Hiring a solar company is a five- or six-figure decision that sits on your roof for 25 years. The difference between a great installer and a bad one rarely shows up in the sales pitch — it shows up in the answers to specific, pointed questions. This guide gives you those questions, organized by stage of the deal, with the actual numbers, cost-per-watt benchmarks, payback math, and warranty terms you should expect to hear back. Print it, bring it to your consultation, and watch how the salesperson responds.
I've sat on both sides of this table — I've bought equipment for installs and I've spec'd systems for homeowners — and I can tell you that the companies with nothing to hide answer these questions fast, in writing, with datasheets attached. The ones who dodge, generalize, or promise to "get back to you" on basic cost math are telling you something important.
Section 1: Questions About the Company Itself
1. How long have you been installing, and how many systems have you completed in my area?
Solar is a local trade. Roof types, permitting authorities, utility interconnection rules, and weather loads vary by jurisdiction. A company with 500 installs in your county knows your AHJ's inspection quirks; a national chain running its first crew in your zip code does not. Ask for the number of local installs and at least three local references you can actually call.
2. Are you licensed, bonded, and insured — and can I see the certificates?
Ask for the contractor license number and verify it with your state board (a two-minute search). Insurance should include general liability and workers' compensation for every person who sets foot on your roof. If a crew member falls and the company is uninsured, the claim can land on your homeowner's policy.
3. Do you use in-house crews or subcontractors?
Neither is automatically bad, but you deserve a straight answer. In-house crews give the company direct quality control. Subcontracted labor is common and legitimate — but then ask who supervises the subs, who warranties the workmanship, and whether the sub carries its own insurance.
4. Who handles permitting and utility interconnection?
The correct answer is "we do, and it's included in the quote." Permit fees, engineering stamps, and interconnection applications are the installer's job. If a company asks you to pull your own permit, that's a red flag — homeowner-pulled permits can shift code liability onto you.
5. What happens to my warranty if your company closes?
Manufacturer warranties on panels and inverters survive the installer; workmanship warranties do not. Ask whether the company offers an insured or third-party-backed workmanship warranty. Also ask how long they've been in business — a 25-year warranty from a two-year-old company is a promise, not a plan.
Section 2: Questions About the Equipment
6. Exactly which panel and inverter models are you quoting — full model numbers?
"Tier 1 panels" is not an answer; it is marketing. Get the manufacturer and full model number for every major component, then look up the datasheet yourself. A quote might propose a panel like the Qcells XL G11.S or the Silfab Elite 370 W N-type TOPCon — both quotable, both verifiable. Cross-check against our best solar panels of 2026 roundup and the inverter buyer's guide.
7. What is the panel's efficiency, degradation rate, and temperature coefficient?
These three numbers determine 25 years of production. Current mainstream mono PERC panels run 20–21.5% efficiency with 0.55%/yr degradation; N-type TOPCon runs 21.5–23% with 0.40%/yr; HJT reaches a -0.26%/°C temperature coefficient versus -0.35%/°C for standard PERC. If the salesperson can't quote these from the datasheet, they haven't read the datasheet.
| Spec to Ask About | Budget Tier | Mainstream (Mono PERC) | Premium (N-type TOPCon/HJT) |
|---|---|---|---|
| Module efficiency | 19–20% | 20–21.5% | 21.5–23%+ |
| First-year degradation | 2.5–3% | 2.0% | 1.0% |
| Annual degradation | 0.55–0.7%/yr | 0.55%/yr | 0.25–0.40%/yr |
| Temperature coefficient (Pmax) | -0.40%/°C | -0.35%/°C | -0.26 to -0.30%/°C |
| Product warranty | 12–15 yrs | 15–25 yrs | 25 yrs |
| Performance warranty (yr 25) | ≥ 80–84% | ≥ 84–87% | ≥ 87–92% |
8. String inverter, microinverters, or optimizers — and why for my roof specifically?
There is no universally correct answer, and any company that says otherwise is selling what it stocks. String inverters win on unshaded, single-plane roofs on cost. Microinverters and power optimizers win on multi-plane, shaded, or complex roofs. Ask the rep to explain the choice using your roof's shading report, not a generic pitch. Browse string inverters and hybrid inverters to understand the categories before the meeting.
