This guide arms you with the questions that expose a solar company's real quality before you sign: total installed cost per watt, warranty lengths, certification, timeline, and what happens when the system underperforms. Ask them all and the weak companies filter themselves out. The answers also tell you whether solar makes sense for your home at all.
PowerOutage.us tracks 950 plus utilities serving 200 million customers across 96 percent of the US. That outage record grounds our installer guidance, so you sign with the company whose system will produce when the grid fails.
The questions to ask before signing anything
A solar purchase runs on the quality of your questions, so you should front-load them before committing to buying solar panels. While comparing solar panels across brands, ask for each panel's efficiency rating and the warranties on every piece of equipment. Verify the company's licensing and insurance and the installation crew's certifications. And get the whole-system price in writing, including labor, permitting, and interconnection, so nothing surprises you on the final bill.
The table below pairs each essential question with the reason to ask it and the benchmark to 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
Local track record predicts your outcome better than any brochure, so you should start there when choosing a solar installer. Ask how many systems they've installed in your area. Frequent local work means real knowledge of your climate's best practices.
An installer with local history should offer references and endorsements from recent clients without hesitation. Request them up front and read them for patterns, not just star counts.
Then confirm certification from the North American Board of Certified Energy Practitioners (NABCEP), the nonprofit that certifies sustainable energy professionals for safe and ethical practice. Long-tenured installers typically carry both the experience and the credentials.
Ask about panel performance and warranty terms
Warranty terms tell you how much the manufacturer trusts its own product. Beyond the solar panel size and the number of solar panels your system needs, pin down how long both the product and performance warranties run, and ask whether the company is financially stable enough to honor them years from now.
Ask for the degradation rate of the manufacturer's panels too, and make the company connect it to your long-term savings projection. A panel with worse degredation quietly rewrites the payback math.
Clarify financials and incentives
The full solar cost picture belongs in one itemized document including the system, labor, permits, interconnection, and any modifications to the installation area, plus a written projection of return on investment and payback period.
Then consider:
- Does the company assist with rebates or SRECs, and which department handles it? If not, can they recommend third-party help? Note that the federal solar tax credit expired at the end of 2025, so state and utility incentives are important to claim if available.
- What financing options are available: loan, lease, or Power Purchase Agreement (PPA)? Ownership structure decides who keeps the incentives and the long-term savings.
Once the financial totality is on paper, the company comparison mostly makes itself.
Understand the installation process and support
Surprise costs and red tape shrink when you map the process early. Ask these before signing:
- What is the timeline from contract to commissioning, and how does it differ for a roof install versus a ground install?
- How do you handle permitting and inspections?
- Is there a dedicated post-installation support team? What information should I have ready when I call, and is warranty service handled by phone, online portal, or both?
Bottom line: ask the right questions to solar companies
The right questions at each step reveal gaps in service and product quality, narrow the field to reputable providers, and show you each company's character before money moves. Reputable manufacturers and installers answer thoroughly and document completely; evasive answers are themselves an answer.
Sometimes the answers add up to "not now," and that's the process working. Going solar isn't for everyone, and it's far better to learn that in the question phase than after the contract.
