The difference between a good and bad solar install is bigger than the difference between panels. Ask these 15 questions, watch for these red flags, and compare quotes using $/W with identical equipment.
Quotes to Get
3+
compare apples-to-apples
Avg Savings
15–40%
from comparing quotes
Workmanship Warranty
10–25 years
minimum 10 years
Red Flag
5-year warranty
walk away immediately
How to Choose a Solar Installer: The Questions That Actually Matter
Choosing a solar installer is the most important decision in your solar journey — more important than panel brand, more important than financing type, more important than system size. A great installer makes solar painless. A bad installer turns your solar investment into a years-long nightmare of leaks, underperformance, warranty disputes, and missed incentive deadlines.
The solar industry has a dirty secret: 30–40% of installations have at least one workmanship defect within the first 5 years (leaks, loose racking, wiring errors, failed inverters due to improper installation). These problems are almost always preventable — if you choose the right installer.
This guide covers the 15 critical questions to ask every installer, how to interpret their answers, red flags to avoid, and how to compare quotes accurately.
15 Questions to Ask Every Solar Installer (With What Good Answers Sound Like)
Are you licensed and insured in my state?
Verify active state contractor license and $1M+ liability insurance.
Do you have NABCEP certification?
North American Board of Certified Energy Practitioners — the industry gold standard.
How many installations have you completed?
Look for 500+ residential installations. Experience prevents costly mistakes.
What equipment do you use (panels + inverter)?
Ask for specific make/model. Compare specs across quotes.
What is your price per watt with this equipment?
The only apples-to-apples comparison metric. Include all costs.
What is your workmanship warranty?
Minimum 10 years. Top installers offer 25 years.
Do you handle permitting and interconnection?
Full-service installers handle everything. Avoid those who leave permits to you.
What is your production guarantee?
The installer should guarantee a minimum annual kWh production.
How do you handle roof damage or leaks?
Clear policy for repair/replacement if their mounting causes issues.
Do you use subcontractors or in-house crews?
In-house crews provide better quality control and accountability.
What monitoring system is included?
Panel-level monitoring (Enphase, SolarEdge) should be standard.
What is your typical timeline from contract to activation?
Expect 6–12 weeks. Longer than 16 weeks is a red flag.
Can I see recent local references?
Ask for 3+ references from homes installed in the past 12 months.
What is your cancellation policy?
You should be able to cancel within 3 business days with full refund.
Will you help me with incentive applications?
Top installers handle SMART, SuSI, SREC, and net metering applications.
Deep Dive: What Good vs Bad Answers Look Like
Question 1: Are you licensed and insured?
Good answer
"Yes, we hold an active [State] Electrical Contractor License #12345 and carry $2 million general liability plus $1 million workers comp. I can email you our Certificate of Insurance."
Bad answer
"We're fully insured." (Vague. No license number. No proof.)
How to verify:
Go to your state's contractor licensing board website and search the license number. Check expiration date, disciplinary actions, and bond status. If they refuse to provide a license number, walk away immediately.
Question 2: Do you have NABCEP certification?
Good answer
"Yes, our lead installer is NABCEP PV Installation Professional certified. Here's his certification number."
Acceptable answer
"We're working toward NABCEP certification but have 800+ successful installations over 6 years. Here are references." (Experience can substitute for certification if verifiable.)
Bad answer
"We don't need NABCEP — it's just a piece of paper." (This is a red flag. NABCEP proves technical competence and adherence to code.)
Question 6: What is your workmanship warranty?
Good answer
"25-year workmanship warranty covering all installation labor, roof penetrations, electrical, and racking."
Acceptable answer
"10-year workmanship warranty. After 10 years, we offer discounted service rates for our customers."
Bad answer
"5 years, but panels have a 25-year warranty so you're covered." (Panel warranty doesn't cover installation defects. A 5-year workmanship warranty means they expect problems and don't want to pay for them.)
Ready to Get a Solar Quote?
Get a free, no-obligation quote from NuWatt Energy. We handle design, permits, and installation.
The Door-to-Door Sales Trap: Why It Costs You 40% More
If a solar salesperson knocks on your door with a "limited-time offer" or "special neighborhood discount," you are about to be drastically overcharged. Here's how the door-to-door sales model inflates your costs — and why you should never sign the same day.
