Arizona Public Service Co

What This Utility Data Tells You

Arizona Public Service Co is an investor-owned utility operating in Arizona under EIA identifier 803. It reports service to approximately 1,370,930 customer accounts and generated about $4.34 billion in annual electric revenue, with a service footprint spanning 276 ZIP codes. Investor ownership puts this utility under the regulatory authority of the state public utility commission, which reviews its rate requests and reliability record.

In 2023, the average Arizona Public Service Co customer experienced 98.6 minutes of power interruptions, a measure known as SAIDI, or System Average Interruption Duration Index. That places this utility well below the 120–180 minute national benchmark, signaling strong grid hardening and fast restoration practices. Over the same period, SAIFI (outage events per customer) was 0.88, putting the typical customer at roughly 1 distinct interruption that year. Once major event days (hurricanes, ice storms) are excluded, SAIDI comes down to 82.1 minutes, and the spread against the headline 98.6 indicates how much weather, versus routine infrastructure, drove the outage total.

The EIA dataset includes 4 years of continuous reporting (2020–2023) for Arizona Public Service Co, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. SAIDI climbed from 84.5 to 98.6 minutes over that window, a shift that can point to worsening weather exposure or delayed grid modernization.