Get the records from your energy company on how much energy you have used in the last five years. You can then use this information to figure out exactly how much power you will need solar energy to provide for you home. Having the past five years is important so that you can see that some years you will need more energy than others.
Testing at around -20c, amazing results.
Panels have to face the sun to draw power. You get the energy from the sun, so it's important for the panels to be located in an area where they can get all the solar energy possible.