Is solar worth it in Illinois in 2026?

For many owner-occupied ComEd and Ameren homes, yes. Illinois Shines REC prices rose for 2026–27 ($80.77/REC ComEd, $70.37/REC Ameren for small systems), the utilities pay a $300/kW smart-inverter rebate, supply-only net metering still credits exports, and rates about 50% above two years ago raise the value of self-generated power. The exact math depends on your home — the calculator above gives an honest estimate.

Yes. The federal residential credit (Section 25D) expired December 31, 2025 — a system bought with cash or a loan in 2026 earns no federal tax credit. Separately, the federal begin-construction window for new projects closed July 4, 2026, which reshaped how lease and PPA offers can carry federal value.

Possibly, through a lease or PPA — but it's offer-specific and dated. Providers whose projects began construction by July 4, 2026 keep a runway generally through 2030; projects started after that must be in service by December 31, 2027 under stricter equipment-sourcing rules. Cash and loan purchases earn no federal credit. Ask whether a given offer still qualifies — and note battery storage kept its longer federal timeline.

Illinois' own agency publishes the figure: the Illinois Power Agency models residential solar at $3,734 per kW-dc in ComEd territory and $3,657 in Ameren territory for 2026 — roughly $26,100 for a 7 kW system before any incentive. That runs about 20% above what national comparison sites publish, and the IPA attributes the gap to Illinois construction labor at about 132% of the national median. Compare quotes in dollars per watt rather than headline totals, and remember the federal residential credit is gone for 2026 cash and loan purchases.

There's no single honest number. With a lease or PPA, a fixed monthly payment or per-kWh rate replaces part of your utility bill and depends on system size and terms. With cash or a loan, the "monthly cost" is your financing payment. What matters is the all-in comparison against the utility bill you'd otherwise keep paying — which is exactly what a review prices for your specific home.

For a typical owner-occupied Illinois home the arithmetic usually lands between roughly 9 and 18 years, and the calculator above shows the whole calculation for your inputs. The single biggest driver of that spread is not your roof — it is whether your installer passes through the Illinois Shines REC value, which the state pays to your approved vendor rather than to you. Pass it through and payback shortens by years; keep it and payback lengthens by years. Without the federal credit for cash buyers payback is longer than it was, while higher 2026–27 REC prices, the $300/kW rebate and rising rates push the other way.

Mostly because of one accounting question that few pages address. Illinois Shines pays for your system's renewable energy credits, but under the 2026 rules the state pays your state-approved vendor rather than you, 50% at energization and the remainder ratably over the following six years. It reaches you only if it is priced into your quote. Estimates that add the full REC value to homeowner cash flow show payback years shorter than it is; estimates that ignore it show years longer. Ask any installer what the REC value is for your system and where it appears in your price.

The State of Illinois models three: 0.5%, 1.7% and 2.5% a year, published on the standard Illinois Shines Disclosure Form so buyers can compare competing offers on the same basis. Our calculator defaults to 2% and lets you set anything from 0.5% to 10%. For context rather than as a forecast, ComEd's summer supply price is currently about 50% above two years ago and PJM capacity has cleared at the federal cap three years running, keeping costs elevated through at least May 2029. Any quote built on a high assumed escalation rate deserves a question about why.

The Illinois Power Agency publishes capacity factors for residential systems: 13% in ComEd's Group B and 15% in Ameren's Group A. Converted, that is roughly 1,139 kWh per kW-dc per year in ComEd territory and about 1,314 in Ameren territory — so a 7 kW system models to roughly 8,000 kWh a year in northern Illinois. Your actual production depends on roof pitch, orientation, shading and equipment, which is what a site-specific design establishes.

It depends on your goals. With cash or a loan you own the system and keep all the Illinois value — including the $20/REC adder Illinois Shines pays customer-owned systems taking no federal credit — but earn no federal credit. A lease or PPA means no large upfront cost, and some offers qualified before the July 4, 2026 deadline may still carry federal value priced into the payment. Neither is automatically better; a review compares both for your home.

Both stack the same programs, but the numbers differ: ComEd's summer rate is 10.399¢/kWh with $80.77/REC for small systems; Ameren's is 11.326¢/kWh with $70.37/REC, on the separate MISO grid. Different rates and program details change system sizing, so the first step is confirming which utility serves your home.

It shouldn't — but it's not automatic. Illinois treats a home solar system as a special assessment under 35 ILCS 200/10-10, so the system's value doesn't raise your property-tax bill, provided you file a one-time Form PTAX-330 with your county assessor.

It changes the math, not the case. Systems interconnected on or after January 1, 2025 earn supply-side credits for exports — with unused credits carrying forward — instead of full retail credit. That rewards right-sizing, self-consumption, and pairing solar with a battery, and the $300/kW smart-inverter rebate applies alongside it. Sizing for the new rules is exactly what a review does.

Sometimes, and the fine print changed in 2026. Supply-only net metering makes storing and using your own power more valuable, and utilities pay $300 per kWh of storage — but since June 1, 2026 taking that rebate commits you to your utility's virtual power plant. In ComEd territory that means five years of scheduled dispatch plus enrollment in a Qualifying Utility Product — Rate BESH is one option, not the only one — for the life of the battery; in Ameren territory it means VPP enrollment and the battery must be paired with on-site solar. ComEd's virtual power plant begins paying enrolled batteries in 2027. Whether it pencils depends on your usage pattern, your rate, and how you weigh that commitment.

Heavy shade usually kills the rooftop math — and we'll tell you so. Illinois community solar is the honest alternative: you subscribe to a local solar farm and earn utility bill credits with no panels on your roof, and it's exactly where our eligibility check routes heavily shaded homes. South- or west-facing roofs with decent sun remain the rooftop sweet spot.

The check takes about 60 seconds — questions about your home, roof, utility, and bill. If it looks like a fit, our review team reaches out to confirm the details and, if you want, sets a time to walk through real numbers for your home. There's no obligation at any step, and if your home isn't a fit, we'll say so instead of pushing.

Honestly: if you rent, plan to move very soon, have a heavily shaded or end-of-life roof, or have a very low bill, the math usually doesn't justify it yet. That's exactly what the eligibility check screens for — and if your home isn't a fit, we'll say so.