Questions to ask a solar company before you sign a contract

Updated

a customer asking a solar installer a question
Ask the right questions about solar to be sure you’re making the right decision.

If you’ve done the research and decided that solar power is right for your home, it’s time to reach out to one of the best solar companies near you. They’ll do a survey of your home and any obstructions in the area around it, then give you an estimate that will show how many solar panels you need, how much they’ll cost, and how soon they’ll pay for themselves.

At this point, you’ll likely have a lot of questions, and you may not even know all the right ones to ask. That’s where we come in.

We’ve prepared this article as a guide to all the questions you should ask a solar installation company before you let them drill into your roof. If the solar company you’ve chosen can answer them to your satisfaction, you can rest assured that you’ve done the right thing - and get ready to soak in the sun!

Information the installer should give you in a quote 

A good solar quote should contain enough information to make you feel confident that the installer knows what they’re doing and will provide you with all the information necessary to make a decision. It should answer more questions than it raises.

We always recommend getting quotes from more than one solar contractor so you can compare what each one offers. It’s also a good way to see which one takes winning your business more seriously. 

Here’s a detailed list of all the information you should expect to see in a solar quote:

Solar quote must-haves: 

  • Solar panel make/model, and number of panels to be installed
  • Total system size in kilowatts (kW)
  • A satellite photo or 3-D representation of your roof showing proposed panel layout
  • Inverter or microinverter model
  • Expected electricity production in kilowatt-hours (kWh) per year
  • Anticipated savings in dollars per year (with a clear number for estimated annual increase in utility rates)
  • Information about any solar incentives for which you qualify
  • Total system cost before and after incentives, broken down by dollars per watt
  • Solar loan upfront/monthly cost and the price if you pay cash
  • Information about warranties on equipment and workmanship

Bonus info: 

  • Multiple options for panels/inverters at different price points
  • Comparison of solar costs vs. estimated utility costs over time
  • Details about the cost to add a home solar battery
  • Information about a solar production monitoring app, such as those offered by Enphase, SolarEdge, etc.

As we said above, a good solar quote should answer the most important questions, like how much the solar panels cost and how much you’ll save. Once you’ve got the quote in hand, it’s time to learn a little more about the company themselves and the process going forward. 

Questions about the installer 

A solar installer adding solar panels to a roof.

Get to know these folks before they get up on your roof.

Unless you’re choosing your sister-in-law’s new solar company because she’s trying to gain some experience, you should pick an installer with a good deal of experience under their belt. You should also make sure they’re licensed to work in your area, and insured against liability for mistakes and accidents. 

Finally, solar installers in the United States have the option of becoming certified by the North American Board of Certified Energy Practitioners (NABCEP). We strongly recommend choosing an installer who will ensure a NABCEP-certified professional will be on site at all times during the installation

Here are the questions you should ask a solar installer about themselves:

  • How long have you been in business?
  • How many solar systems have you installed?
  • Are you NABCEP-certified, licensed, bonded and insured?
  • What is your business license number?
  • Can you share references of at least three satisfied customers?
  • How much experience do you have working with my local utility company?
  • Do you subcontract work on your systems, and if so, how do you ensure your subcontractors do a good job?

Satisfactory answers to these questions should put you at ease that the solar company is well-established and staffed by professionals. The last two questions in particular are important.

Local utility companies all have different rules about how home solar energy systems will connect with their grid, and installers with experience know how to make sure things are done right to ensure that process goes smoothly. 

Subcontractors aren’t a bad thing; in fact, many solar energy companies use subcontracted roofers to attach solar racking systems and master electricians to do final connection of the system to the electrical panel. Still, it’s good to get clarity on it, because top installers will be clear and forthcoming on this point. 

If you use the solar calculator on SolarReviews to find installers near you, you can rest assured that you’ll be matched with certified pros with experience in the solar industry. Our site also has review pages for every installer with information on their certifications and verified reviews from real customers. 

Estimate system size and calculate solar panel costs and savings

Questions about solar equipment 

solar panels on a roof

Ask questions to make sure you’re getting the best solar equipment for your price point.