Real Price Comparison: Same System, Same Equipment
Door-to-Door Quote (Sunrun)
$45,000
($4.50/W)
10 kW, Q Cells panels, Enphase IQ8+
$13,000 markup = 40% over local installer
Local Installer Quote (NuWatt)
$32,000
($3.20/W)
10 kW, Q Cells panels, Enphase IQ8+
Same equipment, $13,000 less
Where does the $13,000 go?
- • $9,000 to the salesperson's commission
- • $2,000 to the national marketing budget
- • $2,000 to corporate overhead
- • Zero dollars go to better panels, better installation, or better service.
How to Protect Yourself
Never sign a solar contract the same day you receive a quote.
Legitimate installers expect you to compare quotes and take 1–2 weeks to decide.
Get at least 3 quotes from different installer types
One door-to-door national company, one regional installer, one local installer. Compare $/W with identical equipment.
Ignore "today only" pricing
Solar prices do not change day-to-day. This is a sales tactic to prevent you from shopping around.
Ask: "What is the salesperson's commission on this sale?"
If they refuse to answer or say "that's confidential," the commission is high — and so is your price.
The Hidden Dealer Fee: What It Is and How to Avoid It
Many solar installers — especially national companies — quote you a price with a built-in "dealer fee" (also called origination fee or financing fee). This is a fee the installer charges you to cover the cost of offering zero-down financing. The problem: the fee is baked into the $/W price, so you pay it even if you pay cash.
How Dealer Fees Work
If you finance, the fee covers the loan origination cost. If you pay cash, the dealer fee is pure profit for the installer — they pocket $5,600 for doing nothing.
Red Flags vs Green Flags
Red Flags to Watch For
- Pressure to sign a contract today or "limited time" pricing
- No physical office or showroom
- Price significantly below market (they are cutting corners)
- Refusal to provide equipment specifications in writing
- No NABCEP certification
- Door-to-door sales with inflated pricing
Green Flags
- NABCEP certified with 500+ installations
- Transparent $/W pricing with equipment specs
- 10+ year workmanship warranty
- In-house installation crews (not subcontracted)
- Handles permitting, interconnection, and incentive applications
- Strong local reviews and references
How to Verify Licenses and Certifications Online
Don't just take the installer's word that they're licensed. Verify it yourself in 5 minutes. Here's how.
State Contractor License Verification
- Massachusetts: mass.gov/dpl — search for "Electrician License Lookup"
- Connecticut: ct.gov/dcp — Contractor License Verification
- New York: dos.ny.gov — License Search
- New Jersey: nj.gov/dca — Contractor License Lookup
- Pennsylvania: dli.pa.gov — Electrician License Verification
What to check: License status (active), expiration date, disciplinary actions, bond amount. If the license is expired or has disciplinary actions, do not hire this installer.
How to Compare Quotes Apples-to-Apples
- Normalize all quotes to $/W using the same system size
- Compare with identical equipment (or adjust for quality differences)
- Include all costs: equipment, labor, permits, monitoring, adders
- Factor in warranty differences (a 25-year warranty has real value vs 10-year)
- Consider the production guarantee — a lower $/W with no guarantee may produce less
Example: Comparing 3 Quotes
Quote A
National Door-to-Door
$13,000 more than Quote C. Hard pass.
Quote B
Regional Installer
Fair price, acceptable equipment. Canadian Solar is mid-tier vs REC premium.
Quote C
Local Installer (NuWatt)
Best value. Premium panels, microinverters, 25-year warranty. Lowest $/W.
How to Negotiate Solar Pricing
Most people don't realize solar pricing is negotiable — especially if you have multiple quotes. Here's how to negotiate effectively without being pushy.
Leverage Multiple Quotes
What to say: "I have three quotes for 10 kW systems. Your price is $3.50/W. I have a quote for $3.20/W with the same equipment and a longer warranty. Can you match or beat that price?"
Good response
"I can do $3.25/W and include a free monitoring upgrade." (They're willing to negotiate.)
Bad response
"Our price is firm. We don't negotiate." (They're either overpriced or inflexible. Move on.)
Get a Transparent Quote from NuWatt
Clear $/W pricing, premium equipment specs, and a 25-year production guarantee — in writing.