Ameren Illinois Company rate plans compared

What does Ameren Illinois cost at a normal month’s usage?

A household using 1,000 kWh a month pays about $2,747 a year on the cheapest of the 2 plans we can price here — DS-1 Residential Zone 2 — and $6,400 on the priciest. Same house, same wires.

Annual cost at Ameren Illinois by monthly usage
A month of	Cheapest, a year	On which plan	Priciest
500 kWh	$1,466	DS-1 Residential Zone 2	$3,292
1,000 kWh	$2,747	DS-1 Residential Zone 2	$6,400
2,000 kWh	$5,133	DS-1 Residential Zone 2	$12,439

The same plan is cheapest at every level of use here, so the answer does not turn on how much you use. Estimates from the filed tariff, priced hour by hour on a household with central air — not a quote.

How much does the plan you pick actually matter here?

Run the same three-bedroom house with central air through every plan Ameren Illinois Company files, and the bill lands anywhere between $2,212 and $5,089 a year. That $2,876 spread is not a difference in electricity — it is the same kilowatt-hours, from the same wires, priced under different rules. Nobody sends you a letter when you are on the wrong side of it.

None of these 2 plans price by the hour, so when you use electricity here makes no difference to what you pay — only how much. That narrows your options to two levers: use less, or pick the plan whose fixed charge and tier structure suit your size of household.

How Ameren Illinois compares across Illinois

Run the same three-bedroom house with central air through its default plan at each of the 2 Illinois utilities we cover, and Ameren Illinois is the dearest of the lot at about $2,212 a year; the state median is $1,648. The cheapest, MidAmerican Energy, charges $1,084 for identical use — a gap set by the address, not by anything either household did.

The other two households tell the same story in different sizes: a small apartment pays about $1,232 here against a state median of $914, and the same house with an electric car charging overnight about $2,966 against $2,208. Effective rate, fixed charge included, is 23.4¢ per kilowatt-hour for the family home.

Inside Ameren Illinois itself, the gap between its cheapest and dearest plan for that house is $2,876 a year — more than the $1,128 between Illinois's cheapest and dearest utilities. Which plan you are on matters more here than which company sends the bill.

Every Illinois utility we cover, priced for the same three households →

Which plan would cost you least?

No bill upload, no sign-up. Tell us roughly what a month costs you and what runs on electricity — we price every plan against the same household and show you the gap.

Start from a household like yours

Then correct anything below that doesn’t match.

A typical monthly bill

$a month

A bill that size works out to about 570 kWh a month on DS-1 Residential Zone 2. If your bill shows a different number of kWh, switch to and use theirs — it is the more accurate of the two.

What else runs on electricity

Electric carcharged at home

Electric water heaterincluding heat pump

Central air conditioningsummer only

Electric heatheat pump or resistance

That adds up to 6,940 kWh a year. Compare it to the total on your bill and adjust until it’s close.

Same usage, different plan

$1,664a year

That is the gap between the cheapest plan you could be on — DS-1 Residential Zone 2 — and the priciest. Not by using less power. By being billed differently for the same power.

Plan	Per year	Vs best
DS-1 Residential Zone 2The hour never matters here — only the season. Rates peak October–May.	$1,685	—
DS-1 Residential Zone 3The hour never matters here — only the season. Rates peak June–September.	$3,349	+$1,664

An estimate, not a quote. Supply charges move month to month, and your real usage pattern is not exactly this one. What it does show reliably is the gap between plans — both are priced off the same assumptions.

Making sense of the bill

Every plan, in detail

Hour-by-hour schedules, tier thresholds, and the tariff each one comes from.