25 Questions to Ask a Solar Installer Before You Sign

The best questions for a solar installer produce something you can check: a license number, a company name, model numbers, a kWh estimate, a cash price and a written warranty. Ask every bidder the same 25 questions below, write the answers down, and compare them side by side. Each question says what a good answer sounds like and, where it matters, the answer that should end the conversation.

Before the first meeting: 10 minutes of prep

Have four things ready. They make vague answers easy to spot.

• Your last 12 months of electricity use in kWh. Your utility account or bills show it. An honest design starts here.
• Your roof’s age and condition. If it is close to replacement, that conversation comes before solar.
• What your utility pays for power you send to the grid. Net metering and export credits are set by your state and utility, so call the utility or check its website. The state incentive guides summarize state programs.
• Your state’s contractor license lookup, bookmarked, so you can check a license number the same day (steps below).

How to check a solar installer’s license

License rules are set by states and sometimes cities or counties. Depending on the state, solar work may need a general contractor license, an electrical license, or a solar specialty license. The FTC advises checking a company with your state contractor licensing board and state and local consumer protection agencies.

1. Get three things in writing: the company’s exact legal name, its license number, and the license type or class.
2. Find your state’s official license lookup. It is usually run by the contractor licensing board, or by the electrical board for electrical licenses. Search for your state’s name plus “contractor license lookup” and use the result on the state government’s site. California’s Contractors State License Board “Check a License” page is one example.
3. Confirm the details match: same legal name as the contract, status active, not expired, and a class that covers electrical or solar work. Note any listed discipline or complaints.
4. Not sure which license your state requires? The Interstate Renewable Energy Council’s National Solar Licensing Database summarizes solar licensing and certification requirements by state.
5. Ask about local registration. Your city or county may require its own contractor registration before it issues a solar permit.

NABCEP certification is different. The U.S. Department of Energy calls it the industry-standard certification for solar professionals, and you can look up a named person in NABCEP’s directory. It shows training and testing, but it does not replace a license your state requires.

Questions about the company

1. What legal company name goes on my contract, and what is its license number and class?
   Good answer: the exact entity name and a number you can verify tonight, matching the contract.
   Walk away if: “We work with licensed partners,” with no number.
2. Who sells, designs, installs and services the system?
   Good answer: each company named. Subcontracting can be fine, but the installing crew’s company should be named and licensed, and you should know whose workmanship warranty covers their work.
3. Can you send a current certificate of insurance?
   Good answer: a certificate from the insurer showing liability coverage and current dates, plus workers’ compensation where your state requires it.
4. How many years have you operated under this name, and can I talk to customers whose systems are three or more years old?
   Good answer: the company’s name history and references for similar roofs near you. A customer from last month can’t tell you how service works in year three.
5. Who is my contact after the system is turned on, and how fast do you respond?
   Good answer: a named service department, phone number, service area and a typical response time in writing, not “call the manufacturer.”

Questions about the roof and design

6. How did you size the system from my actual usage?
   Good answer: it refers to your 12 months of kWh and states how much of that use the system is designed to cover.
   Walk away if: a size was quoted before anyone asked about your usage.
7. What is the first-year production estimate in kWh, and what assumptions produced it?
   Good answer: one kWh figure plus the inputs behind it: roof direction and tilt, shade measured on your roof (not judged from the street), weather data and system losses. Ask whether the estimate already includes losses from heat, wiring and inverter conversion. A good installer says yes and shows them.
8. Is my roof ready to hold panels for 25 years?
   Good answer: the roof’s age and condition noted in writing, any structural review needed, and a plain recommendation to replace the roof first if it is near the end of its life. Taking panels off later costs real money; see solar panel removal and reinstallation.
9. What exact panel, inverter, optimizer, racking and battery models are you proposing?
   Good answer: model numbers in the proposal, so the contract can’t swap equipment without your approval. The solar equipment guide explains what each part does.
10. What are the DC system size, inverter AC size, and expected clipping?
    Good answer: kW DC, kW AC and the modeled kWh lost to clipping each year, rather than “don’t worry about it.”
11. What happens during a power outage?
    Good answer: a straight one. Without a battery, a grid-tied system normally goes down with the grid, according to the U.S. Department of Energy. With a battery, ask which circuits are backed up and how many kWh are usable.
12. What work is excluded?
    Good answer: a list covering roof repair, main-panel upgrade, trenching, tree work and utility fees, each either priced or marked “not included.”

