SAIDI
782 min per year
Average outage minutes (2023)
Green Mountain Power Corp is a investor-owned utility operating in Vermont under EIA identifier 7601. It reports service to approximately 273,285 customer accounts and generated about $0.70 billion in annual electric revenue, with a service footprint spanning 225 ZIP codes. As an investor-owned utility, it operates under state public utility commission oversight that reviews rate cases and reliability performance.
In 2023, the average Green Mountain Power Corp customer experienced 782.4 minutes of power interruptions — a metric called SAIDI (System Average Interruption Duration Index). That is substantially above the 120–180 minute national benchmark, indicating either storm-prone geography, aging infrastructure, or extended restoration windows. SAIFI — the average number of outage events per customer — was 2.51 for the same period, so customers statistically faced roughly 3 distinct interruptions that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 223.8 minutes — the gap between that figure and the headline 782.4 reveals how much weather, not day-to-day infrastructure, drove outages.
The EIA dataset includes 4 years of continuous reporting (2020–2023) for Green Mountain Power Corp, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. SAIDI has increased from 270.0 to 782.4 minutes, which may reflect either worsening weather exposure or delayed grid modernization. All figures on this page come directly from EIA Form 861, the federal annual electric power industry survey, with service territory ZIPs sourced from OpenEI — you can cross-reference them with your own utility bill or use them when comparing providers before relocating.
SAIDI
782 min per year
Average outage minutes (2023)
SAIFI
2.51 interruptions/yr
Outage frequency (2023)
Customers
273,285
Served in Vermont
782 minutes per customer per year
Minutes without power per year (2023)
| Year | SAIDI (min) | SAIDI nMED | SAIFI | Customers |
|---|---|---|---|---|
| 2020 | 270.0 | 270.0 | 1.970 | — |
| 2021 | 327.6 | 269.4 | 2.250 | — |
| 2022 | 970.8 | 280.8 | 2.770 | — |
| 2023 | 782.4 | 223.8 | 2.510 | — |
SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.
Green Mountain Power Corp serves 225 ZIP codes in Vermont.
Green Mountain Power Corp had a SAIDI of 782.4 minutes in 2023, meaning the average customer experienced about 782 minutes of outages that year. This is above the national average, indicating below-average reliability.
Green Mountain Power Corp is classified as a IOU serving Vermont. Investor-owned utilities (IOUs) are for-profit companies regulated by state public utility commissions.
SAIDI (System Average Interruption Duration Index) measures the average total minutes per year that a customer of Green Mountain Power Corp experiences power outages. A lower SAIDI indicates better reliability. The national average is roughly 120-180 minutes per year, so comparing Green Mountain Power Corp's SAIDI to that benchmark shows whether this utility is above or below average.
Green Mountain Power Corp serves approximately 273,285 customers in Vermont. Customer count can affect reliability metrics because larger utilities may face different infrastructure challenges compared to smaller ones.
Green Mountain Power Corp has 4 years of reliability data (2020-2023). SAIDI has remained relatively stable over this period. Review the trend table above for year-by-year detail.
SAIDI "without major event days" (SAIDI nMED) excludes outages caused by hurricanes, ice storms, and other catastrophic weather events. It better reflects day-to-day infrastructure reliability rather than vulnerability to extreme weather. Both standard SAIDI and SAIDI nMED are shown in the reliability trend table above.
Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the U.S. Energy Information Administration (EIA) Form 861. Consult a qualified professional before making decisions based on this data.
Read our methodology — how this data is sourced, computed, and verified.