Why can't the sun supply 100% of your heating
For Northern climates such as Canada, the sun is too weak, the weather
too cloudy, and the climate too cold in winter to use solar for 100% of your
space heating needs. You need a back-up system. If you build too
big a solar system, it will stand useless for a majority of the year, and
you will produce way too much heat during the summer.
However solar can economically provide 50% to 80% of your total energy
needs for space heating. Since solar energy is free for the taking,
this could mean a 50% to 80% reduction of your space heating costs.
Since space heating and DHW is 82% of your total energy consumption, your
energy bills can be cut by up to 64%.
Firewood is generally considered GHG (Green House Gas) neutral, so an air
tight, high efficiency wood stove is ideal to supplement solar water
Radiant floor heating is ideal for use of solar water heating.
Hydronic heating radiators (eg. baseboard hot water radiators) require a
much higher water temperature, so they will work, but are not ideal for
solar water heating.
Next best is an instantaneous water heater powered by natural gas or
Worst of all for the environment and your pocketbook is electric