IOU · Illinois · EIA 56697

Ameren Illinois Company

IOU · Illinois · 691K customers. According to the U.S. Energy Information Administration's EIA Form 861, reliability for 2023 shows SAIDI 592 minutes/customer.

Reliability verdict

Ameren Illinois Company shows near-benchmark chronic reliability in 2023: 114 minutes SAIDI excluding major events (592 minutes including them) across 691K customers.

592 min
SAIDI 2023
1.33
SAIFI 2023
114 min
SAIDI ex-MED
691K
Customers

Chronic reliability judged on SAIDI excluding major event days when reported (IEEE 1366). Source: EIA Form 861 · August 2026.

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Signature read: long interruption minutes vs the 911 utility cohort (>258 min tercile cut).

What long-outage Ameren Illinois Company filings show

Ameren Illinois Company is an investor-owned utility operating in Illinois under EIA identifier 56697. It reports service to approximately 691,223 customer accounts and generated about $1.49 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 Ameren Illinois Company customer experienced 592.1 minutes of power interruptions, a metric called SAIDI (System Average Interruption Duration Index). Excluding major weather events from that total, that falls inside the typical 120–180 minute national benchmark, in line with what most U.S. distribution utilities report. SAIFI, the average number of outage events per customer, was 1.33 for the same period, so customers statistically faced roughly 1 distinct interruption that year. Strip out major event days (hurricanes, ice storms) and SAIDI falls to 113.9 minutes; the difference from the headline 592.1 shows how much of the outage total came from weather rather than everyday grid issues.

The EIA dataset includes 4 years of continuous reporting (2020–2023) for Ameren Illinois Company, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. SAIDI has increased from 223.6 to 592.1 minutes, which may reflect either worsening weather exposure or delayed grid modernization.

F
Reliability Score
37/100
Ameren Illinois Company · 3 of 3 dimensions reported

Based on this utility's own EIA Form 861 reliability record -- baseline (major-event- excluded) outage duration, total outage duration, and outage frequency -- each benchmarked against every reporting utility nationwide. Not a measure of electricity rates or customer service, which this portal does not track.

Baseline Reliability D 113.9 min/yr
SAIDI excluding major-event days — day-to-day grid performance
Total Outage Duration F 592.1 min/yr
SAIDI including storms and major events — the full-year experience
Outage Frequency D 1.33/yr
SAIFI — average number of interruptions per customer per year
SAIDI vs. national mean (341 min) 78.9%

592 outage minutes per customer annually

Ameren Illinois Company SAIDI

Minutes without power per year (2023)

592 SAIDI592 SAIDINat. avg 341341SAIDI592SAIDI

Below Average

SAIDI by year (2020-2023)

Minutes per customer-year · EIA Form 861

Year-by-year SAIDI for Ameren Illinois Company from the same EIA filings as the table below. Lower is better; major-event years can spike the headline figure.

Source: U.S. EIA Form 861 As of August 2026

Ameren Illinois Company SAIDI trend

0 100 200 300 400 500 600 2020 2021 2022 2023 223.6 193.9 162.3 592.1
Year-by-year SAIDI from the same EIA filings as the table below. Lower is better; major-event years can spike the headline figure.

Ameren Illinois Company vs the nationwide SAIDI distribution

Where this utility's headline SAIDI sits among every EIA Form 861 utility with a reported figure

592 Higher than most fewer outage minutes than 14% of 911 utilities

Utilities nationwide, banded by latest reported SAIDI (minutes)

Each bar is a band; taller bars hold more utilities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source U.S. EIA Form 861 reliability filings · August 2026

Price vs. reliability

Where Ameren Illinois Company sits on price vs. reliability

Among the 781 U.S. utilities large enough to report both revenue per customer and a recent outage record, Ameren Illinois Company charges more per customer than 25% of them, and is more reliable (lower SAIDI) than 16% of them, placing it in the quadrant where it pays less and is less reliable. Revenue per customer and outage minutes are independent figures: paying more does not guarantee fewer outages.

