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EnergySavings · Illinois · Comparison

Ameren Illinois Company vs MidAmerican Energy Co: who pays less in Illinois?

Data as of: EIA-861 annual 2024 (released 2025) · EIA monthly state prices February 2026 · EIA weekly heating-fuel survey Mar 30, 2026 · retail-choice registry reviewed Jun 2026 · URDB tariffs pulled Jun 2026. Page generated 2026-06-12.

MidAmerican Energy Co customers paid less: an average 9.99¢/kWh in 2024 versus 15.26¢/kWh at Ameren Illinois Company (EIA-861) — a gap of 5.26¢/kWh, worth about $569 per year at typical usage (10,800 kWh/yr). Their territories meet in 2 IL counties (Henry, Mercer). You cannot switch wires companies — the territory is set by your address, though in Illinois both utilities' customers can shop the supply portion of the bill.

Side by side (IL, EIA-861)

Ameren Illinois Company vs MidAmerican Energy Co — residential averages from federal EIA-861 filings
MetricAmeren Illinois CompanyMidAmerican Energy Co
2024 average price, ¢/kWh15.269.99
2023 average price, ¢/kWh17.049.90
Annual cost at 10,800 kWh, $/yr$1,648$1,079
Residential customers (2024)520,49873,564
OwnershipInvestor-ownedInvestor-owned
Counties served in IL813

Average price = residential revenue ÷ sales (bundled service): the all-in price customers actually paid, including supply, delivery and riders. Profiles: Ameren Illinois Company · MidAmerican Energy Co · Illinois overview.

Where the territories meet

Both utilities file EIA-861 service territory in: Henry · Mercer counties (IL, 2024).

Adjoining or overlapping territory in a county does not mean households there can pick between the two — service maps are parcel-level and fixed. The county overlap mainly matters when choosing where to live or comparing town-level costs.

Can you actually choose between them?

No — not for delivery. Distribution territories are exclusive and set by address; Ameren Illinois Company and MidAmerican Energy Co do not compete for the same meters. Illinois does have retail supply choice: customers of either utility may buy the supply portion from a licensed third-party supplier, or stay on the utility's default supply rate. An offer only saves money if it beats your utility's price to compare (printed on the bill); compare offers at pluginillinois.org. The price gap above mainly matters when choosing where to live, comparing towns, or benchmarking your bill.

Questions people ask

Is Ameren Illinois Company cheaper than MidAmerican Energy Co?
No — in 2024 Ameren Illinois Company customers averaged 15.26 cents/kWh versus 9.99 for MidAmerican Energy Co (EIA-861). MidAmerican Energy Co was cheaper by 5.26 cents, about $569 per year at 10,800 kWh.
Can I switch from Ameren Illinois Company to MidAmerican Energy Co?
No — distribution territories are exclusive and set by address; you cannot pick between the two wires companies. Illinois does allow supply choice: either utility's customers can shop the supply portion at pluginillinois.org if an offer beats the utility's price to compare.
Why is Ameren Illinois Company more expensive than MidAmerican Energy Co?
EIA-861 averages reflect everything customers actually paid — supply costs, delivery rates, riders, and surcharges across each territory. Differences in generation mix, grid investment, storm costs, and customer density between Ameren Illinois and MidAmerican Energy territory all feed the 5.26-cent gap.
About these numbers. Rates shown are averages computed from federal regulatory filings (EIA Form 861) and public tariff databases — confirm with your utility before making decisions; your actual rate depends on your tariff, usage, and riders. Distribution utility is determined by address and generally cannot be chosen; in retail-choice states you may choose your supplier for the supply portion of the bill. Savings figures use 10,800 kWh/yr (US average residential usage) and are estimates, not quotes. EnergySavings is an independent data project by CertiHomes and is not affiliated with any utility, supplier, or government agency.