Solar Loan vs Lease vs PPA vs Cash 2026: True 25-Year Cost Compared

Side-by-side 25-year economics for the four common ways to pay for residential solar: cash, loan, lease, and PPA. On an 8kW system, cash totals $15,680 net out-of-pocket; loan totals about $34,140 over 15 years; lease totals $40,000-$50,000 over 25 years; PPA totals $45,000-$60,000. The major driver of the divergence: who claims the 30% federal ITC. Cash and loan keep ITC with the homeowner; lease and PPA transfer ITC to the finance provider. That's a $6,720 swing on this system, half or more of which flows to provider margin rather than back to the customer.

25-Year Total Cost: 8kW System

Path	Upfront	Annual cost (yr 1)	25-yr total	Owner of ITC?
Cash	$22,400	$0	$15,680 net	Homeowner
Loan (15 yr, 9% APR)	$0	$2,724	$34,140 net	Homeowner
Lease (25 yr, 2.9% escalator)	$0	$1,440	$50,000	Lease company
PPA (25 yr, $0.16/kWh, 2.9% esc)	$0	$1,920	$66,000	PPA provider

Loan total assumes $22,400 system with no dealer markup; real-world loan quotes typically include 20-30% dealer fees raising effective cost. Lease and PPA assume typical residential terms. PPA annual cost based on 12,000 kWh/yr production at $0.16/kWh starting rate.

The Cash Path

Cash purchase delivers the lowest total cost and highest 25-year NPV. The math: pay $22,400 upfront, claim $6,720 federal ITC on your following-year tax return, net $15,680. From there, all solar production accrues as electricity bill savings to the homeowner. No interest, no payments, no escalator, no transfer of ITC.

Opportunity cost consideration: that $15,680 could have stayed invested in a brokerage account earning some rate of return. At 7% real return over 25 years, $15,680 grows to $85,000. Annual solar savings of $1,800/yr (typical for 12,000 kWh production at $0.15/kWh) compounded at 7%: $113,000. Net opportunity cost: solar wins by $28,000 over the 25-year horizon. Adjust for your own expected return rate; the math holds.

Liquidity consideration: $15,680 is meaningful liquidity to commit. Cash works if you have the surplus available, don't need to maintain emergency fund flexibility, and your alternative investment opportunities don't materially exceed the solar internal rate of return (typically 7 to 12% IRR depending on your state).

The Loan Path

Solar loans from specialised solar lenders (GoodLeap, Sunlight Financial, Mosaic, EnerBank, LightStream) are the most common path for homeowners who want ownership but lack upfront cash. Typical terms: 5 to 25 years, 6 to 12% APR, no down payment, no prepayment penalty.

The hidden cost: dealer fees. The solar finance industry has converged on a structure where the installer adds a 15 to 30% markup to the loan principal that's not present in the cash quote. On a $22,400 cash-equivalent system, the loan principal might be $27,776 ($5,376 dealer fee built in). This is on top of the headline APR. Effective loan cost is meaningfully higher than the APR suggests.

How to navigate: always ask for the cash-equivalent price separately from the loan price. The cash price reveals the true system cost. The dealer fee is the cost of having someone else finance the install; treat it as part of the loan cost.

Home equity alternative: HELOC or home equity loan at 7 to 9% APR (current 2026 rates) usually beats a solar loan because there's no dealer fee. You pay the cash quote out of HELOC proceeds. The HELOC interest may be tax-deductible (if used for home improvement, which solar qualifies). Many financially-savvy homeowners use HELOC instead of dealer-fee-laden solar loans.

The Lease Path

Solar leases first appeared in 2008-2010 (SolarCity pioneered) and dominated residential solar through about 2018. Currently still a meaningful share (~25% of installs in 2024 per Wood Mackenzie tracking) but declining as homeowners get smarter about the long-term economics.

Lease structure: the lease company (Sunrun, Sunnova, ADT Solar, Solar Mosaic) installs the system on the homeowner's roof at no upfront cost. The homeowner pays a fixed monthly lease for 20-25 years, with an annual escalator (typically 2.9 to 3.5%) baked in. The lease company owns the system and claims the federal ITC.

Pros: zero upfront cost, no credit check beyond standard background, system maintenance included (lease company handles inverter replacements, warranty issues), monthly payment fixed.

Cons: 25-year total cost is 2.5 to 3.5x the cash equivalent. Annual escalator means payment grows year-over-year. Equipment ownership doesn't transfer until the buyout option period (typically year 5-7), and the buyout prices are typically above fair market value. Home resale becomes complicated (the lease must transfer to the buyer or be paid off). Future utility-rate changes (NEM 3.0 in CA, etc.) don't reduce your fixed lease payment.

The PPA Path

Power Purchase Agreement (PPA) structure: the provider installs the system, owns it, and sells you the electricity it generates at a per-kWh rate. Typical: $0.13 to $0.18/kWh starting rate, with an annual escalator (2 to 4%).

