EIA highlights Maine electric reliability woes

How long was your power out last year? How many times was your utility electricity service interrupted? Recently released federal statistics show that in 2017, the average Maine electricity customer experienced both the greatest number of interruptions and the longest total duration of power outages of any state in the country.

The U.S. Energy Information Administration tracks electric utility service outages. EIA tracks electric utility service interruptions using two reliability metrics developed by the Institute of Electrical and Electronics Engineers (IEEE): System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI). In general, SAIDI tracks the number of hours an average customer went without electricity service in the year, while SAIFI tracks the number of power outages lasting longer than 5 minutes.

According to the EIA, in 2017 the average U.S. electricity customer experienced 1.4 power outages, losing power for an average of 7.8 hours or 470 minutes. EIA notes that 2017 brought more "major events" like hurricanes and winter storms compared to the previous year. Excluding these major events, EIA reports that the average customer experienced just one power outage in 2017, with an average duration of about 2 hours.

But customers in some states suffered more frequent and longer-lasting interruptions in electricity service, and Maine led the pack in these power outage metrics. According to EIA data, the average Maine customer experienced 3 power outages, with an average annual interruption time of 42 hours.

U.S. Energy Information Administration chart presenting data from Annual Electric Power Industry Report, EIA-861.

For example, one major power outage occurred on October 30, 2017. As a result of a wind storm, Maine's largest utility Central Maine Power Company eventually reported that over 470,000 customers -- more than 60 percent of its customer base -- were without power. Two days after the storm, CMP estimated that over 190,000 homes and businesses remained without service. Some customers remained in the dark for a week.