The Homeowner Solar Checklist: What to Ask, What to Have Ready

Most bad solar deals happen because the homeowner shows up with nothing and the rep shows up with everything. This checklist flips that asymmetry. Before any conversation you should know your annual kWh, your rate plan, your roof age, and your one-sentence goal. During the conversation you should be vetting the company, the design, and the contract. By the end you should hold seven specific documents — not promises.

What to gather before any conversation

The most useful 90 minutes on solar happens before any rep is involved. Five items go on one page.

Sit with 12 months of utility bills and record the kWh used and dollars billed per month, then add the columns. That annual kWh is what every honest installer needs to size a system. The dollar total is what your savings get compared against. If a rep talks pricing before asking for the kWh number, they are selling a stock package, not designing one.

Write down your utility's name and rate plan code — printed on every bill. If you are on time-of-use, find the peak window and the on-peak rate per kWh. Your rate plan decides whether solar plus a battery pays off.

Note your roof age, material, and date of last inspection. Solar lives on the roof for 25 years. If yours has fewer than five to seven years left, re-roof first — pulling panels later to replace shingles costs $2,000–$5,000 in remove-and-reset labor.

Photograph your main electrical panel: main breaker amperage, brand, and model. A required main panel upgrade can add $2,500–$6,000 to a job.

Write your goal in one plain sentence. "Lowest possible bill," "backup for storms," "buying an EV next year," and "selling in three years" each imply a different system. Reps who ask for the goal design for you. Reps who skip it sell a stock package.

How to vet the installer itself

Before trusting any proposal, vet the company itself.

Ask for the state contractor license number and classification — C-46 or C-10 in California, ROC with a solar endorsement in Arizona, TDLR Electrical Contractor in Texas. Look it up on the state board's website. Confirm it is active, in the right classification, and free of recent disciplinary actions.

Ask how long they have operated locally — not nationally. A national brand new to your metro for eight months is still new to your permitting office and your utility's interconnection process. Get three local install addresses and verify the permits on your building department's records site.

Ask who actually pulls the permit. The right answer is the same company on your contract, using the same license number, given immediately. Vague answers — "our permitting team handles that," "we work with a partner" — point to permit poaching, where an unlicensed operator pulls under a borrowed license and disappears. Our deep dive on spotting bad solar sales reps and permit poachers covers the mechanics.

Ask who is on the install crew. W-2 employees of the company on your contract, or named subcontractors with their own license numbers — not "we use a great installation partner."

Ask whether anyone on staff is NABCEP-certified. A serious installer names a PV Installation Professional and gives you the ID to verify at nabcep.org.

Insist everything be in writing within 48 hours: scope, equipment models, kW DC, year-1 kWh, warranties, line items, and per-watt price.

How to vet the proposed design

Once the company passes, vet the design.

Ask for the year-1 production estimate in kWh — not an offset percentage. Offset percentages hide the actual production number on purpose. The modeling tool should be named: PVWatts, Aurora Solar, Helioscope, or an inverter-specific tool like SolarEdge Designer.

Ask the assumed degradation rate per year. Tier-1 modules in 2026 land near 0.5%. Below 0.4% is optimistic. Above 0.7% is conservative or older technology.

Ask whether an on-roof shade study was performed. Satellite models miss dense seasonal foliage and small obstructions. A Solmetric SunEye or drone-based survey produces a real annual production number instead of an optimistic estimate.

Ask why panels are placed where they are. South-only is straightforward on clean roofs. South-plus-west captures more late-afternoon production on a time-of-use rate. You do not want panels on a heavily shaded face just to inflate the kW rating and the price.

If a battery is included, ask which circuits stay on, for how many hours, under what loads. A single 13.5 kWh battery typically runs a refrigerator, lights, internet, and a few outlets for 12–24 hours. It does not run central AC or an EV charger for long.

Finally, ask the net metering rule under your utility right now, and which federal tax credit applies. Section 25D expired December 31, 2025 for residential cash and loan. Section 48E remains available under current law for lease and PPA structures if the project starts construction by July 4, 2026, or is in service by December 31, 2027, and the lease company claims the credit and is expected to pass some of that value into your monthly payment.

The 60-second red-flag scan

When time is short, scan for these ten signals. Any one slows you down. Any three means you walk away.

1. "This price is only good today." Honest solar pricing holds for 30 days in writing. Urgency is the product, not the panels.
2. Door-to-door pressure to sign tonight. No 25-year decision needs to happen between dinner and bedtime.
3. No itemized written estimate. If numbers only appear on a tablet, they do not survive scrutiny.
4. Vague answer about who pulls the permit. The right answer is one company name and one license number, given immediately.
5. "You'll save 95% of your bill" with no kWh number. Offset percentages hide reality. Insist on kWh.
6. Federal tax credit cited for a 2026 cash or loan purchase. Section 25D expired December 31, 2025. Any rep still citing the 30% credit on a cash or loan deal is misrepresenting current law.
7. "We're partners with your utility" or "this is a government program." No private solar company is a utility partner. Net metering tariffs are public regulation.
8. No NABCEP-certified person on staff. Not a deal-killer alone, but the engineering culture probably is not there.
9. Rep cannot name the install crew or foreman. Vagueness here means subcontractor chains nobody is managing.
10. Dealer fee disclosure missing. If the APR looks unusually low and the dealer fee is not on the page, a 10–25% hidden cost is rolled into your principal.

Seven documents to hold before signing

Before any signature, you should physically hold seven documents — not verbal promises.

A written, itemized proposal with system size in kW DC, all panel, inverter, and battery model numbers, every labor and permitting line item, total all-in price, and price per watt. A typical 2026 install runs $2.80–$4.20 per watt.

A signed scope of work with warranty terms per component. Workmanship typically runs 10–25 years. Modules run 25 years product and 25 years performance. Inverters run 10–12 years for string and 25 for Enphase microinverters. Batteries run roughly 10 years.

Full financing documents — APR, origination fee, dealer fee, term, total payments, and any prepayment penalty. A "$30,000 system" with a $6,000 dealer fee is actually $36,000 financed. Our solar proposal line-by-line guide shows exactly where to find the dealer fee.

A production estimate with assumptions stated — degradation rate, shade derate, utility rate, and rate escalation. A savings number with no assumptions is marketing.

A copy of the company's license and Certificate of Insurance — General Liability of at least $1 million and Workers' Comp. Call the verification line printed on the COI to confirm the policy is active.

Manufacturer warranty PDFs for panels, inverter, and battery. These live with the equipment and outlast your installer if the company changes hands.

A written notice-of-cancellation form with the deadline filled in. Federal law gives three business days to cancel any door-to-door sale over $25, and many states extend that window for solar specifically.