My neighbor went solar in 2024. Paid $32,000 for a system that was supposed to “eliminate” his electric bill. A year later, he’s still paying $80 a month to the utility, the production numbers don’t match what he was promised, and the installer ghosted him when he asked about it. Turns out the system was undersized for his actual usage, and nobody bothered to mention that before he signed.
That’s what happens when you skip the questions. Solar is one of the best investments a homeowner can make, but only if the system is designed right, installed properly, and priced fairly. The difference between a great solar experience and a terrible one almost always comes down to the installer you choose and the conversation you have before signing anything.
These 17 questions will help you cut through the sales pitch and figure out who actually knows what they’re doing. Print this out, bring it to every consultation, and let the answers tell you everything you need to know.
Before You Contact a Solar Installer
A little prep work makes every conversation more productive and helps you spot bad answers immediately:
- Pull your last 12 months of electricity bills. You need your actual annual usage in kilowatt-hours (kWh), not a guess. This is the single most important number for sizing your system correctly.
- Check your roof’s age and condition. If your roof needs replacing in the next 5-10 years, do that first. Pulling panels off and reinstalling them for a reroof costs $2,000 to $5,000.
- Note any shading issues. Big trees, neighboring buildings, or chimneys that cast shadows on your roof during peak sun hours will reduce production. Walk around your property at midday and take photos.
- Look up your utility’s net metering policy. Net metering lets you sell excess power back to the grid. Some utilities pay retail rate, others pay wholesale, and some have caps. This changes your return on investment significantly.
- Research local and federal incentives. The federal solar tax credit (currently 30% through 2032) is the big one. Your state may offer additional rebates or credits. Know what’s available before the installer tells you.
What to Mention or Send Beforehand
Share these details with each installer before the consultation so they can prepare an accurate proposal:
- Your monthly and annual electricity usage. Send your last 12 months of utility bills, or at minimum the kWh totals for each month. Seasonal variation matters because a system sized for summer usage might fall short in winter.
- Your roof type, age, and orientation. Composition shingles, metal, tile, flat. How old is it? Which direction does the main roof face? South-facing roofs produce the most energy in the Northern Hemisphere, but east-west setups work too.
- Any planned changes to your energy usage. Are you buying an EV? Adding a hot tub? Finishing a basement? Future demand should factor into the system size.
- Your utility company and rate plan. Some utilities have time-of-use rates that change the math on solar significantly. The installer needs this to model your savings accurately.
- HOA restrictions, if any. Some HOAs have rules about panel placement and visibility. Most states have solar access laws that limit what HOAs can restrict, but send the guidelines anyway so there are no surprises.
System Design and Equipment
1. What size system do you recommend for my home, and how did you calculate it?
This is the foundation of everything. A system that’s too small won’t offset your bill. A system that’s too large wastes money. The installer should base their recommendation on your actual electricity usage (from those 12 months of bills), your roof’s available space, shading analysis, and your utility’s net metering policy.
Be skeptical of any installer who gives you a system size during the first phone call without reviewing your usage data. That’s a salesperson, not an engineer.
2. What brand and model of panels will you install?
Not all panels are created equal. Tier 1 manufacturers like LG, REC, Panasonic, SunPower, and Canadian Solar have track records you can verify. Ask for the specific model number, not just the brand. Then look up the panel’s efficiency rating, degradation rate, and warranty terms yourself.
Panels typically degrade 0.25% to 0.5% per year. Over 25 years, that adds up. A panel with a lower degradation rate produces more energy over its lifetime, which means more savings.
3. What inverter technology are you recommending, and why?
The inverter converts DC power from your panels into AC power your home can use. There are three main types: string inverters (cheapest, but one shaded panel drags down the whole string), microinverters (attached to each panel, better for shading), and power optimizers with a string inverter (a middle ground).
If your roof has multiple orientations or any shading, microinverters or optimizers are usually worth the extra cost. An installer who only offers one option without explaining the trade-offs isn’t giving you the full picture.
4. How much energy will this system produce annually, and what assumptions are you using?
Get a specific number in kWh per year, and get it in writing. Then ask what assumptions they’re using: sun hours, shading factor, panel degradation, inverter efficiency. The production estimate should come from modeling software like Aurora or Helioscope, not a back-of-the-napkin calculation.
