Pinnacle West's largest subsidiary is Arizona Public Service Company (APS).

APS, Arizona's largest and longest-serving electricity utility, serves more than one million customers in 11 of the state's 15 counties, with the major exceptions of about one-half of the Phoenix metropolitan area, the Tucson metropolitan area and Mohave County in northwestern Arizona.

Incorporated in 1920 under the laws of the state of Arizona, APS employs nearly 6,200 employees, including employees at jointly-owned generating facilities for which APS serves as the generating facility manager. APS owns 29.1 percent of the Palo Verde Nuclear Generating Station located approximately 50 miles west of Phoenix. Operated by APS, Palo Verde has been the nation's top producer of electricity for the past 14 years. The company also owns and operates seven natural-gas and two coal-powered plants.

Considered by many as the state's largest construction company, APS has built an infrastructure consisting of more than 30,000 miles of transmission and distribution lines and 400 substations.

A leader in renewable technology, APS owns and operates the APS Solar Test and Research Center (STAR), the only facility of its kind in the United States. APS has solar installations across the state. APS owns and operates approximately 5.6 megawatts of photovoltaic solar generation around the state. The company is an active partner in the development and testing of other renewables such as solar trough, biomass, hydrogen and wind technologies.

APS is also a strong community partner. Each year, the company and its employees give back to the community in a variety of ways. In 2005, employees volunteered hundreds of thousands of hours to charitable causes and organizations. From its  programs for supporting children and education; to its commitment to helping small and minority-owned businesses; to its patronage of the arts and culture; to its encouragement of economic development, APS sees itself as an active participant in Arizona's continued well-being.

Each year the company and its employees donate money and time to many charitable causes such as the United Way. In 2005, employees donated more than $2.5 million to charity.

APS is regulated by the Arizona Corporation Commission (ACC). The ACC regulates APS' retail electric rates and its issuance of securities. The ACC must also approve any transfer of APS' property used to provide retail electric service and approve or receive prior notification of certain transactions between Pinnacle West, APS and their respective affiliates.

APS' principal executive offices are located at:
400 North Fifth Street
P.O. Box 53999, Phoenix, Arizona 85072-3999
602-250-1000.

APS Service Territory Maps
Arizona    (PDF)                                                        
Metro-Phoenix  (PDF)