Questions to Ask a Solar Company
For homeowners with a quote on the table, or a salesperson on the way, who want to know what questions to ask about solar panels and the company fitting them. These 59 questions to ask a solar installer follow the decision in order: your home, the panels and equipment, production and your bill, price and financing, the company and its installation, then warranty and service.
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The questions
Each question, and why to ask it
Your home
Is my roof a good candidate for solar panels, and what would make you tell me not to do it?
Why ask it
Direction, pitch, shade and the age of the roofing decide most of it, and a house can fail on any one of them. An installer who can describe the roof they would turn down is easier to believe when they say yours works.
How much electricity do I use in a year, and how much of it is this system sized to cover?
Why ask it
Sizing should start from twelve months of your own bills, not from the square footage of the house. The share of your annual use the design covers, and the reason it stops there, matters because some utilities cap system size or pay little for the surplus.
Did someone go on the roof and into the attic, or was this designed from satellite images?
Why ask it
A remote design is a reasonable first draft, and plenty of quotes begin that way. Rafter spacing, soft decking and the real position of vents only show up in person, so find out when the site visit happens and whether the price can move after it.
Does my roof have enough years left in it, or should it be replaced before the panels go on?
Why ask it
Panels are sold to sit in place for decades, and many roofs will need replacing sooner than that. Lifting an array off and refitting it to reroof is a job with its own bill, so a company that never asks the roof's age is not planning for the second half of the system's life.
Which trees, chimneys or neighboring buildings shade the roof, and at what time of year?
Why ask it
Shade in December falls differently from shade in June, and depending on the inverter one shaded panel can drag down the others wired with it. A shade report broken out by month shows whether trimming a tree or moving a few panels would change the design.
Why are the panels on these roof faces and not the others?
Why ask it
A layout is a set of trade-offs between sun, fire setbacks, vents and how the array looks from the street. The reasons tell you whether a person thought about your roof or software filled the space, and whether fewer panels in better spots would serve you as well.
Can my electrical panel take this system, or does it need an upgrade?
Why ask it
A full or elderly main panel is a frequent reason a solar quote grows after signing. Ask whether anyone opened the cover or only photographed the label, and what an upgrade would cost if the utility or the inspector requires one.
I may add an electric car, a heat pump or a battery later. Should the design allow for that now?
Why ask it
Past bills describe the house you had, not the one you are planning. Adding panels afterward usually means a second permit and sometimes a second inverter, so find out how much room this design leaves and what your utility allows.
Does my homeowners association, a historic district or a local rule limit where panels can go?
Why ask it
Rules on visible panels differ by state, city and association, and some places limit what an association may refuse. The parts to pin down are who files the application, how long approvals nearby have taken, and whether your deposit comes back if the answer is no.
Panels and equipment
Which solar panels are in this quote, by manufacturer and model number, and why those?
Why ask it
A proposal that says only premium or tier one panels has not named a product. With the exact model number you can read the datasheet yourself and check that the panel in the contract is the panel in the pitch.
What is each panel's wattage, and how many panels does the design use?
Why ask it
Panel count multiplied by wattage gives the system size in kilowatts, the number every other figure hangs on. Do that arithmetic yourself and check it against the size printed on the contract.
How quickly do these panels lose output, and what does the maker promise for year twenty-five?
Why ask it
Every panel fades a little each year, and the datasheet states the rate the manufacturer stands behind. The production estimate ought to use that same rate, so ask where it appears in the model.
Are you proposing microinverters, optimizers or a string inverter, and why for this roof?
Why ask it
The choice affects how the array copes with shade, how much electronics sits on the roof, and what gets replaced when something fails. Listen for an answer about your roof rather than about the brand the company happens to stock.
What happens if the panel or inverter model is unavailable when you install?
Why ask it
Months can pass between signing and installation, and substitutions happen in that gap. A clause requiring your written approval of any swap, with equal or better specifications, settles it in advance.
Will the system keep any power on during an outage?
Why ask it
A standard grid-tied system shuts down when the grid does, so that it cannot feed power into lines people are repairing. If backup matters to you, ask which equipment provides it and which circuits in the house it would actually run.
Is a battery worth adding for my house, and what would it add to the price?
