Deciding to power your home with solar energy is one of the smartest financial and environmental moves a homeowner can make. You are effectively pre-paying for decades of electricity at a fixed rate, insulating yourself from volatile utility price hikes while shrinking your carbon footprint. However, the solar industry has grown rapidly, and like any booming market, it has attracted a mix of highly skilled professionals and opportunistic, inexperienced installers.
A solar panel installation is a major construction project involving high-voltage electricity, roof penetrations, and complex permitting. It is not a DIY project, nor is it something you should trust to the first person who knocks on your door. You are entering into a relationship that will last for 25 years or more. The equipment needs to last, the roof needs to stay watertight, and the company needs to be around to service the warranty.
Vetting your installer is arguably more important than the panels you choose. A great installer can make average equipment perform beautifully, but a poor installer can ruin the best equipment on the market—and your roof along with it. To ensure you find a partner who is competent, transparent, and reliable, you need to conduct a rigorous interview.
Here are the 12 essential questions to ask every prospective solar contractor before you sign on the dotted line.
1. Are you licensed, insured, and certified?
This is the gatekeeper question. If the answer is anything less than a definitive “yes” with proof, walk away immediately. Solar installers must possess the appropriate business and contractor licenses for your specific state and municipality. A general electrician’s license is often required, but many states have specific solar classifications.
Beyond basic licensure, look for the gold standard in the industry: NABCEP Certification. The North American Board of Certified Energy Practitioners (NABCEP) offers the most rigorous certification program for PV installation professionals. A company with NABCEP-certified installers on staff has demonstrated a high level of training and commitment to quality.
Ask for proof of:
- General Liability Insurance: This protects your home and property if they accidentally back a truck into your garage or drop a panel through your skylight.
- Workers’ Compensation: This protects you from liability if a worker is injured while on your property. If they don’t have this, you could be sued for medical bills.
2. How many years have you been in business locally?
Solar is a local business. A national company might have a big brand name, but if they just opened a branch in your town last month, they may lack the local knowledge required for a smooth installation. Local longevity matters for two reasons: specific expertise and long-term stability.
An installer who has operated in your area for five or ten years will be intimately familiar with local building codes, wind load requirements, and the quirks of your local utility company’s interconnection process. They know which inspectors are strict about conduit painting and which paperwork gets approved fastest.
Furthermore, solar warranties are long. You want a company that has a track record of survival. If a company has only been in business for six months, relying on their 10-year workmanship warranty involves a significant amount of faith.
3. Do you use in-house crews or subcontractors?
Many solar sales companies do not actually install the panels. They are essentially marketing firms that sign you up and then sell the contract to a third-party installation crew. While subcontracting is common in construction, it can introduce communication breakdowns in solar projects.
If the installer uses subcontractors, ask:
- Who are they?
- Are they local?
- Do they have the same insurance and certifications as the parent company?
- Who is responsible if the workmanship is poor?
Ideally, you want a company with in-house employees. When the installers are W-2 employees of the company you hired, there is usually better quality control, higher accountability, and a stronger commitment to customer satisfaction. The crew wears the company shirt and drives the company truck, meaning they have a stake in the company’s reputation.
4. Can you provide local references I can speak to?
Online reviews are helpful, but they can be curated or faked. Ask for the names and phone numbers of three previous customers in your neighborhood. Specifically, ask for at least one customer whose installation happened more than a year ago.
When you call these references, ask the hard questions:
- Did they finish on time?
- Did the final price match the quote?
- Have you had any issues with the system?
- If there was a problem, how responsive was the service department?
A reputable solar panel contractor will be eager to show off their happy customers. If they hesitate to provide references or claim privacy concerns prevent them from sharing any past client contacts, treat that as a red flag.
5. What specific equipment are you recommending and why?
Not all solar panels and inverters are created equal. You don’t need to be an electrical engineer, but you should understand the basics of what is being installed on your roof.
Ask about the Panels:
- Are they Tier 1 panels? (This generally refers to the financial stability of the manufacturer).
- What is the degradation rate? (How much efficiency do they lose per year?)
- Are they monocrystalline (black, higher efficiency) or polycrystalline (blue, lower efficiency)?
Ask about the Inverters:
The inverter converts the DC power from the panels into AC power for your home. It is the most likely component to fail.
- String Inverters: All panels are linked. If one is shaded, the whole system drops in output.
- Microinverters: Each panel has its own inverter. If one is shaded, the others keep producing.
- Power Optimizers: A hybrid solution.
A good contractor should be able to explain why they chose a specific setup for your specific roof, shading situation, and budget.
6. What is the total warranty coverage?
Solar warranties can be confusing because there are usually three or four different warranties in play simultaneously. You need clarity on each one.
- Equipment Warranty: Covered by the manufacturer. Usually guarantees the panels won’t break for 10-12 years.
- Performance/Production Warranty: Covered by the manufacturer. Guarantees the panels will still produce a certain percentage of power (usually 80-90%) at year 25.
- Inverter Warranty: Often varies from 10 to 25 years depending on the technology.
- Workmanship Warranty: Covered by the installer. This is crucial. It covers the labor and the actual installation (holes in the roof, wiring, racking).
Ask specifically: “If a panel fails in year 5, who do I call? Do I have to ship the panel back to the manufacturer, or do you come out and replace it for free?” You want a company that handles the labor for warranty claims.
