County annual report · FIPS 24031
2021 Montgomery County, MD Power Outage Report
In 2021, customers in Montgomery County, MD went without power for an average of 1.9 hours, a total of 745K customer-hours (Maryland average 2.5 hours). That ranks 16th worst of 24 Maryland counties and 2270th of 2,974 nationally.
Compared with MD, the US and 2020
Coverage line is EAGLE-I's share of Maryland customers tracked each year.
Biggest outages in Montgomery 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 | October 8, 2021 12:15 | October 9, 2021 17:30 | 1d 5h | 42,080 | 15K |
| 2 | August 30, 2021 10:45 | August 31, 2021 02:00 | 15h 15m | 12,912 | 5,284 |
| 3 | June 21, 2021 03:45 | June 24, 2021 02:45 | 2d 23h | 12,270 | 28K |
| 4 | August 9, 2021 12:15 | August 16, 2021 04:30 | 6d 16h | 11,763 | 152K |
| 5 | July 1, 2021 10:00 | July 3, 2021 09:00 | 1d 23h | 8,568 | 49K |
| 6 | August 24, 2021 12:00 | August 26, 2021 05:45 | 1d 17h | 7,686 | 2,932 |
| 7 | July 26, 2021 04:15 | July 28, 2021 07:45 | 2d 3h | 6,352 | 43K |
| 8 | April 30, 2021 09:45 | May 2, 2021 05:15 | 1d 19h | 6,301 | 38K |
| 9 | May 26, 2021 11:00 | May 28, 2021 00:30 | 1d 13h | 5,625 | 19K |
| 10 | May 19, 2021 10:00 | May 21, 2021 07:45 | 1d 21h | 5,196 | 14K |
Outage episodes by size in 2021: 189 reached 100+ customers, 53 reached 1,000+ customers, 4 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 Montgomery 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 |
|---|---|---|---|---|---|
| The Potomac Edison Company | 2021 | 3.3 hrs | 1.26 | 2.9 hrs | 1.20 |
| Baltimore Gas & Electric Co | 2021 | 2.4 hrs | 1.02 | 77 min | 0.77 |
| Potomac Electric Power Co | 2021 | 64 min | 0.56 | 49 min | 0.49 |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 99% of Maryland's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 395,748 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. Montgomery County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Montgomery County, MD 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/maryland/montgomery-county