Pinnacle West Announces Pricing of a Public Offering of 9,774,436 Shares of Common Stock - Seite 2

Pinnacle West will not initially receive any proceeds from the sale of shares of its common stock by the forward sellers or their affiliates to the underwriters. If Pinnacle West elects physical settlement of the forward sale agreements, it expects to use any net proceeds received for investment in its principal subsidiary Arizona Public Service Company to fund capital expenditures and general corporate purposes.

This press release does not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of these securities, in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. The offering of these securities may be made only by means of a prospectus supplement and accompanying base prospectus relating to this offering.

The public offering is being made pursuant to an effective shelf registration statement that has been filed with the Securities and Exchange Commission (the “SEC”). A preliminary prospectus supplement related to the offering has been filed with the SEC and is available on the SEC’s website. In addition, copies of the preliminary prospectus supplement and accompanying base prospectus relating to the shares of common stock being offered may be obtained by contacting: Barclays Capital Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, telephone: [phone] or by emailing [e-mail]; Citigroup, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, telephone: [phone]; Mizuho Securities USA LLC, ATTN: Equity Capital Markets, 1271 Avenue of the Americas, 3rd Floor, New York, New York 10020, telephone: [phone] or by emailing [e-mail]; Wells Fargo Securities, 90 South 7th Street, 5th Floor, Minneapolis, Minnesota 55402, telephone: [phone] or by emailing [e-mail]; or by accessing the SEC’s website at www.sec.gov.

General Information

Pinnacle West Capital Corp., an energy holding company based in Phoenix, has consolidated assets of nearly $25 billion, about 6,500 megawatts of generating capacity and approximately 6,100 employees in Arizona and New Mexico. Through its principal subsidiary, Arizona Public Service, the company provides retail electricity service to approximately 1.4 million Arizona homes and businesses.