How to Choose a Solar Installer: 14 Questions That Filter Out the Door-Knockers

Knowing how to choose solar installer (see our solar installation companies vetting) companies is mostly about filtering out the door-knocker dealers and reaching the actual installation companies that do good work. Residential solar sales is a churn-heavy industry with armies of W-2 and 1099 sales reps who knock door to door, lock homeowners into long PPA or lease contracts, and hand the actual installation to a subcontracted EPC who never met the customer. The good installers exist, but the field is noisy. Here are the 14 specific questions to ask any installer or sales rep, the certifications that mean something, and the contract language that separates a 25-year reliable system from a problem that compounds for two decades.

The door-knocker problem

If a sales rep showed up at your door this month or called you out of the blue offering solar with no money down, you are talking to a dealer, not an installer (see our solar installer finder). Dealers (Sunrun, Sunnova, Trinity, Momentum, Lumio, Pink Energy before its collapse) operate large 1099 sales forces that find customers, sign them to PPA or lease contracts, and then hand the install to a subcontracted EPC (engineering, procurement, construction) crew that the homeowner never met during the sales process.

The dealer model is not inherently bad, but it creates three problems. First, the salesperson does not own the long-term install quality, so design corners get cut and customer complaints route through a call center. Second, the financing structure (PPA or lease) typically locks the homeowner into a 20 to 25 year contract with annual price escalators of 2 to 3 percent, eroding the savings advantage over time. Third, the workmanship warranty is held by the dealer or financing entity, and when those companies merge, restructure, or fail (Pink Energy collapsed in 2022, Sunnova reorganized in 2025), the warranty obligations become a fight rather than a guaranteed service.

The alternative is a regional installer who does sales, design, and installation in-house, typically operating in a metro or state-level service area with a permanent crew and longer business history. Regional installers are not always cheaper than dealers (sometimes they cost more upfront), but the install quality, warranty reliability, and total cost of ownership over 25 years are usually better. This is parallel to the broader pattern we covered in how to choose a roofing contractor.

The 14 questions to ask any solar installer

These questions filter the field. A real installer answers them quickly and in writing. A door-knocker or dealer either deflects, claims confidentiality, or routes you to a follow-up call.

1. Are your installation crews NABCEP-certified? NABCEP (North American Board of Certified Energy Practitioners) is the residential solar industry’s primary credential. The PV Installation Professional certification requires field experience plus an exam. Ask whether the lead installer on your specific project will be NABCEP-certified, not just whether the company has any NABCEP-certified employees on payroll.

2. What state solar contractor license do you hold? Each state defines this differently. California requires a C-46 Solar Contractor license (or a C-10 Electrical license for systems under specific thresholds). Florida requires an ESC (Electrical Solar Contractor) or ECC (Electrical Class C) license. Arizona requires a CR-11 Solar/Wind license. Texas does not require a specific solar license but does require a Master Electrician sign-off on the electrical work. Verify the license number on the state contractor license board database before signing anything.

3. Are you a manufacturer-authorized installer for the panels and inverter in my quote? SunPower Master Dealer, REC Certified Solar Professional, Q CELLS Premium Q.PARTNER, Tesla Certified Installer, and Panasonic Premium Installer are real designations with training and quality requirements. Manufacturer authorization usually includes extended warranty terms that non-authorized installers do not have access to. If your quote specifies SunPower panels but the installer is not a SunPower Master Dealer, ask why.

4. How long has the company been in business under the current name? Solar installer rebrand frequency is high. A company that changed names 18 months ago is probably hiding either a lawsuit, a BBB complaint pattern, or a financial restructuring. Verify the corporate registration history through the secretary of state filings, not just the company website.

5. Who actually manufactures the panels you are quoting? Some quotes list “premium tier 1 panels” without specifying brand and model. Demand the exact model number. The model determines warranty terms, efficiency, degradation rate, and resale value. If the installer refuses to commit to a specific panel in writing, walk away. We get into specific tier-1 brands in best solar panel brands.

