How to Read a Solar Quote, Line by Line
August 29, 2026
VerifiedAugust 28, 2026
Next reviewNovember 28, 2026
AuthorGriffEnergy Research Team
The short answer
A solar quote you can trust names the exact panel and inverter model, states system size in kW DC, gives an annual production estimate in kWh, separates three different warranties, and shows the rebate as a line you can verify yourself. Anything missing from that list is a question to ask before you sign.
Two quotes for the same roof can differ by $8,000 and look nearly identical on the front page. The difference is almost always buried in the specifics. Here is how to read one properly, line by line.
1. System size — in kW DC
Size should be stated in kilowatts DC (panel capacity), and ideally kW AC (what the inverter can deliver) too. “20 panels” is not a size — panel wattage varies enormously. If a quote gives you only a panel count, ask for the DC rating.
2. The exact equipment
You want make and model for both panel and inverter, plus the datasheet. Beware “Tier 1 panels” used as a quality claim — Tier 1 is a Bloomberg New Energy Finance bankability ranking that reflects how often a manufacturer's panels appear in financed projects. It says nothing about durability. For actual reliability, ask whether the module appears on the PV Evolution Labs (PVEL) Top Performer list.
3. Annual production estimate
A credible quote states expected first-year output in kWh and says what it was modelled on — ideally your own 12 months of utility data, plus roof orientation, tilt, shading, and a derate factor for snow and wiring losses. An estimate with no stated assumptions cannot be compared against a competing one.
4. Three separate warranties
| Warranty | Covers | Typical term |
|---|---|---|
| Product | Physical defect in the panel itself | 12–25 years |
| Performance | Output staying above a stated percentage | 25–30 years |
| Workmanship | The installation — leaks, wiring, mounting | 2–25 years (varies most) |
Workmanship is the one that varies most between installers and the one most likely to matter. A 25-year panel warranty means little if the company covers its own labour for two years.
5. The rebate line
Rebates should appear as a clearly labelled program amount you could verify on the government's own page — not blended into a vague “savings” figure alongside an in-house discount. Two specific red flags: any quote applying the federal 30% Clean Technology ITC to a homeowner (it is business-only), and any quote claiming a rebate without mentioning the pre-approval requirement that Ontario's program depends on.
6. What is excluded
Check explicitly for: electrical panel upgrades, roof repair or reinforcement, permit and ESA inspection fees, utility interconnection costs, tree removal, and monitoring subscriptions. These are the classic sources of a post-signature surprise.
How do I compare two quotes fairly?
Divide total price by kW DC to get cost per watt, then check the production estimates were modelled on the same assumptions. Equal price per watt with very different output claims means one estimate is optimistic.
Is a higher price ever justified?
Yes — better inverters, a longer workmanship warranty, in-house crews, and complex roof work all cost more and are often worth it. The point is to see what you are paying for.
What should I never accept?
A lump-sum price with no equipment models, no production estimate, and no written warranty terms — or pressure to sign the same day.
Primary sources
- BloombergNEF — Tier 1 module list methodology (bankability, not quality)
- PV Evolution Labs (PVEL) — Module Reliability Scorecard
- Electrical Safety Authority (Ontario) — contractor licensing and inspection requirements
- Department of Finance Canada — Clean Technology ITC eligibility (corporations only)
Verified August 28, 2026. General guidance only — confirm licensing and program eligibility in your own province before signing. Not financial advice.