When it comes to solar equipment, most installers use high-quality brands with good warranty coverage and longevity, but it always pays to double check. 

You should be 100% sure that what you’re putting on your roof for the better part of the next three decades is built to last and compares favorably to other products on the market. Luckily, SolarReviews offers real customer reviews of solar panels, inverters, batteries, and more. 

That doesn’t mean you shouldn’t ask the installer about the equipment they choose. You should! 

Here are the questions to ask about solar panels and other equipment:

  • Why did you choose the equipment you did?
  • What kind of system do you have on your own roof or business?
  • What warranty protection is available for the solar panels, inverter, etc?
  • What problems have other homeowners had with their solar equipment, if any?
  • Who do I contact if something goes wrong with my equipment?
  • How much would it cost to add a solar battery?
  • Do my solar panels need protection from animals?

Warranties 

One of the best ways to compare brands is by reviewing the solar panel warranties they offer. Warranties should at minimum provide 25 years of coverage for power production and 10 years of coverage for workmanship.

Several manufacturers—like Sunpower, LG, and Panasonic—provide 25-year warranties for both on their top panel models. 

Inverters 

Solar string inverters generally have a warranty of 10 years (but some offer add-on protection for additional years), meaning they’ll need to be replaced at least once during the time you own them. 

Microinverters from companies like Enpahse are warrantied to last 25 years, just like the panels. They can fail from time to time, meaning you might lose power from a single panel while you wait for the replacement.

Batteries 

It’s likely that you’ll never need to have a home solar battery; power outages are generally short, so the only thing you’ll lose is the temporary comfort and convenience of all the electrical appliances in your home. 

However, recent problems in California and Texas have shown that blackouts can be deadly, and the peace of mind that comes from a solar battery can be worth the cost, even if you never need to use it.

Adding batteries to a solar system at the time of installation comes with some specific advantages. When batteries are designed as part of the system, you generally have your choice between DC or AC-coupled. The difference isn’t huge, but it’s worth exploring. 

Some of the installation labor cost might also be reduced, meaning a battery that’s installed concurrently with solar panels may be a bit cheaper than a battery added later.

Further, if you wait to install a battery, you’ll almost certainly be offered the AC-coupled variety (such as the Tesla Powerwall) that stores electricity only after it’s been converted from DC to AC by your solar inverter. That isn’t necessarily a bad thing, but it does lead to a small amount of additional power loss due to the conversion.

Animals 

Pay special attention to this question. Most places in the USA don’t see significant problems from animals messing with solar panel installations, but it’s possible that the squirrels in your neighborhood are extra ornery and like to build nests underneath solar installations or chew exposed wires. 

There are products on the market that fight these problems, and your installer will be able to tell you whether other customers have had trouble with animals. 

Questions about money 

solar panels cost money and save you money

When it comes to financial matters, it pays to check - and re-check - the numbers.

The biggest consideration for most homeowners is cost, and closely tied with that is savings. As we said above, a good solar installer should provide a quote with the total cost, estimated savings per year, and payback period. 

The quote should also include information on the incentives available to you, especially the federal solar investment tax credit (ITC), which can earn you 26% of the cost to install solar panels back as a tax credit the year after installation is complete.

Here are the questions to ask about costs and savings associated with your installation:

  • How can I be sure I am eligible for the solar tax credit?
  • Are there other incentives, and how do they reduce or repay the cost of the system?
  • When are payments for the system due? Is the entire amount due at one time?
  • How long will it take for the solar panels to pay back their cost?
  • What rate of increase in utility costs do you use in your estimates?
  • What financing options are available?
  • Will the payments for financed solar panels increase over time?
  • Will solar panels increase my home value?

Solar tax credit 

It is a sad truth that not all solar salespeople are straight shooters when it comes to your eligibility for solar incentives. You can only claim the 26% solar tax credit if you owe at least that amount in taxes

Put another way, you have to have income. Some retired people have been told they qualify for the tax credit by unscrupulous salespeople even though they don’t have income. Your installer might not be a tax pro, but they should be straight with you about what it takes to qualify for this incentive.

