How Reliable Is Your Arizona Electric Utility?

ARIZONA — Extreme weather made 2020 a bad year for keeping the lights on in the U.S., and climate change is expected to make reliability worse in the future.

The average U.S. electricity customer experienced eight hours of power interruption in 2020, which was the most time since at least 2013, according to the U.S. Energy Information Administration. Customers in Arizona averaged 1.2 hours without power (See how individual utilities performed below.)

The states hit hardest by power outages fluctuated year-to-year depending on storms and other extreme events. California had a rough year in 2019 because of wildfires, and Texas will likely top the charts for 2021 because of a historic ice storm in February that knocked out power to millions.

Alabama, Iowa, Connecticut, Oklahoma and Louisiana customers had the most time without power in 2020.

Louisiana experienced the most active storm season in the state’s history, including Hurricane Rita. Customers in the state averaged 60 hours without power. Alabama was also affected by several hurricanes. Some Connecticut electric customers went without power for more than a week after Tropical Storm Isaias caused widespread tree damage. State regulators fined utility companies for poor performance.

Iowa was hit by a powerful derecho, and Oklahoma experienced an extreme ice storm.

Climate change was expected to have far-reaching consequences for electric reliability, according to a study done by the U.S. Government Accountability Office. More frequent heat waves and wildfires and stronger rainstorms and intense hurricanes will greatly challenge the electric grid in coming years.

Extreme weather associated with climate change will likely mean higher electric costs as utilities strive to make the electric grid more resilient and capable of meeting high demand during intense heat or cold.

The EIA collected outage data from electric utilities annually and asked for information with and without major outages. The two major metrics were the following:

• How often the average customer experienced a non-momentary power outage during a year, referred to as the system average interruption frequency index.
• How many minutes the average customer went without power annually, referred to as the system average interruption duration index.

Most electric utilities used standards developed by the Institute of Electrical and Electronics Engineers to make their calculations. The IEEE used a complex formula based on a utility’s historical data to determine whether an outage qualified as a major event. It also only counted outages longer than five minutes.

Here's how utilities in Arizona did during 2020, according to data from the EIA. Can't find the utility provider you're looking for? Try searching for it here.

Electrical Dist No2 Pinal County

• Owner type: Political Subdivision
• Number of customers: 5,371
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 19.96
• Average customer hours without power, excluding major events: 12.74
• Number of outages for average customer, including major events: N/A
• Number of outages for average customer, excluding major events: N/A

Mohave Electric Cooperative, I

• Owner type: Cooperative
• Number of customers: 42,116
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 1.99
• Average customer hours without power, excluding major events: 1.52
• Number of outages for average customer, including major events: N/A
• Number of outages for average customer, excluding major events: N/A

Sulphur Springs Valley E C Inc

• Owner type: Cooperative
• Number of customers: 52,636
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 2.59
• Average customer hours without power, excluding major events: 2.32
• Number of outages for average customer, including major events: 1.21
• Number of outages for average customer, excluding major events: 1.07

Arizona Public Service Co

• Owner type: Investor Owned
• Number of customers: 1,285,518
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 1.41
• Average customer hours without power, excluding major events: 1.31
• Number of outages for average customer, including major events: 0.86
• Number of outages for average customer, excluding major events: 0.85

UNS Electric, Inc

• Owner type: Investor Owned
• Number of customers: 101,032
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 0.72
• Average customer hours without power, excluding major events: 0.00
• Number of outages for average customer, including major events: 0.81
• Number of outages for average customer, excluding major events: 0.00

Salt River Project

• Owner type: Political Subdivision
• Number of customers: 1,072,666
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 0.79
• Average customer hours without power, excluding major events: 0.68
• Number of outages for average customer, including major events: 0.75
• Number of outages for average customer, excluding major events: 0.69

Tucson Electric Power Co

• Owner type: Investor Owned
• Number of customers: 440,110
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 1.00
• Average customer hours without power, excluding major events: N/A
• Number of outages for average customer, including major events: 0.71
• Number of outages for average customer, excluding major events: N/A

Trico Electric Cooperative Inc

• Owner type: Cooperative
• Number of customers: 50,079
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 2.08
• Average customer hours without power, excluding major events: 0.81
• Number of outages for average customer, including major events: 0.65
• Number of outages for average customer, excluding major events: 0.48

Electrical Dist No3 Pinal County

• Owner type: Political Subdivision
• Number of customers: 27,500
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 0.85
• Average customer hours without power, excluding major events: 0.85
• Number of outages for average customer, including major events: 0.64
• Number of outages for average customer, excluding major events: 0.64

City of Mesa - (AZ)

• Owner type: Municipal
• Number of customers: 16,971
• IEEE standard followed: Yes
• Average customer hours without power, including major events: 1.20
• Average customer hours without power, excluding major events: 0.62
• Number of outages for average customer, including major events: 0.63
• Number of outages for average customer, excluding major events: 0.25

Editor’s note: This list was automatically generated using data compiled by the U.S. Energy Information Administration. Please report any errors or other feedback to content@patch.com.