Pinnacle West Capital Corporation is an American utility holding company that owns Arizona Public Service (APS).

The Childs-Irving Hydroelectric Facilities, began producing power in 1909 to support local mining operations.

1985 earnings reached a new record high at almost US$290 million, and by the end of the year the stock price had doubled from its 1984 low.

[6] In 1987, AZP Group changed its name to Pinnacle West Capital Corporation, and began trading under the new ticker symbol PNW.

However, the stock price reached an all-time peak that year, which was not surpassed for the next decade, as the company ran into troubles through the early 1990s.

However, the thrift was seized by federal regulators in January 1990, due in part to the deterioration in prices in the Arizona real estate market.

[6] The company faced a variety of regulatory disputes due to its operation of Palo Verde and treatment of whistleblowers.

Also in 1995, the utility subsidiary Arizona Public Services issued 30-year Monthly Income Debt Securities paying 10%.

The outage was the result of 23 events that occurred on five power grids in a span of 11 minutes including the APS North Gila Substation.

[17] The outage occurred days before the tenth anniversary of the September 11 attacks, and hours before the United States Department of Homeland Security warned of a potential terrorist attack leading up to the anniversary, but the Federal Bureau of Investigation and SDG&E early in their investigations ruled out terrorism.

[18] On July 7, 2014, APS agreed to a $3.25 million settlement with NERC and FERC related to the September 2011 blackout.

[19] On September 7, 2018, APS cut off the power to 72-year-old retiree Stephanie Pullman, due to a $51 overdue electric bill.

Her death sparked statewide media coverage and street protests over APS's disconnect policy.

[22] Pinnacle West operates and partially owns the Palo Verde Nuclear Generating Station.

Pinnacle West has been in lawsuits with the Department of Energy over the Yucca Mountain nuclear waste repository since 2003.

[22] Pinnacle West owns and operates six natural gas or oil based energy generators.

Red Rock solar plant produces 44MW which are sold for energy credits to institutional buyers.