Table of Contents:
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Before choosing a solar company, ask for the total installed cost per watt and learn how long both the product and performance warranties last.
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Find out how long the installation process will take from contract to activation.
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Make sure the installer you choose is NABCEP certified and has worked extensively in your area.
Although installing a solar panel system involves many steps and several key figures, asking the right questions of a solar company can help clarify the process. In this article, we’ll break down the topics you should ask about and what specific information is important to learn.
Best questions to ask solar companies before signing
Purchasing and installing a solar panel system for your home is a big decision with many factors to consider, so you’ll want to make sure you’re getting the best information possible. Before you commit to buying solar panels, you should ask specific questions of the company and installer.
When researching brands and comparing solar panels, find out what the panels’ efficiency ratings are, and what warranties are available for each piece of equipment. You’ll also need to verify the company’s licensing and insurance, as well as the installation crew’s certifications. And, so you’re not surprised by anything on the final bill, ask for the price of the whole system — including the labor, permitting, and interconnection costs.
Use the table below as a handy guide for what to ask. We’ve included some of the most essential questions, the reason for asking, and a key insight you should look for in the answer.
| Question | Reason | What to know |
|---|---|---|
| What is the efficiency rating of the solar panels you offer? | Higher efficiency panels generate more power in limited space | Panels above 20% efficiency are considered high performing |
| What warranties do you provide on equipment and installation? | Warranties protect your investment from defects or failures | Look for 25-year warranties on panels and at least 10 on labor |
| What is the total installed cost per watt? | Helps you compare quotes across installers on a standardized basis | Market average is about $3.56 per watt (before incentives) |
| How long will installation take, from contract to activation? | Understand project timeline and any potential delays | Permits and inspections often delay installation by weeks |
| What happens if my system underperforms? | Clarifies service and compensation terms | Some companies offer performance guarantees |
| Can you explain net metering rules in my area? | Net metering can drastically affect savings | Rules vary by state and utility, and may be subject to change |
| Do you handle permits, inspections, and interconnection? | Ensures installer takes responsibility for legal and utility paperwork | Full-service installers reduce homeowner stress |
| What financing options do you offer, and who owns the system? | Affects long-term savings and eligibility for incentives | Loans lead to ownership; leases/ppas often exclude tax credits |
Evaluate experience and project history
When choosing a solar installer, you’ll want to evaluate their level of experience and the kinds of projects they’ve successfully completed.
To determine whether an installer is a good fit, you should first ask how many systems they’ve installed locally. If they frequently work in your area, they’ll have a depth of knowledge about best practices for your particular climate.
If the installer has a good bit of experience in your locale, chances are they’ll be willing to provide references and endorsements from other recent clients. Ask for these up front and read through them to learn how others found their services.
Finally, when selecting an installer, you should make sure they’re certified by the North American Board of Certified Energy Practitioners (NABCEP). This nonprofit organization certifies sustainable energy professionals for safe and ethical practices. Installers who have been in business for a long time typically have excellent experience and certifications.
Ask about panel performance and warranty terms
As you’re comparing solar companies, you’ll want to learn as much as possible about their products. Besides the panel size and number of panels you’ll need for a system, find out how long both the product and performance warranties last. You should also ask if the company is financially stable enough to honor said warranties should a problem with your system arise.
You’ll also want to note the degradation rate of the manufacturer’s panels. How might that affect long-term savings?
Clarify financials and incentives
As you get deeper into the process of going solar, you’ll want to be very clear about how much a system will cost you. Request a detailed breakdown of the system itself and its associated costs, including labor, permits, interconnection, and any necessary modifications to the installation area. In addition, request a detailed explanation of your system's projected return on investment and payback period.
You’ll also want to know the following:
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Does the company assist with federal tax credits, rebates, or SRECs? If so, what department should you contact? If not, do they have any recommendations for third-party groups that help with those things? (Note the federal solar tax credit is ending at the end of 2025.)
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What financing options are available: loan, lease, or Power Purchase Agreements (PPAs)?
Once you clarify the financial totality, you’ll have a better idea of what company to go with.
Understand the installation process and support
Installing and maintaining a solar panel system can be a lot of work, so it’s advisable to get clarity on those processes as early as possible. Ask your installer these questions to minimize any surprise costs or confusing red tape:
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What is the timeline from contract to commissioning? How does it differ for a roof install versus a ground install?
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How do you handle permitting and inspections?
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Is there a dedicated support team for post-installation issues? What information should I have on hand when speaking to a representative? Is there an online portal, phone number, or both for warranty issues?
Bottom line: Ask the right questions to solar companies
Asking the right questions at every step of going solar helps you prepare for the amount of money and time required to select and install a system. When comparing companies, these questions will help reveal any gaps in service or product quality, which can help you narrow down the search for a reputable provider. Plus, you’ll get a sense of the company and the installer’s character. Reputable manufacturers and installers will provide thorough answers and complete documentation, so you’ll know exactly what to expect.
These questions may also help you determine that a solar power system is not right for you. Going solar isn’t for everyone, and it’s best to know that before the process gets too far along.
FAQ on solar company questions
Below are a few frequently asked questions about what to ask solar companies:
What questions should I ask about solar?
If you’re considering going solar, you should first ask about the cost of a system, the degradation rate of a manufacturer’s panels, and how long the installation will take from contract to activation.
What should I know before buying solar panels?
We recommend starting by determining your average power consumption, as this will help you decide on the appropriate system size.
How do you decide on a solar company?
When choosing a solar company for your home system, you’ll want to select one that has positive customer reviews and extensive experience installing systems in your area. Installers should be NABCEP certified. A reputable company will answer any questions you have thoroughly.
What is the 20% rule for solar panels?
The 20% states that a solar panel system should generate 20% more power than your home consumes. This helps mitigate power loss during high-use months. It can also refer to an NEC rule that limits system size for safety reasons.