Illinois Electricity Rates 2026: What's Coming This Summer (And How to Prepare)

If your electric bill has felt heavier lately, you're not imagining it. Illinois electricity rates have climbed sharply since 2021 — and they're about to jump again.

This isn't a temporary blip. There are three structural forces pushing rates higher at the same time: a global energy crisis from the Iran conflict, massive data center construction across the state, and record-breaking wholesale capacity auction prices that directly set what you pay per kilowatt-hour.

Here's what's actually happening, what's coming in June, and what your options are.

Where Rates Stand Right Now (April 2026)

Illinois has two major utilities, and both have seen dramatic increases:

ComEd (northern Illinois, Chicagoland):

• Current supply rate: 10.8¢/kWh — up 47% from January 2025
• All-in residential rate: approximately 17¢/kWh
• The ICC approved a $243 million delivery rate hike effective January 2026
• IRA credits of ~$13/month offset some costs through May — but expire before summer

Ameren Illinois (central and southern Illinois):

• Current supply rate: 8.77¢/kWh (first 800 kWh)
• All-in residential rate: approximately 15.5¢/kWh — up 94% since 2021
• Summer all-in rates reach roughly 20¢/kWh (June through September)
• The ICC approved a $48 million delivery rate increase for 2026

For context, both utilities were around 8¢/kWh all-in in 2021. That was just five years ago.

What's Driving the Increases

It's not one thing — it's three things happening simultaneously.

1. Capacity Auction Prices Exploded

This is the biggest single driver, and most people have never heard of it.

Your utility doesn't generate its own electricity. It buys power on wholesale markets run by regional grid operators — PJM for ComEd territory and MISO for Ameren territory. These operators run annual "capacity auctions" where power generators bid to supply electricity. The clearing price flows directly into your rate.

Those auctions have gone haywire:

These aren't typos. PJM capacity costs went up ten-fold in two years. MISO summer capacity went up twenty-two-fold in a single year.

There's no buffer between these auction prices and your bill. When the clearing price goes up, your rate goes up — typically at the next June reset.

2. Data Centers Are Eating the Grid

Illinois has approved 27 of 28 applications for tax-exempt data center status. Another 30+ facilities are planned. These aren't small buildings — a single large data center can consume 600 megawatts, roughly equivalent to powering an entire mid-size city.

Data centers now consume 5.43% of all Illinois electricity. PJM's Independent Market Monitor found that 70% — or $9.3 billion — of the capacity cost increase was driven by data center demand.

The Illinois Power Agency projects capacity shortfalls beginning in 2029 for northern Illinois and 2031 for southern Illinois. Governor Pritzker has proposed a two-year suspension of data center tax incentives starting July 2026 — but the facilities already approved aren't going away.

For a deeper dive on this, see our earlier analysis: Data Centers Drove 70% of Illinois's Capacity Cost Spike.

3. Global Energy Instability

The Iran conflict has sent oil to $112/barrel and disrupted 20% of global LNG supply. Illinois is somewhat insulated because 53% of our electricity comes from nuclear power — but the 17% that comes from natural gas is exposed to global price swings.

More importantly, the next utility procurement auctions will reflect a world where energy is more expensive everywhere. If the conflict isn't resolved before June, elevated gas futures will get baked into the rates you pay for the next 6-12 months.

What's Coming in June 2026

The June rate reset is when the 2026-2027 capacity auction prices take effect. Here's what to expect:

ComEd customers: CUB warns of another 20-25% increase on top of already elevated rates. The IRA credits that softened the blow ($13/month) expire before summer. Combined with the new capacity charge, summer bills could reach $180-220/month for a typical household.

Ameren customers: Summer supply rates historically jump from ~9¢ to ~12¢/kWh as seasonal capacity charges kick in. With the new MISO auction prices, the CUB warns summer bills could hit $200+/month for average homes.

Neither utility expects relief anytime soon. CUB's assessment: rates will stay elevated "for at least the next few years" due to structural demand growth from data centers and infrastructure investment.

How Illinois Compares to the Rest of the Country

Despite the increases, Illinois is still slightly below the national average — but the gap is closing fast.

Source: Choose Energy, April 2026

Illinois went from well-below-average to essentially average in just a few years. And with summer rates pushing toward 20¢+, Illinois could land above the national average by July.

When Will Rates Come Back Down?

The honest answer: probably not for a while. Here's why:

• Data center demand is structural — those facilities run 24/7 for decades. The 27 already approved aren't going away.
• Grid infrastructure costs money — aging transmission lines, new capacity to meet demand, and reliability upgrades all get baked into delivery charges.
• Capacity auctions look forward — even if gas prices stabilize, the auctions are pricing in tight supply margins through at least 2028.
• The Iran conflict — if it persists, global energy costs stay elevated and trickle into US markets.

CUB and industry analysts broadly agree: expect elevated rates through at least 2028-2029, with the possibility of marginal relief if data center growth slows or new generation capacity comes online.

What You Can Do Right Now

You have three realistic options to control your electricity costs:

1. Solar — Lock in your rate for 15-25 years

Solar eliminates your exposure to all three forces pushing rates up. Once panels are on your roof, your energy cost is fixed — no auctions, no data center demand, no geopolitical risk.

• Lease ($0 down): Fixed monthly payment for 15 years, typically lower than your current bill. Battery backup included.
• Cash purchase: Own the system. Federal tax credit + Illinois SREC payments bring the payback to 8-10 years, then free power for 15+ more.
• Solar for All: Income-qualified? The state installs solar at zero cost. No credit check.

2. Energy efficiency — Reduce your usage

This won't stop rate increases, but it reduces the volume they apply to:

• Air-seal and insulate your attic (biggest bang for the buck)
• Smart thermostat programming
• LED lighting throughout
• High-efficiency HVAC when it's time to replace

3. Alternative supply — Shop your rate

Illinois is a deregulated market. You can choose an alternative electricity supplier through the ICC's Plug In Illinois site. Fixed-rate plans can lock in your supply cost — but read the fine print on contract terms and cancellation fees.

The Bottom Line

Illinois electricity rates are up 47-94% since 2021. Another increase hits in June 2026. The forces driving it — data centers, capacity auctions, and global energy instability — aren't temporary.

You can wait and absorb each increase, or you can take control of your energy cost now. The incentives are still available, and the math gets better every time rates go up.

See what solar saves in your city →

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Ryan Cook is the founder of Ltd Solar Consulting, helping Illinois homeowners navigate solar options across Ameren and ComEd territory. Questions? Get a free quote or call (618) 217-2001.