Using that Aussie calculator, which I believe uses Shannow's figures: For a good-sized roof in my area, it shows space for 4.96kW, and the ability to produce 22.77kWh per day. That's 705kWh a month, or about 50kWh shy of what I use presently. I do not run A/C and I heat with gas. For Ontario, the production figure would also be significantly less. Add 264.6kWh a month on top of that for our Tesla charging and there's no way I could operate my house and charge an EV off solar+storage with my roof.
A local industrial solar install (more efficient than rooftop) produces 14,300MWh a year with a 10MW installed capacity. That breaks down to 3.92kWh per kW of installed capacity, or, applied to our earlier rooftop calculation, gives us a more realistic 19.44kWh per day for Canada. Assuming even less efficiency for rooftop, we''ll settle on 19kWh a day.
So let's come up with a hypothetical scenario here based on some generous numbers and our Tesla consumption average from above. We will use wholesale prices with no feed-in tariffs, since the Ontario MicroFIT program ends this year.
Monthly usage: 1,015kWh
Available Installed solar capacity: 4.96kW
Actual installed solar capacity: 4.87kW (using
this kit )
Monthly solar production: 574kWh (based on 18.5kWh per day, adjusting down to the 4.87kW figure)
Cost of solar panels, installed: $8/WUSD as per
this source which is $10.20CDN right now.
Scenario #1: Grid tied, no storage
Cost of solar panels (installed): $50,000CDN (assumes no borrowing costs)
Wholesale rate paid: $0.07/kWh (this is what Australia dropped down to, roughly, when they cancelled their feed-in tariff program)
Solar generation: 574kWh
Utility power purchased: 441kWh
Average utility rate: $0.12/kWh (average-peak)
Result:
Delivery charge: $35.00
Regulatory charges: $4.00
Solar panels: $208.33 (our $50K broken over 20 years, paid monthly)
Solar profit: -$40.18
Utility cost: $52.92
Total: $260.07/month
Scenario #2: Grid-tied, total storage
Cost of solar panels (installed): $50,000CDN (assumes no borrowing costs)
Cost of battery bank: $7,700CDN (assumes no borrowing costs)
Wholesale rate paid: $0.07/kWh
Solar generation: 574kWh
Utility power purchased: 441kWh
Average utility rate: $0.06/kWh (100% off-peak)
Result:
Delivery charge: $35.00
Regulatory charges: $4.00
Solar panels: $208.33 (our $50K broken over 20 years, paid monthly)
Battery bank: $64.17 (our $7,700 broken over 10 years, paid monthly)
Solar profit: -$40.18
Utility cost: $26.46
Total: $297.78/month
Scenario #3: Standard Utility (no solar or batteries)
Utility rate $0.12/kWh (average)
Result:
Delivery charge: $70.00 (approximate)
Regulatory charge: $4.00
Utility cost: $121.80
Total: $195.80/month
Now, we can play around with the per kWh cost and make it more "Europe", which would result in a significant shift in the above numbers. Our 1,015kWh would cost $375.56 in electricity alone in Germany for example. Even more in Denmark.