9. What racking and flashing system will you use on my roof type?
Leaks come from penetrations, not panels. Ask for the racking brand, the flashing method for your specific roof (composition shingle, tile, metal, flat), and whether the racking carries its own warranty. Our racking systems guide explains what good looks like, and our solar mounting systems collection shows the hardware classes.
10. Is any of this equipment refurbished, B-stock, or gray-market?
Discounted equipment is fine when disclosed. Undisclosed gray-market gear can carry no valid US warranty. Ask directly, and get the answer in the contract.
Section 3: Questions About the Money
11. What is the total cash price, and what is the cost per watt?
Cost per watt is the industry's apples-to-apples number: total pre-incentive price ÷ system watts. A $27,000 quote on a 9 kW system is $27,000 ÷ 9,000 = $3.00/W. Residential cash prices in the US typically run $2.50–$3.50/W before incentives, varying by region, roof complexity, and equipment tier. If a company won't state its cost per watt, you cannot compare it to anything.
| Quote | System Size | Total Price | Cost per Watt | Verdict |
|---|---|---|---|---|
| Company A | 8,000 W | $26,400 | 26,400 ÷ 8,000 = $3.30/W | Mid-range, check equipment tier |
| Company B | 8,000 W | $21,600 | 21,600 ÷ 8,000 = $2.70/W | Competitive |
| Company C | 8,000 W | $33,600 | 33,600 ÷ 8,000 = $4.20/W | High — ask what justifies it |
12. Show me the full itemized quote.
Panels, inverter, racking, electrical BOS, permitting, interconnection, labor, monitoring, and margin should each be a line. Bundled "one price" quotes hide where the money goes and make comparison impossible.
13. How exactly do the incentives apply to my quote?
Ask the company to show the federal credit math on the actual quote, plus any state, utility, or SREC programs in your area. The federal credit is a tax credit, not a rebate — you need tax liability to use it. A reputable company will tell you to confirm eligibility with a tax professional. Check current programs on our solar incentives by state page.
14. What's the dealer fee on the financing?
This is the question that separates honest financing from padded financing. Many solar loans carry dealer fees of 15–30% of the loan amount, baked into the principal to buy down the interest rate. A "$25,000 system" financed with a 25% dealer fee is a $31,250 loan for a $25,000 system. Always ask: "What is the cash price, and what is the financed price?" If those numbers differ, the difference is the cost of the loan's rate buydown.
| Financing Scenario ($24,000 cash-price system) | Loan Principal | Rate / Term | Monthly Payment | Total Paid | Total Cost of Financing |
|---|---|---|---|---|---|
| Cash | — | — | — | $24,000 | $0 |
| Low-fee loan | $25,200 (5% fee) | 6.99% / 20 yr | ≈ $195 | ≈ $46,800 | $22,800 |
| High-fee loan | $31,200 (30% fee) | 3.99% / 25 yr | ≈ $164 | ≈ $49,200 | $25,200 |
| Home equity (HELOC) | $24,000 | 8.5% / 15 yr | ≈ $236 | ≈ $42,480 | $18,480 |
Monthly payments computed with the standard amortization formula M = P·r(1+r)ⁿ ÷ ((1+r)ⁿ − 1). For the low-fee loan: r = 0.0699/12 = 0.005825, n = 240, M ≈ $195.15, total ≈ $46,836. The lesson: compare total cost, not monthly payment. The low-payment loan above costs more than the higher-payment HELOC.
