There are many factors that determine if solar panels make sense from the financial standpoint. For example, each unit of energy generated is more valuable if local electricity prices are high, and incentives such as rebates or tax breaks make the technology much more affordable. However, assuming all conditions determined by humans are kept constant, the main factor that influences solar PV system productivity is the availability of sunshine. This article provides a brief overview of how sunshine varies by territory in Canada.
This free map by EcoSmart shows the productivity of solar PV systems in Canada according to location. The results are provided in of kilowatt-hours produced (kWh) per kilowatt of installed capacity (kWp) per year. For example, if you have a 6-kW system in a location with 1500 kWh/kWp/year, you can expect a yearly output of 9,000 kWh from your installation.
The southern portions of these provinces have plenty of locations where you can expect to generate more than 1,600 kWh per kW of solar power capacity each year. In particular, the southernmost part of Alberta and southwestern Saskatchewan have locations where solar PV systems can generate more than 1,800 kWh/kWp/year. Keep in mind, however, that yearly solar irradiation declines as you move farther to the north.
Solar PV systems in these provinces can be expected to generate between 1400 and 1600 kWh per kWp of installed capacity each year. Surprisingly, around 98% of Canada’s solar power capacity is installed in Ontario, which is less sunny than southern Alberta, Saskatchewan or Manitoba. This has been in great part due to the excellent feed-in tariff in Ontario, which is even higher than the retail price of electricity. The growth of solar power in Ontario proves that the technology is viable even with moderate sunshine when the right incentives are in place.
In these provinces, solar PV systems have an average output of 1300 kWh per kWp per year. British Columbia is a special case, having good locations for solar power to the southeast (above 1700 kWh/kWp/year) and unfavorable conditions to the northwest (1000 kWh/kWp/year). In other words, if you install two identical PV systems in northwest and southeast British Columbia, the one to the southeast will be around 70% more productive! Newfoundland and Labrador and Prince Edward Island have uniform irradiation profiles without drastic variation, as you can see in the map linked.
These territories get the least yearly sunshine in Canada, due to their location far to the north and the long winter days they experience. Irradiation levels are typically below 1,000 kWh/kWp/year. However, there are incentives for renewable generation nevertheless, given that it improves energy independence in locations far to the north. In addition, these locations have more expensive electricity, which makes solar generation more valuable and compensates the reduced energy output.