How to Choose a Solar Installer

Solar panels are the reliable part of this decision. Most tier-one panels carry 25-year warranties and degrade slowly, around half a percent of output per year. The variable is the company that designs the system, attaches it to your roof, files the paperwork, and — hopefully — answers the phone in year 11.

The market hasn't made this easy. Hundreds of US solar companies have merged or shut down since 2023, and the incentive rules changed at the start of 2026. Much of the advice ranking online was written for an earlier market. This guide reflects how residential solar is actually sold and installed now, and it treats battery storage as the separate decision it is. We manufacture LiFePO4 batteries for solar storage, so where storage comes up, we'll link you to the technical detail instead of glossing over it.

1. Know who you're actually contracting with

Three business models show up at your door, and they're not the same:

• EPCs (engineering, procurement, construction) design, install, and typically service the system themselves.
• Dealers or brokers sell you the contract and hire a separate installation crew.
• Lead generators run ads or knock doors, collect your information, and sell it to whichever company buys the lead.

There's nothing inherently wrong with a dealer model, but you need to know which one you're dealing with, because the company doing the sales pitch may not be the company on your roof or the company holding your warranty.

If the salesperson can't name the installing company, you're not ready to sign. It's also worth ten minutes on the company's About page and LinkedIn — solar projects go better when the leadership has construction or electrical backgrounds rather than purely sales experience, and when the company has an office or established branch in your state.

2. Verify credentials yourself — it takes about ten minutes

A reputable installer will hand you license numbers. Verify them anyway; it's fast and free.

• State contractor license. In California that's often a C-10 electrical, C-46 solar, or B license; other states use different classifications. Look it up on your state licensing board site and confirm it's active with no major complaints.
• NABCEP certification. The North American Board of Certified Energy Practitioners is the industry's gold-standard credential. Either the company or its lead installer should hold it, and you can confirm the certificate number in NABCEP's public directory.
• Insurance. Ask for proof of general liability and workers' compensation coverage. Request to be listed as an additional insured on the liability policy, and remember to add the finished system to your own homeowners insurance.
• Subcontractor credentials. If any work is subcontracted — electrical and roofing often are — verify the subcontractor's license and insurance too.

3. Check the local track record, not just the brand name

A national brand with a freshly opened local branch isn't the same as a crew that's been pulling permits in your town for six years. Local familiarity matters because permitting timelines, utility interconnection rules, and incentive programs are all set locally. A company that works your area regularly makes fewer costly missteps and gets you to permission to operate faster.

The aged reference is the one most homeowners skip and shouldn't. It tells you how the company behaves after the final check clears: whether monitoring issues get fixed, whether warranty calls are returned. If you can, ask for actual production data from a comparable local system alongside what was originally estimated.

4. Scrutinize the design and the production estimate

A serious proposal starts from twelve months of your utility bills and accounts for roof orientation and pitch, shading from trees and vents, the roof's age, and your electrical panel's capacity. More panels don't equal a better design if they're placed in shaded or awkward zones just to inflate the quote.

Mention your future plans too. If an EV, heat pump, or major addition is plausible within the system's life, a good designer builds in headroom now rather than retrofitting later. That includes your main panel: under the NEC 120% rule, a common 200-amp panel often tops out around a 40-amp solar backfeed breaker before an upgrade or line-side connection is needed.

Then check the math independently. NREL's free PVWatts Calculator lets you enter the proposed size, direction, and angle and returns a third-party production estimate. If the installer's number is dramatically higher, ask why — and treat a refusal to explain it as a warning sign.

Finally, the roof itself. If yours has under roughly ten years of life left, replace it before panels go up. Ask in writing who handles roof penetrations and leaks, and what it costs to remove and reinstall the array for future roof work — it typically runs several thousand dollars, so you don't want to discover that later. For the bigger picture on whether the math works for your home, our breakdown of the advantages and disadvantages of solar energy walks through the tradeoffs honestly.

5. Get exact equipment models in writing

“Tier-one premium panels” is marketing language, not a specification. The proposal should name the panel make and model, the inverter make and model, and the racking system. The same goes for certifications tied to specific equipment — many manufacturers (Enphase and Panasonic among them) run Gold or Platinum installer programs, and you can confirm an installer's status with the manufacturer directly.

Once you have model names, you can compare the actual specs and the warranties attached to each component rather than comparing vibes.

6. If you want backup power, vet the battery separately

Storage keeps showing up in 2026 for real reasons: California's NEM 3.0 net-billing rules pay far less for exported daytime power, grid outages remain a fact of life, and a battery lets you store your own production instead of giving it away. But a battery is a second product — with a second warranty, a second set of specs, and a second set of questions.