15. What is my projected payback period, and show me the assumptions.
Payback = net system cost ÷ annual savings. The assumptions buried inside "annual savings" are where projections get inflated: utility rate escalation, production estimates, and degradation. Demand the inputs. Here is honest math on a typical case:
| Input | Conservative | Moderate | Aggressive (verify before believing) |
|---|---|---|---|
| System size | 9 kW | 9 kW | 9 kW |
| Net cost after 30% credit | $18,900 | $18,900 | $18,900 |
| Year-1 production (kWh) | 11,800 | 12,600 | 13,500 |
| Utility rate ($/kWh) | $0.16 | $0.18 | $0.22 |
| Rate escalation/yr | 2.0% | 3.0% | 5.0% |
| Year-1 savings | 11,800 × 0.16 = $1,888 | 12,600 × 0.18 = $2,268 | 13,500 × 0.22 = $2,970 |
| Simple payback | 18,900 ÷ 1,888 ≈ 10.0 yr | 18,900 ÷ 2,268 ≈ 8.3 yr | 18,900 ÷ 2,970 ≈ 6.4 yr |
| 25-yr net savings (w/ escalation, 0.5%/yr degradation) | ≈ $24,000 | ≈ $37,000 | ≈ $63,000 |
The conservative column sums year-by-year savings: year-1 $1,888 growing 2%/yr minus 0.5%/yr production decline nets roughly $45,600 gross over 25 years, less the $18,900 cost and a mid-life inverter replacement (~$2,500) — around $24,000 net. If a proposal shows you only the aggressive column, ask for the other two. Run your own numbers on our solar ROI calculator.
16. Lease, PPA, loan, or cash — which are you pitching, and why?
Each structure has a legitimate use, and each has a failure mode:
| Structure | You Own the System? | You Get the Tax Credit? | Best For | Watch Out For |
|---|---|---|---|---|
| Cash | Yes | Yes | Maximum lifetime savings | Upfront capital |
| Loan | Yes | Yes | Ownership without upfront cash | Dealer fees; total financed cost |
| Lease | No | No | No tax liability, zero-down | Escalators, home-sale complications |
| PPA | No | No | Pay only for power produced | Per-kWh escalators, buyout terms |
Section 4: Questions About Design and Production
17. How did you calculate my system's size?
Sizing should start from 12 months of your actual kWh usage (ask for your utility's usage history), not from "most homes need 20 panels." The target offset — 100%, 80%, more with an EV coming — should be your decision, made with data. Our solar system calculator and the how many watts to power a home guide show the standard method.
18. What's my shading analysis, and can I see it?
Every serious proposal includes a shade study from a physical site survey or a validated remote tool. Ask to see the solar access percentages per roof plane. A quote produced without anyone looking at your roof — physically or via quality imagery — is a guess.
19. What production number are you guaranteeing, and in what units?
Production estimates should be in kWh per year, for year one, with the weather dataset and loss assumptions stated (soiling, shading, inverter efficiency, wiring, availability — a typical total loss stack is 14–20%). Ask whether the company offers a written production guarantee and what the remedy is if the system underperforms.
20. Will my electrical panel and roof handle this?
Two inspections matter: the roof's remaining life (reroofing under a 25-year array costs $1,500–$3,500 in panel removal and re-install) and the main panel's capacity. A 200 A panel usually accommodates solar with a standard interconnection; older 100 A panels may need an upgrade or a line-side tap. Our guides on upgrading electrical service and the electric panel bus bar explain what inspectors look for.
21. What about batteries — now or later?
Ask whether the proposed inverter is battery-ready (hybrid) or whether storage will require new equipment later. If backup power matters to you, compare solar batteries and read the EG4 vs Tesla Powerwall comparison and our solar battery buyer's guide before signing a solar-only contract that boxes you in. For outage protection without solar, standby generators are a separate, complementary path.
Section 5: Questions About the Contract and Timeline
22. What are the warranty terms, in writing — all four of them?
There are four separate warranties in every solar project. Get each one as a document, not a sentence:
| Warranty | Who Stands Behind It | Typical Term | What to Verify |
|---|---|---|---|
| Panel product warranty | Panel manufacturer | 12–25 years | Covers defects; check claim process and whether labor/shipping are included |
| Panel performance warranty | Panel manufacturer | 25–30 years | Guaranteed output at year 25 (84–92% by tier); degradation schedule in writing |
| Inverter warranty | Inverter manufacturer | 10–12 yrs string / 25 yrs micro | Extension cost; who pays removal labor |
| Workmanship warranty | Your installer | 5–25 years | Roof-penetration coverage length; transferability; what happens if they close |
23. What is the full timeline from signature to permission-to-operate?
Realistic US timelines run 6–16 weeks: site survey (1–2 weeks), design and engineering (1–2), permitting (2–6, jurisdiction-dependent), installation (1–3 days for typical residential), inspection and utility PTO (1–4). Ask where projects currently sit in each stage and who your point of contact is at each handoff.
