Solar panels in Sarnia, ON

Roofs in Sarnia get about 1,360 hours of usable sunlight a year — less than 88% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.

Check your specific roof in Sarnia → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.

What a typical Sarnia solar system costs

A 24-panel system (9.6 kW) is about right for an average Sarnia home using 10,800 kWh a year. It would produce roughly 11,098 kWh annually and offset 100% of that usage.

Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.

Why Sarnia gets 1,360 sun hours

That figure comes from Google's analysis of real rooftops across Sarnia — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Sarnia reaches about 1,469 hours, roughly 8% better than typical.

The numbers behind this page

When Sarnia actually produces

Annual totals hide the thing that catches people out: 37% of Sarnia's yearly sunlight arrives in May–July, and just 12% across November–January.

Sarnia produces about 3.5× as much in Jun as in Dec — a normal mid-latitude swing. Expect real winter shortfall and summer surplus rather than steady year-round output.

The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Sarnia's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.

Cities with almost the same sunlight

These are the closest matches to Sarnia's 1,360 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.

Nearby cities

See all of Ontario → statewide sunlight, rates, incentives and every city we've measured.

Sarnia solar questions

Worth reading before you buy

Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Ontario electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.