Why ask it
A battery changes the cost a great deal, and its value depends on your utility's export rate, any time-of-use pricing and how often the power fails. Have the system priced with and without one, and ask whether the inverter would accept a battery in a few years.
What monitoring comes with it, and can I see output panel by panel?
Why ask it
Monitoring is how you learn that something failed without waiting for a high bill. Find out who else watches the data, whether the app costs anything after the first years, and what it needs from your home internet.
Production and bill
What is your production estimate based on, and which software produced it?
Why ask it
Two companies can model the same roof and land on different numbers, because the figure rests on shade data, pitch, orientation and assumed losses. The inputs measured at your house deserve more trust than the ones read off an aerial photograph.
Can you send me the full production report, not only the summary page?
Why ask it
The full report lists the assumptions behind the headline number, and it is what you will set beside your monitoring data later. A figure said aloud across the kitchen table is not something you can hold anyone to in year two.
How does production change from summer to winter here?
Why ask it
An annual total hides a wide swing between seasons. A month-by-month table shows when you will still be buying most of your power, and it keeps a dark January from looking like a fault.
Does the production guarantee pay me anything if the system falls short?
Why ask it
Some guarantees promise only that a technician will come and look. One worth the name states the payment, how a shortfall is measured, over what period, and who does the measuring.
How does my utility handle net metering or exports, and can that change after I sign?
Why ask it
Export rules come from the utility and its regulator, they differ widely from place to place, and some have been rewritten, with existing customers sometimes protected and sometimes not. Whatever rate the proposal assumes, confirm it with the utility yourself.
Which rate plan does the savings figure assume, and would going solar move me to a different one?
Why ask it
Some utilities place solar customers on a time-of-use or solar-only plan, which shifts the hours when power costs you most. The plan named in the proposal should be one the utility confirms you can actually be on.
Can you walk me through how my bill changes, including fixed charges and any annual true-up?
Why ask it
Bills rarely go to zero: fixed charges, minimum bills and a yearly reconciliation can all remain, depending on the utility. The clearest answer is your last twelve statements reworked line by line under the new arrangement.
What yearly rise in electricity prices does your savings projection assume?
Why ask it
Long projections are very sensitive to this one input, and nobody knows what it will be. Ask to see the same chart with no increase at all, then judge the offer on that version.
How many years until the system pays for itself, and what is counted in that figure?
Why ask it
Payback depends on what went into it: incentives you may not qualify for, loan interest, a replacement inverter, the export rate. Get the calculation in a form you can change and run it again with your own cautious numbers.
Price and financing
Is this a cash purchase, a loan, a lease, or a power purchase agreement?
Why ask it
These are four different products with different owners, tax treatment, and consequences when you sell the house, and sales conversations often blur them into a single monthly payment. Get this answered in one word before any monthly figure is discussed.
What is the price per watt, before incentives?
Why ask it
Price per watt is the simplest way to compare quotes for systems of different sizes. The gross number is the one to line up, since a price quoted after incentives hides the difference between bids.
What is not included in this price?
Why ask it
Exclusions are where quotes diverge: an electrical panel upgrade, trenching, tree work, permit fees, or roof repair can add a great deal. Ask for the exclusions as a written list and compare bids on that basis.
What would a smaller system cost, and how would the payback change?
Why ask it
The last few panels often sit on the weakest roof face and earn the least. Seeing a smaller option priced tells you whether the size was chosen for your bill or for the sale.
If this is a loan, what fee is built into the price, and what would the cash price be?
Why ask it
Solar loans can carry a lender fee folded into the system price, which is why the cash price for identical equipment is sometimes lower. Put the two prices side by side and compare the totals, not the monthly payments.
What are the loan's interest rate, term and total of payments, and can the monthly payment rise?
Why ask it
Some solar loans are written expecting a lump sum partway through the early years, and the monthly amount steps up if it never arrives. Have the lender, not only the salesperson, send the payment schedule for both cases.
If this is a lease or a power purchase agreement, is there an annual escalator, and what is the payment in year fifteen?
Why ask it
An escalator of a few percent a year compounds quietly over a long term. The year-by-year schedule in writing shows it, and the last five years tell you more than the first.
When a lease or power purchase agreement ends, can I renew it, buy the system, or have it taken away?
