Solar Financing Attach Rate and Dealer Fees

Financing is no longer a side option in residential solar; it is how most systems get bought. That makes attach rate, the share of your jobs that are financed, one of the most important numbers in your operation, and it makes dealer fees one of the least understood costs in your pricing. The installers who manage both deliberately close more deals and protect their margin. The ones who treat financing as a black box that the lender controls end up surprised by the fees and exposed to complaints when buyers compare quotes.

Attach Rate Is an Operating Metric, Not a Detail

Attach rate is simply the percentage of sold systems financed with a loan, lease, or power purchase agreement instead of cash. Wood Mackenzie and EnergySage market data have shown loans dominating residential solar financing in recent years, so for most installers the attach rate is high by default. That is not a problem in itself; financing removes the upfront-cash barrier and lifts close rate. The problem is when an installer does not know what that financing is actually costing them, because every financed deal carries an embedded cost that a cash deal does not.

Track attach rate alongside the effective dealer fee per financed deal. Together they tell you how much of your volume depends on financing and what that dependence costs in net revenue. This is a soft cost like any other, which is why it belongs in the broader breakdown covered in where solar soft costs hide: the financing fee quietly raises the price homeowners see and lowers what reaches your bottom line.

How Dealer Fees Actually Work

A dealer fee is what a financing provider charges you to originate a low-rate solar loan. It is usually deducted from the amount you receive or folded into the financed system price. Lawrence Berkeley National Laboratory pricing research has documented that loan-financed solar carries meaningfully higher prices than cash systems, with the gap largely reflecting these embedded fees, which can add ten percent or more to the price. The mechanism is straightforward once you see it: the lower the advertised interest rate, the larger the dealer fee, because the lender has to recover the cost of buying that rate down. The homeowner sees an attractive rate; the cost was moved into the price rather than the rate.

This is why financed and cash quotes diverge, and why pretending they are the same invites trouble. A homeowner who gets a cash quote elsewhere and a financed quote from you will notice the difference, and the honest framing, that the low rate is funded by a fee in the price, is also covered from the sales side in selling solar ROI, where disclosing the fee is treated as protection against cancellations rather than a weakness in the pitch.

Disclosure Protects You

The instinct to bury the dealer fee is understandable and wrong. Regulators have increasingly scrutinized solar financing for exactly the gap between advertised rates and embedded costs, and the LBNL price difference is documented enough that a diligent homeowner can find it. Installers who explain that the low loan rate is funded by a fee built into the price, rather than hiding it, avoid the misrepresentation complaints that have followed the industry. Transparency also strengthens your monthly-payment pitch, because a homeowner trusts a number they understand over one that looks too good until they read the contract.

Give Homeowners the Comparison Up Front

The cleanest way to manage attach rate and protect trust is to let homeowners see the trade-off themselves before the first real conversation. A solar loan calculator on your website lets a homeowner compare their projected monthly payment against their energy savings, so they arrive understanding that financing converts payback into monthly cash flow. That clarity raises attach rate without surprises and hands your sales team the homeowner's financing preference as qualified lead data.

Choosing lender products deliberately, disclosing fees honestly, and qualifying financing preference early all compound with the rest of your unit economics, including the customer acquisition cost that each financed deal has to cover. The full lead-capture system that surfaces financing preference up front lives on the solar installer lead generation pillar.

The Loan-Versus-TPO Mix Is Shifting Again

For several years the residential solar story was the rise of the loan: homeowners wanted ownership and the tax credit, and loans let them have both without paying cash. That picture has started to move. In its U.S. Solar Market Insight commentary, Wood Mackenzie (the analysis it publishes jointly with SEIA) has noted a resurgence in third-party ownership, the lease and power purchase agreement (PPA) products in which a financier owns the system and the homeowner pays for the electricity or rents the equipment. Two forces are pushing the mix back toward TPO. The first is interest-rate pressure: when loan rates climb, the dealer fee needed to buy down an attractive advertised rate grows, and the monthly-payment math gets harder to sell. The second is that TPO lets the financier, who has the tax appetite a typical homeowner may lack, monetize the federal Investment Tax Credit directly and pass part of that value through in the lease or PPA pricing.

For an installer this is not an academic trend; it changes attach strategy and margin per product. A loan deal and a TPO deal carry different dealer-fee structures, different commissions, and different homeowner objections, so an installer who only knows how to sell one product loses deals at the margin when conditions favor the other. The practical move is to treat the loan-versus-TPO mix as something you steer rather than something the market hands you, and to know your net margin on each product separately so you can read a mix shift as a margin event, not just a volume one.