7. How do you handle roof leaks?
This is the number one fear for homeowners. A solar installation involves drilling dozens of holes into your roof to secure the racking system. If not flashed and sealed correctly, these are prime spots for water intrusion.
Ask the contractor to explain their waterproofing method. Do they use specialized flashing? Do they seal the penetrations? More importantly, ask about the warranty regarding roof leaks. Many installers offer a “roof penetration warranty” that lasts for 5 to 10 years. Ensure this is written clearly in the contract. If your roof is old, a good contractor will recommend replacing it before installing solar to avoid the cost of removing and reinstalling panels later.
8. Will you handle all permitting and HOA approvals?
The administrative side of solar is often more time-consuming than the physical installation. There are building permits, electrical permits, and utility interconnection agreements. If you live in a community with a Homeowners Association (HOA), there are architectural review forms.
Your contractor should handle 100% of this paperwork. They know the specific code language required by the city and the technical specs required by the utility. If a contractor asks you to pull your own permits, do not hire them. That places the liability and the headache squarely on your shoulders.
9. What tax credits and incentives am I eligible for?
The financial viability of solar often hinges on incentives, specifically the federal Investment Tax Credit (ITC). As of 2024, this allows you to deduct 30% of the cost of your solar system from your federal taxes.
However, solar contractors are not tax professionals. While they can give you general estimates of your savings, they should be careful about promising specific dollar amounts unless they know your tax liability.
Ask them to list out every rebate and incentive included in their proposal:
- Federal ITC
- State-level tax credits
- Local utility rebates
- SRECs (Solar Renewable Energy Certificates)
Make sure you understand which of these are instant discounts taken off the price and which are credits you have to wait to file for next April.
10. Can you explain the financing options and the total cost of ownership?
You typically have three ways to pay for solar:
- Cash: Highest upfront cost, best long-term savings.
- Solar Loan: You own the system, but pay interest.
- Lease/PPA (Power Purchase Agreement): The solar company owns the system; you buy the power.
If you are taking out a loan, ask about “dealer fees.” Many “low-interest” solar loans come with massive upfront dealer fees (sometimes 20-30% of the project cost) baked into the total loan amount to buy down the interest rate. Ask for the cash price versus the financed price to see the difference clearly.
If they pitch a lease or PPA, ask about the escalator clause. This is a clause that increases your monthly payment by a certain percentage (often 2.9%) every year. Ensure you aren’t signing up for a bill that will eventually become more expensive than the utility company.
11. How does the grid interconnection and Net Metering work?
Unless you are going completely off-grid with massive batteries, you will remain connected to the utility grid. Net Metering is the policy that allows you to send excess energy back to the grid during the day and get credit for it, which you use at night when the sun is down.
Net Metering rules vary wildly by state and utility provider. Some utilities offer a 1-to-1 credit (the best deal), while others pay you a wholesale rate for your exports but charge you a retail rate for imports (the worst deal).
Ask your contractor to explain the specific Net Metering policy for your utility.
- When does the credit cycle reset?
- Do credits expire?
- Are there mandatory fixed charges just for having solar?
- What happens if the grid goes down? (Hint: Unless you have a battery, your solar shuts off too).
12. What is the timeline from signature to power-on?
Solar is not an instant gratification purchase. Due to supply chain logistics, permitting backlogs, and utility inspections, the process can take anywhere from 6 weeks to 6 months.
Ask for a realistic timeline that outlines the steps:
- Site survey
- Engineering design
- Permit submission
- Installation (usually 1-3 days)
- City inspection
- Utility inspection
- Permission to Operate (PTO)
The gap between installation and PTO—where the panels are on your roof but you aren’t allowed to turn them on yet—can be frustratingly long. A good contractor will set realistic expectations for this “dead period.”
Frequently Asked Questions
Should I get a battery backup with my solar panels?
It depends on your goals. If your main goal is financial savings, batteries often lengthen the payback period because they are expensive. However, if your goal is energy resilience and having power during blackouts, a battery is essential. Standard solar systems automatically shut off during grid outages to protect utility workers from back-feeding electricity.
Does solar increase my property taxes?
In many states, the answer is no. Over 30 states have property tax exemptions for renewable energy systems, meaning the added value to your home (which can be significant) is not assessed for tax purposes. Ask your contractor about the specific laws in your state.
What happens if I sell my house?
If you own the system (cash or paid-off loan), the solar panels are a valuable asset that increases home value. If you have a lease or a PPA, you generally have to transfer that agreement to the new home buyer. This can sometimes complicate the sale if the buyer does not want to assume the lease terms.
Protecting Your Investment
Installing solar panels is one of the few home improvements that pays for itself and then generates profit. But that return on investment relies heavily on the system being designed correctly, installed safely, and priced fairly.
Don’t be afraid to be demanding during the interview process. A high-quality contractor will appreciate that you are an informed consumer and will have no trouble answering these 12 questions transparently. If a salesperson dances around the details of the warranty, hides the dealer fees, or pressures you to sign today to “lock in a deal,” show them the door.
Get at least three quotes. Compare the equipment, the warranties, and the vibes you get from the company. The cheapest quote is rarely the best value in the solar industry. You are looking for a partner for the next 25 years—choose wisely.