Ameren Illinois Company vs. a 40-utility national peer sample, price percentile vs. reliability percentile. Scatter plot of 41 data points (bubble-sized by third dimension). 050100150 050100150 Best valuePays for itCheap + riskyWorst deal Price percentile Reliability percentile Point, Price percentile: 0 · Reliability percentile: 25Point, Price percentile: 3 · Reliability percentile: 37Point, Price percentile: 5 · Reliability percentile: 27Point, Price percentile: 8 · Reliability percentile: 75Point, Price percentile: 10 · Reliability percentile: 43Point, Price percentile: 13 · Reliability percentile: 87Point, Price percentile: 15 · Reliability percentile: 12Point, Price percentile: 18 · Reliability percentile: 20Point, Price percentile: 20 · Reliability percentile: 15Point, Price percentile: 23 · Reliability percentile: 72Point, Price percentile: 25 · Reliability percentile: 5Point, Price percentile: 30 · Reliability percentile: 100Point, Price percentile: 33 · Reliability percentile: 35Point, Price percentile: 35 · Reliability percentile: 60Point, Price percentile: 38 · Reliability percentile: 32Point, Price percentile: 40 · Reliability percentile: 40Point, Price percentile: 43 · Reliability percentile: 65Point, Price percentile: 45 · Reliability percentile: 47Point, Price percentile: 48 · Reliability percentile: 0Point, Price percentile: 50 · Reliability percentile: 10Point, Price percentile: 53 · Reliability percentile: 77Point, Price percentile: 55 · Reliability percentile: 82Point, Price percentile: 57 · Reliability percentile: 90Point, Price percentile: 60 · Reliability percentile: 70Point, Price percentile: 63 · Reliability percentile: 2Point, Price percentile: 65 · Reliability percentile: 62Point, Price percentile: 68 · Reliability percentile: 95Point, Price percentile: 70 · Reliability percentile: 67Point, Price percentile: 73 · Reliability percentile: 50Point, Price percentile: 75 · Reliability percentile: 45Point, Price percentile: 78 · Reliability percentile: 92Point, Price percentile: 80 · Reliability percentile: 17Point, Price percentile: 83 · Reliability percentile: 97Point, Price percentile: 85 · Reliability percentile: 30Point, Price percentile: 88 · Reliability percentile: 22Point, Price percentile: 90 · Reliability percentile: 80Point, Price percentile: 93 · Reliability percentile: 55Point, Price percentile: 95 · Reliability percentile: 85Point, Price percentile: 98 · Reliability percentile: 57Point, Price percentile: 100 · Reliability percentile: 52Ameren Illinois Company, Price percentile: 25 · Reliability percentile: 16
Ameren Illinois Company vs. a 40-utility national peer sample, price percentile vs. reliability percentile.

Revenue per customer: $2,148/year · Latest SAIDI: 592.1 minutes/year.

SAIDI 2023 breakdown: 592.1 minutes

Reliability Trend (2020–2023)

Year SAIDI (min) SAIDI nMED SAIFI Customers
2020 223.6 101.3 1.040 1,249,150
2021 193.9 117.8 1.110 1,251,487
2022 162.3 114.9 1.020 1,251,346
2023 592.1 113.9 1.330 1,249,587

SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.

Service Area

Ameren Illinois Company serves 500 ZIP codes in Illinois.

6051860531605366053760541605456054860549605516056060911609126091860921609226092460926609276092860929609306093160932609366093860941609426094560946609486094960951609526095360955609566095760958609596096060962609636096460966609686097060973609746123161234612356123861254612596126061272612776128161283613016131261314613156131661317613206132261323613256132661327613296133061334613356133661337613386134061341613426134461345613486134961350613546135661359613616136261363613676136861369613706137161373613746137561376613796140161410614116141261413614146141561416614176141861419614206142161422614236142561427614286143061431614326143461435614366143761438614396144061441614426144361447614486144961450614516145261453614546145561458614596146061462614656146661467614696147061472614736147461475614766147761478614796148061482614836148461485614866148861489614906149161501615166151761519615206152361524615256152661528615296153061531615326153361534615356153661537615396154061541615426154361544615456154661547615486155061552 and 300 more

Frequently Asked Questions

How reliable is Ameren Illinois Company?

Ameren Illinois Company had a SAIDI of 592.1 minutes in 2023 including major weather events, but 113.9 minutes excluding them (the industry-standard measure of routine reliability, so the gap traces back to a major storm that year, not a chronic issue). Leaving aside major weather events, that figure sits close to the national average.

What type of utility is Ameren Illinois Company?

Ameren Illinois Company is classified as a IOU serving Illinois.

How many customers does Ameren Illinois Company serve?

Ameren Illinois Company serves approximately 691,223 customers in Illinois.

How has Ameren Illinois Company's reliability changed over time?

Ameren Illinois Company has 4 years of reliability data (2020-2023). SAIDI has held roughly steady across these years. Review the trend table above for year-by-year detail.

Utility Profile

Type
IOU
State
Illinois
Customers
691,223
Annual Revenue
$1.49B
EIA ID
56697

Utilities with similar EIA profiles

Two cross-state peer sets for Ameren Illinois Company. Same-state SAIDI neighbors stay in Read-with below; these neighborhoods are nearest other-state utilities with at least 10,000 reported customers.

Similar customer count

Nearest utilities by Form 861 customers (691K here), outside Illinois.

Similar chronic SAIDI

Nearest utilities by latest SAIDI minutes (592.1 here), outside Illinois, excluding the customer-peer set.

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 · methodology.