There are a lot of great solar installer/installation companies out there, but it’s always good to know how many years of experience they have installing grid-tied PV systems or off-grid PV (if you want off-grid). And make sure their electrical and general contractor licenses are current, and have no pending judgements or liens against it. Also, some solar rebate and incentive programs require installers to have solar-specific credentials-solar contracting licenses or solar certifications, like NABCEP accreditation.
NABCEP (North American Board of Certified Energy Practitioners) is committed to providing a certification program of quality and integrity for both solar professionals and solar consumers/public it is designed to serve. NABCEP certification is given to solar installers who demonstrate competence through 58 hours of training and 10 hours of OSHA construction safety.
Go to NABCEP for NABCEP’s list of certified solar installers.