24. Who is my contact after the system is on?
Monitoring setup, warranty claims, and production questions all happen after the crew leaves. Ask for the service department's contact path and response-time commitment. A company with no service department is a company that sells systems, not one that maintains them.
25. What isn't in this quote?
The most valuable question on this list. Common exclusions: main panel upgrades, roof repair, tree removal, trenching, structural engineering for questionable rafters, utility fees, and monitoring subscription costs after year one. Every exclusion you surface now is a change order you avoid later.
The Red Flags That Should End the Conversation
- Pressure to sign today. Utility programs and equipment prices do not expire at midnight. Urgency is a sales tactic, full stop.
- No cost-per-watt disclosure. If they won't give you the number, they don't want you to compare it.
- Production estimates with no stated assumptions. Ask for the weather file, loss stack, and degradation schedule.
- "The tax credit pays for it." The credit is 30% of cost, requires tax liability, and arrives at tax time — not at signing.
- No physical or quality remote roof assessment. A quote without a roof look is a placeholder.
- Vague equipment lists. "Premium Tier 1 panels" is not a model number.
- A financed price presented as the cash price. Ask the two-price question every time.
I've watched customers save five figures just by asking the dealer-fee question out loud — the number appears on the contract within minutes once the rep knows you know it exists. And I always tell people: get three quotes, line them up side by side on cost per watt, equipment model numbers, and warranty documents, and the right choice usually makes itself obvious within an afternoon.
Prefer to skip the sales process entirely? Portlandia Electric Supply is an equipment supplier, not an installer — we sell the same complete solar kits, panels, inverters, and racking the pros use, at transparent per-watt prices, and we'll help you or your electrician spec the system. Start with our solar installation guide, check commercial installation costs for larger projects, or call us for a no-pressure equipment quote you can use as a benchmark against any installer's proposal.
Section 6: Questions About Monitoring, Net Metering, and Your Utility
26. How will I monitor my system, and is there a subscription fee?
Every modern inverter platform has a monitoring app, but some charge subscription fees after an initial period and some lock advanced data behind paid tiers. Ask: Is monitoring included for the life of the equipment? Can I see per-panel production (standard with microinverters and optimizers, optional on string systems)? Who gets alerted if production drops — me, or the installer? A company that monitors your system and calls you when something breaks is worth paying for; a monitoring portal you never open is not.
27. What are my utility's net metering rules, exactly?
This answer changes the economics more than any equipment choice. Ask the company to state, in the proposal: your utility's export compensation rate (full retail, avoided cost, or a hybrid), true-up period, whether credits roll over, and any interconnection fees or required insurance. Under full retail net metering, oversized systems can still pencil; under avoided-cost export, self-consumption and batteries matter far more. If the salesperson can't explain your specific tariff, they sized your system blind. Cross-reference with our state incentives page.
28. Will my meter and service need changes?
Older meters sometimes need utility replacement for bidirectional metering — usually free, but it can add weeks. Ask whether the interconnection application covers this and who schedules it.
Section 7: Roof, Structure, and Insurance Questions
29. What is my roof's condition, honestly, and what happens if it needs work in year 12?
A comp shingle roof with fewer than 10 years of life left should be reroofed before solar — or you pay $1,500–$3,500 later to remove and reinstall the array. Ask the company to document remaining roof life in writing, and ask exactly what a remove-and-reinstall costs with them. Some companies bundle one R&R into the workmanship warranty; most don't.
30. Is my roof structure adequate, and who certifies that?
A solar array adds roughly 2.5–4 pounds per square foot — well within code for sound construction, but questionable on undersized or damaged rafters. Ask whether a structural review is included and who signs it. Tile and slate roofs need specialists; ask how many tile-roof installs the crew has done and what the breakage allowance is.
