Power outage statistics vary sharply by state and by whether major events are included. The U.S. Energy Information Administration’s Electric Power Annual 2024, Table 11.3, reports 2024 reliability metrics for customers in eight states, including annual outage duration, interruption frequency, and average restoration time.
Table of contents
- How to read these outage statistics
- 2024 state comparison
- Outage duration with major events
- Outage duration without major events
- Interruption frequency
- Average restoration time
How to read these outage statistics
The source uses three standard reliability measures. SAIDI is the System Average Interruption Duration Index, reported here in minutes per year. It describes the average annual interruption duration represented in the metric. SAIFI is the System Average Interruption Frequency Index, reported as interruptions per year. CAIDI is the Customer Average Interruption Duration Index, reported in minutes per interruption.
Each state has a set of figures that includes major events and another set that excludes major events. That distinction matters because a major event can greatly increase annual outage minutes and the average time associated with an interruption. The two sets should therefore be read as different views of the same 2024 reliability record, not as interchangeable measurements.
The table also reports the percentage of customers represented in the reliability metrics. Those reported coverage figures range from 87.0% in Vermont to 100.4% in Florida. The percentages are reproduced as reported in EIA Electric Power Annual 2024 Table 11.3; they are not adjusted here.
2024 state comparison
The comparison below places the major-event and non-major-event values together. All measurements are for 2024, and every value comes from EIA Electric Power Annual 2024 Table 11.3.
| State | Customers reported | SAIDI with major events | SAIDI without major events | SAIFI with major events | SAIFI without major events |
|---|---|---|---|---|---|
| Maine | 100.3% | 1,748.6 min/year | 274 min/year | 3.636 | 2.139 |
| Massachusetts | 92.3% | 102 min/year | 76.1 min/year | 0.843 | 0.743 |
| Vermont | 87.0% | 696.7 min/year | 275 min/year | 2.516 | 1.661 |
| Florida | 100.4% | 1,321.5 min/year | 66.4 min/year | 1.770 | 0.762 |
| South Carolina | 96.5% | 3,136.5 min/year | 117.8 min/year | 2.365 | 1.207 |
| Texas | 98.1% | 1,270.6 min/year | 129.4 min/year | 2.114 | 1.218 |
| Arizona | 96.6% | 87.5 min/year | 72 min/year | 0.988 | 0.898 |
| California | 100.0% | 279.6 min/year | 158.2 min/year | 1.345 | 1.154 |
The table makes the spread visible without combining the states into an unsupported average. With major events included, South Carolina has the highest reported SAIDI at 3,136.5 minutes per year. Arizona has the lowest at 87.5 minutes per year. Without major events, Maine and Vermont are close at 274 and 275 minutes per year, while Florida has the lowest reported SAIDI at 66.4 minutes per year.
Outage duration with major events
SAIDI with major events measures the largest annual duration values in this group. South Carolina’s 2024 figure was 3,136.5 minutes per year. Maine reported 1,748.6 minutes per year, Florida 1,321.5, and Texas 1,270.6. Vermont reported 696.7 minutes per year, while California reported 279.6.
The lower end of the same comparison was Massachusetts at 102 minutes per year and Arizona at 87.5 minutes per year. These figures describe the 2024 values with major events included; they do not forecast future outage duration.
The difference between states is also visible in the associated CAIDI values. South Carolina’s CAIDI with major events was 1,326.3 minutes per interruption. Florida’s was 746.6 minutes, Texas’s was 600.9 minutes, and Maine’s was 480.9 minutes. Vermont reported 276.9 minutes per interruption, California 208 minutes, Massachusetts 120.9 minutes, and Arizona 88.6 minutes.
For interruption frequency with major events, Maine reported 3.636 interruptions per year. Vermont reported 2.516, South Carolina 2.365, Texas 2.114, and Florida 1.77. California reported 1.345 interruptions per year, Arizona 0.988, and Massachusetts 0.843.
These three measures do not rank states identically. South Carolina has the highest major-event SAIDI and CAIDI in the supplied 2024 figures, while Maine has the highest major-event SAIFI. That means duration and frequency provide different information about the outage experience represented by the metrics.
Outage duration without major events
The non-major-event figures provide a separate comparison of routine reliability measurements as reported by EIA. Vermont’s SAIDI without major events was 275 minutes per year, and Maine’s was 274 minutes per year. These were the highest values in this eight-state set.
Texas reported 129.4 minutes per year without major events, followed by South Carolina at 117.8 and California at 158.2. In ascending order among the remaining states, Massachusetts reported 76.1 minutes, Arizona 72, and Florida 66.4 minutes per year.
The associated non-major-event SAIFI values were 2.139 interruptions per year for Maine and 1.661 for Vermont. Texas reported 1.218, South Carolina 1.207, and California 1.154. Arizona reported 0.898 interruptions per year, Massachusetts 0.743, and Florida 0.762.
Non-major-event CAIDI also varies. Maine reported 128.1 minutes per interruption, Vermont 165.5, Texas 106.2, South Carolina 97.6, California 137.1, Massachusetts 102.3, Florida 87.1, and Arizona 80.1. The values show why annual duration and average duration per interruption should be kept separate when comparing outage statistics.
Interruption frequency
SAIFI focuses on how often interruptions occur in the annual reliability metric, rather than how long the interruptions last. With major events included, Maine’s reported 3.636 interruptions per year was the highest figure in this comparison. Vermont’s 2.516 and South Carolina’s 2.365 followed. Texas reported 2.114, Florida 1.77, and California 1.345.
The two lowest major-event frequencies were Arizona at 0.988 interruptions per year and Massachusetts at 0.843. The non-major-event pattern was lower in every state listed: Maine fell to 2.139, Vermont to 1.661, South Carolina to 1.207, Texas to 1.218, Florida to 0.762, California to 1.154, Arizona to 0.898, and Massachusetts to 0.743.
The supplied figures therefore show a consistent directional change between the two reporting treatments: for every listed state, SAIFI with major events is higher than SAIFI without major events. The size of that change differs by state, but no additional combined statistic is needed to see the pattern.
Average restoration time
CAIDI expresses the average duration per interruption in the 2024 reliability metrics. With major events included, the reported values ranged from 88.6 minutes per interruption in Arizona to 1,326.3 minutes per interruption in South Carolina. Florida’s value was 746.6 minutes, Texas’s 600.9, and Maine’s 480.9.
Vermont’s major-event CAIDI was 276.9 minutes per interruption. California reported 208 minutes per interruption, Massachusetts 120.9, and Arizona 88.6. These values provide context for the SAIDI and SAIFI figures: a state may have a comparatively low interruption frequency while still recording a longer average interruption, or it may have more frequent interruptions with a different average duration.
Without major events, Vermont’s CAIDI was 165.5 minutes per interruption and California’s was 137.1. Maine reported 128.1, Texas 106.2, Massachusetts 102.3, South Carolina 97.6, Florida 87.1, and Arizona 80.1.
For readers using these statistics for everyday preparedness, the most useful distinction is the measurement frame. The 2024 EIA table separates ordinary reliability results from results that include major events, and it reports annual duration, annual frequency, and minutes per interruption as different measures. The state values above preserve those distinctions and the reported customer-coverage percentages, so comparisons can be made without treating one metric as a substitute for another.