How to Choose a Solar Installer You Can Trust

Why the installer matters

Panels and inverters from established manufacturers are fairly reliable. Roof leaks, poor wiring, under-sized systems, and slow service usually come from the installation. That's why choosing who installs your system deserves as much attention as choosing what goes on your roof.

Credentials to check

• A valid contractor license in your state, and a licensed electrician on the job
• Certificates of liability insurance and workers' compensation
• NABCEP certification, the leading industry credential for solar professionals
• Several years installing in your area, and familiarity with your utility's interconnection rules
• References from local customers whose systems have been running for a few years

Compare quotes on equal terms

Get at least three proposals and line them up side by side:

• Total price and cost per watt: total price divided by system size in watts
• Equipment: the specific panels, inverters, and racking, plus their warranties
• Estimated annual production (kWh), and whether it's guaranteed
• Assumed electricity rate and incentives behind the savings estimate
• Workmanship warranty length and what it covers, including roof penetrations

Red flags

• Pressure to sign the same day, or "expiring" discounts
• Savings estimates that assume big future rate increases
• Vague answers about who owns the system or what happens when you sell
• Large upfront deposits before permits are approved
• Reluctance to put production estimates or warranties in writing

Questions to ask every installer

Do you use your own crews or subcontractors? Who handles permits, inspections, and utility approval? How long until the system is turned on? Who do I call if production drops in year eight? What does your workmanship warranty cover, and is it transferable if I sell my home?