SAIDI
93 min per year
Mean outage duration per year (2023)
What This Utility Data Tells You
Commonwealth Edison Co is an investor-owned utility operating in Illinois under EIA identifier 4110. It reports service to approximately 3,242,491 customer accounts and generated about $4.06 billion in annual electric revenue, with a service footprint spanning 500 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 Commonwealth Edison Co customer experienced 93.3 minutes of power interruptions, a metric called SAIDI (System Average Interruption Duration Index). Excluding major weather events from that total, that places this utility well below the 120–180 minute national benchmark, signaling strong grid hardening and fast restoration practices. Over the same period, SAIFI (outage events per customer) was 0.61, putting the typical customer at roughly 1 distinct interruption that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 35.0 minutes, the gap between that figure and the headline 93.3 reveals how much weather, not day-to-day infrastructure, drove outages.
The EIA dataset includes 4 years of continuous reporting (2020–2023) for Commonwealth Edison Co, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. SAIDI dropped from 341.1 to 93.3 minutes across that span, a direction regulators and prospective customers tend to watch closely.
SAIFI
0.61 interruptions/yr
Average interruption count (2023)
Customers
3,242,491
Served in Illinois
SAIDI vs. National Average (180 min) 23.3%
93 outage minutes per customer annually
Annual minutes without electric service (2023)
Reliability Trend (2020–2023)
| Year | SAIDI (min) | SAIDI nMED | SAIFI | Customers |
|---|---|---|---|---|
| 2020 | 341.1 | 40.0 | 0.830 | 4,153,856 |
| 2021 | 101.6 | 43.5 | 0.770 | 4,175,582 |
| 2022 | 65.8 | 37.6 | 0.630 | 4,194,257 |
| 2023 | 93.3 | 35.0 | 0.610 | 4,210,328 |
SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.
Service Area
Commonwealth Edison Co serves 500 ZIP codes in Illinois.
6000160002600046000560006600076000860009600106001160012600136001460015600166001760018600196002060021600226002560026600296003060031600336003460035600376003860039600406004160042600436004460045600466004760048600506005160053600556005660060600616006260064600656006760068600696007060071600726007360074600756007660077600786007960081600826008360084600856008660087600886008960090600916009360094600956009660097600986009960101601026010360104601056010660107601086010960110601116011260113601156011660117601186011960120601216012260123601246012660128601296013060131601326013360134601356013660137601386013960140601416014260143601446014560146601476014860150601516015260153601546015560156601576015960160601616016260163601646016560168601696017060171601726017360174601756017660177601786017960180601816018360184601856018660187601886018960190601916019260193601946019560196601976019960201602026020360204602086020960290603016030260303603046030560399604016040260403604046040660407604086040960410604116041260415604166041760419 and 300 more
Frequently Asked Questions
How reliable is Commonwealth Edison Co?
Commonwealth Edison Co had a SAIDI of 93.3 minutes in 2023 including major weather events, but 35.0 minutes excluding them (the IEEE-standard measure of day-to-day reliability, the gap reflects a major storm that year, not chronic performance). Excluding major weather events, this is below the national average, indicating above-average reliability.
What type of utility is Commonwealth Edison Co?
Commonwealth Edison Co is classified as a IOU serving Illinois.
How many customers does Commonwealth Edison Co serve?
Commonwealth Edison Co serves approximately 3,242,491 customers in Illinois.
How has Commonwealth Edison Co's reliability changed over time?
Commonwealth Edison Co has 4 years of reliability data (2020-2023). This utility's SAIDI has stayed fairly flat over the period. Review the trend table above for year-by-year detail.
Utility Profile
- Type
- IOU
- State
- Illinois
- Customers
- 3,242,491
- Annual Revenue
- $4.06B
- EIA ID
- 4110
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.