltage direct current lines, as well as 900 substations with an installed transformer capacity of 353,166 megavolt-amperes; and distribution system included 143,349 megavolt-amperes of transformer capacity and 10,178,243 units of support with a total line length of 542,567 circuit kilometers. The company provides electricity to residential, commercial, educational, industrial, agricultural, street lighting, and overnight power usage. It also provides engineering and construction services for utility plant and others; utility plant maintenance, electric power information technology, resources development, facility maintenance, electric meter reading, and security services; and engages in nuclear fuel, fly ashes recycling, utility plants construction and operation, and wood pellet utilization businesses. Korea Electric Power Corporation was founded in 1898 and is headquartered in Naju-si, South Korea.

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.

IDACORP, Inc., together with its subsidiaries, engages in the generation, transmission, distribution, purchase, and sale of electric energy in the United States. The company operates 17 hydropower generating plants located in southern Idaho and eastern Oregon; three natural gas-fired plants in southern Idaho; and interests in two coal-fired steam electric generating plants located in Wyoming and Nevada. As of December 31, 2023, it had approximately 4,762 pole-miles of high-voltage transmission lines; 23 step-up transmission substations located at power plants; 21 transmission substations; 11 switching stations; 30 mixed-use transmission and distribution substations; 186 energized distribution substations; and 29,714 pole-miles of distribution lines, and 131 MW of battery storage, as well as provides electric utility services to approximately 633,000 retail customers in southern Idaho and eastern Oregon. The company serves commercial and industrial customers, which involved in food processing, electronics and general manufacturing, agriculture, health care, government, and education. It also invests in housing and other real estate tax credit investments. IDACORP, Inc. was founded in 1915 and is headquartered in Boise, Idaho.

Avista Corporation, together with its subsidiaries, operates as an electric and natural gas utility company. It operates in two segments, Avista Utilities and AEL&P. The Avista Utilities segment provides electric distribution and transmission, and natural gas distribution services in parts of eastern Washington and northern Idaho; and natural gas distribution services in parts of northeastern and southwestern Oregon, as well as generates electricity in Washington, Idaho, Oregon, and Montana. This segment also engages in the supply of electricity to customers in Montana; and wholesale purchase and sale of electricity and natural gas. The AEL&P segment offers electric services in Juneau, Alaska. The company generates electricity through hydroelectric, thermal, wind, and solar generation facilities. As of December 31, 2023, it supplied retail electric services to approximately 416,000 customers; and retail natural gas services to approximately 381,000 customers. The company also operates five hydroelectric generation facilities with capacity of 102.7 MW; and four diesel generating facilities with a capacity of 107.5 MW. It also engages in venture fund investments, real estate investments, and other investments. Avista Corporation was incorporated in 1889 and is headquartered in Spokane, Washington.