How Big a Solar System Does My Home Need?
Divide your yearly electricity use by the yearly output per kW where you live. NRCan's figures run from 937 kWh per kW in St. John's to 1,360 in Regina. A home using 9,000 kWh a year in Toronto, at 1,163 kWh per kW, needs roughly a 7.7 kW system.
Start with your bills
Add up 12 months of kWh from your electricity bills. Use the whole year: heating, cooling and any EV or heat pump you plan to add.Roof direction and shade
NRCan's output assumes south-facing panels tilted at your latitude. Shade, roof direction and tilt change your result, so ask installers for a site-specific estimate.Don't oversize
In several provinces exports earn less than the retail rate, and credits carry for limited periods (12 months in Ontario; Quebec's surplus bank resets every 24 months). Size to your own use unless a quote shows otherwise.Plan for new loads
A heat pump or EV charger raises your use. If one is coming within a few years, tell installers so the inverter and panel space allow for it.



