How to read a solar panel quote

What size and price figures should a solar quote show?

Start with the system size in kilowatts DC, the number of panels and the rating of each panel. Multiply panels by watts to check the figure. Then divide the total price by the system watts to get price per watt, the cleanest way to compare a 6 kW quote with an 8 kW one. Do the same arithmetic on every quote, using the cost before any rebate or tax treatment so you compare like with like.

Costs vary by province, year, roof type and equipment, so the guides to solar panel cost in Canada and in Alberta explain the drivers rather than fixed numbers. Your quotes set the real figures.

How is the production estimate calculated?

A quote should state expected annual production in kWh and how it was derived. Ask for the tilt, azimuth, shading loss, the soiling and snow assumptions, inverter losses and the year-one degradation rate. If the estimate comes from modelling software, the installer should be able to show the report. Two quotes for the same roof that differ sharply in production are a prompt to ask why.

Compare the estimate with your own use. Your bill shows annual kWh, and the sizing guide shows how to relate a system to that figure. For context on how modelled and measured output can differ, the monitored results at Drake Landing are a reminder that real years vary from design values.

Beware of savings claims that assume rate increases without stating them. A fair quote shows the assumed electricity rate and escalator, so you can rerun the payback with your own numbers using the payback guide.

Which equipment and warranties should be named?

Panels, inverter type (string, microinverter or optimizer) and racking should each be named with model numbers. If a quote says "premium panels" or "tier one" without a model, you cannot check specifications. The inverter guide explains the trade-offs, especially under partial shade.

Warranties come in three kinds: product, performance and workmanship. The quote should state the length of each, who honours it and whether labour for removal and replacement is covered. If the installer closes, the manufacturer warranty may be all you have, so ask what happens then. The warranty explainer goes through the wording to check.

What is commonly left off a solar quote?

• Electrical panel upgrade or a service-size change.
• Roof repairs, reroofing or structural review.
• Tree removal or shading mitigation.
• Permit and utility interconnection fees, plus the meter change.
• Monitoring set-up and ongoing fees for the app.
• Rapid-shutdown equipment, where local code requires it.
• Removal and re-installation if the roof will need replacing within the panel life.

Ask for each of these as included, excluded or "to be determined after inspection". For permitting, see the notes on Alberta permits, and for how credits for exported power work in the province, the net metering guide. Rules differ elsewhere, so ask your provincial regulator or utility.

How do payment terms and incentives change the comparison?

Look at the deposit, the milestone payments and what you owe if the project stalls. Financing offers should show the interest rate, term and any dealer fee built into the price. The financing guide covers loans, leases and power purchase agreements, and how to compare them with a cash price.

Incentives, grants and tax measures change. Check the Government of Canada energy-efficiency pages, the provincial energy ministry and your utility for what is open now, and ask whether the quote already subtracts any of it. If you are also choosing between installers on credentials and track record, use the separate installer checklist; this guide is about the document itself.

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