31. How does this affect my homeowner's insurance?
Most carriers add a rooftop array to your dwelling coverage for a modest premium increase — call your agent before signing. Ask the solar company for the documentation insurers typically want: permit records, electrical inspection, and equipment UL listings.
32. What happens when I sell the house?
Owned systems transfer cleanly and typically add value. Leased systems and PPAs must be transferred to the buyer or bought out — a friction point that kills real estate deals every year. If there's any chance you'll move within the contract term, weight that heavily in the financing decision.
Section 8: DIY and Owner-Supplied Equipment — Ask This Too
33. Will you install equipment I supply myself?
Many local electricians and installers will install owner-supplied equipment for labor-only pricing, and the savings are real. The math on a 9 kW system:
| Path | Equipment Cost | Labor + Permits | Total | Effective $/W |
|---|---|---|---|---|
| Turnkey national installer | (bundled) | (bundled) | $27,000 | $3.00/W |
| Owner-supplied kit + local installer | $11,000–$14,000 (panels, inverter, racking, BOS) | $6,000–$9,000 | $17,000–$23,000 | $1.89–$2.56/W |
| Full DIY (where legal) | $11,000–$14,000 | Permits only, $500–$1,500 | $11,500–$15,500 | $1.28–$1.72/W |
The trade-offs are real: DIY means you own the design liability, the roof work, and the warranty coordination; owner-supplied means the installer's workmanship warranty covers labor but not equipment defects. For many homeowners the middle path — a complete solar kit from us plus a licensed local installer — is the value sweet spot. Our installation guide and DIY solar kits show what's involved before you commit.
Section 9: Maintenance, Cleaning, and Long-Term Ownership
34. What maintenance does the system actually need?
Solar is low-maintenance, not no-maintenance. Ask the company to spell out: panel cleaning frequency for your climate (in most regions rain suffices; dusty agricultural and desert areas may need annual cleaning), inverter service life (string inverters typically need one replacement in 25 years at $1,500–$3,000 installed; microinverters are rated 25 years), vegetation management, and what a service call costs after the workmanship warranty expires.
35. What are the most common failure points you've seen — and how are they covered?
This question tells you whether you're talking to a real operator. The honest answers: inverter failures, monitoring communication dropouts, roof leaks at poorly flashed penetrations, wire damage from critters (ask about critter guards), and optimizer failures under heavy shade cycling. A company that claims "nothing ever fails" has installed nothing.
The Quote Comparison Worksheet
When your three quotes arrive, score them on this table. Anything left blank by the company is a follow-up call:
| Line Item | Quote A | Quote B | Quote C |
|---|---|---|---|
| Cash price / cost per watt | |||
| Financed price / dealer fee % | |||
| Panel manufacturer + full model number | |||
| Inverter type + model | |||
| Year-1 production (kWh) + assumptions stated | |||
| Product / performance / inverter / workmanship warranty terms | |||
| Roof-penetration warranty length | |||
| Exclusions (panel upgrade, reroof, tree work) | |||
| Timeline to PTO + payment schedule | |||
| Local references provided |
Payment schedule deserves a special word: a reasonable structure is a small deposit (check your state cap — California limits home-improvement deposits to $1,000 or 10%, whichever is less), a progress payment at installation, and final payment at inspection or PTO. Never pay in full before the system passes inspection. I've been called in to rescue projects where the homeowner paid 100% up front and the crew vanished after day one — the deposit structure is your only leverage, so keep it until the job is actually done.
And one last instinct to trust: the quality of the sales conversation predicts the quality of the installation. A rep who answers every question on this page with documents instead of adjectives works for a company whose crews pull permits, flash penetrations correctly, and answer the phone in year nine. That company is rarely the cheapest quote, and it's almost always the best deal.
Section 10: Timing, Permits, and HOA Questions
36. What permits and inspections will this project need, and what do they cost?
Most jurisdictions require a building/electrical permit for solar; some add structural review for older roofs. Fees run $100–$600 in most US jurisdictions. Ask the company to name every permit it will pull and every inspection the system will pass — and to put the permit numbers on your final paperwork. An unpermitted array can force removal at resale and void insurance claims.
