IOU Vermont

Green Mountain Power Corp

782min
SAIDI 2023
2.51
SAIFI 2023
273,285
Customers

What This Utility Data Tells You

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

SAIDI vs. National Average (180 min) 100.0%

782 minutes per customer per year

Green Mountain Power Corp SAIDI

Minutes without power per year (2023)

782 SAIDI782 SAIDINat. avg 120120SAIDI782SAIDI

Below Average

Reliability Trend (2020–2023)

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.

Service Area

Green Mountain Power Corp serves 225 ZIP codes in Vermont.

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Frequently Asked Questions

How reliable is Green Mountain Power Corp?

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.

What type of utility is Green Mountain Power Corp?

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.

What does SAIDI mean for Green Mountain Power Corp?

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.

How many customers does Green Mountain Power Corp serve?

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.

How has Green Mountain Power Corp's reliability changed over time?

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.

What is SAIDI without major event days?

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.

Utility Profile

Type
IOU
State
Vermont
Customers
273,285
Annual Revenue
$0.70B
EIA ID
7601
Data Source: U.S. Energy Information Administration Form 861 annual electric power industry survey. ZIP service territory from OpenEI.

Related

Data sourced from official EIA reliability statistics and OpenEI utility rate database. See our methodology for details. Retrieved and formatted by PlainUtility Editorial

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.