Solar: Cash vs. Loan
Solar's high upfront cost makes financing common, and understanding exactly what that financing costs against paying cash is one of the most consequential decisions in the whole purchase.
At your inputs, paying cash costs $1,400 less over 10 years.
| Pay cash total cost over the horizon | $23,000 |
|---|---|
| Finance with a solar loan total cost over the horizon | $24,400 |
Breakeven: The higher upfront cost is offset by year 9.2, after which paying cash stays cheaper.
- This uses planning estimates you entered, not a contractor quote or guaranteed savings.
- This treats financing cost through the annual payment you enter; use the solar loan payment tool for an exact schedule.
What this also tells you: If your annual costs are 20% higher or lower than entered, the recommendation could flip: it ranges from $2,080 favoring financing with a loan to $4,880 favoring paying cash.
This is a planning estimate based on your entries. It does not size equipment, determine electrical or building-code compliance, verify incentive eligibility, or replace a contractor quote or professional energy audit.
Why this decision comes up
Few homeowners have $16,000 or more in cash readily available for solar, and understanding the real cost of financing versus paying cash is central to the decision.
How this is calculated
Both paths are compared as total cost over your ownership horizon: net cost plus annual cost carried forward. The financed path's annual cost should include the loan payment.
A worked example
With the defaults (cash: $16,000 upfront, $700/year; financed: $0 upfront, $2,440/year; 10-year horizon), cash totals $23,000 against $24,400 for financing, a $1,400 advantage for cash at these defaults, reflecting the interest cost baked into the financed option's higher annual payment.
Common mistakes
A common mistake is comparing a financed system's monthly payment against the sticker price of paying cash, rather than the full total cost over the same horizon.
Limitations
This does not model your loan's exact amortization; it uses whatever annual cost you enter. See the solar loan payment tool for an exact monthly payment.
Common questions
How should I estimate my financed annual cost?
Add your loan payment to any remaining electricity cost solar doesn't cover. Use the solar loan payment tool to compute an exact monthly payment from your principal, APR, and term first.
Do you own the system either way?
Yes, both cash and loan financing mean you own the system outright, unlike a lease or PPA where a third party retains ownership. See those tools for that different structure.
Does a 0% promotional solar loan change this?
Yes, if you genuinely qualify for a 0% loan with no added fees, the financed path's annual cost should reflect only the principal repayment, no interest, which changes this comparison significantly.
Does a home equity loan work the same way as a dedicated solar loan?
The comparison logic is the same regardless of loan type. Use your actual loan's rate and term to compute the annual cost figure this tool needs.
What if I plan to pay off the loan early?
An early payoff reduces total interest paid compared to the full-term schedule. If you're confident you'll do this, that changes your effective financed annual cost in cash's favor, though less dramatically than a full-term loan comparison suggests.