Press release content from Business Wire. The AP news staff was not involved in its creation. Pinnacle West Reports 2021 First-Quarter Earnings May 5, 2021 GMT PHOENIX--(BUSINESS WIRE)--May 5, 2021-- Pinnacle West Capital Corp. (NYSE: PNW) today reported consolidated net income attributable to common shareholders of $35.6 million, or $0.32 per diluted share of common stock, for the quarter ended March 31, 2021. This result compares with $30.0 million, or $0.27 per diluted share, for the same period in 2020. First-quarter 2021 results were positively impacted by weather, higher transmission revenues, and higher pension and other postretirement non-service credits. These factors offset a moderate increase in operations and maintenance expenses, due largely to higher planned plant outages to perform seasonal maintenance ahead of summer demand.