37. My HOA has architectural review — do you handle that?
In most states, solar access laws limit how much an HOA can restrict panels, but the application paperwork is still real. Experienced local companies have a template ready; ask whether HOA submission is included and how long their last few HOA approvals took in your neighborhood.
38. What happens if my project sits in a queue?
Permitting and utility interconnection queues are the schedule killers, not the install itself. Ask for the company's current average days-to-PTO for your utility specifically — a company installing weekly in your territory knows the real number. Build that number into any "cancel your utility bill by summer" expectations.
Section 11: The Questions to Ask Yourself Before Any of This
Three self-checks sharpen every conversation above. First, your usage: pull 12 months of kWh history from your utility portal so every sizing discussion starts from data, not averages. Second, your horizon: if you might move within five years, owned systems with strong payback still work, but leases and long loans need a harder look. Third, your roof's remaining life: a $0 repair now beats a $3,000 remove-and-reinstall in year eight. Walk into the consultation with those three answers and you are already better prepared than most buyers the rep will meet this month.
Section 12: After You Sign — The Handoff Questions
39. What documentation do I receive at closeout?
A complete closeout package includes: signed permits and inspection cards, the PTO letter from your utility, equipment datasheets and warranty registrations (confirm the installer registered them — unregistered warranties sometimes default to shorter terms), as-built drawings showing panel layout and string configuration, monitoring account credentials, and the final invoice matching the contract. Ask for this list before signing so it's an expectation, not a favor.
40. Who do I call in year three when something looks wrong?
Get the service workflow in writing: the phone number or portal for warranty claims, expected response time, and whether service labor is covered under the workmanship warranty or billed. The best installers answer this before you ask. The ones who hesitate are telling you the answer.
Forty questions is a lot — but this is a 25-year asset bolted to your house. A trustworthy company will welcome every one of them, because good operators answer with documents, and documents are cheap when the work is sound.
Keep this page open during your consultations and mark off each answer as you get it. The companies worth hiring will hand you documents faster than you can write the questions down — and when you find one, you'll know the difference immediately. When you're ready to benchmark equipment pricing, Portlandia Electric Supply publishes per-watt costs on every panel, inverter, and kit we sell, no appointment required.
Frequently Asked Questions
What is a good cost per watt for solar?
For US residential systems, a cash price of $2.50–$3.50 per watt before incentives is the normal range, varying by region, roof complexity, and equipment tier. Quotes above $4.00/W need a specific justification — premium equipment, difficult roof, panel upgrade — and quotes below $2.20/W deserve extra scrutiny of the equipment and warranty terms.
How many quotes should I get before choosing a solar company?
Three is the working standard. Compare them on cash cost per watt, exact equipment model numbers, year-one production estimates with stated assumptions, and all four warranty documents. More than five quotes usually adds confusion rather than information.
What is a dealer fee in solar financing?
A dealer fee is a charge — often 15–30% of the loan — added to the principal so the lender can advertise a low interest rate. It makes monthly payments look attractive while raising the total cost. Always ask for both the cash price and the financed price; the difference reveals the fee.
Should I get a battery with my solar system?
It depends on your goal. For pure bill savings under net metering, batteries rarely pay back quickly. For backup power during outages or in areas with time-of-use rates and weak export compensation, storage can be worth it. At minimum, choose a battery-ready hybrid inverter so adding storage later doesn't require replacing equipment.
How do I verify a solar company's license?
Ask for the contractor license number and check it on your state licensing board's website — the search takes about two minutes and shows status, complaints, and bond information. Also request certificates for general liability and workers' compensation insurance, and confirm the policy is current.
Is it cheaper to buy solar equipment and hire my own installer?
Often, yes. Buying equipment direct from a supplier and hiring a licensed electrician or local installer for labor can cut total cost meaningfully versus turnkey national installers — the trade-off is that you manage the project and the workmanship warranty comes from your installer rather than one bundled provider.
