County annual report · FIPS 17111
2018 McHenry County, IL Power Outage Report
In 2018, customers in McHenry County, IL went without power for an average of 3.7 hours, a total of 447K customer-hours (Illinois average 2.5 hours). That ranks 32nd worst of 102 Illinois counties and 1314th of 2,798 nationally.
Compared with IL, the US and 2017
Coverage line is EAGLE-I's share of Illinois customers tracked each year.
Biggest outages in McHenry County, 2018
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | September 25, 2018 18:00 | September 27, 2018 23:30 | 2d 5h | 24,431 | 220K |
| 2 | October 20, 2018 17:00 | October 22, 2018 07:30 | 1d 14h | 4,796 | 26K |
| 3 | August 28, 2018 16:00 | August 30, 2018 08:00 | 1d 16h | 4,338 | 28K |
| 4 | February 16, 2018 14:30 | February 17, 2018 03:00 | 12h 30m | 2,520 | 3,186 |
| 5 | June 26, 2018 14:00 | June 28, 2018 00:30 | 1d 10h | 2,114 | 4,056 |
| 6 | November 26, 2018 02:30 | November 29, 2018 04:00 | 3d 1h | 2,059 | 24K |
| 7 | April 14, 2018 05:00 | April 16, 2018 01:00 | 1d 20h | 1,801 | 13K |
| 8 | September 2, 2018 03:00 | September 5, 2018 00:00 | 2d 21h | 1,739 | 16K |
| 9 | September 25, 2018 04:00 | September 25, 2018 06:30 | 2h 30m | 1,585 | 1,753 |
| 10 | July 3, 2018 12:00 | July 4, 2018 10:30 | 22h 30m | 1,282 | 1,804 |
Outage episodes by size in 2018: 131 reached 100+ customers, 16 reached 1,000+ customers, 1 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 McHenry County reported on EIA Form 861 for 2018, 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 |
|---|---|---|---|---|---|
| Commonwealth Edison Co | 2018 | 2.0 hrs | 0.82 | 58 min | 0.70 |
| Rock Energy Cooperative | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 92% of Illinois's customers in 2018; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 120,381 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. McHenry County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), McHenry County, IL annual power outage report, 2018, 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/2018/illinois/mchenry-county