How home solar panels work in Canada

What do solar panels on a house actually do?

A solar panel is a flat array of photovoltaic cells. When light hits them, they push out direct-current electricity. An inverter turns that into the alternating current that your home uses, and the power goes first to whatever is running in the house, with any excess going to the grid. At night or on dull days you draw from the grid as before, so most homes keep their utility connection.

Panels are usually rated in watts, and modern residential panels often fall in the range of a few hundred watts each. A typical system is described by its total size in kilowatts. If you want to translate that into panels for your own house, our guide on how many solar panels a house needs shows the method.

Do solar panels work in a Canadian climate?

Yes. Cold air actually helps panel efficiency, and long summer days produce a lot of energy. The weak months are December and January, when days are short, the sun is low and snow can sit on the array. Many Canadian cities get a solar resource comparable to places in Europe where rooftop solar is common. Annual output varies by region and by the way the roof faces, which our guides on peak sun hours and the best panel direction explain.

For what to expect in the cold months, read solar panels in winter. Production estimates from installers are modelled figures, not promises, and how to read a solar production estimate shows what to check.

What parts make up a home solar system?

• Panels. The generating modules, mounted on a roof or on the ground.
• Racking. The frame that attaches the panels and keeps them secure against wind and snow.
• Inverter. The device that converts DC to AC; see solar inverter types.
• Meter and connection. Where the system links to the utility, under that utility's interconnection rules.
• Monitoring. Software that shows what the array produces.
• Optional battery. For backup or time-shifting, covered in solar battery storage in Canada.

Most grid-connected systems switch off during a grid outage for safety unless they were designed with a battery and a backup circuit. Grid-tied versus off-grid solar sets out that difference.

What does it cost, and is it worth it?

The price depends on system size, roof complexity, equipment, region and the year you buy, so quotes decide. Cost is the largest factor in whether solar pays back, alongside your electricity rate, how much of the output you use yourself and what your utility pays for the surplus. See solar panel cost in Canada and whether solar panels are worth it for the details.

Net metering and similar programmes differ by province and utility, and they change, so check the terms with your utility and provincial energy ministry before committing. Federal and provincial incentives and loans have existed in different forms; look at the Government of Canada energy-efficiency pages for what is currently available.

Where does solar thermal fit in?

Solar panels in common use make electricity, but sunlight can also heat water or air directly. The Drake Landing Solar Community in Okotoks, Alberta, used 800 flat-plate collectors, which are thermal collectors rather than PV panels, to heat a district loop for 52 homes. The collectors fed a borehole heat store. See how solar collection worked at Drake Landing, and the comparison of solar thermal and solar PV to see which suits which job.

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