PHOENIX - 3/18/08

Arizona Public Service Co. (APS) is encouraging its customers to go paperless – to just drop that old habit of receiving monthly bills in the mail and receive an online version instead. For each customer who does so from March 1 to June 1, APS will donate $1 to a non-profit organization that conducts research to improve the health of trees in urban environments.

APS is teaming up with the Tree Research and Education Endowment Fund (TREE Fund) for this Go Paperless campaign. It’s quick and easy to sign up for paperless bills. A promotional hyperlink on the aps.com home page sends customers to the “Go Paperless” option. The link allows customers who have not yet registered for an account on aps.com to register and “Go Paperless” at the same time.

“This online option, besides being an environmentally friendly way to pay bills, is also convenient for our customers,” said Kelley Ryan, account executive, APS Customer Information and Programs Department.

The program allows customers to:

· Receive e-mail notifications when their bill is ready to be viewed · Access their statements online and print if needed for record keeping purposes · Download all account and usage history · Reduce the possibility of mail fraud and identity theft

A thank you e-mail is sent to the customer, and at the end of the campaign, customers who sign up will get another e-mail stating how many have joined them in the effort. In the first week alone, almost 1,000 customers switched to paperless billing.

APS uses 455,000 pounds of paper in just one year for printing bills for its 1.1 million customers. If all of these customers join the effort, more then 5,000 trees could potentially be saved a year. It would also eliminate 489 pounds of toxic air pollutants, 517,000 pounds of solid waste and 4 million gallons of wastewater annually.

“This is a great way for our customers to help the environment,” said Mike Neal, manager, APS Forestry and Special Programs, also on the board of the TREE Fund. “And APS gets the opportunity to donate to an important research organization dedicated to the health and survivability of our urban forest.”

The TREE Fund is a non-profit organization committed to helping people, trees and the environment and is dedicated to funding projects to advance the knowledge of arboriculture.

APS, Arizona's largest and longest-serving electric utility, serves about 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 Corporation (NYSE: PNW).