Work through these before you accept a storage add-on:

• Chemistry. Lithium iron phosphate (LiFePO4) is the standard for home storage because of its cycle life and thermal stability. We compared the options in our guide to what makes a high-quality solar battery.
• Capacity and power. Usable capacity (kWh), not just nominal, plus continuous and peak power output (kW).
• What it actually backs up. Whole-home backup or a critical-loads subpanel? A gateway or automatic transfer switch is usually required.
• Cycle life and throughput warranty. A battery warranty stated only in years tells you little. Look for warranted cycles or warranted energy throughput, and check what voids it.
• The BMS. The battery management system protects against overcharge, deep discharge, and overheating — here's how a BMS works and why it matters.
• Compatibility. Confirm the battery works with the proposed inverter and panels, and ask who services a battery fault — the installer, the manufacturer, or both.

If you're comparing form factors, wall-mounted units like our power wall solar batteries save floor space, while all-in-one solar battery systems combine the inverter and battery in one enclosure. Larger homes sometimes land on stacked rack batteries or high-voltage solar batteries. For sizing, the logic behind a 15 kWh home battery is a useful starting point, and our lithium-ion battery buying guide covers the full decision.

7. Map every warranty layer — including installer failure

Four warranty layers typically come with a solar system, and they're backed by different companies:

For each one, ask who files the claim, whether labor and shipping are covered, what's excluded, and whether coverage transfers if you sell the home.

Here's the part homeowners consistently underestimate: a workmanship warranty is only as durable as the company behind it. A three-year-old company advertising a 25-year workmanship warranty may simply not exist when you need it — and plenty of solar businesses have closed in the last few years, voiding those promises. Prefer a solid, realistic workmanship term, ideally insurance-backed or covered by a third-party residential solar warranty provider. Get roof-leak responsibility in writing, and ask directly what happens to your coverage if the company is acquired or goes under.

8. Compare total cost, not the monthly payment

For a price benchmark, systems on the EnergySage marketplace averaged roughly $2.50–$2.60 per watt before incentives in mid-2026, with state averages ranging from around $2.25/W in Texas to about $2.67/W in Connecticut. Convert every quote to cost per watt — total system cost divided by capacity in watts — so you're comparing the same unit.

Then check what's actually included: permits, utility interconnection, monitoring, any panel upgrade, the battery, and tree or electrical work. A low headline price with exclusions isn't a low price.

Financing deserves the same scrutiny:

• Cash or loan. For loans, compare the APR, term, total projected payments, any dealer fee built into the price, and what happens if you sell the home.
• Lease or PPA. Confirm who owns the system and any credits, the payment escalation schedule, transfer requirements, and cancellation terms. Leases and PPAs can complicate home sales.
• Mechanic's lien risk. If an installer doesn't pay its subcontractors or suppliers, a lien can land on your property. Ask for lien waivers as part of the contract and final payment.

Because the federal credit is gone, recalculate the payback on 2026 terms — it will generally stretch by several years compared with quotes you may have seen from friends. State, local, and utility incentives still exist and vary enormously; the DSIRE database is the place to check what applies to you. Our overview of home energy storage battery systems explains how storage changes that math.

9. Know your cancellation rights before you sign

If a contract is signed anywhere other than the seller's permanent place of business — at your kitchen table, a home show, or a door-to-door visit — the FTC's Cooling-Off Rule generally gives you three business days to cancel for a full refund, and the seller is required to provide a cancellation form. State rules sometimes add further protections.

Before signing, read the change-order, price-escalation, and delay clauses. Never sign a contract with equipment models, prices, or warranty terms left blank, and keep copies of the proposal, contract, and warranties.

A question script you can send as-is

Copy this into an email to each installer. Consistent answers make the quotes genuinely comparable.

Hi, I'm evaluating installers for a residential solar system and would
like the following in writing:

1. Exact legal company name on the contract, and your state contractor
   license number.
2. NABCEP certification number for the company or lead installer.
3. Will your own employees do the install, or subcontractors? If subs,
   what work do they handle and what are their license numbers?
4. Proposed panel, inverter, and racking makes and models.
5. System size in kW, estimated first-year production, and the shade,
   weather, and loss assumptions behind it.
6. Full warranty terms: product, performance, inverter, workmanship,
   including who files claims and whether labor/shipping are covered.
7. Itemized total price and what it includes (permits, interconnection,
   monitoring, panel upgrades).
8. If batteries are offered: chemistry, usable kWh, kW output, backup
   configuration, cycle/throughput warranty, and BMS details.
9. Projected timeline from contract to permission to operate.
10. A copy of the standard contract, including cancellation, change-order,
    and lien terms.

Thanks.

Simple comparison scorecard

Score each proposal on the same categories. A company doesn't need identical answers to its competitors — it needs answers that are specific, documented, and understandable.

Frequently asked questions

The core message is simple: the panels are dependable, so spend your energy vetting the company behind them — who they are, what they've built nearby, what happens if things go wrong, and whether every promise is on paper. If backup power is part of your plan, start with our wall-mounted solar batteries and all-in-one storage systems, or talk to our team about sizing for your home.