FindSolar.caA solar quote is a one-page document that decides a five-figure purchase, and most homeowners read only two lines of it: the price and the monthly payment. Installers know this. The quotes that deserve your signature survive a reading of all twelve numbers below; the ones that do not are counting on you stopping at two.
The twelve numbers
One: DC system size in kW, the foundation of everything. Two: total installed cash price before incentives, the only price that compares across quotes. Three: dollars per watt, which is two divided by one, and the industry's honest yardstick. Four: estimated annual production in kWh. Five: production per installed kW, which is four divided by one, and should sit near your region's planning range of roughly 950 to 1,300 kWh per kW; our verification guide shows how to check it against free government tools. Six: the panel make, model and wattage. Seven: the inverter make, model and AC size. Eight: panel product and performance warranty years. Nine: inverter warranty years. Ten: workmanship warranty years, covering the labour and your roof penetrations. Eleven: any rebate assumed in the price, which must match a program that is actually open. Twelve: on financed quotes, the APR, the term, and the total of payments, the number the monthly payment is designed to hide.
The two comparisons that expose a bad quote
First, compare dollars per watt across quotes with everything held equal: cash price, before incentives, same scope. A quote that only looks competitive after a rebate, or only as a monthly payment, is not competitive. Second, compare each quote's production-per-kW claim against the same independent number for your address. Two installers quoting the same roof should not disagree by 20% on how much sun it gets; if they do, one of them is optimistic in exactly the direction that flatters their payback slide.
The DC versus AC size question
Quotes often pair, say, 8.2 kW of panels with a 7.6 kW inverter. That is not a trick: designers deliberately size panels above the inverter because panels rarely hit their lab rating on a roof, and a small amount of clipped production on perfect days is a fair trade for a cheaper, better-utilized inverter. A ratio up to about 1.2 is conventional. It only becomes a question worth asking when the gap is much larger than that.
What should be in writing beyond the numbers
Who owns the workmanship warranty if the installer is bought or folds, whether subcontractors do the roof work, who files the utility paperwork, and what happens to the schedule if utility approval is slower than promised. A quote that answers those in writing was written by a company planning to still exist in year nine; our installer comparison guide covers the rest of that judgment.
Questions homeowners ask
What is the first number I should look at on a solar quote?
DC system size in kW, then the total installed cash price before incentives. Those two give you dollars per watt, the yardstick every other comparison hangs on. A quote that leads with the monthly payment instead is steering you away from both.
What is a good price per watt, and what should be included?
Compare quotes on the same basis: cash price, before rebates, covering equipment, installation, permits and utility paperwork. Our cost calculator shows the planning range for your system size and province. Any quote compared after rebates or through financing needs converting back to cash-before-incentives first.
How can I tell if the installer's production estimate is realistic?
Divide estimated annual kWh by system kW and compare the result with an independent figure for your address from NRCan's maps or the satellite mode in our calculator. Inside about 10% is normal modelling variance. A fifth higher with no site-specific reason is a red flag; our verification guide walks through the check.
Why are the DC panel size and inverter AC size different?
Designers deliberately put more panel capacity than inverter capacity, commonly up to a ratio of about 1.2, because panels rarely produce their full rating on a real roof. A little clipping on the best days is a fair trade for better inverter economics. It is a question worth asking only when the gap is unusually large.
What warranty details should appear in writing on the quote?
Four separate items: panel product and performance warranty, inverter warranty, racking warranty, and the installer's own workmanship warranty covering labour and roof penetrations. They have different lengths and different owners. A quote that lumps them into one reassuring number has answered none of them; our warranty guide untangles the stack.
How do I compare a cash quote with a financed solar quote?
Convert the financed offer to three numbers: the cash-equivalent system price, the APR with its term, and the total of all payments. Financed quotes sometimes carry a higher system price than the same installer's cash deal, which is where dealer fees hide. Our financing calculator puts cash, loan and lease side by side.