How to Choose a Solar Installer: 15 Questions to Ask

Knowing how to choose a solar installer matters more than picking a panel brand. The installer designs the system, pulls the permits, puts holes in your roof and stands behind the work for years. The FTC warns homeowners about high-pressure sales and misleading savings claims, so go in with a checklist and get at least three quotes.

How to Choose a Solar Installer: 15 Questions

Company and credentials

Are you licensed in my state, and can I see the license number?
Do your installers hold NABCEP certification?
Do you use your own crews or subcontractors?
How many years have you installed in my area, and can I talk to recent customers?
Are you insured for liability and workers’ comp?

Design and equipment

Exactly which panels, inverters, racking and battery (brand and model)?
What annual kWh do you estimate, and what tool did you use (for example, NREL PVWatts)?
Does my roof or main panel need work first, and is it in the price?

Price and financing

What is the total cash price and price per watt?
If financed, what is the APR, term, and any dealer fee built into the price?
Does your savings estimate assume a federal tax credit? (The 25D credit ended for systems placed in service after Dec 31, 2025.)
What utility rate increase do you assume?

Warranties and service

What’s covered by your workmanship warranty, and for how long?
Who handles monitoring and repairs, and what if your company closes?
Who handles permits, interconnection and PTO, and what’s the timeline?

Red Flags

“Free solar” or “government program” pitches
Pressure to sign the same day
Savings estimates that assume a tax credit you can’t claim
Unwilling to give a cash price
Vague equipment lists (“tier 1 panels”)
Door-to-door sellers who can’t show a license

Comparing Quotes

Item	Quote A	Quote B	Quote C
System size (kW DC)
Annual kWh estimate
Cash price
Price per watt
Workmanship warranty
Battery included?

Use the same bill data for all three so estimates are comparable.

After You Sign

Keep copies of the contract, the final design, equipment serial numbers and every warranty document. Ask for monitoring app access on day one, and check production against the estimate each month for the first year. If output falls well short, raise it with the installer early, while the workmanship warranty and any production guarantee are clearly in force.

How to Check a License and Certification

State contractor license: search your state’s contractor licensing board by company name or license number. Confirm it’s active and covers electrical or solar work.
NABCEP certification: search the North American Board of Certified Energy Practitioners’ directory for the company’s installers. NABCEP’s PV Installation Professional certification is the best-known credential.
Insurance: ask for a certificate of insurance showing liability and workers’ compensation.
Local experience: ask for addresses of recent installs near you, or customers you can call.

Worked Example: Scoring Three Quotes

Fill in the comparison table, then calculate two numbers for each quote:

$/W = cash price ÷ (kW DC × 1,000)
$ per first-year kWh = cash price ÷ estimated yearly kWh

Item	Quote A	Quote B	Quote C
System size	7.2 kW	8.0 kW	6.8 kW
Annual kWh estimate	9,700	10,900	9,600
Cash price	$25,200	$32,000	$23,800
$/W	$3.50	$4.00	$3.50
$ per first-year kWh	$2.60	$2.94	$2.48

Illustrative. Quote C has a slightly smaller system but a strong production estimate per watt. Ask C how it got that estimate. If one quote’s kWh per kW looks much higher than the others for the same roof, ask for the PVWatts or shade report. Benchmarks: LBNL’s 2024 medians were $3.5/W cash and $4.0/W overall. See how much do solar panels cost.

Warranties to Compare

Warranty	Who provides it	What to check
Panel product and performance	Panel maker	Years, and output guaranteed at the end (often about 25 years)
Inverter or microinverter	Inverter maker	Years (string inverters often 10–12, microinverters often 25)
Battery	Battery maker	Years, cycles or MWh, capacity retention
Workmanship	Installer	Years, and whether roof leaks are covered
Roof penetration	Installer	Separate leak warranty, if offered

Manufacturer warranties come from the maker, but the installer usually handles claims. Ask who does the labor for a warranty replacement. See home battery warranties compared.

Questions About Batteries and Backup

If the quote includes storage:

What loads will be backed up, and is it whole-home or a critical loads panel? See critical loads panel explained.
What’s the battery’s continuous kW, and can it start my AC?
Does it need a main panel upgrade?
How will it operate under my utility’s tariff? See is a solar battery worth it.

Contract Terms to Read Before Signing

Cancellation window. The FTC’s Cooling-Off Rule gives three days to cancel many sales made at your home. Check your contract and state law.
Payment schedule. Avoid paying most of the price before installation.
Production estimate and any guarantee.
Change orders. How price changes are handled if the roof or panel needs work.
Completion timeline and what happens if permits are delayed.

Step-by-Step: From Quotes to Signature

Gather 12 months of bills and panel photos.
Request three or more quotes using the same data.
Verify licenses and NABCEP certification.
Score quotes by $/W and $ per kWh.
Compare warranties and financing (see solar loan dealer fees).
Read the contract and payment schedule.
Sign, then follow the installation process step by step.

FAQ

How many solar quotes should I get?

At least three from licensed local installers.

Is a national installer better than a local one?

Not necessarily. Compare licensing, reviews, warranty and service.

What is NABCEP?

A widely recognized certification body for solar professionals.

Should I choose the cheapest solar quote?

Not automatically. Compare price per estimated kWh, equipment, warranties and the installer’s credentials. A slightly higher price from a well-established installer can be the better value.

How do I verify a solar installer’s license?

Search your state contractor licensing board online by company name or license number, and check NABCEP’s directory for certified installers.

What is a workmanship warranty?

The installer’s own warranty on the installation work, such as wiring, mounting and roof penetrations. Terms vary widely, so compare years and what’s covered.

Should I pay a deposit to a solar installer?

Many contracts include a deposit. Keep it modest, and tie larger payments to milestones like installation and passed inspection.

Do solar installers handle permits?

Most full-service installers pull permits, submit the interconnection application and schedule inspections. Confirm it in the contract.

Sources: FTC, “Solar Power for Your Home”; U.S. DOE, “Homeowner’s Guide to Solar Financing”; NABCEP (nabcep.org); NABCEP certification directory; FTC Cooling-Off Rule. Accessed Oct 2026.