Other incentives like solar rebates or SRECs don’t require income to claim, and your installer should be the expert in helping you get qualified and claim those incentives.

Savings estimates 

Another place where some salespeople don’t tell the whole truth is in solar savings estimates. These calculations rely on information about how much electricity your solar panels will make each year, the average annual increase in the cost of that electricity on your energy bills, and whether your state offers net metering

Your installer should be able to give you a straight answer about the calculations they used to determine solar production for your rooftop. Installers may use one of the many expensive software programs that can do these calculations, but you can use the free PVWatts tool from the National Renewable Energy Laboratory to get a ballpark idea of whether their numbers are right.

As for utility rates: in most of the US, utility rates increase by about 2.5-3.5% per year. Certain places have very low historical increases while others have very high increases. You can get the historical rate of increase from your utility company or by looking back at old electricity bills at the amount you pay per kWh. 

If your solar quote shows a projected increase of more than 3.5%, ask the solar company to show proof that their numbers match the historical rate of increase, or run the savings estimate again using a lower rate. 

Financing 

Finally, it’s very important to find out about financing options and their effect on final cost. 

Nearly all solar companies work with financing companies to provide solar loans, which offer low monthly payments rather than a big upfront charge. Other companies will offer solar leasing or power purchase agreements (PPAs), which means the solar company owns the panels and you pay a monthly lease payment or per-kWh charge for the solar energy the panels make,

One important thing to know here is that solar installers who offer loan financing often end up passing a finance charge onto customers who sign up for that financing. You should ask the installer for the cash price vs financed price, and if the difference seems too great to you, consider using your preferred bank to obtain a HELOC equal to the cash price.

HELOCs are harder to obtain than other solar loans, but don’t have finance charges so you’ll save money while still financing the total cost. In addition, solar panels increase the value of your home, so a HELOC won’t necessarily decrease the amount of equity you have in your home as much as it would if you were financing another type of home improvement.

Enter your zip code and amount of your most recent energy bill to see average solar panel costs in your area

Questions about the work being done 

a team of solar installers adding a panel to a rooftop installation

Installing the panels is the “glamorous” part, but the installation process has many other steps.

Once you’ve settled on the price and payment schedule, it’s time to think about the practical matter of getting this stuff on your roof and kicking out kilowatts. 

Here are the questions to ask about the installation process:

  • What are the steps of the installation process?
  • How long will it take to complete the process, and what is the timeline?
  • What if you don’t finish the work on time?
  • What guarantees do you offer for your work?
  • What happens if a leak develops well after the panels have been installed?

Installation process 

These questions are all about the process. A good installer should be able to give you a timeline and commit to meeting it. There are certain things within their control, like initial start dates, and things out of their control, like permitting timelines and scheduling an inspection from the utility company prior to getting final permission to operate (PTO).

In general, it can take as little as two or as many as six months for the whole process to get done. Installers need to do a site visit, submit a system design to the local authority, get a permit, schedule the installation, do inspections, and get final permission to interconnect and operate your system on the grid. 

They should be open with you about what this process looks like and how they’ve worked with your utility company in the past.

Guarantees 

If the installer can’t finish the work on time, it may mean you don’t qualify for incentives that were available at the time you signed the contract. 

A good example of this is back in 2019 when the federal solar tax credit decreased from 30% to 26% of costs. Anyone who didn’t have a completed solar installation by December 31st didn’t get to claim the 30% credit.

Your installer should be willing to give you a guarantee or pay the difference between incentives you thought you’d get and incentives you can’t claim because of their going over the time estimate to complete the installation. 

They should also give you a guarantee that their work will not damage your home, and offer protection for you against roof leaks, broken tiles, and other damage. The best installers offer workmanship warranties for at least 5 years after installation so you can feel confident that they do quality work. If any problems occur from shoddy workmanship, they usually occur soon after installation.

Questions about the future 

a cracked solar panel

Know what to do in the unlikely event that one or more panels suffers damage.

Now that you’ve squared away info about how and when the system will be installed and how much it will cost, it’s time to think about what happens during all the years you’ll be harvesting energy from the sun. 

