Solar Lease vs Buying Panels: I Did the Math for Illinois

This is the question that comes up in every single consultation I do. "Should I lease or buy?" And the real answer is: it depends on what you're optimizing for.

I'm going to lay out the actual math for both options using a standard 8kW south-facing system with no shade in Ameren territory. Real numbers, not ranges from a national website that doesn't know what Ameren charges or what Illinois Shines pays.

The Cash Purchase

Through our installer network, I'm currently getting cash prices at $2.20 to $2.40 per watt. The state average is around $3.15/watt — we've been able to bring costs down significantly through our partner relationships. On an 8kW system, that's about $17,600 before incentives.

Here's where it gets interesting.

• Ameren DG rebate: $300 per kW = $2,400
• Illinois Shines SREC: approximately $8,400 paid directly to you

Your net cost after everything: roughly $6,800.

The SREC is the big number, so let me be specific about how it works. You'll receive about 50% of the REC value in your first year after your system is approved through Illinois Shines. The remaining 50% comes in quarterly payments over the next 6 years. REC values actually went up for the new program year. It all adds up, but you need to be comfortable with the payout timeline.

At $6,800 net cost, you're looking at a payback period of roughly 4-5 years based on current Ameren rates. After that, your electricity is essentially free minus delivery fees for the remaining 20+ years of the system's life.

The Solar Lease

A $0 down lease works differently. You don't own the system — our installer partner does. They claim the SREC and any remaining tax credits, and in exchange they give you a monthly payment that's on average roughly half or less of your current utility bill. The exact amount varies depending on your roof, shade, system size, and energy usage. If you want battery backup — a Tesla Powerwall 3 — that's about $70/month on top of the solar payment.

Here's what you do get: a fixed rate for 15 years. No escalator clause. While Ameren inflates historically at about 6% per year on average, compounding over time, your solar payment stays exactly the same. You're stepping off the inflation wheel on one of your most volatile monthly expenses.

What Happens at Year 15

This is where it gets interesting — and where most articles leave out the details.

At the end of the 15-year lease, you have the option to buy the system at fair market value. That value is assessed by an independent third party at the time of buyout — not made up by the leasing company. After 15 years of use, solar panels still have plenty of life left (most are warranted for 25-30 years), but their fair market value is typically a small fraction of the original cost.

Here's the part that doesn't get talked about much: if the leasing company wanted to remove the panels instead of selling them to you, they'd have to come out, take the system off, and restore your roof to its original condition. That's expensive and time-consuming. Our install partners have told us directly — they have very little interest in doing that. It costs them more to remove and restore than the equipment is worth.

What that means in practice is there's a real chance the leasing company will accept a reasonable offer from the homeowner to buy out the system, even below the assessed fair market value. They'd rather close the account than send a crew out to your roof.

Once you own the system, your electricity cost drops to essentially delivery fees. No more lease payment. No more utility supply charges. Just the panels on your roof doing their thing for another 10-15 years.

Who Should Buy vs. Lease

I've done enough of these to see the pattern.

The cash buyer has the capital on hand and wants the absolute lowest total cost. They understand they're paying $19,200 today and getting 50% of their REC value in the first year, with the remaining 50% in quarterly payments over 6 years. They're comfortable with that timeline because they can see the math: a net cost under $9,000 for a system that eliminates their electricity bill for 25 years. That's a return most investments can't touch.

The lease customer has decent to good credit, doesn't want to tie up $17,600, and cares most about locking in a predictable payment. They're not trying to optimize for the cheapest total cost — they're trying to get off the utility rate escalator. The lease customer looks at their Ameren bill going up $40 this summer, then another $40 next summer, and decides they'd rather pay a flat amount that doesn't change for 15 years.

Neither one is wrong. They're solving different problems.

The Math Over 15 Years

Let's project this out. Assuming Ameren's historical 6% annual increase:

By year 15, the lease customer has been saving more every single year as the gap between their fixed payment and the rising utility bill widens. The cash buyer has been saving from day one. And at year 15, the lease customer has a clear path to owning the system outright for a fraction of what it originally cost.

Both beat doing nothing. Both beat inflation. The difference is when the savings start and how they accumulate.

One Thing Both Types Agree On

Every customer I work with — cash or lease — gets this: inflation is a death by a thousand cuts on your energy bill. They're not interested in paying a number that goes up every year for a commodity they can't live without. They like the idea of fixing that cost, and they like having backup power when the grid goes down.

Whether you buy or lease, you end up in the same place: not wondering what Ameren is going to charge you next summer.

If you want to see the math for your specific situation, call me at (618) 217-2001 or use our savings calculator. I'll walk you through both paths with your actual bill and your actual roof.

Sources:

• Illinois Shines Program Year 2025-26
• CUB: 2026 Power-Bill Guide
• WCIA: Ameren Customers to See 18-22% Rate Hike