Compare this estimate against your annual usage. If they’re promising 100% offset, dig into the math. Some installers inflate production numbers to close the deal.
5. Will you perform a shade analysis of my roof?
Any reputable installer will do a thorough shading analysis using satellite imagery, drone photography, or on-site measurements with a Solar Pathfinder or similar tool. Shading from trees, vents, chimneys, and neighboring structures can cut production by 10-30%.
If someone eyeballs your roof from the driveway and says “looks good,” that’s not analysis. That’s guessing.
Installation and Permitting
6. Who handles the permits, utility interconnection, and inspections?
Solar installation requires building permits, electrical permits, and utility interconnection agreements. A full-service installer handles all of this. You shouldn’t be the one calling the building department or filling out utility paperwork.
Ask specifically about the interconnection timeline. In some areas, the utility takes 2-8 weeks to approve your system after installation. Your panels might be on the roof but you can’t legally turn them on until the utility gives the green light.
7. Will you need to upgrade my electrical panel?
Older homes with 100-amp or 150-amp electrical panels often need an upgrade to 200 amps before solar can be installed. This adds $1,500 to $4,000 to the project. A good installer identifies this during the site survey, not on installation day.
Ask upfront whether a panel upgrade is needed and whether it’s included in the quoted price.
8. Do you use your own installation crews or subcontractors?
In-house crews give the installer direct control over quality. Subcontracted crews can be fine, but you want to know who’s on your roof, whether they’re insured, and who’s responsible if something goes wrong. If they use subs, ask whether the installer still warranties the work.
9. What does the installation process look like, and how long will it take?
Most residential solar installations take 1-3 days for the physical work. But the total timeline from contract signing to system activation can be 2-4 months once you factor in permitting, equipment delivery, and utility approval.
Get a realistic timeline with milestones. “We’ll have you up and running in a few weeks” is vague. “Permit submitted by week two, installation in weeks four through five, utility approval by week eight” is a real answer.
Warranties and Long-Term Performance
10. What warranties come with the panels, inverter, and workmanship?
Three separate warranties matter here. Panel manufacturers typically warrant 25 years of production (guaranteeing at least 80-85% output at year 25). Inverters carry 12-25 year warranties depending on type. And the installer should warranty their workmanship (the physical installation) for at least 10 years.
Get all three warranty documents in writing. A verbal “we stand behind our work” means nothing when your roof is leaking around a panel mount five years from now.
11. What happens if a panel or inverter fails? Who do I contact, and who pays?
Clarify the process before you need it. Does the installer handle warranty claims directly, or do you contact the manufacturer yourself? Will they cover the labor to remove, replace, and reinstall a failed panel, or just the panel itself? Some manufacturer warranties cover parts but not labor, which means you’re paying $500 to $1,000 for a technician to swap a “free” replacement panel.
12. Do you offer a production guarantee?
Some installers guarantee that your system will produce a minimum number of kWh per year. If it falls short, they compensate you for the difference. This is a strong sign of confidence in their system design.
Not every installer offers this, but it’s worth asking. And if they do, read the fine print. What counts as “falling short”? What’s the compensation method? Is there a minimum shortfall threshold before they pay?
Pricing and Financing
13. What is the total installed cost, and what does that include?
Get an all-in number that covers equipment, labor, permits, inspections, shipping, monitoring hardware, and utility interconnection fees. Then ask what’s NOT included. Panel upgrades, tree removal, roof repairs, and trenching for ground-mount systems are common add-ons that balloon the price if you don’t catch them early.
In 2026, residential solar costs typically range from $2.50 to $3.50 per watt before incentives. For a 10 kW system, that’s $25,000 to $35,000 before the federal tax credit.
14. How do the financing options work, and what’s the true cost of each?
Cash purchases give you the best return on investment. But most homeowners finance. The main options are solar loans, home equity loans, leases, and power purchase agreements (PPAs).
With a loan, you own the system and keep all incentives. With a lease or PPA, the company owns the system and you pay a monthly fee for the power. Leases and PPAs can complicate home sales and usually deliver lower long-term savings. Ask for the total cost over the full term of any financing option, not just the monthly payment.
15. How do I claim the federal solar tax credit?
The federal Investment Tax Credit (ITC) currently covers 30% of your total system cost. It’s a tax credit, not a deduction, which means it reduces your tax bill dollar for dollar. You must own the system (not lease it) to claim it.
