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Quote checker

Compare solar quotes: price per watt and production against NREL benchmarks

Enter the size, price and production estimate from one quote, or from two or three. The checker converts each price to dollars per watt against NREL's cost benchmark, compares each production estimate with PVWatts for your ZIP and roof, shows where the quotes disagree, and lists questions to ask before you sign.

The quoteQuote A
Optional: panel count, wattage, offset claim
Quote B
Optional: panel count, wattage, offset claim
Quote C (optional)
Optional: panel count, wattage, offset claim
Your home

Source: Virginia average, 12 months to July 2026. Edit it to match your bill ÷ kWh.

Sun data: Virginia median (PVWatts) · 1,366 kWh per kW per year, south-facing

Rate growth

Other assumptions (degradation 0.5%/yr, fixed charges $15/mo, SRECs $30 for 10 years, federal credit 0%) match the calculator. All assumptions.

$2.95

Price per watt DC

At benchmark

10,928

PVWatts expects, kWh/yr

1,366 kWh per kW for this roof

100%

Installer ÷ PVWatts

Plausible

83%

Of your usage, PVWatts

installer's estimate: 83% of 13,107 kWh/yr

11.0 yrs

Break-even, modeled

with PVWatts production, nominal

$35,680

25-year net benefit

savings minus price, undiscounted

Price

Between NREL's $2.78 floor and $3.25/W (its $2.95 modeled market price plus 10%).

Production

Within 10% under to 8% over PVWatts for this location, orientation and shade.

Your price per watt against the benchmarksYour quote$2.95NREL floor$2.78NREL market$2.95
NREL floor and market price: Q1 2025 cost benchmark, 8 kW residential PV-only system, 2024 dollars. Reviewed 2026-10-07.

If the installer's production estimate were right, break-even would be 11.0 yrs instead. Savings rise and fall with that number, so the checker tests it.

Quote AQuote B
Size 8.00 kW DC 8.00 kW DC
Price per watt DC $2.95 At benchmark $3.54 Above benchmark
Price before incentives $23,600 $28,320
PVWatts production, kWh/yr 10,928 1,366 kWh per kW · 83% of your usage 10,928 1,366 kWh per kW · 83% of your usage
Installer's estimate, kWh/yr 10,928 1,366 kWh per kW · 83% of your usage 100% · Plausible 12,458 1,557 kWh per kW · 95% of your usage 114% · Optimistic
Break-even, modeled 11.0 yrs 13.2 yrs
Net benefit, nominal $35,680 $30,960
Break-even if the installer were right 11.0 yrs 11.5 yrs
Panel math — —

Break-even and net benefit use PVWatts production for this roof over 25 years; dollars are nominal and undiscounted.

Where the quotes disagree

  • Quote B costs $0.59/W more than Quote A (20%), about $4,720 at 8 kW. That is more than the 10% that roof and equipment differences normally explain; ask Quote B what the extra buys.
  • Quote B expects 1,557 kWh per kW a year; Quote A expects 1,366, 14% apart for the same roof. Ask both which tilt, orientation, shade and loss assumptions they used.
  • Quote B is above PVWatts for this roof while Quote A is within it. Ask Quote B what the design assumes that the other does not, and which kWh the production guarantee is written for.
Price per watt of each quote against the benchmarksQuote A$2.95Quote B$3.54NREL floor$2.78NREL market$2.95
NREL floor and market price: Q1 2025 cost benchmark, 8 kW residential PV-only system, 2024 dollars. Reviewed 2026-10-07.

Questions to ask the installer

  • The price is below $2.78/W, NREL's minimum sustainable price. What is excluded: permitting, interconnection, monitoring, roof attachments? Is this a cash price, or a financed price with the dealer fee stripped out?
  • The price is above the NREL benchmark. What drives it: premium modules, a steep or complex roof, a main-panel upgrade, a battery or re-roofing folded into the price? B
  • The production estimate is below PVWatts. Is that because of shade or orientation, or is it a deliberately conservative number?
  • The production estimate is above PVWatts for this roof. Which shade analysis and which system losses did the design assume? B
  • The production estimate is well above PVWatts for this location and orientation. Can I see the shade report, and what annual kWh is the production guarantee written for?
  • Panel count × panel watts does not match the stated kW DC. Which number are the price and the production estimate based on?
  • Expected production is more than 10% above my usage. Year-end surplus credits pay a fraction of retail, so why is the system larger than my usage?
  • The quote does not state an annual production figure. What is it, in kWh per year? Savings depend on that number more than on any other.
  • Is this a cash price? If financed, what is the dealer fee and what would the cash price be?
  • Which inverter (string, optimizers or microinverters), and how long is its warranty? Inverters are the part most likely to need replacing first.
  • Will your own crew install it, or do you subcontract the installation? Who handles a service call if something fails?
  • Which panel, and what are its product and performance warranties?
  • What is your labor and workmanship warranty? If a panel or microinverter fails, will you cover the labor to replace it?
  • What does the price include: permitting, interconnection, monitoring, a main-panel upgrade if needed?

