When researching for a good solar panel installer, don't forget the Internet. Yes you may start out in the phone book, but the Internet will give you a lot more information as well. You may find testimonials from other clients and ideas for contractors that you may not have realized are out there.
Solar Energy in our Atmosphere notes.
Check that your solar-energy installer has the proper licenses and insurance. Installing solar panels on a steep roof is a delicate job, and you should feel confident that your installers know what they are doing. At a minimum, look for a contracting license, workers compensation insurance, and general liability insurance.