Why ask it
The end of the term feels distant at signing, yet it decides whether you finish with panels you own, a new contract or a bare roof. The contract should name each option, how a buyout price is set, and who pays to take the equipment down.
Who owns the system, and who can claim any tax credit or rebate?
Why ask it
Under a lease or power purchase agreement the company usually owns the equipment, and incentives tend to follow the owner. Credits and rebates change and depend on where you live and on your own taxes, so check what you could claim with a tax professional before it goes into the savings math.
Which incentives does this quote count on, and what if one ends or I do not qualify?
Why ask it
Programs open, close and run out of money, sometimes between signing and switch-on. Find out which applications the company files, which are left to you, and whether the price moves if one falls through.
What is the payment schedule, and what is the final payment tied to?
Why ask it
A large share paid before anything is on the roof leaves you little leverage. Payments tied to milestones, with the last one due only after the utility grants permission to operate, keep both sides interested in the finish. Some places also cap the deposit a contractor may take, so ask how it works where you live.
Will there be a lien or fixture filing on my property, and what happens if I sell?
Why ask it
Some financing arrangements place a filing against the property that surfaces during a sale and can hold up a closing. You want to hear what the filing does, how it comes off, and exactly how the agreement passes to a buyer.
If I sign and then change my mind, how do I cancel and what would I owe?
Why ask it
Cancellation rights for a sale made in your home differ by state and country, and the contract may add terms of its own. Have the clause, the deadline and the address for a written cancellation pointed out before you sign anything on a tablet.
Company and installation
How long has the company installed solar under this name, and how many systems have you put up in my utility's territory?
Why ask it
Every utility and permit office has its own habits, and a company learns them one job at a time. Local volume also suggests a service truck will be somewhere nearby when you need one.
Do you work for the company that will install this, or for a sales firm that hands the job on?
Why ask it
Some solar is sold by dealers who pass the signed contract to a separate installer, and the person at your table may never see the roof. Knowing which company holds the contract tells you whose license, insurance and warranty you are really checking.
Who does the installation: your own crews or subcontractors?
Why ask it
Subcontracting is normal and not automatically a problem, but it decides who comes back for a warranty visit. Ask whose name appears on the workmanship warranty and whether that company works in your area year round.
Which licensed electrician is on this job, and who pulls the permit?
Why ask it
Licensing rules vary by state and country, and the license holder is sometimes not the person on the roof. With the license number you can look it up with the body that issued it, which is worth more than a screenshot.
Can I speak to three customers you installed for near here more than a year ago?
Why ask it
Local addresses from a year ago beat online reviews, because you can look at the workmanship and ask the owner what the first twelve months were like. A company unwilling to name anyone nearby has answered a different question.
How long from signing to permission to operate, and where do jobs usually stall?
Why ask it
Permitting, utility interconnection and inspection each have a queue of their own, and the wait between signature and switch-on is where patience runs out. Recent timelines from your own city are more use than a company-wide average.
Who files the utility interconnection application and books the inspections?
Why ask it
The utility paperwork is a project of its own, with forms, fees and sometimes a meter swap. Get a name for each step and a promise of updates during the weeks when nothing visible is happening.
If the inspector or the utility requires changes, who pays for them?
Why ask it
A failed inspection or a demand for extra equipment can add a cost nobody priced. The contract should say whether that lands on the installer or on you, and whether your deposit comes back if the utility refuses the connection.
How many days is the crew on my roof, and when is the power off?
Why ask it
The roof work is often short compared with the waiting on either side of it. The hours without power matter if someone works from home, relies on medical equipment or keeps a full freezer.
How are roof penetrations flashed, and does the work affect my roof warranty?
Why ask it
A leak, if one comes, tends to start at a mounting point and can take years to show. Ask what flashing is used, whether the roofing manufacturer accepts it, and who pays for a leak, and get that answer into the contract rather than leaving it in conversation.
Where will the inverter, the disconnect and the conduit go?
Why ask it
This is the part of a solar job you look at every day from the driveway. Ask for the conduit runs to be drawn on the plan, whether they can pass through the attic, and where each wall-mounted box will hang.
How do you protect the roof, gutters and garden while you work, and who pays if something is damaged?
Why ask it
Cracked tiles, dented gutters and trampled beds are the ordinary damage on a rooftop job. Learn how to report it and how soon, and have the company's insurer send the liability certificate to you directly.
