Solar Answers → Bills & Net Metering
Why is my Ameren bill so high?
Ameren Illinois' summer supply price is 11.326¢ per kWh, effective June 1 through September 30, 2026 — about 39% above summer 2024. Two things drive it: a regional capacity auction that cleared roughly fourteen times its 2024 price, and delivery-rate increases that took effect January 1. Ameren passes supply costs through without markup, so most of the increase is the wholesale market rather than the utility's margin.
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.
What is Ameren's electricity rate right now?
Ameren Illinois' Price to Compare — the supply portion of your bill — is 11.326¢ per kWh from June 1 through September 30, 2026. That figure is three things added together: 8.2¢ for electricity supply, 0.308¢ for the supply cost adjustment, and 2.765¢ for transmission service.
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.
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 August 2026.
Swipe the table sideways to see every column →
| Line item | Amount | Effective | Resets |
|---|---|---|---|
| Monthly customer charge | $8.55 | Jan 1, 2026 | January |
| Meter charge | $5.96 | Jan 1, 2026 | January |
| Electricity supply | 8.2¢/kWh | Jun 1, 2026 | June and October |
| Supply cost adjustment | 0.308¢/kWh | current | periodically |
| Transmission service | 2.765¢/kWh | Jun 2026 | January |
| Distribution delivery — summer | 7.811¢/kWh | Jan 1, 2026 | January |
| Distribution delivery — non-summer | 4.572¢ first 800 kWh 2.427¢ over 800 kWh | Jan 1, 2026 | January |
| EDT cost recovery | 0.12567¢/kWh | Jan 1, 2026 | January |
| Taxes and municipal charges | Varies by locality | — | — |
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). Supply and transmission: Plug In Illinois, Illinois Commerce Commission, effective June 1, 2026. 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.
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 (Jun–Sep) | Non-summer (Oct–May) | |
|---|---|---|
| Supply, first 800 kWh | 11.326¢/kWh | 8.769¢/kWh |
| Supply, over 800 kWh | No separate tier published | 7.850¢/kWh |
| Distribution, first 800 kWh | 7.811¢/kWh | 4.572¢/kWh |
| Distribution, over 800 kWh | 7.811¢/kWh (flat) | 2.427¢/kWh |
Summer supply effective June 1–September 30, 2026 (Plug In Illinois). Non-summer supply figures are the January–May 2026 rates and include supply, transmission and the supply cost adjustment (Citizens Utility Board, 2026 Power-Bill Guide). 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. In January that month costs about $126 before taxes. In July, the identical 833 kWh costs about $175.
Calculated from the rates in the tables above: Citizens Utility Board 2026 Power-Bill Guide (January 19, 2026) for delivery and non-summer supply, 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 $49 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.
That is your bill at today's rates. Solar does not change those rates — it changes how many kilowatt-hours you buy at them, and the fixed charges stay either way. Whether that math works on your particular roof takes about a minute to find out, it costs nothing, and it tells you no when the answer is no.
Check my eligibility →These rates are out of date. The figures behind this estimate were current through September 30, 2026 and Ameren has reset its prices since then. Treat the numbers below as historical and check your current rate with Ameren or the Citizens Utility Board before relying on anything here.
Rates used are current as of August 3, 2026 and valid through September 30, 2026, when Ameren's supply price next resets. This is an estimate of the charges listed above only — it excludes taxes, municipal charges and any rider or assistance program specific to your account, so your actual bill will differ. It is not a quote, a guarantee, or advice. Always verify against your own bill. If you continue to the eligibility check, the usage figure you entered comes with you so you don't have to look it up twice.
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 at the annual June reset.
The scale of the move is the story. The auction covering June 2026 through May 2027 cleared at $424.30 per megawatt-day — roughly fourteen times the 2024 capacity price of about $30. The year before that was worse: MISO's 2025/26 auction cleared at a record $666.50 per megawatt-day, more than twenty times the prior year.
Here is the part that surprises people. Because $424.30 is lower than $666.50, this summer's supply rate is actually below last summer's — 11.326¢ now against 12.18¢ in summer 2025. Prices are still far above where they were two years ago, but the direction over the past twelve months has been down, not up. Any page telling you this summer's spike was caused by 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.
Wondering whether solar would actually change your bill?
The eligibility check is free, takes about a minute, and if your roof or your usage doesn't suit it, it tells you that instead of booking you a sales call.
Check my eligibility →How much more am I actually paying?
About 39% more for summer supply than in 2024, which the Citizens Utility Board puts at roughly $16 extra for every 500 kWh you use. For a household at Ameren's stated typical usage of around 833 kWh a month, that is on the order of $26 more a month on the supply line alone, before the January delivery increases are counted.
