APS Prepared to Serve Customers this Summer

March 19, 2008

Phoenix, AZ  -   APS is prepared to provide its more than 1 million retail customers with a reliable supply of safe electricity through the year's hottest months, company officials told the Arizona Corporation Commission (ACC) today at its summer assessment briefing.

This message was part of APS' annual report to the ACC of its plans for meeting the energy needs of its customers when demand is at its peak. The presentation included forecasted summer peak, an inventory of the available resources to serve that peak, a summary APS' implemented and planned system improvements, and the company's preparedness to respond to wildfires and other emergencies.

"We believe we're in excellent position to meet our customers' energy needs when demand is at its highest," said Daniel Froetscher, APS General Manager of Energy Delivery. "In 2007 alone, we constructed or rebuilt almost 100 miles of transmission lines and completed a number of substation upgrades that will help ensure our customers remain comfortable when summer temperatures are the hottest."

This summer, APS has forecasted a peak of 7,202 megawatts (MW). Between its existing generation, and long-term and short-term contracts, APS has 8,485 MW of resources available to help meet summer peak. (The summer peak - the 15-minute period when APS customers require the most energy - typically occurs in July or August between 5 and 6 p.m.)

Meanwhile, in Yuma, the other metropolitan load area served by APS, the company has forecasted a summer peak of 426 MW with total resources of 565 MW available.

While APS has continuously managed its system to meet peak demand, these efforts also have helped improve the company's system reliability. In 2007, for example, the company recorded its all-time best year for fewest outages per customer. According to the company's interruption frequency index metrics, APS customers experienced an average of 0.98 outages, down from 1.00 in 2006 and 1.66 a decade ago.

In addition to building and maintaining infrastructure, planning to meet the needs of a service territory comprised of more than 34,000 square miles means being prepared for any contingency. Wildfires, summer storms and unforeseen circumstances require coordination among federal, state, county and local authorities, in addition to other electric utilities. APS' system is designed to withstand unexpected loss of certain facilities without impacting customers.

Salt River Project and Tucson Electric Power also made presentations to the ACC.

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

Damon Gross
(602) 250-2269