The Critical Questions To Ask Before Hiring A Solar Company

A salesperson sits across your kitchen table, tablet in hand, promising you’ll eliminate your electric bill and pay for the whole system in seven years. The numbers look great. The rep is friendly. And you’re about to sign a contract worth $25,000 or more without asking a single hard question. I’ve watched this happen to neighbors, clients, and friends. The solar industry has real, reputable contractors in it, but it also has high-pressure closers who disappear after installation day. Knowing which questions to ask, and when to ask them, is the only thing standing between you and a decision you’ll regret for the next 20 years.

Equipment: What Exactly Are You Buying?

This is where most homeowners go soft, and it’s where contractors can swap in cheaper gear without you noticing. Get specific. Ask for the exact make and model of the panels, inverter, and mounting hardware before you agree to anything.

Panels aren’t all equal. A 400-watt panel from Tier 1 manufacturer like REC, Panasonic, or Canadian Solar is not the same as a 400-watt panel from some no-name brand you can’t find documented anywhere. Ask the contractor to show you the panel’s datasheet. You want the temperature coefficient (aim for around -0.30%/°C), the degradation warranty, and whether the manufacturer has a U.S. presence for warranty claims.

Inverters matter just as much. String inverters are cheaper but create a weak-link problem: if one panel underperforms due to shade or debris, the whole string drops. Microinverters (Enphase dominates this space) or DC optimizers (SolarEdge) solve this by optimizing each panel individually. Ask which system you’re getting and why. If a contractor can’t explain the tradeoffs, that’s a red flag.

Also ask: “Will you honor the equipment warranty, or do I deal directly with the manufacturer?” Some installers act as the warranty handler. Others will point you straight to a manufacturer’s customer service line in a different country. Know what you’re walking into.

Contractor Credentials: Don’t Take Their Word for It

I’ve seen subcontractors do the actual work on at least half the residential installs I’ve inspected. That’s not automatically bad, but you need to know who’s on your roof.

Ask these directly:

• “Are you licensed to do electrical work in this state, or do you subcontract the electrical portion?” In most states, the final electrical connections require a licensed electrician. Find out if that person works for the company you’re hiring.
• “Is your company NABCEP-certified?” The North American Board of Certified Energy Practitioners offers the gold standard credential in this industry. Not every good installer has it, but serious companies pursue it.
• “Can I see proof of liability insurance and workers’ comp?” Get the certificates, not just a verbal yes. If an uninsured worker falls off your roof, your homeowner’s insurance could be on the hook.
• “How long has your company been operating under this name?” Some companies fold, rebrand, and reopen to shed warranty obligations. Check their standing with the state contractor licensing board yourself. It takes five minutes.

EnergySage’s market data consistently shows that installer quality varies dramatically by region, and the cheapest quote rarely correlates with the best long-term outcome. Three quotes is a minimum. Five is better.

System Sizing: Are They Designing for Your Actual Usage?

A properly sized system starts with your electric bills, not with a satellite photo of your roof. Ask the contractor: “What 12 months of electric bills are you using to size this system?”

If they didn’t ask you for bills, or if they’re sizing based on a neighbor’s house or an industry average, walk away. Your consumption pattern is specific to you. A house with two electric vehicles, a hot tub, and a well pump needs a very different system than a house with gas appliances and minimal AC usage.

Ask about your offset percentage. Most grid-tied systems are designed for 80 to 100 percent offset of annual consumption. Going above 100 percent sounds great but often doesn’t pay off because most utilities won’t credit you dollar-for-dollar for excess generation (net metering rate structures vary by state and utility).

If you’re considering battery storage, ask: “What critical loads can the battery power, and for how long?” A single Tesla Powerwall holds about 13.5 kWh of usable capacity. That’ll run a refrigerator, some lights, and a phone charger for maybe 24 hours. It won’t power your central AC and your 240V electric range. Be realistic about what you’re buying.

A home energy monitor can also help you understand your actual consumption before you sign anything. The Emporia Vue or similar monitors let you see exactly what your major appliances draw, so you can have an informed conversation about sizing rather than relying entirely on the contractor’s proposal.

Helpful resource: Emporia Smart Outlet with Energy Monitoring is a top-rated option for this. (As an Amazon Associate this site earns from qualifying purchases.)

Financing: Read Every Line Before You Sign

The monthly payment might look better than your current electric bill. That doesn’t mean the deal is good.