Swipe the table sideways to see every column →
| Period | Supply price, first 800 kWh | Note |
|---|---|---|
| Summer 2024 | ≈ 8.15¢/kWh | The baseline the 39% figure is measured from |
| Summer 2025 | 12.18¢/kWh | The peak — driven by the $666.50 capacity auction |
| Oct 2025 – Dec 2025 | 8.402¢/kWh | Non-summer rate |
| Jan 2026 – May 2026 | 8.769¢/kWh | Rose with the January transmission reset |
| Jun 2026 – Sep 2026 (current) | 11.326¢/kWh | Below summer 2025, well above 2024 |
| From Oct 1, 2026 | Not yet published | Expected to fall; not finalised as of this review |
Sources: Citizens Utility Board rate alerts 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.
Will my Ameren rate go down on October 1?
Probably, but the figure has not been published. Ameren's supply price resets on October 1 every year, and non-summer rates have historically been lower than summer ones. As of the Citizens Utility Board's most recent update, the October 2026 non-summer price had not been finalised.
We do not estimate this number, and we would be cautious about anyone who does. A published rate "projection" is a sales tool, not a fact. The figure appears first on the Illinois Commerce Commission's Plug In Illinois site, usually with a same-day Citizens Utility Board alert.
Our commitment: we update this page, and the calculator above, the day the October figure is published.
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.
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 2025, the Citizens Utility Board found that ComEd and Ameren residential customers together lost more than $258 million in a single year, and more than $2 billion since 2015, to alternative electricity suppliers.
"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.
Peak Time Rewards
Ameren pays a bill credit for each kilowatt-hour you cut during called events — $1.05 per kWh for the winter 2025-26 and spring 2026 seasons, up from $0.75 in summer 2025. It is real money for shifting or pausing usage on a handful of days. The catch is that it only pays during events, measured against your own baseline, 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.
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. 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.
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.
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 summer supply price rose to 11.326 cents per kWh on June 1, 2026, about 39% above summer 2024, driven by regional capacity auction costs. 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?
11.326 cents per kWh for the first 800 kWh, effective June 1 through September 30, 2026. That figure combines 8.2 cents of electricity supply, 0.308 cents of supply cost adjustment and 2.765 cents of transmission service. It 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 January to May 2026, supply was 8.769 cents for the first 800 kWh and 7.850 cents above that, while distribution was 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 pays roughly $175 before taxes in July against roughly $126 in January 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 at the June reset. The auction covering June 2026 through May 2027 cleared at $424.30 per megawatt-day, roughly fourteen times the 2024 price.
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?
Summer supply is about 39% above summer 2024, which the Citizens Utility Board puts at nearly $16 more for every 500 kWh used. Compared with summer 2025 specifically, this summer is actually cheaper — 11.326 cents against 12.18 cents — because the capacity auction cleared lower.
Will my Ameren rate go down on October 1?
Ameren's supply price resets every October 1 and non-summer rates have historically been lower. The October 2026 figure had not been finalised as of the most recent Citizens Utility Board update, and we do not estimate it. A lower rate against higher winter usage can still produce a larger bill.
Should I switch to an alternative electricity supplier?
Approach with caution. Reviewing state data in August 2025, the Citizens Utility Board found ComEd and Ameren residential customers lost more than $258 million in a single year and more than $2 billion since 2015 to alternative suppliers. 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. Fixed charges of $14.51 a month continue regardless.
Related answers
Find out whether your home is even a candidate for solar.
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Free eligibility check · ComEd & Ameren · No obligationThe Day Company is an Illinois solar and battery information resource and a lead-generation business. We are not affiliated with Ameren Illinois. Information you submit may be used by our review team and authorized partners to contact you about your request. Checking eligibility creates no obligation, and no figure on this site is a quote or a guarantee.
Sources
- Citizens Utility Board — 2026 Power-Bill Guide (January 19, 2026) — the delivery-side figures on this page: 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, the per-500-kWh figure, and the $424.30 capacity auction result
- Plug In Illinois — Ameren Illinois Price to Compare (Illinois Commerce Commission) — the current supply, supply cost adjustment and transmission components
- Citizens Utility Board — October 2025 non-summer price alert — the 8.402¢ figure in the rate history
- MISO — 2025/26 Planning Resource Auction results — the $666.50 per megawatt-day record
- 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 retail electricity suppliers (August 21, 2025) — the $258 million and $2 billion figures
- 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 August 3, 2026.
Changelog: August 2026 — v1 published.
Update triggers: this page and its calculator are revised when Ameren's October 1 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.