Questions about price, financing and the contract

13. What is the total cash price, and the price per watt?
    Good answer: one number for the complete scope, divided by the system’s watts. Use it to compare bids in the solar quote guide.
    Walk away if: the conversation keeps returning to the monthly payment.
14. If I finance, what is the amount financed, the APR, the total of payments, and any dealer or lender fee?
    Good answer: both the cash price and the financed amount, with the difference explained. The CFPB found fees that raised some solar loan balances by 30% or more over the cash price (August 2024 report).
15. Does the monthly payment assume I make a large prepayment?
    Good answer: a payment schedule that shows what you owe if you never prepay. The CFPB found many solar loans re-amortize to a higher payment, often in month 19, unless the borrower prepays about 30% of the loan, an amount sized to the old federal credit.
    Walk away if: the low payment depends on a 30% tax refund you won’t get.
16. Which incentives am I eligible for in 2026, and who receives them?
    Good answer: named state, utility or local programs with their current status, plus a clear statement that the federal homeowner credit (Section 25D) is not available for systems installed after December 31, 2025, per the IRS. For a lease or PPA, the company that owns the system may claim its own business credit; any benefit to you shows up only in the written price. The contract should also say who keeps renewable energy certificates.
    Walk away if: a 30% federal credit is promised on a 2026 cash or loan purchase.
17. What does the savings estimate assume?
    Good answer: the yearly utility-rate increase, your utility’s export rate and your usage are written on the proposal. Ask for a version with no rate increase. The FTC notes future utility prices are hard to predict.
18. What happens if the system produces less than promised?
    Good answer: a written production guarantee that says how output is measured and how a shortfall is paid, or an honest explanation of why there isn’t one.
19. What is the payment schedule?
    Good answer: payments tied to defined milestones such as permit approval, installation, inspection and permission to operate.
20. How do cancellation and change orders work?
    Good answer: the cancellation deadline and method in writing, and a rule that any price change needs your signed approval. Sales made at your home may carry a federal three-day cancellation right; the solar scams guide explains when it applies.
21. For a lease or PPA: what is the escalator, and how do transfer, buyout and end of term work?
    Good answer: the yearly increase and its schedule, the transfer steps if you sell the house, a buyout price or formula, and what happens at the end of the term (renew, buy or remove). The solar lease exit guide covers each route.

Once you have the cash price and finance terms from every bidder, compare solar payment options using the total cost and obligations.

Questions about warranty, permits and handoff

22. What do the product, performance and workmanship warranties each cover, and does the workmanship warranty cover roof leaks at the attachments?
    Good answer: the years for each, in writing, with roof penetrations named. Equipment warranties come from manufacturers; the holes in your roof are the installer’s responsibility.
    Walk away if: “the panels have a 25-year warranty” is the whole answer.
23. Who files warranty claims and pays for labor, shipping and roof access, and who takes over if you close?
    Good answer: “We file the claim,” with labor coverage stated in years, plus whether the manufacturer’s warranty still applies if the installer goes out of business. See solar panel repair costs for what an uncovered claim can cost.
24. Who handles permits and the utility application, and how long do they take in my town?
    Good answer: the installer files both and gives a local range for permit, inspection and permission to operate, with what can delay each. A national average is a weak answer. The permits and inspections guide explains each step.
25. What documents and accounts will I get at the end, and who watches the monitoring?
    Good answer: plans, model and serial numbers, warranty registrations, inspection sign-off, permission to operate, and monitoring access in your name, plus whether anyone alerts you when production drops.

One-page bidder scorecard

Fill one column per installer. A blank row is a question to send back before you sign.

You don’t need perfect answers to all 25. You need honest, written ones. A company that hedges on its license, won’t give a cash price and promises an expired credit has already told you what you need to know; compare its pitch with the solar scam red flags.