Estimate what solar does against your Ameren Illinois bill
Enter your bill and we’ll size the array that would cover it, and show the gross value of that production at your rate. It does not net off the customer charge, taxes or what you would still draw at night — for that, use the bill savings calculator. Nothing is sent anywhere; this runs in your browser.
An estimate from your own numbers, not a quote, and not a savings figure. It assumes 400 W panels, an 80% system derate and no roof constraints. Your real number depends on orientation, roof area and your utility’s export credit. Savings are not guaranteed.
Illinois · Updated September 2026
Why your Ameren Illinois bill is so high
Ameren Illinois charges about 11.3¢ per kilowatt-hour. Here is what that costs at your usage, what has changed, and what a roof produces against it.
See my numbersWhat 11.3¢ costs at your usage
| If you use | Monthly | Annually |
|---|---|---|
| 600 kWh/month | $68 | $814 a year |
| 900 kWh/month | $102 | $1,220 a year |
| 1,200 kWh/month | $136 | $1,627 a year |
| 1,500 kWh/month | $170 | $2,034 a year |
Energy charges only, at 11.3¢/kWh. Your bill also carries a fixed customer charge and taxes. Source: Illinois Commerce Commission via PlugIn Illinois, effective June 1 – September 30, 2026.
Three reasons a bill jumps
The rate changed
Filed rate changes are public and dated. The current ones for Ameren Illinois are in the table above. Most of the recent regional increases have landed in delivery and transmission, which you cannot shop away by switching suppliers.
Your usage changed
Air conditioning, electric heat, an EV or a heat pump can move consumption 30–50% without anything else changing. Compare kilowatt-hours against the same month last year, not dollars — dollars move with the rate.
The billing period was longer
A 34-day cycle against a 28-day one is 21% more energy at the same daily usage. Check the service period dates before assuming a rate rise.
What to do about it
In order of how much they move the number: reduce the kilowatt-hours you buy, shift usage into cheaper hours if you are on time-of-use, and generate your own. Solar addresses the third and it only makes sense once you know your real rate and your real usage.
Project your bill forward · Ameren Illinois rate detail · Net metering in Illinois
Common questions
Why is my Ameren Illinois bill so high?
Three things move it: the rate, your usage, and the length of the billing cycle. Compare kilowatt-hours to the same month last year first — dollars move with the rate, kilowatt-hours are the actual quantity.
How much is Ameren Illinois per kWh?
About 11.3¢ — Price to Compare — supply plus transmission, before delivery. Divide your bill total by kWh used for your own all-in figure.
Will solar eliminate my bill?
No. You keep a fixed customer charge and you still draw at night. Solar reduces how many kilowatt-hours you buy, which is a different thing from a zero bill.