Installing solar panels in Ontario, step by step

What happens before the panels go on the roof?

The first visit checks the roof, shading and the electrical service. A competent installer measures the roof, notes the orientation and age of the shingles, looks at the main panel and models the expected yearly production. If the roof will need replacing within a few years, it is cheaper to do that first than to remove the array later. The model should show assumptions you can read, as described in how to read a solar production estimate.

Then comes the written quote. Comparing solar quotes and the installer checklist set out what to ask each company.

Which permits and approvals does an Ontario system need?

Three layers of approval usually apply, and each has its own timing.

• Municipal. A building permit may be needed, depending on the roof structure and local bylaws. Ask your municipality.
• Electrical safety. A new system is normally inspected by the Electrical Safety Authority, which reviews the wiring before it is energized.
• Utility. The local distribution company reviews the connection application, may need a meter change and gives permission to operate.

A good installer files these for you and gives you the dates. For comparison, Alberta's version of the paperwork is described in solar panel permits in Alberta, but Ontario's offices and forms are different.

What does installation day look like?

Crews mount the racking, secure it to the roof structure with sealed fasteners, set the panels, run the wiring to the inverter and tie into the electrical panel. A typical residential job takes a few days, depending on size and weather. Snow, ice and wind can delay roof work, so winter schedules are less predictable. The installation process guide goes through each stage, and inverter types explained helps you understand the equipment in the basement or on the wall.

When can you switch the system on?

Only after the inspection passes and the utility confirms the connection. Running a system early can break the rules and void warranties. Once it is live, confirm that the meter and billing reflect net metering, and keep the commissioning documents, warranties and permit records. The monitoring guide explains what to track in the first year to make sure the output matches the estimate.

Incentive paperwork, if you use any program, often needs invoices and inspection records, so keep them together. The solar paperwork and tax checklist lists what to save, and the Government of Canada energy-efficiency pages and the Ontario energy ministry show what programs currently ask for.

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