12 Questions to Ask a Solar Installer Before You Sign

Why the questions matter more than the pitch

Most solar sales conversations are built to move you toward a signature, not to inform you. The presentation looks polished, the monthly payment sounds small, and the savings chart climbs neatly to the right. None of that tells you whether the deal is actually good. What tells you is how the installer answers direct questions, especially the uncomfortable ones about price, warranty, and what happens if something goes wrong.

A good installer welcomes hard questions because clear answers are how they win against cheaper, sloppier competitors. A high-pressure outfit gets vague, changes the subject, or leans on urgency. The twelve questions below are designed to surface that difference fast. They work best when you ask them of more than one installer, because the answers only mean something when you have something to compare them against.

Price and contract

1. What is the total cash price, and what is the price per watt? The total price and the price per watt are the only numbers that let you compare installers apples to apples. Monthly payments and "savings" figures can be engineered to look attractive. Get the cash price in writing even if you plan to finance.
2. What exactly is included in this price? Permits, inspections, electrical upgrades, roof penetrations, monitoring, and any trenching should all be spelled out. The cheapest quote often becomes the most expensive once "extras" are added later.
3. If I finance, what is the interest rate and is there a dealer fee built into the price? Many solar loans carry a hidden dealer fee that inflates the system price, sometimes by a large margin, in exchange for a low advertised rate. Ask for the cash price and the financed price so you can see the gap.
4. Is this price good if I take it home and decide next week? Honest pricing holds. A discount that vanishes unless you sign tonight is a closing tactic, not a real savings.

Equipment and production

5. What panel and inverter brands are you installing, and what are their warranties? Ask for specific models, not "tier one panels." Look at the product warranty, the performance warranty, and the inverter warranty separately, since they often differ.
6. How did you calculate my production estimate? A serious installer bases production on your roof's orientation, pitch, shading, and local sun data, not a generic statewide average. Ask what happens if the system underproduces against the estimate.
7. Do I actually need a battery, and why? Batteries add real cost. Sometimes they make sense for backup or for utilities that pay little for exported power, and sometimes they are oversold. Ask the installer to justify it for your specific situation.

Company, warranty, and service

8. What is your contractor license number, and how long have you installed in my area? Look the license up with your state board. Local track record matters, because the company has to still be around to honor the warranty.
9. Who handles the workmanship warranty, and for how long? There is a difference between the equipment maker's warranty and the installer's own labor warranty on the roof and wiring. Ask who you call if the roof leaks in year four, and get the answer in writing.
10. Can I speak to three customers you installed for locally in the past year? Recent, local references are hard to fake. Ask them about the install timeline, cleanup, and how the company responded to any problems.
11. What happens to my warranty if you go out of business or get acquired? Solar companies merge and close often. Ask whether equipment warranties are registered directly with the manufacturer and how service would be handled if the installer disappears.
12. What is the full timeline from signing to the system being switched on? Permitting and utility interconnection can take weeks or months depending on your area. A clear, honest timeline is a sign of an installer who has done this many times locally.

How to use the answers

Write the answers down for each installer in a simple side-by-side. You are not looking for the one with the smoothest pitch. You are looking for the one whose numbers are clear, whose warranty is real, and whose references check out, at a fair price per watt. Often the most honest installer is not the cheapest sticker and not the most expensive, but the one who answered every question without flinching.

This only works if you have more than one installer to compare. A single quote gives you nothing to measure against, which is exactly the position high-pressure sales reps want you in. Getting three competing quotes first means these twelve questions do real work, because you can see whose answers hold up.