Solar Loan vs. Cash in Minnesota: Which Costs Less?
Same 8 kW system, five ways to pay for it. Here is what each one really costs over 25 years, and why the loan with the lowest rate can be the worst deal.
Reviewed by John Ihle, MN Master Electrician (AM005101) · NABCEP-credentialed · iSolar, Saint Paul Park, MN · Last reviewed October 2026
The short answer: Paying cash is usually the cheapest way to own solar in Minnesota. In our $25,000 example, cash nets about $22,700 more than it costs over 25 years, a 10-year loan at an example 7% nets about $12,900, and a low-rate loan hiding a 30% dealer fee ends up costing more than the system saves.
The short answer
If you have the cash and it isn't your emergency fund, paying cash is almost always the cheapest way to own solar. You pay no interest, and every dollar of bill savings goes back to you. A loan lets you own the system without draining savings, but interest reduces your lifetime return, and a loan with a hidden dealer fee can wipe it out entirely.
The rest of this post puts numbers on that, using one Minnesota system and four ways to pay for it.
The example system
To keep the comparison fair, every option below pays for the same system:
- 8 kW rooftop system on a south-facing Twin Cities roof
- $25,000 installed price (about $3.13 per watt, within the $3.00–$3.25/W range price trackers show for Minnesota)
- 10,000 kWh produced in year one (1,250 kWh per kW)
- Each kWh worth 14¢ in year one, rising 3% a year; panels losing 0.5% output a year
- No federal tax credit, since the homeowner credit ended for systems installed after 2025
- No Xcel Solar*Rewards incentive included, which would improve every option
Under those assumptions the system saves about $1,400 in year one (roughly $117 a month), about $15,700 over 10 years, $35,700 over 20 years and $47,700 over 25 years.
Cash vs. loan: the worked example
The loan rates below are illustrative examples only, not offers from any lender. Real rates depend on your credit, the lender and market conditions. We used 7% APR for an honest, no-dealer-fee loan and 3.99% for a "low-rate" loan that carries a 30% dealer fee, a fee size the Consumer Financial Protection Bureau found is common.
| Option | Amount financed | Monthly payment | Total paid | 25-year savings minus total paid |
|---|---|---|---|---|
| Cash | $0 | $0 | $25,000 | +$22,700 |
| 10-year loan, 7% APR (example) | $25,000 | $290 | $34,833 | +$12,900 |
| 20-year loan, 7% APR (example) | $25,000 | $194 | $46,518 | +$1,200 |
| 25-year "3.99%" loan with 30% dealer fee (example) | $32,500 | $171 | $51,410 | −$3,700 |
| 15-year HELOC, 8% (example, variable in practice) | $25,000 | $239 | $43,004 | +$4,700 |
A few things jump out:
- Cash wins on lifetime value by a wide margin. Payback in this example lands around year 15, and everything after that is profit.
- Shorter loans beat longer loans. The 10-year loan costs about $9,800 in interest; the 20-year loan costs about $21,500.
- The "low-rate" loan is the worst deal, even though its monthly payment is the lowest and its rate looks the best. The dealer fee added $7,500 to what you borrow before a single dollar of interest.
Month one: the cash-flow reality
Lifetime value is one lens. Monthly budget is another, and it's where many homeowners get surprised.
In year one, our example system saves about $117 a month. Every loan payment above is higher than that, so in the early years a financed system usually costs more each month than it saves. The 20-year loan is about $77 a month out of pocket at the start; the 10-year loan is about $173. As utility rates rise, the gap narrows, and once a loan is paid off the full savings are yours.
Anyone who tells you a financed system will be "cash-flow positive from day one" in Minnesota in 2026 should show you the math with a realistic rate, no federal credit and no dealer-fee-subsidized interest rate. Sometimes it works, for example with very high usage or a large Solar*Rewards incentive. Often it doesn't.
What about the return on cash you keep?
A fair objection to paying cash: that money could be earning something elsewhere. True, and worth weighing honestly. In our example, $25,000 of solar returns about $47,700 in bill savings over 25 years, which works out to a steady, tax-free reduction in a bill you'd otherwise keep paying. Compare that with what your cash realistically earns after taxes, not with a best-case market year.
