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Why is my Ameren bill so high?

There is also a second answer, and it is the one almost nobody explains: Ameren's rate is tiered at 800 kWh — but only from October through May. In summer, that cheaper second tier disappears on both the supply and the delivery side, at exactly the time of year your usage climbs. That is why an identical amount of electricity costs dramatically more in July than in January.

Independent public sources we cite and link — The Day Company is not affiliated with or endorsed by Ameren Illinois, the Citizens Utility Board, MISO, or the Illinois Commerce Commission. We are an Illinois solar and battery information resource and a lead-generation business.

Published August 3, 2026 · Last reviewed September 29, 2026 · ~20 min read · Facts verified at primary sources September 2026 · By The Day Company Editorial Team

What is Ameren's electricity rate right now?

Ameren Illinois' Price to Compare — the supply portion of your bill — is 10.441¢ per kWh on the first 800 kWh a month and 8.262¢ on every kilowatt-hour beyond that, from October 1, 2026 through May 2027. It combines three parts: the electricity supply price, a 0.308¢ supply cost adjustment and a 2.765¢ transmission charge, which has applied since June 2026 and resets in January.

The Price to Compare is a benchmark, not your whole bill. It covers only the electricity itself. Delivery charges, the fixed monthly charges and taxes are billed separately by Ameren no matter who supplies your power, which is why a supply-rate comparison never tells you what your bill will be.

One point worth stating plainly, because it is the source of a lot of misplaced anger: Ameren does not profit on the supply price. Default supply is procured under the Illinois Power Agency's plan and passed through to customers at cost. Ameren earns on delivery service. When the supply price rises, that is the wholesale market moving, not a margin decision.

Key numbers, October 2026

Swipe the table sideways to see every column →

Sources: Citizens Utility Board (September 28, 2026 price alert; 2026 Power-Bill Guide), Plug In Illinois (Illinois Commerce Commission) and MISO (April 28, 2026 auction results). Verified September 29, 2026.

What are all the charges on an Ameren bill?

More lines than most people realise, and they reset on three different schedules. Supply changes twice a year, in June and October. Transmission changes each January. Delivery rates change each January. The table below is a residential DS-1 bill as of October 2026.

Swipe the table sideways to see every column →

Delivery-side figures: Citizens Utility Board 2026 Power-Bill Guide, published January 19, 2026, effective January 1, 2026 (the customer charge was formerly $8.72 and the meter charge $5.32). Price to Compare: Citizens Utility Board price alert, September 28, 2026 (October 2026–May 2027). Supply cost adjustment and transmission: Plug In Illinois, Illinois Commerce Commission, effective June 2026; Plug In Illinois had not yet posted October's itemized supply price at this review. The $8.55 customer charge is a base tariffed charge plus supplemental rider charges covering low-income program subsidies, renewable and clean-coal costs, real-time-pricing program costs and uncollectibles.

Two of those lines are worth understanding before anything else. The customer and meter charges total $14.51 a month and you pay them whether you use a single kilowatt-hour or none at all. And the distribution delivery charge is the line that behaves completely differently in summer — which is the next section. How a typical total compares across the state: the average electric bill in Illinois.

What is the 800 kWh tier, and why does summer cost so much more?

Ameren's residential rate steps down after 800 kWh — but only from October through May. In the summer months of June through September, both the supply rate and the distribution delivery rate are flat: every kilowatt-hour costs the same. The cheaper second tier simply is not there during the four months when air conditioning drives usage highest.

Swipe the table sideways to see every column →

Summer supply effective June 1–September 30, 2026 (Plug In Illinois). Non-summer supply is the October 2026–May 2027 Price to Compare, which includes supply, transmission and the supply cost adjustment (Citizens Utility Board, September 28, 2026). Distribution figures effective January 1, 2026 (Citizens Utility Board). Ameren does not publish a separate summer supply rate above 800 kWh, so we do not model one.

The effect is larger than most people expect. Take a household using 833 kWh in a month — roughly the 10,000 kWh a year Ameren describes as typical. At this winter's rates — October 2026 through May 2027 — that month costs about $139 before taxes. At summer 2026 rates, the identical 833 kWh cost about $175.