A good installer will walk you through the process, but they shouldn’t be giving you tax advice. Confirm the credit amount based on your quoted price and talk to your tax preparer about your specific situation.
Monitoring and Maintenance
16. What monitoring system is included, and can I access it?
Modern solar systems come with monitoring that shows real-time production, historical data, and alerts for underperformance. You should be able to access this through an app on your phone. Some systems also monitor individual panel performance, which makes it easy to spot problems.
A home energy monitor that tracks both solar production and household consumption gives you the full picture of where your energy goes.
17. What maintenance does the system need over its lifetime?
Solar panels require surprisingly little maintenance. No moving parts means there’s not much to break. But they do need occasional cleaning (dirty panels produce less), and you should visually inspect them a couple of times a year for damage or debris buildup.
Inverters may need replacement once during the system’s 25-year life. Trees grow and create new shading over time. Keeping a solar panel cleaning kit on hand lets you handle basic cleaning yourself instead of paying $150 to $300 for a professional cleaning.
Typical Cost Range and Factors
Here’s what residential solar typically costs in 2026:
System costs (before incentives):
- Small system (5-7 kW): $12,500 - $24,500
- Medium system (8-10 kW): $20,000 - $35,000
- Large system (11-15 kW): $27,500 - $52,500
After the 30% federal tax credit:
- Small system: $8,750 - $17,150
- Medium system: $14,000 - $24,500
- Large system: $19,250 - $36,750
What drives the price:
- System size. More panels and a bigger inverter cost more. Size should be based on your usage, not a sales target.
- Panel brand and efficiency. Premium panels (SunPower, REC Alpha) cost more per watt but produce more per square foot and degrade slower.
- Inverter type. Microinverters add $1,000 to $3,000 compared to a basic string inverter, but perform better with shading.
- Roof complexity. Multiple roof planes, steep pitches, and tile roofs increase labor time and mounting hardware costs.
- Electrical panel upgrades. An upgrade from 100-amp to 200-amp service adds $1,500 to $4,000.
- Your location. Labor rates, permitting costs, and local competition all vary by market.
- Battery storage. Adding a battery system tacks on $10,000 to $20,000 but provides backup power and can improve economics depending on your utility rate structure.
Red Flags vs. Green Flags
| Red Flag | Green Flag |
|---|---|
| Pressure to sign today with a “limited time” discount | Written proposal that’s valid for 30+ days so you can compare bids |
| Quotes a system size before reviewing your electricity usage | Asks for 12 months of utility data before designing the system |
| Only offers leases or PPAs, not purchase options | Explains cash, loan, lease, and PPA options with true cost comparisons |
| Can’t name the specific panel brand and model | Provides spec sheets for the exact panels and inverter proposed |
| No mention of permits, inspections, or interconnection | Handles all permitting and interconnection as part of the price |
| Promises “free” solar or “no cost” electricity | Gives honest production estimates and explains the payback period |
| Vague warranty terms: “We stand behind our work” | Provides written panel, inverter, and workmanship warranty documents |
| Door-to-door salesperson with aggressive closing tactics | Company you contacted based on reviews, referrals, or research |
Money-Saving Tips
- Get at least three quotes. Solar pricing varies by 20-40% between installers for the same system. Three quotes show you the real market rate and expose outliers.
- Claim every available incentive. The federal 30% tax credit is the biggest, but check for state rebates, utility incentives, and local programs. Some states offer additional credits worth $1,000 to $5,000. Use the DSIRE database to find programs in your area.
- Buy, don’t lease. Purchasing your system (even with a loan) almost always delivers better long-term savings than a lease or PPA. You keep the tax credit and any SRECs (solar renewable energy credits).
- Time your purchase wisely. Many installers offer end-of-quarter or end-of-year discounts to hit sales targets. December and January are often slower months with better pricing.
- Skip the premium panels if your roof has plenty of space. High-efficiency panels make sense on small or complex roofs. If you’ve got a big, unshaded south-facing roof, mid-tier panels give you more watts per dollar.
- Consider your roof first. If your roof is 15+ years old, replacing it before installing solar avoids the $2,000 to $5,000 cost of removing and reinstalling panels later.
- Pair panels with behavior changes. Run heavy appliances (dishwasher, laundry, EV charger) during peak production hours to use your solar power directly instead of drawing from the grid at night.