The calculation also changes with your situation. If paying cash would empty your emergency fund, a loan is the safer move even though it costs more. If you're carrying credit card debt, paying that off first beats either option. And if you might sell the house within five years, the shorter your commitment and the smaller your fees, the better.
Finally, remember the example leaves out Xcel Solar*Rewards. If you secure a spot, the 10-year production incentive improves every row of the table, and it helps a financed system most in exactly the early years when the loan payment outruns your savings.
The dealer-fee trap
A dealer fee is a charge the lender takes from the installer, who raises the price of the system to cover it. The CFPB's 2024 report on solar financing found these fees typically run 10% to 30% of the cash price and can exceed 50%, and that they are usually left out of the cost-of-credit figures lenders show borrowers.
The giveaway is a gap between the cash price and the financed price. To protect yourself:
- Ask every installer for the cash price in writing, even if you plan to finance.
- Ask directly: "Does this loan carry a dealer fee, and how much is it?"
- Compare the total of payments across options, not the monthly payment or the rate.
- Be wary of loans that assume a lump-sum paydown around month 18. That structure was built for a 30% federal credit that homeowners can no longer claim.
Our post on predatory solar financing walks through real-world examples. iSolar offers a OneEthos solar loan with no dealer fee, so the financed system price matches the cash price.
The HELOC option
If you already have home equity, a home equity line of credit (HELOC) or home equity loan can be a reasonable way to pay for solar. Points to weigh:
- Rates are often variable. A HELOC payment can rise when rates rise. A fixed-rate home equity loan avoids that.
- Your home is the collateral. Missing payments puts your house at risk in a way an unsecured loan doesn't.
- Interest may be deductible. The IRS allows a deduction for home equity interest only when the money is used to buy, build or substantially improve the home that secures the loan, and only if you itemize. Ask your tax preparer whether solar qualifies for you.
- Closing costs and time. Opening a new line can take weeks and carry fees; an existing line is simpler.
Because you pay the installer directly from a HELOC, you also get the cash price, with no dealer fee in the picture.
How to choose
| If this describes you | Consider |
|---|---|
| You have savings beyond a solid emergency fund | Cash, for the best lifetime return |
| You want to keep cash available and plan to stay 10+ years | A shorter-term, no-dealer-fee solar loan |
| You have an existing low-rate HELOC | Drawing on the HELOC, if you're comfortable using home equity |
| You may move within a few years | Cash or a loan with no prepayment penalty; avoid long terms with large fees |
| Your household qualifies for income-based programs | Check Xcel Income-Qualified Solar*Rewards first; its $3.00/W incentive may cover most of the cost |
You can also mix them: a partial cash payment plus a smaller loan cuts interest while keeping some savings in the bank.
Run your own comparison
Use our solar payback calculator to test your own price, usage and rate, then read our financing options to see how cash and loan payments work with iSolar. When you're ready, request a free quote and we'll show your cash price and your financed price side by side.
Sources
Frequently asked.
Is it better to pay cash or finance solar panels?
Cash gives the best lifetime return because you pay no interest. Financing makes sense if you'd rather keep your savings, but choose a no-dealer-fee loan and the shortest term you can comfortably afford.
Do solar loans save money right away?
Usually not in Minnesota in 2026. Without the federal credit, most loan payments are higher than first-year bill savings, so you're paying a bit each month at first. The gap narrows as utility rates rise and disappears once the loan is paid off.
How do I know if a solar loan has a dealer fee?
Ask for the cash price and the financed price in writing. If they differ, the difference is usually a dealer fee. You can also ask the installer directly how much the lender charges them.
Can I use a HELOC to pay for solar panels?
Yes. A HELOC or home equity loan lets you pay the cash price, and interest may be deductible if the money substantially improves your home and you itemize. Keep in mind HELOC rates are often variable and your home secures the debt.
What happens to my solar loan if I sell my house?
Most solar loans are paid off at closing from the sale proceeds, much like other debts. Check whether your loan has a prepayment penalty and whether a lien or UCC filing is attached to the system.
Should I get a 10-year or 20-year solar loan?
A shorter term costs far less interest; in our example, about $9,800 versus $21,500. A longer term lowers the monthly payment. If the shorter payment fits your budget, it's usually the better deal.
Have a question we haven't covered?
Talk to a local iSolar expert — free, no pressure. Call (651) 565-1140.