What gets checked
Seven engineering cross-checks: the panel arithmetic against the quoted kW, the inverter against your continuous load and against the array (clipping), the surge requirement your motor loads create, the inverter type against your backup need, the battery's usable capacity against your backup hours, and — if you provide your monthly units — the quoted size against what your usage actually justifies.
Why we keep prices out
Prices move weekly and vary by city; a "fair price" verdict would be stale the day we wrote it. Engineering does not move. Verify the components here, then judge the money by dividing the total by kW and running it through the payback calculator.
How to use the verdicts
A red flag is a reason to renegotiate the component, not necessarily to walk away — most installers will fix a specification when a customer asks the right question. Take the specific numbers this tool gives you into that conversation.
What should I check in a solar quotation?
Five things: panel count × wattage actually equals the quoted kW; the inverter covers your simultaneous load with ~30% headroom and matches the array; the inverter type matches your backup need; the battery covers your backup hours at its real usable capacity; and the size fits your usage rather than the seller's target.
The quotation says 7 kW but panels add up to less — is that normal?
No. Count × wattage is the real system. A small rounding gap is fine; a shortfall of 10% or more means you are paying for capacity that is not on the roof.
Can this tool tell me if the price is fair?
We deliberately keep prices out — markets change weekly. It checks the engineering. For the money side, divide the total by kW and put it through our payback calculator.