If you’re financing the purchase, ask for the APR, the loan term, and whether there’s a dealer fee baked into the loan. Many solar loans include a “dealer fee” of 10 to 30 percent of the system cost, paid to the installer by the lender. This fee is often rolled into your loan principal invisibly. Ask directly: “Does this loan include a dealer fee, and how much is it?” A $25,000 system with a 25 percent dealer fee means the lender gave the contractor $31,250 and you’re paying off the higher number.

If they’re proposing a lease or PPA (Power Purchase Agreement), understand that you don’t own the panels. You’re paying for the electricity they produce, usually at a rate that escalates 1 to 3 percent per year. Ask: “What happens when I sell my house?” Leases transfer to the new buyer, which can complicate real estate transactions. Some buyers balk at assuming a 20-year energy contract.

If you’re paying cash, ask about the federal Investment Tax Credit. As of 2025, the residential clean energy credit is 30 percent of the total system cost. The U.S. Department of Energy’s guidance for homeowners confirms this credit applies to panels, inverters, batteries, and installation labor. You need to owe federal taxes to use it. Ask your contractor if they can walk you through the ITC, but verify the numbers with your tax professional.

Permits, Inspections, and the Utility Interconnection

A contractor who wants to skip permits is a contractor who wants to skip inspections. Don’t let it happen.

Ask: “Will you pull all required permits, and is that included in my quote?” In most jurisdictions, a solar installation requires both a building permit and an electrical permit. Some areas also require a separate structural review if your roof load is a concern. All of this should be in the contract.

The interconnection process is separate from the permit process and often slower. This is the approval from your utility company to connect your system to the grid. Ask: “How long does interconnection typically take in my area, and who manages that process?” In some utility territories, you’re waiting two weeks. In others, it’s three to four months. You should know this upfront.

After installation and inspection, ask who handles the Permission to Operate (PTO) from the utility. Until you receive PTO, you legally cannot turn your system on. Some contractors hand you the application and wish you luck. Good ones manage it for you. Know which kind you’re dealing with.

Post-Installation: What Happens After the Check Clears

The contract is signed, the system is on, and the rep who sold you the job hasn’t returned your last two calls. This is disappointingly common.

Ask before you sign: “What does your warranty actually cover, and who do I call when something goes wrong?” There are three different warranties in play: the panel product warranty (usually 10 to 12 years), the panel performance warranty (usually 25 years guaranteeing a certain output level), and the workmanship warranty from the installer (anywhere from 1 year to 10+ years). Get all three in writing and confirm the installer’s workmanship warranty is backed by the company, not just by the individual salesperson’s promise.

Ask: “Do you offer monitoring, and is it included?” Most modern systems come with monitoring apps, but some contractors charge a monthly fee for access to the data. Others set it up and never explain how to use it. You should know your system’s daily production the same way you know your electric bill.

Ask about their response time for service calls. “What’s your average response time for a warranty repair, and do you have technicians local to my area?” A company headquartered three states away that subcontracted your install may not prioritize a service call in year five.

Comparing Proposals: A Practical Checklist

When you have two or three quotes in front of you, compare apples to apples using this framework:

If one quote is dramatically cheaper than the others, find out why before you celebrate. It’s usually cheaper panels, a shorter workmanship warranty, or a subcontractor crew with less oversight.

You’re making a two-decade financial decision about your home. The good news is that most of the information you need is available before you commit, if you ask for it directly. Good contractors welcome these questions. They’ve heard them before, they have the answers ready, and they understand that an informed customer is a satisfied customer. The ones who hedge, deflect, or rush you past the hard parts are telling you something important. Listen to what they’re not saying.

Sources

• Emporia Smart Outlet with Energy Monitoring
• Renogy 100W 12V Flexible Solar Panel
• EG4 Battery Monitor Shunt for Solar Systems
• Renogy 200W Solar Starter Kit + 30A Charge Controller
• Renogy 2×100W Monocrystalline Solar Panels

Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.

• Renogy 200W Solar Starter Kit + 30A Charge Controller (~$169), Complete beginner solar kit, 200W monocrystalline panel, charge controller, and mounting hardware included.
• Renogy 2×100W Monocrystalline Solar Panels (~$99), Expandable 200W panel set from the most trusted DIY solar brand, used widely in off-grid and home backup systems.

Photo: Hoan Ngọc via Pexels

Recommended Resources

Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.

• Renogy 200W Solar Starter Kit + 30A Charge Controller (~$169), Complete beginner solar kit, 200W monocrystalline panel, charge controller, and mounting hardware included.
• Renogy 2×100W Monocrystalline Solar Panels (~$99), Expandable 200W panel set from the most trusted DIY solar brand, used widely in off-grid and home backup systems.