Ameren Illinois Company

What This Utility Data Tells You

Ameren Illinois Company is a 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). 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 1.33 for the same period, so customers statistically faced roughly 1 distinct interruption that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 113.9 minutes — the gap between that figure and the headline 592.1 reveals how much weather, not day-to-day infrastructure, drove outages.

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. 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.