Calculated from the rates in the tables above: Citizens Utility Board 2026 Power-Bill Guide (January 19, 2026) for delivery, the Citizens Utility Board's September 28, 2026 alert for the non-summer Price to Compare, and Plug In Illinois for the summer Price to Compare effective June 1, 2026. Excludes taxes and municipal charges. 833 kWh is one twelfth of the 10,000 kWh a year Ameren describes as typical residential usage.

Same house, same usage, roughly $36 more — driven entirely by which rates are in force. That is the honest answer to "why is my bill so high in summer." It is not only that you are using more. It is that you are using more at the exact moment the rate structure is least forgiving.

What would my Ameren bill look like?

Enter your monthly usage and pick a season. This applies the 800 kWh tier correctly and shows the supply, delivery and fixed-charge split — the breakdown your bill does not lay out clearly. It runs entirely in your browser and nothing is sent anywhere.

Why did Ameren's price go up in the first place?

Capacity costs. Ameren sits in MISO, the grid operator covering central and southern Illinois, and MISO runs an auction that pays generators to be available when demand peaks. Those results feed straight into what Ameren pays for power, and then into your supply rate.

The scale of the move is the story. MISO's 2026/27 auction cleared summer capacity — June through August — at $424.30 per megawatt-day in the zones that include Illinois, roughly fourteen times the 2024 summer price of about $30. The year before was worse: the 2025/26 summer price hit a record $666.50 per megawatt-day, more than twenty times the prior year. Capacity is priced by season, and the rest of the 2026/27 year cleared far lower:

Swipe the table sideways to see every column →

Source: MISO, 2026 Planning Resource Auction results, released April 28, 2026.

Here is the part that surprises people. Because $424.30 is lower than $666.50, summer 2026's supply rate came in below summer 2025's — 11.326¢ against 12.18¢. October runs the other way: the new non-summer price of 10.441¢ is about 24% above last October's 8.402¢, so the cheaper season is not as cheap as it was a year ago. Any page blaming this summer's rate on the $666.50 auction has the wrong year.

The underlying causes are not mysterious: electricity demand is growing, older generating plants are retiring, and the margin between available supply and peak demand has narrowed. Advocacy groups including the Citizens Utility Board also point to large new loads such as data centres as a driver — that is their assessment rather than a regulator's finding, and we flag it as such.

Is this the same increase ComEd customers are seeing?

Same story, different market — and the numbers cannot be compared directly. ComEd sits in PJM, a separate grid operator with a completely different auction design. Both regions have hit record capacity prices for the same underlying reasons, but putting their dollar figures side by side would be misleading.

The difference is structural. MISO's auction is prompt — it procures capacity roughly one to two months before the year it covers, and clears seasonally and by zone. PJM's auction is forward, procuring about three years ahead on an annual basis. Different lead times, different products, different accreditation rules. A "$424 versus $329" comparison would look meaningful and mean nothing.

If you are on ComEd rather than Ameren, the equivalent explanation for your bill is on why is my ComEd bill so high, which covers PJM's auctions and ComEd's own delivery charges.

How much more am I actually paying?

For the months ahead, about 24% more than a year ago: the new non-summer price for the first 800 kWh is 10.441¢ against 8.402¢ last October — roughly $16 more a month on 800 kWh, on the supply line alone. Summer 2026 ran about 39% above summer 2024, which the Citizens Utility Board put at roughly $16 extra for every 500 kWh.

Swipe the table sideways to see every column →

Sources: Citizens Utility Board rate alerts (including September 28, 2026) and the 2026 Power-Bill Guide; Plug In Illinois (Illinois Commerce Commission). Non-summer figures include supply, transmission and the supply cost adjustment. The summer 2024 figure is implied by the Citizens Utility Board's statement that summer 2026 runs about 39% above it.

Delivery went up too, on a separate track. The Illinois Commerce Commission approved a $308.6 million multi-year delivery increase for Ameren in December 2024 covering 2024 through 2027, then a further $48 million reconciliation in December 2025 — less than the $59.6 million Ameren requested, after the Commission struck $11.2 million from the filing.

Did Ameren’s rate go down on October 1, 2026?

