American Electric Power Company is a public utility holding company. The public utility subsidiaries of the company provide electric service, consisting of generation, transmission and distribution, on an integrated basis to their retail customers. The service areas of the company's public utility subsidiaries cover portions of the states of Arkansas, Indiana, Kentucky, Louisiana, Michigan, Ohio, Oklahoma, Tennessee, Texas, Virginia and West Virginia. Transmission networks are interconnected with distribution facilities in the territories served. The company's service company subsidiary provides accounting, administrative, information systems, engineering, financial, legal, maintenance and other services.

CenterPoint Energy owns interests in Enable Midstream Partners, LP. The company's subsidiaries own and operate electric transmission and distribution, electric generation and natural gas distribution facilities, supply natural gas to commercial and industrial customers and electric and natural gas utilities and provide underground pipeline construction and repair services, energy performance contracting and sustainable infrastructure services. The company's segments include: Houston Electric T&D, which consists of electric transmission and distribution services in the Texas Gulf Coast area; and Energy Services, which consists of non-rate regulated natural gas sales and services operations.

Consolidated Edison is a holding company. Through its subsidiaries, the company is engaged in provision of energy services. The company's subsidiaries include: Consolidated Edison Company of New York, Inc.'s principal business operations are its regulated electric, gas and steam delivery businesses; Orange & Rockland Utilities, Inc.'s principal business operations are its regulated electric and gas delivery businesses; Con Edison Clean Energy Businesses, Inc. develops, owns and operates renewable and energy infrastructure projects and provides energy-related products and services to wholesale and retail customers; and Con Edison Transmission, Inc. invests in electric and gas transmission projects.

Duke Energy is a holding company. Through its subsidiaries, the company operates as an energy company. The company's segments include: Electric Utilities and Infrastructure, which provides retail electric service through the generation, transmission, distribution and sale of electricity to customers within the Southeast and Midwest regions of the United States; Gas Utilities and Infrastructure, which conducts natural gas operations, as well as owns, operates and has investments in various pipeline transmission and natural gas storage facilities; and Commercial Renewables, which acquires, develops, builds, operates and owns wind and solar renewable generation throughout the continental United States.

Edison International is a holding company. Through its subsidiary, Southern California Edison Company (SCE), which is an investor-owned public utility, the company is primarily engaged in the business of supplying and delivering electricity to southern California. The company is also the parent company of Edison Energy Group, Inc., a holding company for Edison Energy, LLC, which is engaged in the business of providing energy services to commercial and industrial customers. SCE supplies electricity to its customers through transmission and distribution networks. Its transmission facilities include sub-transmission facilities and are located primarily in California but also in Nevada and Arizona.

Exelon is a utility services holding company engaged in the generation, delivery and marketing of energy through Exelon Generation Company, LLC and the energy distribution and transmission businesses through Commonwealth Edison Company, PECO Energy Company, Baltimore Gas and Electric Company, Potomac Electric Power Company, Delmarva Power & Light Company and Atlantic City Electric Company. Through its business services subsidiary Exelon Business Services Company, LLC, the company provides its subsidiaries with a variety of support services.

PG&E is a holding company that conducts its business through Pacific Gas and Electric Company (Utility), a public utility engaged in the sale and delivery of electricity and natural gas to customers. The Utility generates electricity and provides electric transmission and distribution services throughout its service territory in northern and central California to residential, commercial, industrial, and agricultural customers. The Utility provides natural gas transportation services to small commercial and residential customers and to industrial, commercial, and natural gas-fired electric generation facilities that are connected to the Utility's gas system in its service territory.

Sempra Energy is an energy-services holding company. The company's segments are: San Diego Gas & Electric Company, which provides electric services and natural gas services in Southern California; Southern California Gas Company, which owns and operates a natural gas distribution, transmission and storage system that supplies natural gas in Southern California and portions of central California; Sempra Texas Utilities, which includes Oncor Electric Delivery Company LLC that provides electricity to consumers; Sempra Mexico, which develops, owns and operates, or holds interests in, energy infrastructure in Mexico; and Sempra LNG, which develops projects for the export of liquefied natural gas.

Xcel Energy is a regulated electric and natural gas delivery company which serves customers in mid-western and western states, including portions of Colorado, Michigan, Minnesota, New Mexico, North Dakota, South Dakota, Texas and Wisconsin. The company's reportable segments include: regulated electric utility, which generates, transmits and distributes electricity in Minnesota, Wisconsin, Michigan, North Dakota, South Dakota, Colorado, Texas and New Mexico; regulated natural gas utility, which transports, stores and distributes natural gas primarily in portions of Minnesota, Wisconsin, North Dakota, Michigan and Colorado; and other, which includes steam revenue and appliance repair services.