Roof Mounting Angle

Some very common questions about mounting collectors on your roof include...

  • What angle?
  • Which Direction?
  • Solar PV or Solar Water Heating?
  • I don’t have a south facing wall?
  • Can I mount them on a wall?

Which direction should I mount solar Collectors

Solar Panels should be placed on a south facing roof. Also they can be mounted on a south facing wall.
In fact, anywhere between South-West and South East will give good results.
 
If you are limited to an East-West facing system, then you will most likely need two panels to provide the same amount of hot water as a single south-facing roof slope. The most frequent solution to this problem is normally to mount one panel on the east slope and a second panel on the west slope. A special controller is available for East/West facing installations.

If your roof faces east or west within 20 degrees of south then the reduction in heat output is minimal.

Solar Collector Angle

The panels should be mounted at the angle of your latitude. In Calgary, our latitude is 51 Degrees, hence the panels ideally should be placed at an angle of 51 degrees inclination.  This is a generic angle as a compromise between summer and winter sun.
 
In winter the angle should be 15 degree higher than your latitude (at 66 degrees in Calgary). In practice though, the extra 15 degrees inclination in winter will make little real effect on the heat produced. Most people simply mount them flush to their roof. The extra cost of trying to stand panels off the roof to achieve better efficiency would probably be better spent on purchasing a second panel!

Can I mount them on a wall

The panels will function anywhere between 15 and 90° angle of inclination from the horizontal. They cannot be mounted flat on a flat roof but they can be mounted vertically.
 
Our SunRain solar collectors come with their own mounting frame so if you have a shallow roof (30 degrees) then the 25 degree frames can be mounted and the panel will be sitting at 55 degrees.

Solar PV or Solar Water Heating?

The inclination rules are more or less the same for solar PV as for the solar water heating.  However Solar PV is much more effected by an east or west orientation.  The flat surface of the PV panels means power drops off rapidly as the sun is in the east or west.  This is why many PV systems are mounted on movable tracking systems.

Evacuated tubes are round and the passively track the sun as it moves from east to west.