From summer, yes. From last year, no. On October 1, 2026 Ameren's Price to Compare fell to 10.441¢ per kWh on the first 800 kWh a month and 8.262¢ beyond, about 8% below the summer's 11.326¢. But it is about 24% above last October's 8.402¢, which is why the Citizens Utility Board calls this a second year of the price spike.

One caution about reading a lower autumn number as relief: a bill is price multiplied by usage. A lower winter rate against higher winter usage can still produce a bigger bill, particularly in an all-electric home or one with electric backup heat. And the 800 kWh tier means the second half of a high-usage winter month is billed far more cheaply than the first — which is a genuine benefit of the non-summer structure. If you are weighing solar against winter bills, production drops in the darker months too: how solar performs through an Illinois winter.

Just want to know if solar is worth exploring? Jump to the solar section below.

What can I actually do about an Ameren bill?

More than nothing, and less than the internet promises. Here are the real options, with what each is genuinely worth and what the catch is.

Be careful with alternative suppliers

This is the offer that arrives at the door and in the mail whenever prices spike, and the evidence on it is stark. Reviewing state data in August 2026, the Citizens Utility Board found Illinois consumers have lost about $2.3 billion to alternative electricity suppliers since 2015; its 2025 review put ComEd and Ameren residential customers' losses at more than $258 million in a single year.

"The numbers show that going with an alternative supplier can be a risky, financially painful gamble."

Sarah Moskowitz, Executive Director, Citizens Utility Board, August 2025

That does not make every offer bad, but it means the burden of proof sits with the seller. Compare any offer against Ameren's current Price to Compare, read the term and the renewal language, and be sceptical of a teaser rate that resets. The same scepticism applies to solar quotes — how to tell if a solar quote is a good deal covers the checks that work on any offer, along with dealer fees hidden in solar loans and how to verify an installer. And if your town has negotiated a municipal aggregation deal, CUB's advice is not to assume it beats Ameren's price — confirm the rate and when the offer expires.

Peak Time Rewards

Ameren pays a bill credit for each kilowatt-hour you cut below your own baseline during called events. The credit is reset each season from market prices: for the June 2025–May 2026 program year it ran from $2.67 per kWh in summer 2025 to $0.40 in winter, according to Ameren's Rider PTR schedule. It is real money for shifting or pausing usage on a handful of days. The catch is that it only pays during events, and it is not a rate reduction.

Hourly or time-based pricing

Real Time Pricing and Power Smart Pricing charge you closer to what power actually costs hour by hour. These genuinely benefit households that can move heavy loads — laundry, dishwasher, EV charging, pool pumps — to overnight hours. They can also cost more in summer if your usage is concentrated in the afternoon, so they suit a specific kind of household rather than everyone.

Efficiency and assistance

Ameren's efficiency programme offers rebates including $100 toward an ENERGY STAR smart thermostat and substantially more toward heat pumps. On the assistance side, LIHEAP eligibility runs to 60% of state median income, and from June 2026 Ameren has a new affordability programme that caps electric bills at 3% of monthly income for non-heating customers and 6% for heating customers, for households at or below 300% of the federal poverty level. LIHEAP recipients within that threshold qualify automatically.

Battery and demand-response programmes

Ameren's Scheduled Dispatch Virtual Power Plant launches in 2027 and will pay customers who let Ameren dispatch a home battery during summer afternoons. It is also now tied to Ameren's battery rebate, which changes the calculation for anyone considering storage — the details, and what Ameren has and has not yet published, are on Ameren's virtual power plant explained. Whether a battery is worth adding at all, separate from any single program, is its own question: is a home battery worth it in Illinois? Every Illinois battery program is in one place on battery incentives in Illinois.

You may also have seen offers bundling a free home battery with a discounted electricity plan. Those exist in Illinois but are ComEd territory only as of August 2026 — we cover them on battery and supply bundles in Illinois if you want to understand the category, or if you are moving into ComEd territory.

Does solar actually help with an Ameren bill?

It changes a different variable than everything above. Switching suppliers or shifting usage changes the price you pay per kilowatt-hour. Solar changes how many kilowatt-hours you buy at whatever that price becomes. Whether that is worth the cost of the equipment depends entirely on your roof, your usage and your bill.

