How you pay for solar changes who owns the system, who captures the incentives, and what the whole thing costs over 25 years. The 2026 expiration of the homeowner federal credit reshuffled this comparison, so ignore any advice written before it.
Cash: cheapest, if you have it
Paying cash means no interest and full ownership — the production, the warranties, and the home-value uplift are yours. An 8 kW system at $2.75/W runs about $22,000 in 2026, with no federal credit to soften it for purchases after 2025. The real question is opportunity cost: cash into solar earns its "return" as avoided electricity bills, roughly 7–12% equivalent yield in high-rate states. Whether that beats your alternatives is a portfolio question, not a solar question.
Loan: ownership without the lump sum
Solar loans preserve ownership while spreading cost. The math is straightforward — interest raises total cost 20–40% over a 15–20-year term — but the pricing often isn't: many solar loans embed dealer fees of 15–30% into the quoted system price to buy down the advertised rate. Always ask for the cash price and the financed price side by side; the gap is the real cost of the loan. Full checklist in Solar Loans: What to Watch For.
Lease / PPA: the incentive flows elsewhere
Under a lease or power-purchase agreement, a company owns panels on your roof and sells you the output at a monthly rate, usually with a ~2.9% annual escalator. Here's the 2026 wrinkle: while homeowners lost the §25D credit, third-party owners can still claim the separate commercial credit (§48E) for a while longer — so leasing companies kept a subsidy that buyers lost, and lease offers now look artificially competitive against purchases. The catches are unchanged: 25 years of payments that usually exceed an owned system's cost, no home-value uplift (an active lease can complicate a home sale), and escalators that outpace flat utility rates.
How to actually decide
Run all three side by side in the Loan vs. Lease vs. Cash Comparator with your real quote. As a rule of thumb: cash wins if the money isn't needed elsewhere; a clean low-fee loan wins if you want ownership without the lump sum; a lease wins only if you can't use ownership at all and the escalated payment stream still beats your utility's trajectory.
Solar is one piece of a bigger household-finance picture. For decisions that touch your taxes, retirement timeline, or home equity, it can be worth talking to a financial advisor through a directory like AdvisorWorld — alongside primary sources such as DOE, DSIRE, and the IRS.