Ameren Illinois Electricity Rates in 2026: What Are You Actually Paying?

What are Ameren Illinois electricity rates? If you want to know what Ameren charges per kWh in 2026, the answer depends on which part of the bill you mean. (A kWh, or kilowatt-hour, is the unit on your bill.) The short answer: you pay a supply rate and a separate delivery rate.

An Ameren Illinois bill has two major parts: supply and delivery. Ameren Illinois is the delivery utility. It runs the local electric system and charges for distribution, metering, customer service and grid infrastructure. Your electricity supply, however, can come from Ameren's default service, an alternative retail electric supplier or municipal aggregation.

Ameren says it doesn't control or profit from electricity market prices. Supply costs are passed through to customers. So there's no single, universal “Ameren Illinois rate per kWh.” Here's how the pieces fit together, and why supply prices have been so elevated.

What Is Ameren Illinois' Current Price to Compare?

The Price to Compare is Ameren's default price for supply and transmission. For the non-summer period of October 1, 2026 through May 31, 2027, Ameren Illinois' residential Price to Compare has two tiers:

• First 800 kWh: 10.441¢/kWh
• Usage above 800 kWh: 8.262¢/kWh

Both tiers include Ameren's supply charge, a supply cost adjustment and a 2.765¢/kWh transmission charge.

That's the benchmark to use when you compare a competitive supplier's offer against Ameren's default supply.

How Does That Compare With Summer and Last Year?

The summer Price to Compare that ran from June 1 through September 30, 2026 was 11.326¢/kWh for the first 800 kWh. The new fall price is about 8% lower than that. But it's still about 24% higher than last October's price of 8.402¢.

Summer 2026 was about 39% higher than Ameren's summer 2024 price. It was slightly below the very high summer 2025 rate of about 12.18¢. Compared with summer 2024, customers were paying nearly $16 more for every 500 kWh, by one estimate.

Why Are Ameren Supply Prices Elevated?

One major reason is MISO capacity pricing. Ameren Illinois is part of MISO, the Midcontinent Independent System Operator. ComEd is part of PJM instead. MISO runs a capacity auction to make sure enough power plants are available to meet future demand.

For summer 2026, the capacity price in Ameren's region cleared at $424.30 per MW-day. The comparable summer 2024 price was about $30 per MW-day, so 2026 is roughly 14 times the 2024 level. Summer 2025 was higher still at about $666.50 per MW-day. A MISO software coding error was one factor in that result, and Ameren customers later received a bill credit.

What Is Capacity?

Capacity is different from the electricity you use today. It's essentially a payment to make sure enough generation is available if demand peaks. Think of it as insurance for grid reliability.

For most Ameren customers, capacity is built into the supply rate rather than shown as its own line. By one estimate, capacity makes up roughly 20% of the supply price on average. MISO's capacity prices are seasonal and drop sharply after summer. So Ameren's supply price typically falls in October, which is what happened this year.

Why Are MISO Capacity Costs So High?

• Data center demand: new and proposed data centers are raising forecasts of future electricity demand.
• A new pricing method: MISO adopted a Reliability-Based Demand Curve, designed to send stronger price signals for new capacity. Consumer advocates have raised affordability concerns.
• Interconnection delays: new power projects can wait years to connect to the grid.
• Generation mix: much of MISO's dependable summer capacity still comes from coal and natural gas plants, some of which are retiring.

It would still be too simple to call this “the data center rate.” Market design and available generation matter too.

Why the Price to Compare Isn't Your Total Ameren Illinois Electricity Rate

This is the most important point. You still pay Ameren for delivery, no matter who supplies your electricity. Here are Ameren's standard 2026 DS-1 residential delivery charges, as of January 1, 2026:

• Customer charge: $8.55/month
• Meter charge: $5.96/month
• Summer distribution delivery charge: 7.811¢/kWh
• Non-summer distribution charge: 4.572¢/kWh for the first 800 kWh and 2.427¢/kWh above 800 kWh

Riders, taxes and other adjustments apply on top of these. Ameren has also asked regulators for an additional $65.3 million delivery reconciliation increase (a true-up of past costs). A decision is expected in December 2026.

What Does 1,000 kWh Cost in October?

Here's a simplified non-summer example for 1,000 kWh on Ameren's default supply:

• Supply and transmission: 800 × 10.441¢ + 200 × 8.262¢ = about $100.05
• Distribution delivery: 800 × 4.572¢ + 200 × 2.427¢ = about $41.43
• Customer and meter charges: $14.51

That's about $156 before riders, taxes and other adjustments. In summer, the same 1,000 kWh carries a much higher delivery charge: 7.811¢ on every kWh. So the bill climbs even with no change in usage.

How to Calculate Your Effective Ameren Rate

Divide total electric charges by total kWh. A $212 bill for 1,050 kWh works out to about 20.2¢/kWh.

That number is useful for understanding your whole household cost. But don't compare a supplier's offer against it. The right supplier comparison is supplier offer vs. Ameren's Price to Compare. Ameren itself advises customers to compare supply costs, not delivery charges.

Delivery Rates Are Much Lower Outside Summer

Ameren's delivery charge is seasonal. The same kWh costs 7.811¢ to deliver in summer but 4.572¢ (or 2.427¢ above 800 kWh) the rest of the year. That makes summer AC efficiency particularly valuable in Ameren territory.

