Illinois Electricity Rates: ComEd vs Ameren Price to Compare 2026

Updated on September 6, 2026

There is no single number for Illinois electricity rates — the state runs on two grids. Northern Illinois is ComEd territory on the PJM grid, where the summer 2026 price to compare is 10.399¢/kWh. Central and southern Illinois are Ameren territory on the MISO grid, where it is about 11.33¢/kWh. Both rose on June 1, but by very different amounts, and both are shoppable because Illinois has retail electric choice.

Why Illinois electricity rates depend on which half of the state you live in

Illinois electricity rates are split between two investor-owned utilities that sit on two different regional grids. That is unusual, and it is the reason a single statewide rate figure is misleading.

ComEd serves Chicago and the northern counties and belongs to PJM Interconnection, the grid stretching east to the Atlantic. Ameren Illinois serves the center and south — Springfield, Champaign, Peoria, Carbondale — and belongs to MISO, which runs north to south through the middle of the country. Each grid procures capacity separately, in its own auction, on its own schedule. When those auctions produce different results, Illinois electricity rates diverge even though the state’s law and regulator are the same.

That is exactly what happened this year, and it produced a result most residents would not predict.

ComEd vs Ameren: what each pays this summer

The headline is counterintuitive: downstate customers are paying more per kWh this summer than Chicago-area customers. Illinois electricity rates are usually discussed as if the metro is the expensive market. For summer 2026, the supply side of the bill says otherwise.

One caveat worth stating plainly: the price to compare is the supply-and-transmission benchmark, not your total bill. Delivery charges, taxes, and riders differ between the two utilities as well, so the gap in what you actually pay per month will not match the gap in these two numbers exactly.

What actually caused the June 1 increase?

Capacity costs — payments generators receive for promising to be available on peak-demand days, separate from the electricity they actually generate. Think of it as a standby fee the grid pays to guarantee supply on the hottest afternoon of the year.

MISO’s summer capacity auction cleared at $666.50 per MW-day, against roughly $30 per MW-day the previous year — an increase of about 2,122%. That result is the single biggest driver behind the Ameren side of Illinois electricity rates this summer. PJM’s auction also cleared higher, but the pass-through to ComEd customers was far more moderate, which is why northern Illinois saw roughly 9% rather than 29%.

Two structural forces sit behind both auctions: older generation retiring faster than new capacity is being built, and demand rising from data centers and electrification. Neither is a short-term condition, which is why capacity costs are worth understanding rather than treating as a one-off. The U.S. Energy Information Administration publishes state-level price history if you want to see how Illinois compares nationally over a longer window.

What’s next: ComEd’s $15.3 billion grid plan (and your bill)

The bigger story for ComEd customers is still ahead. In January 2026, ComEd filed a $15.3 billion grid-modernization plan covering 2028–2031 with the Illinois Commerce Commission (ICC), which has up to 11 months to review it. The plan funds reliability upgrades, three new Chicago substations plus two more elsewhere, and capacity upgrades at 70+ existing substations — driven largely by soaring demand, with data centers accounting for roughly 47% of the new substation demand, plus EV growth (Illinois targets 1 million EVs by 2030) and home electrification.

What it means for your bill: if approved as filed, the grid plan would add about $2.50–$3 per month starting in 2028 — on top of a separate ~$3/month bump from a $243 million rate increase already approved. ComEd’s average residential bill is around $106/month today. The Citizens Utility Board (CUB) is pushing back on what it calls “wasteful, inefficient” spending — in 2023 it helped cut a similar ComEd request by about 25%. Because these are delivery charges (not the supply price you can shop), the final figure may land lower after the ICC review, but the direction is up.

Can you shop your supplier in Illinois?

Yes — Illinois electricity rates are shoppable in both utility territories. Illinois has had retail electric choice since the late 1990s, and residential customers can select a competitive supplier for the supply portion of the bill. Your utility continues to own the wires, read the meter, send the bill, and restore power after a storm — switching suppliers changes none of that.

The official comparison tool is Plug In Illinois, run by the Illinois Commerce Commission. It lists only certified suppliers and presents offers in a standardized format, which makes it considerably more useful than a broker site that earns a commission on the enrollment.

There is a third category worth knowing about. Many Illinois communities run municipal aggregation, negotiating a supply rate on residents’ behalf and enrolling households automatically unless they opt out. If your town does this, you may already be on an aggregation rate rather than the utility default — which means the price to compare is not your benchmark. Check the supply line on your bill before shopping.

And a handful of Illinois municipalities own their own electric utilities entirely. Those residents cannot shop supply at all, regardless of what a marketer claims at the door.

What’s the best electricity plan in Illinois?

The best of the Illinois electricity rates offers is the one that beats your actual benchmark on a fixed term without recovering the difference in fees. Four tests before you sign:

• Confirm which utility quotes the offer. A supplier comparing against ComEd’s 10.399¢ is not making a relevant claim to an Ameren customer, and vice versa.
• Fixed rate, stated term. Variable pricing in a year of elevated capacity costs is a poor bet.
• Compare across the whole term, not today. Illinois electricity rates reset October 1, so a 12-month lock should be judged against expected annual pricing rather than the summer peak.
• Check monthly fees and cancellation terms. A one-cent gain on 800 kWh is about $8 a month — real, but easily erased by a $9 service charge.

Illinois also has an unusually active consumer advocate in the Citizens Utility Board, which publishes independent analysis of supplier offers and utility rate filings. Checking an independent source before enrolling costs nothing.

Three mistakes that cost Illinois households money

• Letting a fixed contract roll to variable. This is the most common way Illinois electricity rates quietly climb. Most suppliers move you to month-to-month pricing when a term ends rather than renewing the fixed rate. Diarize the end date the day you sign.
• Comparing against the wrong benchmark. If your community runs aggregation, an offer that beats the utility default may still be worse than what you pay now.
• Enrolling at the door. Verify any supplier is certified on the state site before handing over an account number. Legitimate offers survive a day’s delay.

If you believe you were switched without clear consent, the Illinois Commerce Commission accepts and investigates complaints. Keeping the enrollment paperwork makes that process much easier.

FAQ

Running a business in Illinois? Commercial accounts shop differently — see our business electricity guide for rate structures and contract terms.

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