The PPA rate is initially lower than retail electricity rate, so the homeowner sees an immediate bill reduction. Over time, both the PPA rate and the retail electricity rate escalate; if the PPA escalator is higher than the utility's actual rate growth, the PPA can eventually cost more per kWh than buying from the utility directly. This happens occasionally in real-world cases.

Total 25-year cost is similar to or higher than lease. PPA total depends on production: high-production years cost more than low-production years (you pay per kWh). Lease total is fixed regardless of production.

Same major drawbacks as lease: ITC transfer to provider, no equity build, complicated home resale, high buyout prices.

Decision Framework

Choose cash if: You have the liquidity, you plan to stay in the home 10+ years, your investment alternatives don't materially exceed solar IRR (7-12%), and you want simplest long-term ownership.

Choose loan if: You don't have upfront cash but have decent credit and want ownership benefits (ITC, equity, simple resale). Prefer HELOC or home equity loan over dealer-fee-laden solar loan when possible.

Choose lease or PPA if: You have poor or no credit history that disqualifies you from a loan, OR you're certain you'll move within 5-7 years and don't want to coordinate ownership transfer, OR you cannot use the ITC (no federal tax liability) and want some pass-through of the credit value via lower payment. These are narrow cases.

For most homeowners with adequate credit and tax liability to use the ITC, cash or loan ownership is meaningfully better long-term economics than lease or PPA.

Frequently Asked Questions

Which solar financing option is cheapest over 25 years?

Cash purchase wins outright on total cost. Example for an 8kW system: $22,400 gross / $15,680 net after federal ITC, then $0 of additional payments over 25 years. Loan: $28,000 to $32,000 total (cost + interest). Lease: $40,000 to $50,000 in lease payments over 25 years. PPA: $45,000 to $60,000 in PPA payments. Cash wins by 50 to 70% over lease/PPA across the lifecycle. The catch: cash requires the full $15,680 net upfront.

Why do installers push lease and PPA?

Three reasons. First, installer revenue: lease and PPA deals deliver the installer a larger total contract value (the lease company pays the installer the full system cost minus the lease finance company's margin, plus the installer often gets origination commissions). Second, qualification: lease and PPA don't require homeowner credit qualification for a loan, so they convert more sales. Third, the homeowner pays nothing upfront, so closing the sale is easier. The economics of these deals favor the lease company and installer; the homeowner gets a smaller share of the long-term savings.

Who claims the federal ITC on a lease or PPA?

The lease company or PPA provider claims the 30% federal ITC, not the homeowner. This is a major distinguishing factor of lease/PPA vs ownership (cash or loan): the $4,200-$8,000 federal credit on a typical system goes to the corporate provider, not the household. The provider does pass through some of that value as a lower monthly payment, but typically only 30-50% of the credit value reaches the customer. The remaining 50-70% becomes provider margin.

What about a solar loan?

A solar loan keeps ownership with the homeowner: you get the 30% federal ITC and any state credits. Cost: 7-12% APR typical for solar loans from GoodLeap, Sunlight Financial, Mosaic, LightStream, and other solar lenders. On a $22,400 system financed at 8.99% APR over 15 years, monthly payment is about $227, total payback $40,860 (principal $22,400 + interest $18,460). Subtract the ITC ($6,720 claimed in year-1 tax return) and net out-of-pocket is $34,140. Still more than cash ($15,680 net) but the homeowner keeps the ITC.

What are dealer fees on solar loans?

Solar loan dealer fees range from 15% to 30% of the system cost. On a $22,400 system with 24% dealer fee, the loan principal is $27,776 even though the system costs $22,400. Cash-equivalent quote ('what's the price if I pay cash?') is usually $4,500-$8,000 less than the loan quote. The dealer fee is a finance company markup paid to the installer for originating the loan. Always ask for the cash-equivalent quote separately from the loan quote. The cash difference is your effective loan cost above the headline APR.

What's the difference between lease and PPA?

Lease: fixed monthly payment (e.g., $120/month for 25 years with 2.9% annual escalator), you get all the solar production, regardless of how much it actually generates. PPA: per-kWh payment (e.g., $0.16/kWh of production, escalating 2.9%/year), you pay for what's produced. Practically similar for the homeowner: both are 20-25 year contracts with the solar company, neither builds equity, both transfer ITC to the provider. PPAs have slightly more upside in below-expected production years and downside in above-expected years; leases are flat regardless.

Can I buy out a lease or PPA?

Yes, but the buyout prices set in lease/PPA contracts are typically higher than what the equipment is worth. Standard contract terms include a 5-year or 7-year buyout option (after which the homeowner can purchase the equipment for fair market value as defined in the contract). Real buyout prices on 5-7 year old systems run $12,000 to $18,000 for equipment that has perhaps $5,000 to $8,000 of fair market value. Buyouts make financial sense only if you're selling the home and the buyer won't accept the lease transfer.