Solar Loans Above 4% Are a Financial Trap, Money Guy Brian Preston Warns

May 20, 2026 - 07:12

A caller to the Money Guy Show thought she had financed solar panels on a manageable 30-month loan. Brian Preston ran the numbers and told her the truth. At $120 a month against a $30,000 balance at 12% interest, she was actually looking at something closer to a 250-month obligation. That is 21 years of payments for a system that might not even last that long.

The gap between perception and reality is where solar loans become dangerous, Preston explained. Many homeowners focus on the monthly payment amount and assume the term matches what they heard from the salesperson. But when the interest rate climbs above 4%, the math shifts dramatically. At double-digit rates, the loan can stretch out for decades, eating up any savings the solar panels were supposed to provide on electric bills.

Preston pointed out that solar loans with high interest rates often get sold alongside promises of immediate savings. But if the interest on the loan cancels out the reduction in your power bill, you are not saving money. You are just shifting where the money goes. The homeowner in this case was paying $120 per month for 21 years. That adds up to over $30,000 in interest alone on top of the original $30,000 balance.

The lesson is simple. If you are going to finance solar panels, the interest rate needs to stay low. Anything above 4% starts to turn the deal into a long-term financial drain. And if the rate is in double digits, you are better off skipping the panels entirely until you can pay cash or find a better loan. Otherwise, you might end up paying for solar power long after the panels have stopped working.