Financing
Enter your system price and APR. Compare a 10-year loan, a 15-year loan, and a cash purchase side by side, options especially relevant on a fixed income.
How it works
Step 1
Use a real quote from an installer and the APR from a lender, or a typical current rate if you're still in the early research stage.
Step 2
Shorter terms and cash purchases tend to matter more for retirees prioritizing predictability over the lowest possible monthly payment. The 10-year loan term calculator and 15-year loan term calculator go deeper on each option individually.
Step 3
Cash has the lowest total cost now that no federal credit applies to either path, but check how much of your savings that would use before deciding a shorter loan isn't the more comfortable option.
The federal residential solar tax credit expired for systems installed after December 31, 2025. All three totals shown here reflect the full system price with no credit applied, which is the accurate picture for a 2026 purchase regardless of tax liability. If you installed by that deadline and have unused credit carrying forward, the carried-forward credit tool covers that narrower situation. The IRS Form 5695 instructions confirm the current eligibility rules.
A shorter loan term means less total interest paid and a clearer end date that fits within a retirement planning horizon, both valuable when income is fixed rather than expected to grow. On a $24,000 system at 6.99% APR, a 10-year loan totals about $33,424 with a $279 monthly payment, while a 15-year loan totals about $38,805 with a lower $216 payment, a tradeoff between monthly affordability and total cost. The total cost of ownership calculator can help you compare that tradeoff against your specific numbers.
Paying cash outright avoids all loan interest entirely, totaling $24,000 on the same system, meaningfully less than either loan option now that no tax credit applies to either path. For a retiree with sufficient savings who won't need that cash for other near-term purposes, this is often the lowest total-cost path, though it does mean giving up liquidity. Your rate depends heavily on your credit, and the Consumer Financial Protection Bureau's guide to credit reports and scores explains how scores and reports work.
Paying cash saves the most in total dollars, but retirement often comes with a greater emphasis on keeping accessible savings for healthcare costs, unexpected repairs, or other needs. If depleting your cash reserves for a cash purchase would leave you uncomfortable, a shorter loan term is a reasonable middle path that still limits total interest compared to a longer term.
Have a clear sense of your available cash beyond an emergency fund and how a monthly payment would fit into your fixed income budget before choosing between these paths. The cash purchase vs financed payback comparison goes deeper into that specific tradeoff, and the monthly budget fit calculator can help confirm a loan payment fits comfortably within a fixed income. A roof that needs work changes the loan amount. The roof replacement cost calculator in our Solar + Roofing Integration section can help you check re-roofing costs before you finance.
Questions
It depends on available cash and how much of a monthly payment fits your fixed income budget. On a $24,000 system, a 10-year loan at 6.99% APR totals about $33,424 with a $279 monthly payment, a 15-year loan totals about $38,805 with a lower $216 payment, and paying cash outright totals $24,000, the lowest total cost if the cash is available without depleting emergency savings.
A shorter term means the loan is paid off within a more predictable planning horizon and accrues less total interest, both of which can matter more on a fixed income where minimizing long-term obligations is often a priority over minimizing the monthly payment.
No, the federal residential solar tax credit expired for systems installed after December 31, 2025, so it no longer factors into this comparison for a new purchase, regardless of tax liability. If you installed by that deadline and have unused credit carrying forward, it can still be claimed on a prior year's return.
Cash avoids all loan interest and is often the lowest total-cost option if the funds are available without depleting emergency savings needed for other purposes. Weigh the tradeoff between locking up that cash and the interest saved carefully, since liquidity can matter more in retirement than earlier in life.
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