Warranty and service
How long is each of the three warranties: panels, inverter, and your workmanship?
Why ask it
These are three promises from different parties, and a sales meeting can blur them into one number. The lengths vary by brand and by installer, and the workmanship warranty is the one that covers the roof work and wiring this company did.
If your company closes, who honors the workmanship warranty?
Why ask it
Solar installers do go out of business, and a workmanship promise is only as good as the company behind it. Sort the obligations into those that sit with the equipment manufacturer or a third party and those that depend on this company still trading in ten years.
Who pays for labor when a panel or inverter fails under the manufacturer's warranty?
Why ask it
A manufacturer's warranty may send a replacement part and nothing else. The trip, the roof work and the shipping can fall to you unless the installer's terms or the maker's labor allowance cover them, so read that line before you rely on it.
Who do I call when production drops, and how quickly does someone come?
Why ask it
An array can sit half dead for months if nobody is assigned to notice. Ask whether the company employs its own service technicians, what a visit costs once the workmanship term ends, and who files the claim with the manufacturer.
What does it cost to take the panels off and put them back if the roof needs work?
Why ask it
Sooner or later a roof needs a repair underneath the array. Get a per-panel or flat price for removal and reinstallation now, and ask whether letting another company do it would affect the warranty.
Do the panels need cleaning or any regular maintenance?
Why ask it
Rain does most of the washing in some climates, while dust, pollen, birds or snow change the answer in others. Ask what they recommend where you live and which cleaning methods, pressure washing for one, the panel maker would refuse to cover.
Do the warranties transfer to a new owner, and is there a fee or a form?
Why ask it
Transfers are sometimes automatic and sometimes need paperwork within a set window after the sale. A buyer's agent will want to know, so keep the answer with the house documents.
Do I need to tell my home insurer, and does the system change my coverage?
Why ask it
Policies treat rooftop solar differently, and some insurers want to hear about it before it goes up. The installer can tell you what other customers found, but the answer that counts comes from your own insurer, in writing.
Getting through a solar sales process
Practical guidance for the conversation itself
Where to start in the list
- If you are still deciding whether solar energy suits the house at all, begin with Your home and Production and bill. Those two groups can end the conversation before price ever matters.
- If the solar panels themselves are what you want to understand, Panels and equipment covers the model, the inverter type, batteries, outages and monitoring.
- With two or three quotes in hand, go to Price and financing and put the same questions to every solar panel installer, so the answers line up in one table.
- When one company is ahead, Company and installation and Warranty and service hold the answers to get into the contract before the crew arrives, not after it has left.
Before you sign anything
- Get three quotes, each stating system size in kilowatts, panel and inverter models, price per watt, and the annual production estimate. Quotes without those four cannot be compared.
- Do not sign at the first meeting. A discount that expires tonight, or a tablet handed to you at the door, is a reason to stop rather than to hurry.
- Check the contractor license and complaint history with whichever body licenses contractors where you live, and find out whether the salesperson works for the company doing the installation.
- Confirm incentives with a tax professional and with your utility rather than with the salesperson, since whether you can use a tax credit depends on your own tax position.
Reading the paperwork
- Read the contract, not the proposal. Only the contract binds anyone, and the two often differ.
- Look specifically for what happens if production falls short, if the roof leaks, if the utility refuses interconnection, or if you sell the house.
- Note the cancellation window. Many places give a few days to cancel a door-to-door sale in writing, and it is worth using if you feel rushed.
- Get any verbal promise about future rate rises, equipment upgrades, or referral payments written in or treat it as not said.
During and after installation
- Photograph the roof before work starts and again once the array is up.
- Where the contract allows it, hold the final payment until the utility has granted permission to operate and the system is producing.
- Compare your first full sunny month against the estimate, and again after a year. Raise a shortfall in writing while the workmanship warranty is well within its term.
- Keep the plan set, permit, interconnection approval, warranty documents, and monitoring login together. A buyer or an appraiser will ask for them.
Warning signs
- A monthly payment quoted with no system size, equipment models, or price per watt.
- A production estimate noticeably higher than other bidders gave for the same roof.
- Pressure to sign before anyone has inspected the roof or the electrical panel.
- A claim that the system will eliminate your electricity bill completely.