Two things are specific to Ameren territory and genuinely favourable. First, for systems interconnected on or after January 1, 2025, Ameren credits both supply and transmission service for excess generation sent to the grid — ComEd credits supply only, so an Ameren credit is worth more per kilowatt-hour. The mechanics are on Ameren net metering.

Second, Ameren pays a $300 per kW smart inverter rebate on residential solar and $300 per kWh on paired battery storage, which since June 1, 2026 requires enrolling the battery in Ameren's virtual power plant. Ameren is also Group A in the Illinois Shines programme, which pays for the renewable energy credits your system produces. The full stack is on Illinois solar incentives 2026. Not sure what size system your usage actually needs? how many solar panels you need in Illinois covers the method.

What solar does not do is eliminate a bill. The fixed customer and meter charges of $14.51 a month continue regardless, and you still pay delivery on every kilowatt-hour you draw from the grid. We set out honestly what remains on what your bill looks like after solar, and what a system actually costs in Illinois on how much do solar panels cost in Illinois.

For the payback math at this October's rates, see is solar worth it in Illinois? — and in the Peoria area, solar panels in Peoria covers the local specifics. Weighing a lease or PPA instead of buying? Lease vs PPA vs buying, compared.

If you want to know whether your specific home is even a candidate, that is a free eligibility check — not a quote, not a savings promise, and it tells you no when the answer is no.

Ameren bill FAQ

Why did my Ameren bill go up in 2026?

Two increases landed on different schedules. Ameren's supply price, driven by regional capacity auction costs, rose to 11.326 cents per kWh for summer 2026, about 39% above summer 2024, and from October 2026 through May 2027 it is 10.441 cents for the first 800 kWh — about 24% above last October. Separately, Ameren's delivery charges rose on January 1, 2026, including the customer charge, meter charge and per-kWh distribution rate.

What is Ameren's Price to Compare right now?

10.441 cents per kWh for the first 800 kWh a month and 8.262 cents beyond, from October 1, 2026 through May 2027. It combines the electricity supply price, a 0.308-cent supply cost adjustment and a 2.765-cent transmission charge, and covers the supply portion of your bill only, not delivery, fixed charges or taxes.

What is the 800 kWh tier on my Ameren bill?

Ameren's residential rate steps down after 800 kWh, but only in the non-summer months of October through May. From October 2026 through May 2027, supply is 10.441 cents for the first 800 kWh and 8.262 cents above that, while distribution is 4.572 cents and 2.427 cents respectively. In summer both rates are flat.

Why does my Ameren bill cost so much more in summer?

Because the cheaper second tier disappears exactly when usage peaks. In summer, supply and distribution are both charged at a single flat rate on every kilowatt-hour. A household using 833 kWh paid roughly $175 before taxes at summer 2026 rates, against roughly $139 at October 2026–May 2027 rates for identical usage.

What is MISO and why does it raise my bill?

MISO is the regional grid operator covering central and southern Illinois. It runs auctions that pay generators to be available at peak demand, and those costs flow into what Ameren pays for power and then into the supply portion of your bill. Its 2026/27 auction cleared summer capacity at $424.30 per megawatt-day in the zones that include Illinois, roughly fourteen times the 2024 summer price, while fall, winter and spring cleared between $7.61 and $35.97.

Is Ameren's increase the same as ComEd's?

Same causes, different market, and the numbers are not comparable. Ameren is in MISO and ComEd is in PJM. MISO's auction is prompt, seasonal and zonal; PJM's is forward and annual. Both have hit record capacity prices for similar reasons, but comparing their dollar figures side by side would be misleading.

How much more am I paying than last year?

This October's price for the first 800 kWh, 10.441 cents, is about 24% above last October's 8.402 cents — roughly $16 more a month on 800 kWh. Summer 2026 supply ran about 39% above summer 2024, which the Citizens Utility Board put at nearly $16 more for every 500 kWh, though it was slightly cheaper than summer 2025: 11.326 cents against 12.18 cents.

Did Ameren's rate go down on October 1, 2026?

Yes, from summer: it fell about 8%, to 10.441 cents for the first 800 kWh and 8.262 cents beyond, through May 2027. But it is about 24% above last October's price, and a lower rate against higher winter usage can still produce a larger bill.