Attach Rate and Approval Rate Are Different Numbers

Financed solar runs on lender credit approval, and that is the constraint a high-attach strategy quietly runs into. A homeowner can want a loan, and your salesperson can pitch one perfectly, and the deal still stalls because the lender declines the application or only approves it at a worse tier than the advertised rate assumed. Solar lenders price by credit tier, the same way auto and home lenders do, so a homeowner's FICO band largely determines whether they qualify for the headline rate, a higher rate, a larger required down payment, or nothing at all. EnergySage and lender disclosures consistently describe this tier dependence, even though the exact share of declined applicants varies by lender and by the mix of homeowners a given installer serves.

That is why attach rate and approval rate deserve separate tracking. Attach rate tells you how many sold systems were financed; approval rate tells you how many homeowners who wanted financing could actually get the product you pitched. If your approval rate is soft, a flashy advertised rate is doing you less good than it looks, because a meaningful slice of your pipeline never qualifies for it. Watching the two numbers side by side keeps you honest about where deals really die, and it tells you when the answer is a different lender or a cash and TPO alternative rather than a better script.

Ownership, the ITC, and Why It Changes the Pitch

The single fact that reshapes every financing conversation is who owns the system, because ownership decides who claims the tax credit. With cash or a loan the homeowner owns the system and claims the federal residential clean-energy credit themselves; with a lease or PPA the third-party financier owns it and claims the credit instead, then reflects part of that value in the customer's rate. SEIA's explainer material on the Investment Tax Credit lays out this ownership-and-tax distinction, and it is the reason loan and TPO products are priced and pitched so differently. A loan proposal can lean on the homeowner capturing the credit; a TPO proposal cannot, and has to win on simplicity, maintenance coverage, and predictable payments instead.

Getting this wrong in a proposal is a compliance and trust problem, not a rounding error. A salesperson who implies a leasing customer will personally receive a tax credit they are not entitled to has set up a cancellation, a complaint, and possibly a regulatory inquiry. The discipline is simple: state plainly which party owns the system and therefore which party claims the credit on every quote, and never let the tax-credit framing migrate from a loan or cash deal onto a TPO deal where it does not apply.

One Lender Is a Single Point of Failure

Many installers run their entire financed pipeline through a single provider because it is simpler, and that simplicity is a hidden risk to attach rate. A lone financing partner can raise its dealer fees, tighten its credit box, reprice its advertised rates upward, or exit residential solar entirely, and any one of those moves can crater your financed volume overnight with no warning and no alternative ready. The solar finance market has seen exactly these shocks as rates moved and several providers retrenched, so the exposure is not hypothetical. Carrying two or three lender relationships is the cheapest insurance an installer can buy against it.

Redundancy does more than protect against an outage. With multiple lenders you can route a marginal-credit homeowner to whichever partner has the friendlier credit box, compare dealer fees on the same loan term, and keep negotiating leverage that a captive single-provider installer simply does not have. The cost is a little more operational complexity in your sales tooling; the payoff is that no single counterparty controls whether your customers can buy from you.

A Simple Cash, Loan, or TPO Decision Framework

Steering a homeowner to the right product comes down to three readable inputs: tax appetite, credit tier, and cash position. A homeowner with cash on hand and the tax liability to use the credit is usually best served by cash or a short loan, because they avoid the embedded dealer fee and capture the full ITC themselves. A homeowner with strong credit but no spare cash is the natural loan customer: they keep ownership and the tax credit while spreading the cost. A homeowner with thin credit, little tax liability, or no desire to manage a system is the clearest TPO candidate, since the financier carries the credit and the maintenance and the customer just buys predictable power.

The dealer-fee math behind that steering is worth making concrete, with round numbers labeled purely illustrative. Suppose a 25,000 dollar system. Lender A advertises a low rate but charges a 20 percent dealer fee, so roughly 5,000 dollars of fee is buried in the price and the homeowner finances about 30,000 dollars. Lender B advertises a higher rate with only a 10 percent fee, burying about 2,500 dollars and financing roughly 27,500 dollars. The headline rate makes Lender A look better, but the homeowner pays for the deeper fee through a larger balance, and your net per deal can be thinner too. These figures are illustrative, not quoted; the point is that comparing advertised rates without comparing dealer fees on the same system size and term tells you almost nothing about which product is actually cheaper for the customer or healthier for your margin. Track the effective fee per financed deal, not the marketing rate, and the right product choice usually becomes obvious.