SAIDI
39 min per year
Mean outage duration per year (2023)
What This Utility Data Tells You
Town of Wellesley - (MA) is a municipally-owned utility operating in Massachusetts under EIA identifier 20310. It reports service to approximately 10,596 customer accounts and generated about $0.04 billion in annual electric revenue, with a service footprint spanning 11 ZIP codes. As a municipal utility, it is typically governed by a local board or city council and is exempt from federal income tax.
In 2023, the average Town of Wellesley - (MA) customer experienced 38.5 minutes of power interruptions, a metric called SAIDI (System Average Interruption Duration Index). That is comfortably under the 120–180 minute national benchmark range, a sign of solid grid resilience and quick outage response. SAIFI, the average number of outage events per customer, was 0.63 for the same period, so customers statistically faced roughly 1 distinct interruption that year.
The EIA dataset includes 4 years of continuous reporting (2020–2023) for Town of Wellesley - (MA), which lets you see whether reliability is trending up or down rather than judging from a single snapshot. Over that span, SAIDI rose from 31.0 to 38.5 minutes, possibly reflecting tougher weather years or grid upgrades that have not caught up yet.
SAIFI
0.63 interruptions/yr
Average interruption count (2023)
Customers
10,596
Served in Massachusetts
SAIDI vs. National Average (180 min) 9.6%
39 minutes per customer per year
Minutes without power per year (2023)
Reliability Trend (2020–2023)
| Year | SAIDI (min) | SAIDI nMED | SAIFI | Customers |
|---|---|---|---|---|
| 2020 | 31.0 | - | 0.493 | - |
| 2021 | 24.9 | - | 0.479 | - |
| 2022 | 31.7 | - | 0.700 | - |
| 2023 | 38.5 | - | 0.633 | - |
SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.
Service Area
Town of Wellesley - (MA) serves 11 ZIP codes in Massachusetts.
0176002030024570246202464024680248102482024920249302494
Frequently Asked Questions
How reliable is Town of Wellesley - (MA)?
Town of Wellesley - (MA) had a SAIDI of 38.5 minutes in 2023. Leaving aside major weather events, that figure comes in under the national average, pointing to above-average reliability.
What type of utility is Town of Wellesley - (MA)?
Town of Wellesley - (MA) is classified as a Municipal serving Massachusetts.
How many customers does Town of Wellesley - (MA) serve?
Town of Wellesley - (MA) serves approximately 10,596 customers in Massachusetts.
How has Town of Wellesley - (MA)'s reliability changed over time?
Town of Wellesley - (MA) 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.
Utility Profile
- Type
- Municipal
- State
- Massachusetts
- Customers
- 10,596
- Annual Revenue
- $0.04B
- EIA ID
- 20310
Explore
Source: U.S. Energy Information Administration Form 861 annual electric power industry survey · ZIP service territory: OpenEI. Disclaimer: informational only, not professional advice. See full disclaimer.
Every figure on PlainUtility is rendered directly from the U.S. Energy Information Administration's Form 861 reliability data, no number is typed in by an editor. This utility's SAIDI/SAIFI figures are rendered directly from EIA Form 861 reliability files. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2020-2023.