Should I switch to an alternative electricity supplier?

Approach with caution. The Citizens Utility Board's August 2026 review of state data found Illinois consumers have lost about $2.3 billion to alternative suppliers since 2015, and its 2025 review put ComEd and Ameren residential losses at more than $258 million in a single year. Compare any offer against Ameren's current Price to Compare and read the renewal terms carefully.

Does Ameren profit when the supply price goes up?

No. Default supply is procured under the Illinois Power Agency's plan and passed through to customers at cost, without markup. Ameren earns on delivery service instead, which is why the supply price tracks procurement and auction results rather than Ameren's own margins.

Does solar make sense on Ameren?

It depends on your roof, usage and bill, but Ameren territory has two advantages. Systems interconnected on or after January 1, 2025 receive credits for both supply and transmission service, where ComEd credits supply only, and Ameren pays a $300 per kW smart inverter rebate plus $300 per kWh on paired storage enrolled in its virtual power plant. Fixed charges of $14.51 a month continue regardless.

Related answers

More answers for Ameren homes: whether your roof gets enough sun · roof requirements · what an HOA can and can’t block · how panels hold up to hail · selling a house with solar · solar and property taxes · does Illinois have a state solar tax credit? · did the federal credit end? · Illinois solar facts.

Sources

Sources · 12 documents behind this page

• Citizens Utility Board — Ameren's new price: 10.441¢ per kWh for the first 800 kWh — September 28, 2026 — the October 2026–May 2027 Price to Compare and the 8% and 24% comparisons
• Citizens Utility Board — 2026 Power-Bill Guide — January 19, 2026 — customer charge, meter charge, distribution delivery rates and the 800 kWh tier structure
• Citizens Utility Board — why is Ameren's electricity price spiking? — June 11, 2026 — the 39% comparison and the per-500-kWh figure
• Plug In Illinois — Ameren Illinois Price to Compare — Illinois Commerce Commission — the supply cost adjustment and transmission components
• Citizens Utility Board — October 2025 non-summer price alert — the 8.402¢ and 7.483¢ figures in the rate history
• MISO — 2026/27 Planning Resource Auction results — April 28, 2026 — the $424.30 summer price and the fall, winter and spring prices
• MISO — 2025/26 Planning Resource Auction results — the $666.50 per megawatt-day summer record
• Ameren Illinois — Rider PTR Peak Time Rewards credit schedule — the seasonal credit per kWh of load reduction
• Ameren Illinois — customer-owned solar, net metering and rebates — the $300/kW and $300/kWh rebates and the post-2025 crediting rules
• Citizens Utility Board — review of state data on alternative suppliers — August 10, 2026 — the $2.3 billion figure
• Citizens Utility Board — review of state data on alternative retail electricity suppliers (August 21, 2025) — the $258 million single-year figure
• Illinois Commerce Commission — Ameren delivery rate orders, December 2024 ($308.6 million multi-year) and December 2025 ($48 million reconciliation, Docket 25-0382)

How to cite this page: The Day Company, "Why is my Ameren bill so high?", theday.company/answers/why-is-my-ameren-bill-so-high, last reviewed September 29, 2026.
Update triggers: this page and its calculator are revised when Ameren's June 1, 2027 supply price is published, when the January delivery and transmission rates reset, and when MISO posts its next Planning Resource Auction result. The calculator displays an automatic warning if its rates pass their validity date without being updated.

Changelog · last updated September 29, 2026 · 3 updates

1. September 29, 2026 — Updated for Ameren's October 2026–May 2027 price (10.441¢ for the first 800 kWh, 8.262¢ beyond) across the short answer, a new key-numbers table, the rate tables, the rate history, the summer-versus-winter chart and the calculator. Corrected three errors: MISO's $424.30 is the summer capacity price, not a full-year figure, and the other seasons are now shown; the summer price breakdown did not add up to its published total; and the Peak Time Rewards credits now match Ameren's schedule. Added updated alternative-supplier figures, a share row, tap-to-open sources and changelog, and links to more guides. Site-wide header and footer update.
2. August 7, 2026 — Logo and social-sharing metadata corrected; added links to vetting a solar quote, whether a battery is worth it, and system sizing.
3. August 3, 2026 — Published.