What are typical solar loan interest rates?

Solar loan rates typically range from 5.99%–14.99% depending on your credit score, loan term, and lender. Solar-specific loans from companies like Mosaic, GoodLeap, and Dividend offer rates around 6–10% for qualified borrowers. Home equity loans or HELOCs often offer lower rates (5–8%) if you have sufficient home equity.

How long are solar loan terms?

Solar loans are typically available in 5, 10, 15, and 25-year terms. Shorter terms mean higher monthly payments but less total interest. A 10-year loan on a $16,000 system at 7% APR costs about $186/month and $22,300 total. A 25-year term lowers the payment to $113/month but increases total cost to $34,000.

What is the best solar loan term?

A 10-year solar loan at 6–9% APR is the most common and cost-effective for most homeowners. The monthly payment should be less than your current electric bill, ensuring day-one savings. Longer 20–25 year terms reduce payments further but significantly increase total interest paid. Never extend a solar loan beyond the system's expected life (25–30 years).

Are there solar-specific loan products?

Yes. Solar-specific loans from Mosaic, Sunlight Financial, GreenSky, and others are designed for solar and often unsecured (no home equity required). They typically offer better rates than personal loans but charge dealer fees (2–5%) that get built into the system cost. Compare the all-in APR — not just the stated interest rate — when evaluating solar loan products.

Solar Loan Calculator

Calculate your monthly solar loan payment, total interest cost, and net savings after financing. See whether your electricity savings exceed your loan payments from day one.

Loan Amount ($)

Interest Rate (%)

Loan Term (yrs)

Annual Savings ($)

About This Calculator

The Solar Loan Calculator helps you understand the real cost of financing a solar installation and whether the loan payments make sense relative to your electricity savings. Solar-specific loans have become the most popular way to go solar, with specialized lenders offering terms from 5 to 25 years at rates typically ranging from 3.99% to 8.99% depending on credit score and lender. Unlike leases, loans preserve your right to claim the federal tax credit and build full ownership equity — but the interest cost is real and worth quantifying before you sign.

The monthly cash flow figure is the most practically useful output: if your monthly electricity savings exceed your loan payment from day one, the system is cash-flow positive immediately — you spend less total per month with solar than without it. At $150/month in savings and a $130/month loan payment, you are cash-flow positive by $20/month from the start. The "Interest as % of Principal" result shows the true interest burden: a 7% loan over 12 years carries roughly 47% of the principal in total interest charges.

To get accurate inputs, request loan quotes from multiple lenders — your solar installer may have a preferred lender, but you should also check local credit unions, Mosaic Solar, LightStream, and GoodLeap. Compare APR (not just interest rate), origination fees, and prepayment penalties. Dealer fees charged by some solar lenders (sometimes 5–20% of loan amount) inflate the effective rate significantly — ask for the all-in APR. Your annual electricity savings can be estimated using the Solar Panel Savings Calculator.

Solar loans at reasonable rates remain one of the best financing tools available for home improvements, combining low interest rates (relative to HELOCs in rising-rate environments) with ownership, tax credit eligibility, and immediate bill reduction. The key is securing the right rate and understanding total interest cost before committing to a 12- or 25-year term.

Calculations based on NREL solar modeling data and industry-standard assumptions, built and maintained by the independent SolarToolsOnline research team.

Estimates only — not financial, tax, or legal advice. Verify important results with a licensed solar installer or financial professional before making decisions.