Rooftop Solar · Buyer Education
10 questions to ask any
rooftop solar installer
before signing
The average Sol Country visitor who goes into an installer conversation informed gets a better system at a better price. These are the questions that separate good installers from bad.
Before you talk to any installer, find out which programs exist where you live — net metering rules, SREC markets, HEAR rebates, and utility incentives. Then ask these 20 questions, in writing, of every company that quotes you. The federal 30 percent residential credit (Section 25D) expired December 31, 2025, so a 2026 quote that still applies it to a cash or loan purchase is wrong. Sol Country does not compare quotes for you. We make sure you know what to ask, then point you at EnergySage, which does quote comparison better than anyone.
Last updated August 2026
Step one
Know your programs before
the sales call
Installers are not obligated to tell you about every program you qualify for, and many salespeople genuinely do not know the details. Walking in already knowing your state's net metering rules and rebate landscape changes the entire conversation.
The short list
The 10 questions
Ask all ten on the first call. Send them by email so the answers are written down. A good installer will not mind - the ones who do mind have just told you something useful.
Question 01
Are you NABCEP certified, or do you have NABCEP certified installers on your team - not just subcontractors?
Why it mattersNABCEP certification requires extensive training and testing. 'Our team includes NABCEP certified professionals' is different from 'we use a NABCEP certified subcontractor on some jobs.'
Question 02
What warranties do you offer, and who backs them - you or the manufacturer?
Why it mattersA 25-year workmanship warranty backed by a small local installer is worth less than a 10-year warranty backed by a large company. Ask who you call in year 15 if something goes wrong.
Question 03
Do you handle permitting and utility interconnection, or is that my job?
Why it mattersPermitting delays are the number one cause of solar project frustration. Installers who handle interconnection in-house move faster and are accountable for delays.
Question 04
Is this quote itemized? What does it include, and what does it not include?
Why it mattersHidden fees for monitoring, critter guards, electrical panel upgrades, and roof reinforcement can add $1,000 to $5,000 to a quote that looked competitive.
Question 05
Are you registered for my state's SREC or incentive program, and will you handle the application on my behalf?
Why it mattersIn New Jersey, Illinois, and other SREC states, registration must happen before construction begins. Missing that step can permanently disqualify the system from program payments.
Question 06
Do you use subcontractors for any part of the installation?
Why it mattersSubcontractors are not inherently bad, but the installer should be transparent about it. Accountability gets murky when multiple companies are involved.
Question 07
How do you size the system? What data are you using?
Why it mattersAn installer who sizes from your actual 12 months of utility bills and local sun hours is more reliable than one using generic estimates. Ask to see the solar irradiance data they used.
Question 08
What happens if my roof needs work in the next five years?
Why it mattersRemoving and reinstalling panels for roof work costs $1,500 to $3,000. Ask about roof condition requirements before installation and what your options are if you need roof work later.
Question 09
Will you add a battery now or later? Is the inverter battery-ready?
Why it mattersIn California under NEM 3.0, adding a battery alongside solar is almost always better economics than retrofitting later. In other states, at minimum confirm the inverter is battery-ready so you keep the option.
Question 10
What is your timeline from contract to energized system?
Why it mattersPermitting, interconnection approval, and installation scheduling mean most systems take two to four months from contract to generating power. Unrealistic timelines are a red flag.
Bonus question
If I'm in a signed balcony solar state, can you also install a balcony solar system?
Why it mattersMost rooftop solar installers do not offer balcony solar, but some do. If you rent, or want a smaller system first, ask. You might not need to find a separate company.
Going deeper
The full 20
Ask all of them. Send them by email so the answers are written down. A good installer will not mind — the ones who do mind have just told you something useful.
Group 1 · The company
Most rooftop solar complaints come down to who did the work, not which panel went on the roof. Start here.
Question 01
Are you the company that will physically install my system, or do you subcontract?
Why it mattersSales organizations and installers are often different companies. If a subcontractor does the work, your warranty conversation gets complicated fast.
A good answer sounds likeA direct answer either way, plus the name of the crew's employer and who to call if something leaks two years from now.
Red flagVague answers like 'we have partners in your area' or refusing to name the installing entity.
Question 02
What is your license number in this state, and who holds it?
