How do you choose among photovoltaic providers?

Compile a list of prospective photovoltaic providers. (Those closest to you should have the lowest travel costs). Contact these providers and find out what products and services they offer. The following questions may give you a good sense of their capabilities:

Has the company installed grid-connected photovoltaic systems?

If not, has it installed grid-independent (or stand-alone) photovoltaic systems? Experience in installing grid-connected systems is valuable because some elements of the —particularly interconnection with the local utility—are unique to these systems. Because grid-connected systems are relatively uncommon, however, most contractors with photovoltaic experience have worked only on stand-alone systems. So, they have experience with all aspects of photovoltaic system installation except connection with the . However, a competent company with photovoltaic experience should not be eliminated just because it has not yet installed grid-connected PV. Experience with off- is valuable, because grid-independent systems are more technically complex than grid-tied systems.

How many years of experience does the company have installing photovoltaic systems?

This issue speaks for itself: A contractor who has been in business a long time probably understands how to work with customers and to compete effectively with other firms.

Is the company properly licensed?

Photovoltaic systems should be installed by an appropriately licensed contractor. This usually means that either the installer or a subcontractor has an electrical contractor's license. Your State Electrical Board can tell you whether a contractor has a valid 's license. Local building departments might also require that the installer have a general contractor's license. Call the city or county you live in for additional information on licensing.

A rebate program may require that, in addition to being properly licensed, installers must demonstrate that they have special knowledge about installing photovoltaic systems. This special knowledge may be demonstrated in one of the following ways:

  • Possession of a solar contractor specialty license, issued by a local building jurisdiction, that recognizes—through testing or other means—special knowledge of photovoltaic systems
  • Certification in photovoltaic systems by a group such as the state chapter of SEIA
  • A letter from the photovoltaic system manufacturer stating that the installer has the experience and training needed to install the system properly.

Does the company have any pending or active judgments or liens against it?

As with any project that requires a contractor, due diligence is recommended. Your state electrical board can tell you about any judgments or complaints against a state-licensed electrician. Consumers should call the city and county they live in for information on how to evaluate contractors. The Better Business Bureau is another source of information.