"$0 down" solar: what it means and what it costs

Where the money actually goes

"Zero down" tells you something true and narrow: you will not write a cheque today. It says nothing at all about what the system costs, and in this market the two have come apart in a specific, documented way.

The Consumer Financial Protection Bureau's report puts the mechanism plainly. Solar-specific lenders "assess hidden fees that increase the amount of the loan principal above the cash price". Within the industry those fees go by several names, and the Bureau lists them: "program fees", "lending fees", "finance fees", "platform fees", "original issue discounts", and "dealer fees".

Then the Bureau's own worked example, verbatim: "consider a solar project that would cost $30,000 if the consumer paid in cash ('cash price'), with a $9,000 hidden fee (30 percent of the cash price)... The loan documents would show a loan principal of $39,000 plus interest. The lender would remit the $30,000 cash price to the installer and keep the $9,000 hidden fee."

The word doing the work there is keep. This is not the installer charging more. It is a fee added to what you borrow and retained by the lender, in exchange for offering a low advertised rate. On the Bureau's finding, fees like this "typically range from between 10 to 30 percent of the cash price but can exceed 50 percent".

And the Bureau notes what you are usually told about it: lenders "often do not indicate that these fees are a markup from the total cash price that consumers pay for the system installation", and "salespeople offering financing often do not explain the difference in the cash price and loan principal".

Why the interest rate can be low and true at the same time

The advertised rates on these loans are genuinely low. The Bureau found that "the stated annual percentage rates (APRs) on solar-specific loans typically range from 1 to 7 percent". That is a real number and nobody is lying about it.

The issue is what it is a rate on. Interest at 2.99% on $39,000 is more money than interest at 2.99% on $30,000, and the extra $9,000 is not a cost you would have had if you paid cash. The rate is low; the base it applies to is inflated. The Bureau's own qualification: those stated APRs "often do not include fees that increase the loan principal on top of the cash price of the solar panels".

We are not going to give you a number for how much this raises your true cost, and it is worth saying why. The Bureau published the stated-APR range and the fee range but did not publish a figure for the gap between advertised and effective cost. Any such number circulating is somebody's calculation on assumed inputs, not a regulatory finding. What we can tell you is exactly how to work it out for your own quote, which is the next section.

One more thing about term. The Bureau found that "solar-specific loan term lengths typically range from 8 to 25 years, but industry data show solar loans are typically repaid in 7 to 9 years due to prepayments". That gap between the term you sign and the term people actually run is not an accident, and it connects to the next problem.

The tax credit is not a discount, and the "net cost" is not the loan

The second problem the Bureau identified is about how the federal credit is presented, and it compounds the first.

Verbatim: "Many solar loan sales pitches promote the 30 percent federal 'Investment Tax Credit' for residential solar installations with a presumption of universality. However, the tax credit is not a guarantee, it depends on the consumer's federal tax liability."

That is the part that gets glossed. It is a credit against tax owed. A household with little or no federal tax liability may not be able to use all of it, or any of it, in the way a proposal assumes. The Bureau makes the distributional point explicitly: "Low-income consumers are less likely to receive a tax credit and therefore more likely to face unexpected costs."

Then the presentation problem: "Compounding the potential harm are solar loan marketing materials that deduct the presumed tax credit from the loan amount to present a so-called 'net cost.' This framing can hide the true cost of the loan by leading consumers to believe that the 'disclosed net cost' is in fact the loan principal."

So a proposal may show you a number that is neither the cash price nor the amount you are borrowing. It is the amount you are borrowing, minus a credit you have not received and may not fully receive. And the amount you are borrowing may already include a fee you were not shown.

Two subtractions and one addition, none of them labelled. That is why the single most useful question is about the number underneath all of it.

None of this makes solar financing a bad idea

The Bureau’s findings need care about what they do and do not establish, because the temptation is to over-read them.

They describe practices found in a market examination. They do not say every solar loan carries a hidden fee, they do not say every salesperson conceals the cash price, and they do not say financing is worse than paying cash for everyone. Borrowing at a low rate to buy a productive asset can be a perfectly sound decision.

What the findings do establish is that the pricing of these loans has a specific structure most borrowers are not shown, and that the structure makes ordinary comparison shopping unusually hard. If you cannot see the cash price, you cannot compare a solar loan to any other way of paying for the same equipment, and the whole normal machinery of consumer judgement stops working.

So the ask is small. Get the cash price. Get the principal. Get the total of payments. If those three numbers are on the table, an ordinary person can make an ordinary decision, and most of what is on this page stops mattering.