Price and production are within the benchmarks. The general questions above still apply.

Inverter and wiring failures in NREL's reliability study

In NREL's analysis of 100,000 U.S. systems over 5 years, inverters were the component that failed most often (4–6% of systems) and panel failures were rare (0.2%). Breakers, fuses, wiring, connectors and strings wired backwards showed up often in the first year, which the authors read as an installation-quality problem: a properly installed system should need none of those replaced in year one. A quote that is cheaper because of the inverter or the electrical work saves money on the two parts most likely to fail. Source.

A second quote for the same size is the most useful check. This button sends the sizes, prices and estimates (not your labels) to the Virginia installer behind this site.

Get a competing quote

How it works

What the checker computes

  1. Price per watt = price ÷ (kW × 1,000). Below NREL's $2.78 minimum sustainable price, at benchmark up to $3.25 (the $2.95 modeled market price plus 10%), or above benchmark, with the percentage above the market price shown.
  2. Production: PVWatts for your ZIP (south-facing, 25° tilt, 14% losses) × orientation × shade = what this roof should make. The installer's kWh divided by that is the ratio: conservative below 90%, plausible to 108%, optimistic to 120%, very optimistic beyond.
  3. Payback reuses the calculator's formulas with the quoted size and price and PVWatts production. Nominal dollars, no financing, no discounting.
  4. Panel math: panels × watts should equal the stated kW within 5%, and expected production more than 10% above your usage raises the oversize question.
  5. Comparing quotes: the same checks for each, then the $/W spread, kWh per kW on same-size quotes, mixed production verdicts and panel wattage differences, side by side.

Every threshold is on the methodology page, and this guide explains why they sit where they do. For the sales-side checklist (warranties, financing terms, installer track record), see how to compare solar quotes.

Questions

Questions about the quote checker

Where does the price benchmark come from?
NREL's Q1 2025 cost benchmark, which models a turnkey 8 kW residential PV-only system from its parts: $2.95 per watt DC is the modeled market price and $2.78 is the minimum sustainable price, the least a solvent installer can charge, both in 2024 dollars and before incentives. NREL publishes no Virginia-only figure, so the checker uses the national benchmark. Reviewed 2026-10-07; links on the methodology page.
Why would a real quote come in above the NREL benchmark?
NREL models a cash price for an 8 kW system with standard modules on a simple roof. Smaller systems, premium modules, steep or complex roofs, a main-panel upgrade and local permitting all add to the price per watt, which is why the checker allows 10% above the market price (up to $3.25) before it calls a quote above benchmark. Financed quotes often include a dealer fee that the lender charges the installer, so enter the cash price; a financed price can read above benchmark for reasons that have nothing to do with the system.
Why compare the production estimate to PVWatts instead of trusting the installer?
PVWatts is NREL's physics model on typical-year weather, run here for a south-facing roof at 25° tilt with 14% system losses, then scaled by the orientation and shade you pick. A good design can beat it by a few percent. An estimate more than 8% above it calls for a question, and one more than 20% above it calls for the shade report. The comparison is only as good as the orientation and shade you select.
What if my quote includes a battery, a panel upgrade or a new roof?
Take those out before entering the price. The benchmarks are for a PV-only system. NREL's same benchmark puts a 13.5 kWh battery at about $1.64 more per watt of PV, so a bundled price would read as expensive for the wrong reason.
Is the payback here the same as the calculator's?
Same formulas, two differences: the system size and price come from the quote instead of being derived from your bill, and production is PVWatts for your roof rather than the installer's estimate. The line under the chart shows the other case. Dollars are nominal and undiscounted, financing interest is ignored, and the federal residential credit is 0% for homeowner-owned systems installed in 2026 or later.
How does compare mode decide two quotes disagree?
Each quote is checked on its own first. Then: the dearest and cheapest price per watt are compared, and a gap over 10% is called more than roof and equipment differences normally explain. Two quotes within 10% of each other in size are treated as designs for the same roof, so if their kWh per kW differ by more than 8% both installers get a question. A mix of optimistic and plausible production verdicts is pointed out. Panel wattages 20 W or more apart are noted as a likely newer or more efficient module. Every threshold is on the methodology page.
Why does the page talk about inverters and workmanship?
Those are the parts of a residential system that fail most often. In NREL's analysis of 100,000 U.S. systems over 5 years, inverters failed most often (4 to 6% of systems), panel failures were rare (0.2%), and breakers, fuses, wiring and strings wired backwards clustered in the first year, which the authors read as installation quality. A quote that is cheaper because of the inverter or the electrical crew saves money on the two parts most likely to fail.
Are installer names sent anywhere?
No. The label you give each quote stays in your browser: it is not put in the page address and not sent with the quote request. The button under the results sends sizes, prices and production estimates only, plus the home inputs you entered.
Does this tell me whether to sign?
No. It tells you where the quote sits against public benchmarks and gives you the questions to ask. A quote above benchmark can still be the right one if the roof is hard, the equipment is better or the warranty is longer. A second quote for the same size is the most useful check; the button under the results requests one.