9 questions to ask when choosing a solar installer

Choosing a solar installer can feel daunting if you’re not sure what to look for.  Solar panels aren’t a one-size-fits-all product, and there are important factors to consider when making this big financial investment.  Understanding what types of questions to ask potential installers will help you find the best company for your specific needs. 

EnergySage has helped connect thousands of homeowners with installers, so we put together a list of the most helpful questions prospective buyers can ask to select the right installer and the best solar panel system for their needs. Good installers want you to ask questions, ranging from panel size and hardware requirements to warranty packages and financing options, to installer licenses and certifications.

Before we get to the questions, we want to explain how we choose the best solar installers for our platform. We have high standards and a vigorous vetting process for the solar installers we partner with across the country.  To join the EnergySage Marketplace, installers must meet the following  qualifications: 

• At least three years of experience installing solar

• Licensed and insured for solar installations in their operating states

• NABCEP certified

• A track record of excellent customer service and quality installations

• Installs high-quality, reputable solar equipment

If an installer doesn't meet our standards, they can't join. If they stop meeting them, they can't stay. That said, you should still do your own vetting—starting with these questions.

Any reputable installer should be able to provide references you can speak with directly. Given the size of this investment, it's reasonable to be specific about the kind of references you want.

If you're planning a ground-mounted system, ask for a reference from a similar installation. If you want to see a system in person, ask for a nearby reference. It's also worth requesting a reference from an installation that's at least a few years old—that way you can learn how the company handles service calls and post-installation support, not just how the original installation went.

Look at how long the company has been operating. Solar panels last 25 to 30 years and if your system needs servicing a decade from now, you want your installer to still be around. Beyond longevity, ask about their total number of installations. Volume indicates experience, and experienced installers are less likely to encounter surprises on your project.

Total installs matter, but so does local experience. Installers who have worked in your area for a while will be more familiar with your utility's interconnection process, local permitting requirements, available solar incentives, and any region-specific code considerations. That familiarity can speed up your installation timeline and help you avoid costly mistakes that out-of-market companies might not anticipate.

Solar installers should carry the licenses and insurance required to operate in your state, which can vary by location. Most licensing information is publicly available online, and any reputable installer should be able to provide documentation upon request.

Beyond the basics, look for additional certifications. The North American Board of Certified Energy Practitioners (NABCEP) Solar PV Installation Professional Certification is the industry standard. Many reputable companies have at least one NABCEP-certified lead installer on staff. If an installer you're seriously considering doesn't have this certification, it's worth asking why—and possibly looking elsewhere

With the federal Investment Tax Credit (ITC) having expired as of December 31, 2025, how you finance your system matters more than ever. Most installers can facilitate multiple payment structures: cash purchase, solar loan, lease, or power purchase agreement (PPA). Ask which options they offer, what the total cost looks like under each, and whether any dealer fees are baked into the loan rate.

It's also worth asking whether they work with financing partners who can pass commercial tax credits through to you—an increasingly common arrangement since the residential credit expired. For a full breakdown of your options, see our guide to paying for solar.

Not every company can install on the same schedule. If timing matters to you—for instance, if you want to start generating electricity before summer peak rates kick in—ask for a timeline upfront.

The overall process depends on your installer's availability, your area's permitting and interconnection timelines, and the size and complexity of your system. Most residential installations take anywhere from a few weeks to a few months from contract to permission to operate. A company that can give you a clear, realistic estimate is usually better organized than one that can't.

Solar panels and inverters come with manufacturer warranties, but the workmanship warranty, covering the quality of the installation itself, is provided by your installer. These warranties typically range from one to ten years and vary significantly between companies.

Before signing, ask exactly what's covered, whether there are any exclusions, and what happens if the installer goes out of business before the warranty expires. Some national installers back their warranties with insurance products specifically for this scenario—worth asking about if the company is relatively young.

Subcontracting is common and normal in the solar industry and many installers use subcontractors for electrical work, roofing, or portions of the installation. What matters is transparency. Ask upfront who will actually be performing the work on your home, what portion of the job they'll handle, and what oversight the company you're contracting with has over them.

At the end of the day, the most important question is who stands behind the quality of your installation, regardless of who physically did the work.

You want to know that someone is keeping an eye on your system after installation, not just you. Many reputable installers set up monitoring alerts so they can see immediately when something is wrong with a customer's system, often before the customer even notices.

Most companies include monitoring as a standard part of their service at no extra charge. If an installer wants to charge you separately for monitoring, treat it as a red flag. It's a service that should come standard—and the fact that it doesn't tells you something about their approach to post-installation support.

Online reviews aren't a substitute for direct references, but they're a useful gut check. Focus on platforms with verified reviews—the Better Business Bureau, Google, and the EnergySage Marketplace itself, where reviews come from homeowners who actually completed an installation through our platform. Look for patterns across reviews rather than isolated incidents. Remember, every company has an outlier and repeated complaints about the same issue are a signal worth paying attention to.

EnergySage is the nation's online solar marketplace. When you register for a free account, solar companies in your area compete for your business with custom quotes tailored to your home. Compare equipment, warranties, financing, and price side by side—all in one place. Get free quotes today.