6. Will your own employees do the install, or are you subcontracting it? Some installers maintain a sales arm with no installation crews and subcontract everything to a separate EPC. This is fine if disclosed but problematic if hidden, because the subcontractor’s quality and warranty obligations may differ from what the sales process implied.

7. Who holds the workmanship warranty, and what does it cover specifically? The workmanship warranty paperwork should name the company on the hook and define coverage scope (roof penetrations, racking, wiring, labor for warranty repairs, roof leak coverage). Five to 10 year workmanship is low end. Twelve to 25 years is what to look for. We detailed the warranty side in solar roof warranty.

8. What happens to my workmanship warranty if your company goes out of business? The good answers are: (a) we carry third-party warranty backstop insurance (SolarInsure, Power Production Services (see our what solar installation services include guide), OmniShield); (b) we are part of a manufacturer-administered installer program (SunPower Complete Confidence, REC ProTrust) that takes over labor coverage on certified installer failures. The bad answer is silence or “we have been in business 15 years and we are not going anywhere.”

9. What lien rights does your subcontractor have on my house? If the installer uses subcontractors (electricians, roofers, equipment suppliers), those subcontractors can place mechanic’s liens on the property if they are not paid by the prime contractor. Ask for unconditional lien waivers from every subcontractor before final payment, and verify the lien-release process is in the contract.

10. What monitoring platform comes with my system, and who pays for the data plan? Enphase Enlighten, SolarEdge mySolarEdge, and Tesla Solar App are the major platforms. Each requires either home WiFi or a cellular modem. Ask whether the cellular plan is included for life (some installers cover the first year and then bill the homeowner $5 to $10 per month forever) and whether the homeowner has direct portal access or only the installer can see production data.

11. Can I expand the system later, and what does that cost? Adding panels in years 3 to 10 is common as electrification grows household demand. Some installers price expansion at a steep premium because the inverter, racking, and electrical service may need upsizing. Get the expansion cost in writing as a fixed-rate addendum. Microinverter systems expand more cleanly than string inverter systems.

12. What does it cost to remove and reinstall the array if I need to reroof in 10 years? Asphalt shingles last 20 to 30 years. Solar panels last 25+ years. If your roof was already mid-life when you went solar, you will likely need to remove and reinstall the array for a reroof before the panels die. Removal and reinstall costs $2,500 to $7,000 depending on system size. Get the price quoted in writing now. Some installers include free removal and reinstall in extended workmanship warranties; many do not.

13. What is the decommissioning cost at end of life, and what happens to the panels? At year 25 to 30, the system will be at the end of its useful life. Removal, panel recycling, and roof patching cost $2,000 to $5,000 in 2026 dollars. Some leases and PPAs require the homeowner to fund decommissioning. Read the contract for this clause.

14. Can I see cash, loan, lease, and PPA quotes for the same system, side by side? The honest installer prepares all four. The cash quote is your baseline (total system cost minus 30 percent ITC equals out-of-pocket). The loan quote shows monthly payments and total interest. The lease quote shows fixed monthly payments with annual escalator. The PPA quote shows per-kWh price for production with annual escalator. The four numbers reveal the real economics of each financing structure. If the installer pushes only one option, they are optimizing for their commission, not your savings. We covered the financing side at roof financing options.

Reading the lease and PPA contract for escalator and end-of-term traps

If you are considering a lease or PPA, the two clauses that matter most are the escalator and the end-of-term option. The escalator is the annual percentage increase in lease payment or PPA per-kWh price. Aggressive escalators (3 percent or higher) compound over 20 to 25 years and erode the savings advantage. A 25-year contract at 2.9 percent escalator results in a year-25 payment that is roughly double the year-1 payment. A 0 percent escalator (fixed payment for life) is rare and worth a premium.

The end-of-term option defines what happens after the lease or PPA expires. Common options are: (1) buy out the system at fair market value, defined in the contract; (2) extend the lease for another 5 or 10 years at a renegotiated rate; (3) decommission the system at the homeowner’s expense. The contract should specify which options exist and define fair market value (typically a depreciation schedule).

Hidden traps include early-termination clauses that require the homeowner to pay off the remaining lease term plus a removal fee if the house is sold to a buyer who refuses to assume the lease. This can run $25,000 to $50,000 on a partially elapsed 25-year lease. Read the assignment and assumption clause carefully.

Verifying the installer’s track record

Beyond the 14 questions, three additional verifications are worth the time. First, check the BBB profile and state attorney general consumer complaints filings for the specific company name and any prior names. Solar dealer complaints typically cluster around door-to-door sales misrepresentation, warranty denial, and system underperformance. Patterns in complaint history matter more than a single grievance.

Second, check Solar Reviews, EnergySage, and SolarReviews.com for installed-customer reports on the specific company. Filter for reviews from the last 2 years and look at any reviewer that documented a warranty claim outcome. The hardest test of an installer is what they do when a panel fails in year 4. The reviewers who lived through that experience are the most useful data source.

Third, ask for three reference installations within 30 miles of your home, completed 3 to 5 years ago. Drive by and look at the array. Look for sagging panels, discolored racking, exposed wiring, leaking penetrations, or vegetation growing through the rails. Call the homeowners if they will talk and ask about warranty service experience. We applied a similar reference-verification framework in questions to ask any roofing contractor and red flags from a roofing contractor.

What a good quote looks like

The deliverables a real installer provides before you sign: (1) site survey report with shading analysis using a Solmetric Suneye or similar tool, showing per-month production estimates; (2) production estimate with PVWatts or equivalent simulation, broken out by panel and orientation; (3) system one-line electrical diagram showing inverter, optimizers or microinverters, monitoring equipment, and main panel interconnection; (4) racking layout with attachment points overlaid on the roof, showing rafter-mount versus solid-deck mount and how penetrations are flashed; (5) net cost calculation in cash, loan, lease, and PPA scenarios, including ITC, state incentives, SREC market value, and net metering policy; (6) warranty package with all three warranties named and durations confirmed; (7) installation timeline including permitting, AHJ inspection, utility interconnection, and PTO (permission to operate) milestones.

If a quote is missing any of these items, the installer is operating at a lower standard than the field expects in 2026. Either request the missing pieces or move on to a quote that includes them.

The dealer-versus-installer disclosure question

One direct question forces honesty: “Are you the entity that will hold the workmanship warranty, do the installation, and be on the contract, or are you a sales agent for a different EPC?” The dealer answers: “We work with a network of installation partners.” The installer answers: “Yes, our crews install, our warranty, our contract.” Both are legitimate business models, but the homeowner needs the disclosure to evaluate who is on the hook for the next 25 years.

Sunrun, Sunnova, Trinity Solar, Lumio, and similar national brands operate primarily as dealers or hybrid dealer-installer models. Regional installers (Sun Run Inc was originally regional, NJ Solar Power, A1A Solar Contracting, Sunworks, ION Solar in some markets, Solar Energy World, Baker Electric Home Energy, and dozens of others in major metros) generally do their own sales, design, and installation.

The bottom line

The 14 questions filter the door-knockers and dealers from the real installers in roughly 30 minutes of conversation. Verify NABCEP certification, state license, manufacturer authorization, years in business, and the warranty backstop. Demand cash, loan, lease, and PPA quotes side by side. Read the lease or PPA escalator clause and end-of-term option carefully. Drive by 3 to 5 year old installations from the same crew and verify the workmanship held up. The 25-year financial outcome of a residential solar system depends on the installer’s competence and longevity more than on the panel brand or the inverter choice.

For installer cost comparison, see solar installation cost in 2026. For the warranty paperwork that the installer should provide, see solar roof warranty. For inverter architecture choice within a quote, see microinverter vs string inverter. For solar economic context, see net metering explained and the 2026 solar tax credit. For broader solar shingles versus rack-mount panels comparison, see solar shingles vs panels. The full Solar cluster index is in the learning hub.