Ameren Illinois Company: power outages per year
In 2025 the average Ameren Illinois Company customer was without power for 4.8 hours, more than the Illinois average of 2.4 h; up from 3.7 h in 2024. The utility served 1,251,245 customers in Illinois and ranks #1 of 2 large Illinois utilities by outage hours.
By year
| Year | Hours (with major events) | Hours (without) | Interruptions | Customers |
|---|---|---|---|---|
| 2025 | 4.8 | 2.2 | 1.2 | 1,251,245 |
| 2024 | 3.7 | 2.0 | 1.1 | 1,249,900 |
| 2023 | 9.9 | 1.9 | 1.3 | 1,249,587 |
| 2022 | 2.7 | 1.9 | 1.0 | 1,251,346 |
| 2021 | 3.2 | 2.0 | 1.1 | 1,251,487 |
| 2020 | 3.7 | 1.7 | 1.0 | 1,249,150 |
"With major events" includes storm days that utilities may exclude from their own reliability targets; it is what customers actually live through. The gap between the two columns shows how much of the year's outage time came from big storms.
Backup power for Ameren Illinois Company outages
An average outage here lasted about 4.0 hours in 2025. Size backup for the longest outage you want to ride through, not the average.
Other large utilities in Illinois
FAQ
How many hours a year are Ameren Illinois Company customers without power?
4.8 hours per customer in 2025 including major event days (2.2 h without them), as Ameren Illinois Company reported to the U.S. EIA.
How long does a typical Ameren Illinois Company outage last?
About 4.0 hours on average in 2025 (total outage minutes divided by the number of interruptions). Storms make single events much longer.
Source: U.S. EIA Form 861, Reliability file, 2020–2025. Data snapshot . Utilities ranked nationwide →