Why it mattersElectrical and roofing work is licensed at the state level. You can verify a license number in minutes on your state licensing board's website.
A good answer sounds likeA number you can look up, held by the company doing the work, not a borrowed license from another firm.
Red flag'We're fully licensed and insured' with no number offered.
Question 03
How many systems have you installed in my utility's territory in the last 12 months?
Why it mattersInterconnection paperwork and inspection quirks are utility-specific. Local volume predicts how smoothly your permit-to-power goes.
A good answer sounds likeA specific number and a couple of nearby install addresses or references.
Red flagNational totals used to dodge the local question.
Question 04
Who handles the permit, inspection, and utility interconnection application?
Why it mattersThe gap between install day and permission to operate is where most timelines slip. Someone has to own it.
A good answer sounds likeThe installer owns all three, in writing, with a typical timeline in weeks for your jurisdiction.
Red flagAny part of it pushed onto you as the homeowner.
Group 2 · The production estimate
The number that decides whether solar pays off is annual kWh production. Ask how it was calculated.
Question 05
What tool produced my production estimate, and can I see the shading analysis?
Why it mattersA modeled estimate from PVWatts, Aurora, or Helioscope with real shade data is auditable. A number typed into a sales slide is not.
A good answer sounds likeA named tool, a shade report from your actual roof, and annual kWh in year one.
Red flagAn estimate with no shading input, or a refusal to share the underlying report.
Question 06
What annual degradation rate did you assume, and what does year 25 look like?
Why it mattersPanels lose output every year. A savings pitch built on year-one production overstates lifetime value.
A good answer sounds likeA stated rate (commonly 0.25 to 0.55 percent per year, per the panel warranty) applied in the savings model.
Red flagFlat production for 25 years in the savings table.
Question 07
What electricity rate escalation did you assume?
Why it mattersAggressive utility rate inflation is the easiest way to make any system look like a bargain.
A good answer sounds likeA stated percentage with a source, ideally your utility's own filed history rather than a national average.
Red flagAnything at or above 5 percent per year with no source.
Question 08
Is there a production guarantee, and what happens if we miss it?
Why it mattersA guarantee turns the estimate from marketing into a contract term.
A good answer sounds likeA written guarantee with a percentage threshold, a measurement method, and a cash remedy.
Red flag'We've never had a system underperform.'
Group 3 · Price and financing
Section 25D, the 30 percent federal residential credit, expired December 31, 2025. Any quote still pricing it in is out of date.
Question 09
What is the total price in dollars per watt, before and after every incentive?
Why it mattersDollars per watt is the only number that compares cleanly across quotes and system sizes.
A good answer sounds likeGross price, system size in DC watts, dollars per watt, and each incentive listed separately with its source.
Red flagOnly a monthly payment, or a 'today only' discount.
Question 10
If this is a loan, what is the APR and is there a dealer fee built into the cash price?
Why it mattersLow-APR solar loans are frequently funded by a dealer fee added to the system price. You pay it either way.
A good answer sounds likeThe APR, the term, and the cash price with the dealer fee stripped out so you can compare.
Red flagRefusing to quote a cash price alongside the financed price.
Question 11
If this is a lease or PPA, what is the escalator and what happens when I sell the house?
Why it mattersEscalators compound for 20 to 25 years, and an unassumable agreement can complicate a home sale.
A good answer sounds likeA stated escalator (zero is best), transfer terms in writing, and a buyout schedule.
Red flag'The escalator is standard' with no number.
Question 12
For a lease or PPA, are you claiming the Section 48E credit, and does the system meet the domestic content rules?
Why it matters48E runs through 2027 for third-party-owned systems, but domestic manufacturing requirements can affect whether the credit lands and how the deal is priced.
A good answer sounds likeA clear yes or no on 48E, and a straight answer about equipment sourcing.
Red flagConfusion between 25D and 48E, or a promise that you personally get a 30 percent credit on a leased system.
Group 4 · Equipment and warranties
Three warranties matter, and they are usually held by three different companies.
Question 13
Exactly which panels and inverters, by model number?
Why it matters'Tier 1 panels' is a marketing phrase, not a spec. Model numbers let you read the actual datasheets.
A good answer sounds likeModel numbers on the proposal, matching what shows up on install day.
