County annual report · FIPS 17131
2021 Mercer County, IL Power Outage Report
In 2021, customers in Mercer County, IL went without power for an average of 5.8 hours, a total of 52K customer-hours (Illinois average 2.3 hours). That ranks 15th worst of 102 Illinois counties and 1183rd of 2,974 nationally.
Compared with IL, the US and 2020
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in Mercer County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | January 1, 2021 15:15 | January 1, 2021 23:30 | 8h 15m | 5,250 | 3,682 |
| 2 | January 5, 2021 16:00 | January 6, 2021 13:15 | 21h 15m | 5,013 | 6,213 |
| 3 | December 16, 2021 01:00 | December 17, 2021 03:00 | 1d 2h | 1,634 | 2,752 |
| 4 | October 22, 2021 03:15 | October 22, 2021 08:30 | 5h 15m | 1,600 | 6,983 |
| 5 | March 18, 2021 09:30 | March 19, 2021 11:15 | 1d 1h | 1,282 | 2,509 |
| 6 | June 19, 2021 04:15 | June 21, 2021 07:45 | 2d 3h | 938 | 4,995 |
| 7 | November 11, 2021 12:15 | November 11, 2021 15:30 | 3h 15m | 919 | 2,132 |
| 8 | August 20, 2021 00:15 | August 20, 2021 01:15 | 1h | 893 | 893 |
| 9 | August 11, 2021 00:15 | August 12, 2021 09:45 | 1d 9h | 783 | 4,722 |
| 10 | December 11, 2021 08:15 | December 11, 2021 17:15 | 9h | 580 | 2,238 |
Outage episodes by size in 2021: 24 reached 100+ customers, 5 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Mercer County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| Ameren Illinois Company | 2021 | 3.2 hrs | 1.11 | 2.0 hrs | 0.88 |
| MidAmerican Energy Co | 2021 | 1.9 hrs | 1.04 | 75 min | 0.74 |
| Ameren | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 98% of Illinois's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 8,972 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Mercer County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Mercer County, IL annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/illinois/mercer-county