Glossary
Net Metering: A billing arrangement where your utility credits you for excess solar electricity you send to the grid. When your panels produce more than your home uses, the surplus goes to the grid and reduces your bill. Policies vary widely by state and utility.
Inverter: The device that converts direct current (DC) electricity from your solar panels into alternating current (AC) electricity that your home appliances use. String inverters handle the whole array at once, while microinverters are installed on each individual panel.
Kilowatt-hour (kWh): The standard unit of electricity consumption. One kWh is the energy used by a 1,000-watt appliance running for one hour. Your monthly electric bill shows how many kWh you used. The average U.S. home uses about 10,500 kWh per year.
Solar Renewable Energy Credit (SREC): A tradeable certificate representing one megawatt-hour of solar electricity produced. In some states, utilities must purchase SRECs to meet renewable energy mandates, creating an additional income stream for solar system owners.
Degradation Rate: The rate at which solar panels lose efficiency over time. Most panels degrade 0.25% to 0.5% per year. A panel with a 0.25% degradation rate will still produce about 94% of its original output after 25 years.
Helpful Tools and Resources
Dirty panels lose 5-25% of their output. A cleaning kit with an extension pole and soft brush lets you maintain peak production without climbing on the roof or paying for a cleaning service.
Track your solar production and household consumption in real time. See exactly where your energy goes and identify opportunities to shift usage to peak solar hours for maximum savings.
Solar systems add electrical complexity to your home. A whole-house surge protector guards your panels, inverter, and appliances against power surges from lightning and grid fluctuations.
- DSIRE (Database of State Incentives for Renewables & Efficiency): The most comprehensive database of solar incentives, rebates, and policies by state. Check here before your first installer meeting.
- EnergySage Solar Marketplace: Compare multiple solar quotes from pre-screened installers. Great for understanding fair pricing in your area.
- NABCEP (North American Board of Certified Energy Practitioners): Look for NABCEP-certified installers. This is the gold standard certification for solar professionals.
Quick Reference Checklist
Pull this up on your phone during every solar consultation:
- What size system do you recommend, and how did you calculate it?
- What brand and model of panels will you install?
- What inverter technology are you recommending, and why?
- How much energy will this system produce annually?
- Will you perform a shade analysis of my roof?
- Who handles permits, interconnection, and inspections?
- Will I need an electrical panel upgrade?
- Do you use your own crews or subcontractors?
- What does the installation process look like, and how long?
- What warranties cover panels, inverter, and workmanship?
- What happens if a panel or inverter fails?
- Do you offer a production guarantee?
- What is the total installed cost, and what’s included?
- What are the financing options and true costs?
- How do I claim the federal tax credit?
- What monitoring system is included?
- What maintenance does the system need?
Frequently Asked Questions
How many solar quotes should I get before choosing an installer?
Three is the minimum. Solar pricing varies significantly between installers, even for identical equipment. Three quotes help you understand the fair market price in your area and make it easy to spot bids that are too high or suspiciously low. Compare not just the total price, but the equipment specs, warranties, and what’s included in each proposal.
How long do solar panels actually last?
Most panels are warrantied for 25 years, but they don’t stop producing after that. They just produce a bit less each year due to degradation. Many panels installed in the 1990s are still producing electricity today. Expect your panels to last 30-40 years with gradually declining output. The inverter will likely need replacement once during that period (every 12-25 years depending on type).
Will solar panels damage my roof?
A properly installed system should not damage your roof. In fact, panels protect the shingles underneath from UV exposure and weather, often extending the life of that portion of the roof. Problems happen when installers cut corners on mounting hardware, flashing, or waterproofing. That’s why choosing a reputable installer with a strong workmanship warranty matters so much.
Do solar panels work on cloudy days?
Yes, but at reduced output. Solar panels produce electricity from light, not direct sunlight. On a cloudy day, you might see 10-25% of rated production. On an overcast day with bright skies, you could see 50-70%. Your annual production estimate already accounts for average cloud cover in your area, so the yearly numbers should be reliable even if individual days vary a lot.
What happens to my solar panels if I sell my house?
Owned systems (purchased outright or with a loan you’ve paid off) transfer to the buyer and typically increase home value. Studies show homes with solar sell for 4-6% more. Leased systems can complicate a sale because the buyer must agree to take over the lease. That’s one more reason buying is usually better than leasing.