County annual report · FIPS 47187
2020 Williamson County, TN Power Outage Report
In 2020, customers in Williamson County, TN went without power for an average of 2.0 hours, a total of 253K customer-hours (Tennessee average 6.5 hours). That ranks 55th worst of 84 Tennessee counties and 2238th of 3,019 nationally.
Compared with TN, the US and 2019
Coverage line is EAGLE-I's share of Tennessee customers tracked each year.
Biggest outages in Williamson County, 2020
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | May 3, 2020 19:45 | May 9, 2020 10:15 | 5d 14h | 12,540 | 151K |
| 2 | November 10, 2020 05:00 | November 10, 2020 06:00 | 1h | 5,290 | 4,378 |
| 3 | April 6, 2020 11:45 | April 6, 2020 12:30 | 45m | 4,747 | 2,374 |
| 4 | July 17, 2020 17:45 | July 21, 2020 02:00 | 3d 8h | 2,947 | 6,645 |
| 5 | January 10, 2020 03:45 | January 10, 2020 23:00 | 19h 15m | 2,668 | 5,271 |
| 6 | May 25, 2020 18:15 | May 26, 2020 09:30 | 15h 15m | 2,387 | 3,705 |
| 7 | June 1, 2020 13:00 | June 2, 2020 00:30 | 11h 30m | 2,378 | 621 |
| 8 | October 2, 2020 06:30 | October 2, 2020 08:15 | 1h 45m | 2,352 | 3,528 |
| 9 | August 18, 2020 09:45 | August 18, 2020 11:30 | 1h 45m | 2,274 | 690 |
| 10 | January 17, 2020 01:15 | January 17, 2020 09:00 | 7h 45m | 2,199 | 3,345 |
Outage episodes by size in 2020: 79 reached 100+ customers, 24 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 Williamson County reported on EIA Form 861 for 2020, 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 |
|---|---|---|---|---|---|
| Duck River Elec Member Corp | 2020 | 6.1 hrs | 2.08 | 1.9 hrs | 1.49 |
| Middle Tennessee E M C | 2020 | 4.0 hrs | 1.58 | 58 min | 1.05 |
| City of Dickson | 2020 | 15.9 hrs | 4.52 | 2.7 hrs | 3.74 |
| Nashville Electric Service | 2020 | 30.9 hrs | 2.52 | 1.7 hrs | 1.44 |
| Columbia Power System - (TN) | 2020 | 16.5 hrs | 2.85 | 14.6 hrs | 2.66 |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 73% of Tennessee's customers in 2020; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 123,583 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. Williamson County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Williamson County, TN annual power outage report, 2020, 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/2020/tennessee/williamson-county