According to industry data, Unit 3 produced more electricity than any other reactor in the U.S. in 2011 and was the second most productive in the world. Despite a scheduled refueling outage in the spring of 2011, Unit 2 was the third most productive reactor in the U.S. and ranked 10th in the world. Unit 1, which had a scheduled refueling outage in the fall of 2011, ranked 14th in the U.S. and 30th in the world. Palo Verde?s three reactors are part of 104 operating units in the U.S. and 435 in the world.

?Our investment in equipment upgrades and our employees? efforts to continually improve safety and overall plant performance has resulted in many successes,? said Randy Edington, Executive Vice President and Chief Nuclear Officer for Arizona Public Service Co., the operator and largest owner of Palo Verde. ?We are proud of our accomplishments in enhancing plant operation and will continue to strive to improve our record. We will stay on our course to achieve our mission to ?SAFELY and efficiently generate electricity for the long term.? ?

From 2002 to 2010, Palo Verde installed new steam generators, high-efficiency turbine rotors, new reactor vessel heads and rapid refueling machines in all three units. These large investments resulted in increased output by about 200 megawatts and reduced down time for refueling and maintenance.

Other 2011 accomplishments include:

Palo Verde is the largest nuclear power plant in the nation. Its three units can generate more than 4 million kilowatts of safe, clean, reliable, low-cost electricity every hour ? enough to serve about 4 million people.

Palo Verde is operated by APS and jointly owned by APS, Salt River Project, Southern California Edison Co., El Paso Electric Co., Public Service Co. of New Mexico, Southern California Public Power Authority and the Los Angeles Department of Water & Power.

APS, Arizona?s largest and longest-serving electricity utility, serves more than 1.1 million customers in 11 of the state?s 15 counties. With headquarters in Phoenix, APS is the principal subsidiary of Pinnacle West Capital Corp. (NYSE: PNW).