Solar + an EV in Illinois: what it actually saves in 2026

Scale that up: an 8 kW system in Chicago produces roughly 10,000 kWh a year — on the order of an average U.S. household's entire annual electricity use, EV included. So the question for most EV owners isn't whether solar can cover the car. It's what each of those kilowatt-hours is worth under the rules Illinois uses now — and that changed recently, in ways a lot of published guides (and installer quotes) haven't caught up with.

For years, Illinois net metering worked like a battery you didn't have to buy: a kilowatt-hour you exported on a sunny afternoon cancelled a kilowatt-hour you bought back that night, at the full retail rate. Under the state's Climate and Equitable Jobs Act, that ended for new systems. Solar interconnected on or after January 1, 2025 is credited for exports at the electricity supply rate only — a setup often called Smart Solar Billing. Customers who were already on the old full-credit terms keep them; new systems don't get them.

Put numbers on it. ComEd's published price to compare — the supply benchmark — is 10.103¢ per kWh for October 2026 through May 2027, before delivery. Grid power bought back costs the full retail rate, roughly 16¢ per kWh all-in on a typical residential bill. So the same 3,600 kWh your EV uses in a year is worth about $575 if your solar runs your home and car directly, versus about $365 if it's exported and credited at the supply rate. That gap — not the panels — is what should drive your decisions: self-consumed solar is now worth noticeably more than exported solar.

The mechanics otherwise work as ComEd's net metering guide describes: your meter tracks power in both directions, your bill reflects the net, credits for excess roll forward, and more than 30,000 ComEd customers already participate. If you're on ComEd's Hourly Pricing rate, export credits are valued at the market price in the hour the power was generated — sunny midday hours often price well, which softens the supply-only change for households that can also shift usage into the day.

Illinois Shines (the Adjustable Block Program), run by the Illinois Power Agency, is state-funded and independent of the federal programs — the agency states plainly that it continues after the federal changes. It works on credits, not your electric bill: every 1,000 kWh your system generates earns one Renewable Energy Credit (REC), and the program buys 15 years of your RECs under a contract arranged by a state Approved Vendor (usually your installer).

The current prices, published for the 2026-27 program year: a homeowner system of 10 kW AC or smaller in ComEd territory is priced at $80.77 per REC, and because the federal homeowner credit disappeared, this program year adds $20 per REC for systems the customer owns (rather than leases). For systems 25 kW and smaller, the utility pays the vendor 50% of the 15-year value when the system is energized, with the rest paid quarterly over six years. How much of that reaches you — as a lower price or a payment — is set by your installation contract, and the state's Disclosure Form, which your vendor must give you before you sign, shows your project's estimated REC payment. That form, not a sales brochure, is the number to hold onto.

An illustration, with the inputs on the table: an 8 kW system making ~10,000 kWh a year earns 10 RECs a year, or 150 over the 15-year contract. At $100.77 per REC ($80.77 + the $20 ownership adder), that's roughly $15,100 in gross contract value — paid to the Approved Vendor, with your share determined by your contract. Separately, ComEd pays a distributed generation rebate of $300 per kW of solar capacity for systems using a smart inverter (an 8 kW system: about $2,400), plus $300 per kWh for a battery paired with an eligible system; check the current terms at ComEd.com/DGrebate. One caution: program capacity is allocated in blocks, and in busy years categories have filled and waitlisted — your vendor's submission timing is part of the deal.

This is the single most repeated stale claim in solar right now. The Section 25D residential clean energy credit — the 30% federal tax credit for homeowner-owned solar — is not allowed for expenditures made after December 31, 2025, per the IRS's guidance on the One Big Beautiful Bill Act. The IRS also closes the obvious workaround: an expenditure counts as made when installation is completed, so a contract signed or paid in 2025 for a system finished in 2026 never qualified.