Red flag'Or equivalent' language with no approval step before substitution.
Question 14
What are the three warranty terms: product, performance, and workmanship?
Why it mattersPanels and inverters are warrantied by their manufacturers. The roof penetrations and labor are warrantied by the installer, and that is the one that fails when a company closes.
A good answer sounds likeWritten terms for all three, with the workmanship term at 10 years or more.
Red flagA single 25-year number covering everything.
Question 15
What happens to my workmanship warranty if your company goes out of business?
Why it mattersSolar installer turnover is real. Manufacturer warranties survive; labor warranties often do not.
A good answer sounds likeAn honest answer, plus whether the warranty is backed by a third party or insurance.
Red flagTreating the question as an insult.
Question 16
How does this system handle a future battery or EV charger?
Why it mattersRetrofitting storage onto a system that was not planned for it can mean new equipment and another permit.
A good answer sounds likeA note on inverter type, main panel capacity, and what a later battery addition would involve.
Red flagNo answer, or an upsell pitch instead of an answer.
Group 5 · Roof and after-install
Your roof is the mounting surface and the thing most likely to generate a claim.
Question 17
How many years of roof life are left, and do you recommend re-roofing first?
Why it mattersRemoving and reinstalling an array to replace shingles typically costs thousands.
A good answer sounds likeA candid assessment, including telling you to wait or re-roof first.
Red flagNever mentioning roof age at all.
Question 18
How are penetrations flashed and sealed, and is that covered in writing?
Why it mattersLeaks are the most common post-install complaint on rooftop solar.
A good answer sounds likeA named flashing method and roof-penetration coverage inside the workmanship warranty.
Red flag'Our crews are careful.'
Question 19
How do I monitor production, and who watches for faults?
Why it mattersA dead inverter can go unnoticed for months if nobody is monitoring.
A good answer sounds likeMonitoring app access on day one, plus whether the installer proactively alerts on outages.
Red flagMonitoring sold as a paid add-on with no baseline visibility.
Question 20
Can I have the full contract to read overnight before I sign anything?
Why it mattersEvery legitimate installer says yes. This is the single most useful question on the list.
A good answer sounds likeYes, without friction, and the price is the same tomorrow.
Red flagPricing that expires when the salesperson leaves your kitchen.
Section 25D, the 30 percent residential credit for systems you own, expired December 31, 2025. Section 48E still applies to third-party-owned systems (leases and PPAs) through 2027, and to standalone battery storage on a longer runway. If a salesperson blurs those two, slow the conversation down. More on financing →
Step three
Walk away signals
None of these guarantee a bad installer. All of them justify getting another quote before you sign.
A discount that expires today
Solar equipment pricing does not change hourly. Deadline pressure exists to prevent you from getting a second quote.
A quote that still includes the 30 percent federal residential credit
Section 25D expired December 31, 2025 for homeowner-owned systems. A proposal that still applies it to a cash or loan purchase is either outdated or misleading.
'Free solar' or 'the government is paying for it'
Usually a lease or PPA with an escalator. Those can be reasonable deals, but they are not free and you do not own the system.
Signing on a tablet before you have read the contract
Ask for the PDF. Read the escalator, the transfer clause, and the cancellation window.
No mention of your roof's age or condition
A salesperson optimizing for a signature will skip the conversation that could delay the sale.
Only one quote
Dollars per watt varies widely between installers in the same ZIP code. One quote is a price, not a market.
Step four
Where to actually get quotes
Sol Country is not a quote marketplace and does not plan to become one. Here is the honest division of labor.
Use EnergySage for
Comparing multiple quotes side by side
EnergySage has a decade of installer data, verified customer reviews, and a standardized quote format that makes dollars-per-watt comparison straightforward. That is a better tool than anything we would build, so use it.
Not an affiliate link. Sol Country earns nothing if you use EnergySage.
Use Sol Country for
Knowing your programs and a verified starting point
Our installer directory is intentionally short. It lists companies we have verified, with state-specific program notes attached. It is a starting point, not a complete list of installers in your state — treat it as one or two of the three quotes you should get.
Get three quotes. Ask all 20 questions of each. Compare dollars per watt, not monthly payments. Read the contract overnight. That process, more than any single product choice, decides whether rooftop solar works out for you.