Taking a course on energy on Coursera. I stumble on this Canadien web site:
Where you can find the number of kWh yearly average per kW of solar panel installed.
The FAQ page explains the calculation:
So for my location, the early average if the panels are tilted to my latitude (optimal), I get around 1200kWh/kW. So if I install this panel of 140W (cost around 300$), I will get:
1200*(140/1000) = 168kWh per year. Divide this by 365 days and 24h, this give 19.2WattsHr in average over the year for this 140W panel... or 19.2/140*100 = 13.6% capacity factor.
So my 140W panel, gives me a early average of 19.2W. If I need to power and average house in Canada, which is 12,000kWh/year, this is around 1.4kWh. So I would need 1400W/19.2W = around 73 panels of 140W or around 22,000$ just for the panels, without counting the batteries and installation.
I would also need a lot of space! Around 850 square foot or around 30 foot x 30 foot of south facing space. And I would need to clear the snow of those panels during 3-4 months.
In Quebec, I spend less than 4000$ per year on electricity (I burn wood during winter time). So to pay for the panels only, it would be 5.5 years of return... With the whole cost, installation, batteries, we can easily double that number to around 10 years.