Solar panel systems are meant to last for at least 25 years, but things can go wrong, and it pays to be prepared for if that happens.

Here are the questions you should ask about the future:

  • How will I be able to monitor the solar energy my system generates?
  • What happens if the solar panels don’t produce as much energy as you claim?
  • How long will my contract with the utility company last?
  • What happens if I need my solar panels removed to have work done on my roof?
  • What if a solar panel fails due to a manufacturing defect or breaks because of a storm or other natural disaster?
  • What if I want to add additional panels to my installation? What about a battery?
  • What happens if I move while still paying off the panels?

Monitoring software and systems 

By the time your panels are installed and fully operational, you’ll be itching to see a real-time readout of just how much energy they’re producing (and how much money you’re saving) at any given time. 

Your installer should be able to tell you about any solar monitoring software they use, or at least show you how to use a third-party solution like the Sense energy monitor to track your solar production and consumption.

If you get solar panels through a PPA or lease, your installer will probably include a production guarantee. That means you should expect a minimum number of kWh per year, and if the leased panels don’t make that much, your contract should have a clause that describes how the company will reimburse you, usually a monthly bill credit. 

When you’re buying solar panels with cash or a loan, you generally won’t get a production guarantee from the installer. That doesn’t mean you should suffer with low power output. If your panels aren’t generating what you think they should, your first call should be to the installer. But even before the panels get up on the roof, ask the company what kind of after-sales service they’ll provide if you run into problems. 

Know your contract 

Be sure to ask about your net metering contract. It used to be that many states with net metering rules allowed those homeowners who signed up to stay on the arrangement indefinitely. 

Now, as net metering changes take place all over the country, you may only be guaranteed the full retail rate for 10 or 20 years. It pays to ask rather than be surprised when your utility switches you to a different plan after a decade or two.

Panel failure and damage 

If a solar panel fails because of a manufacturing defect, you should hear from the installer whether they want you to contact them first or reach out to the manufacturer for warranty repair. The answer to this question will likely be different whether you own the solar panels or lease them. 

Side note: solar panels are covered by most homeowners’ insurance policies. If you own the system and your panels are physically damaged, your insurance company will likely pay for any repairs, minus your deductible. 

Big, structural change 

As we’ve said a dozen times now, solar panels are designed to last for a very long time. 

Unless you get them installed on top of a brand new roof, chances are good you may someday have to remove them and have a roofing company install new shingles or tiles. The very best installers will offer to do this for you for a modest fee, and you may even ask to have them write it into the contract. 

If your energy needs change or your energy usage increases after, say, starting a family or buying an electric car, you may want to consider adding additional panels to your installation someday down the road. It’s very important to ask about that possibility before you get the first panels on your roof, because there may be limitations or other considerations that would prevent you from adding panels in the future

For example, you may have limited roof space, and installing some less-efficient panels now would take up the entire available surface. Instead, your installer might convince you to install more efficient panels that take up less space, so there will be room for an expansion in the future. 

Additionally, the possibility of adding solar panels in the future may lead your installer to recommend an inverter rated to handle more power, or to recommend microinverters, which allow for future panels to be added without making modifications to your existing setup.

The final word on asking a solar installer questions 

Choosing to install solar panels on your home is a big deal, and if you’re like most people, you’ll want to make sure you’re making a smart choice and asking the right questions. 

You don’t have to ask every question we outlined above, and you can do a lot of your own research right here using the “learn solar” menu (to the right on desktop or by clicking on the “+” button on mobile.

Whatever questions you do ask, your installer should have a good, logical answer for, and they shouldn’t have any problem answering. You can tell the difference between a good and bad installer by how willing and open they are about answering all your queries. 

Solar panels represent the ideal of a low-maintenance product, and once yours are fully installed and activated, you may never have to contact your installer again. Still, you’re about to enter into a 25-year relationship with a company, so you should make sure they are ready to be there for you. 

Find out what your solar panel payback period will be
 - Author of Solar Reviews

Ben Zientara

Solar Policy Analyst and Researcher

Ben is a writer, researcher, and data analysis expert who has worked for clients in the sustainability, public administration, and clean energy sectors.

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