Cutting 500 kWh of summer AC use avoids about $39 in distribution charges alone. That's before you count the supply and transmission you also didn't buy.

Supplier Choice Is a Real Lever, but Be Careful

If you choose an alternative supplier, it generally replaces Ameren's supply and transmission charges. Ameren keeps delivering the power. That means a high bill can sometimes be improved without buying any equipment.

For example, a fixed offer of 9.5¢/kWh against the current 10.441¢ benchmark is about 0.94¢ less on the first 800 kWh each month. But look closely. Ameren's own price drops to 8.262¢ above 800 kWh. So a flat 9.5¢ offer can actually cost more in a high-usage month.

The track record in Ameren territory is also a caution. An August 2026 review of state data looked at Ameren customers with alternative suppliers. Over the year reviewed, they paid about 3.05¢/kWh more on average than default supply. The highest variable rate observed was 38¢/kWh. Compare fixed vs. variable pricing, monthly fees, contract term, cancellation fees and renewal rules before switching.

Municipal Aggregation Is Especially Common in Ameren Territory

As of May 2026, about 40% of Ameren residential customers were with an alternative supplier. About 62% of those were in municipal aggregation programs, where a town picks a supplier for its residents. Your community may have chosen a supplier for you. Check the supplier line on your bill and compare its rate with the Price to Compare.

Compare kWh Before Comparing Dollars

Suppose August 2025 was 900 kWh and $170, and August 2026 was 1,300 kWh and $255. It's easy to say “Ameren raised my bill $85.” But usage rose about 44%. The home deserves a look: AC, a heat pump, electric water heating, a pool, an EV or more people at home.

If usage barely changed but the bill jumped, that points to price: the supply rate, a supplier contract, transmission, delivery charges or riders.

What About Power Smart Pricing?

Ameren offers Power Smart Pricing for eligible residential customers. The supply price changes hour by hour based on the MISO wholesale market. Ameren posts the next day's prices each evening after 5 p.m. so you can plan.

Prices tend to be highest on summer late afternoons and during heat waves or prolonged freezes. Unlike a traditional time-of-use plan with a fixed peak window, the price can change every hour of every day. That creates more opportunity and more volatility.

Ameren recommends staying on the program for at least one year so you can judge results across seasons. Good loads to shift include EV charging, the dishwasher, laundry, water heating, pool equipment and battery charging. A household with little flexibility may see little benefit.

EV Owners Have Another Option

Ameren's ChargeSmart program rewards EV charging during its preferred window of 11 p.m. to 7 a.m. Credits are 2¢/kWh in summer and 1¢/kWh the rest of the year. It's worth investigating before simply sizing a solar system to cover EV charging.

HVAC Can Matter More Than the Rate Plan

Suppose a supplier saves you 1¢/kWh. At 15,000 kWh a year, that's about $150. Now suppose an inefficient AC wastes 4,000 kWh a year. At an all-in cost around 20¢, that's roughly $800 a year.

Supplier choice matters. The home itself may matter more.

What About Solar and Batteries?

New Illinois solar systems that started net metering after January 1, 2025 no longer get the old full-retail treatment. Ameren says new customers receive only supply and transmission service credits for exported electricity. That makes self-consumption and efficiency more important. A solar kWh used inside the home avoids a full retail purchase. An exported kWh is worth less.

Ameren offers a $300/kW-DC rebate for qualifying solar with a smart inverter. It also offers $300/kWh for qualifying storage charged by the solar system. Illinois Shines REC incentives (payments for the clean energy your system produces) can add value. With Power Smart Pricing, a battery can store solar or cheap power and reduce purchases in expensive hours. But a battery still has to justify its installed cost, financing, efficiency losses and degradation.

Four Ameren Customers Can Have the Same $250 Bill and Need Different Solutions

• Home A: An alternative supplier is charging 15¢/kWh. Best first move: change supplier.
• Home B: Summer kWh jumped 40% because of an aging AC. Best first move: HVAC diagnosis.
• Home C: EV and flexible loads can shift overnight. Best investigation: Power Smart Pricing and ChargeSmart.
• Home D: An efficient home with steady high usage and a strong roof. Best next move may be solar.

The Best Order for an Ameren Illinois Customer

1. Identify your supplier: Ameren default supply, an alternative supplier or aggregation.
2. Compare your supply rate with the current Price to Compare, including the 800 kWh tier.
3. Compare kWh year over year to see whether usage changed.
4. Diagnose HVAC and efficiency, especially summer use.
5. Evaluate timing: decide whether Power Smart Pricing fits the household.
6. Evaluate solar using the post-2025 Illinois rules.
7. Evaluate battery storage separately, based on hourly pricing, export value and backup needs.

The Ashborn Approach

Before recommending equipment, Ashborn Partners looks at the whole picture:

• Your rates: Ameren supply, any alternative supplier or aggregation contract, and summer vs. non-summer delivery
• Your home: historical kWh, HVAC and insulation
• Your options: Power Smart Pricing, EV charging, solar and battery storage

You can't control MISO capacity prices. You can control how exposed your home is to them.

Ameren Illinois rates, supplier offers and tariff adjustments can change. The residential Price to Compare for October 1, 2026 through May 31, 2027 is 10.441¢/kWh for the first 800 kWh and 8.262¢/kWh above 800 kWh. Delivery charges shown are for standard DS-1 residential service in 2026. Riders, adjustments and taxes also apply.