Two things that are still true: if your system's installation was completed by December 31, 2025, the 30% credit is still yours to claim on your 2025 return. And if a company offers you a lease or power purchase agreement priced with a federal credit baked in, that credit belongs to the company that owns the panels — it may lower your lease price, but it is not a credit you claim, and it comes with not owning the system (and, typically, not receiving the Illinois Shines ownership adder). For a system you buy in 2026, the incentive stack is Illinois Shines plus ComEd's rebates plus your bill savings — anyone's quote that shows a 30% federal line item for a purchased system is working from an old script.

Here's the timing problem nobody puts in the brochure: your panels peak around midday, and most home charging happens overnight, because that's when the car is home. Without a battery, your noon solar goes to the grid (earning the supply-rate credit) and your car charges at night on grid power (at the full retail rate). On paper over a year, the amounts can roughly cancel — but under supply-only crediting, the round trip leaks value. Three honest ways to close the gap:

• Charge when the sun is up, when you can. Work-from-home days and weekends are real charging time. Smart chargers let you schedule midday sessions, and under supply-only credits a kilowatt-hour straight into the car is worth the full retail rate instead of the ~10¢ export credit — the single biggest free win in the current rules.
• Size the array to your daytime life, not just your annual total. An array matched to what your home (plus daytime charging) actually uses while the sun shines wastes less value on low-paid exports than a maximally oversized one.
• Consider a battery for the right reasons. A home battery is the only way to literally run the car on your own solar after dark, and it doubles as outage backup. Under the new credit rules it also keeps more of your solar at full retail value. But it's a major added cost, it wears, and "it pays for itself" is a claim to make a vendor prove with your numbers — ComEd's $300-per-kWh storage rebate (tied to a time-variant rate and its battery dispatch program) helps, but doesn't settle the question by itself.

None of this makes solar a bad deal for an EV household — an EV is actually the best solar customer there is, because the car is a big, flexible load that can soak up daytime production. It just means the winning design in 2026 is use it yourself first, not export and net it out later.

If you're sequencing the projects: the charger first, almost always. A Level 2 installation is a one-day, four-figure project that changes how you use the car from the first night — full battery every morning, all charging inside cheap overnight hours. Our installation cost Q&A covers what it runs in the Chicago area and the questions to ask; the ComEd rebates guide tracks what's actually available for charger installs right now (the short version: the 2026 round is spoken for, and the next round's terms are already published).

Solar is a bigger, slower decision — roof condition, quotes, the Illinois Shines paperwork — and nothing about it is harmed by having the charger in first. If anything, a few months of charging data tells you exactly how many kilowatt-hours the car really uses at your house, which is the number that sizes the solar array correctly. When the solar quote comes, you'll know whether the "EV package" upsell matches your actual driving or is just a bigger array.

It tends to pencil when…

• Your roof cooperates: a south-, southeast- or southwest-facing roof with real life left in it and little shade. Re-roofing first, or panels on a roof that needs replacing in five years, wrecks the sequence.
• You'll stay a while. Solar is a long-horizon asset; the value stacks up over years of bills, not months.
• You can use power during the day — someone home, appliances you can run on timers, and an EV that can charge on sunny afternoons at least sometimes. Under supply-only credits, daytime use is where the money is.
• Your quote is clean: the state Disclosure Form's REC estimate is in writing, the federal credit is not in the math for a purchased system, and the export assumptions use supply-rate credits, not the old full-retail ones.

It doesn't — yet — when…

• The roof is old or shaded. Fix the roof situation first, or wait; panels on a dying or tree-covered roof produce disappointing numbers at full price.
• A move is likely in the next few years. You may recover value in a sale, but you won't control the timeline — don't count on it.
• The car is rarely home in daylight and your usage is small. Low self-consumption plus low total usage is the weakest case under current credit rules.
• The pitch depends on programs you can't verify. If a quote leans on a credit or rebate the salesperson can't point to on an official page — the IRS's, the Power Agency's, ComEd's — that's your answer.

Local installer pages: Naperville · Schaumburg · Aurora · Elgin · Arlington Heights · Bartlett · Streamwood. And before the solar quotes start, it helps to know what charging adds to your electric bill in the first place.