As you are aware, the sun rises from the east and sets in the west. During the regular tracking though, the sun moves towards the north, making north the best face to maximise your solar gain.

Another factor to take into account when optimising your solar gain is the season. As you can see in the diagram, solar gain in summer is higher due to the position of the sun. In winter, the sun is further north, however the angle is not as optimal compared to summer.

This being said, if you have northern facing roof space free from any obstructions such as trees or buildings, then you should opt to install solar panels there, so that you are guaranteed the best solar gain.

Solar Gain and solar panel direct

Solar gain and solar panel directional losses

  • You can also install solar panels on the east and the west facing front

It’s not uncommon to have solar panels installed on the east or west facing sides of your home or business. Although the solar gain is lower, the directional losses are not that great.

  • The solar panel directional losses for north-east and north-west vary from around 3% to 4%.
  • For an east or west facing roof, your solar gain loss will be around 12% to 18%

An experienced solar installer or sales rep will be able to work out the optimum solar panel direction and angle on your property, to will give you the most solar gain and best return on investment. Although not essential, it is advised that you ask for a plan or design for your solar power system, outlining the options for installation and the exact location where the solar panels will be placed.


“What if a sales rep or installer recommends that I install the solar panels on the south facing roof?”

“I suggest you get a second opinion. Honestly, it’s a no brainer! Unless of course you live in the northern hemisphere.”


What our viewers are saying

    • We've helped over 15,000 Australians switch to solar power. Join the rooftop revolution!.

Cairns Value Solar


This was the cheapest quote by far and as much as i could tell was for same or similar equipment as other installers were offering. We got about 10 quotes.

The sales rep was organised and obliging and replied to questions efficiently. One good thing was the price was all inclusive, no extras to come and no conversations that started ‘this is your quote but it may change when we come to install’ which one company tried – bad line.
The installation was good, the wrong inverter was put in on the first day but changed on the second day and to be honest we had changed our mind about 20 times as to which one we were having. Overall, for a major purchase it was a simple and pretty pleasurable experience.

One thing that would have been good was a 10 year warranty on the inverter but we can purchase this after sale which we will probably do.

Chris Black

Next: What time do solar panels work?

    • The solar gain is higher in mid-day when the sun’s high up in the sky.


Get 3 FREE Solar Power Quotes!

 By 5 star rated Australian solar companies