Questions to Ask a Potential Solar Contractor

How to find an installer

Finding a trustworthy and experienced installer is for many homeowners one of the biggest obstacles on their way to go solar. The recent spike in demand has led to companies entering the market that are more focused on the quick buck and on a long-term customer relationship. To distinguish the good apples from the few bad ones can be difficult.

One option is to go with the big, well-established installers. There is no reason to discount the local guys, however. They might in fact be able to give you a more customized quote and won’t try to push a product on you because it’s the most lucrative for their shareholders. In the end it’s up to the homeowners to do their proper due diligence. You can find a database of installers on the Go Solar California website. 

Here are a few resources and questions that might help you with the process.

Questions you should ask your installer

How many years of experience does your company have with solar installation?

Request a list of past customers whose installations resembled the one you are considering and who can provide references. One strategy is to ask for two customer contacts from the vendors’ latest completed jobs.

Is your company licensed?

You can confirm licensing by contacting the California Contractors State Licensing Board:

For you to obtain certain rebates, your contractor may have to demonstrate special knowledge about solar installations through one or more of the following:

Possession of a solar contractor specialty license issued by a local building jurisdiction, and/or ensure your installer has worked with the building department in your city or jurisdiction.

Certification in PV systems by a program such as the North American Board of Certified Energy Practitioners (NABCEP), preferably certification as a NABCEP PV Installation Professional. 

Remember to be sure that your contractor’s license and certifications are sufficient for solar incentive requirements. These requirements are expected to shift over time.

Does your bid include the cost of all required permits or inspections?

The bid should include having the system installed and running, as well as the cost of hardware, permits, sales tax, and engineering reports (if needed). Be clear about whether you will be paying the full price, and receiving rebates later -- or paying the after-incentive price, with your installer receiving the rebate directly. As always with big purchases, you should get at least three bids from three different installers. To make sure that all the bids you receive are based on the same information and requirements, be sure that each bid specifies system type and size, energy output, maintenance requirements, and cost.

What kind of warranty and maintenance agreement do you offer?

A system warranty is crucial in comparing bids. Make sure your contractor agreement is explicit about what issues the contractor will handle, and what service to expect should something go wrong.

The modules are usually warranted for 20+ years, and the inverter generally for five or ten years plus extended coverage for some specific failures.

In choosing a solar installer, competing project bids will typically vary less than five percent. Price is not as important a factor as trust. You want to have confidence that this person or this company will stand behind their installation for at least five, and hopefully for the next twenty years.

Does your company offer a variety of products?

You want access to the best components for your particular site. Some contractors may only offer one brand of inverter or module—which is fine, if that’s the best type of equipment for your application.

What kind of maintenance will I need to provide and at what intervals?

Reduce worry and help avoid system failure and costly replacement of parts in the years ahead by requesting or creating a simple maintenance sheet and checklist, laminating it, and keeping it in a prominent location near your inverter.

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

The California Contractors State Licensing Board can tell you about any complaints against state licensed contractors. The Better Business Bureau is another good source for such information.

Other resources:

Find out about the incentives you will be able to claim here:

The Clean Energy State Alliance published a comprehensive and easy to understand homeowners guide to financing (February 2015):

The annual National Solar Tour is a great way to meet installers and investigate their products directly. This event happens every year on the first weekend in October: