When selecting a renewable energy Professional, look for a company that has experience installing (or other professional services you desire) the type of renewable energy system you seek. Ask them how many years they`ve been in business, ask what licenses they hold, and get (and check) references. Also ask if they have any specific manufacturer or industry training or certifications. Remember, renewable energy systems are an asset, that properly installed should provide many years of reliable service. You want a qualified professional. Get several bids, but picking the lowest bid is not necessarily the goal. Choose experience and quality too. Also compare warranty and service policies offered by competing bids.
Also use a service such as ContractorCheck.com to verify the company`s status
Check with your State or County to make sure your Professional is properly licensed or certified for the work (which can vary from local to local). If you plan to use any incentive programs to help pay for the cost of your system, check to make sure the Professional you choose qualifies for that incentive program.
Go to www.solar-estimate.org