Roofs typically include several slopes, each facing a different direction. If solar panels are fitted to a slope that faces south, they will typically produce more energy than the same panels on a north facing slope. The direction the panels face and the angle of the roof is important!
It may of course be possible to fit panels to multiple slopes on your roof - for example having panels on both east and west facing slopes can be highly effective. However, for the purposes of the Virtual Solar and Battery Simulation, we want to identify the best single slope of your roof for solar power generation.
Don’t worry about getting this perfect - we will always ensure an expert does a full roof survey before offering to install solar and battery at your home. If you follow the advice and examples below, the data you see in the app will closely follow the advice of an expert.
Which slope of my roof do I pick?
When selecting the appropriate slope, choose the slope that faces furthest south. The only reason to select a different slope is if the most southerly facing slope is small or is heavily shaded by, for example, nearby trees. If your roof slopes east/west, choose the east facing slope if you use more electricity in the morning, and west facing if you use more in the evening.
After identifying the slope, the app helps you to input its slope and orientation.
How do I work out the slope of my roof
We recommend doing it by eye. The images in the app accurately show you what different angles look like. Select the one that looks most like your home. This isn’t exact - we will rerun these calculations with exact data before any installation is offered.
How do I work out orientation
Start by centring your home in the middle of the map and press next. On the next page rotate the arrow until the arrow points to the slope of your roof where the panels would go.
Example homes:
Simple roof with two slopes
Select the half of the roof that faces most towards the south. In this example, the slope selected faces east by southeast.
Roof that slopes down in 4 directions
There are four slopes on this house. The most southerly facing slope is small so instead choose the larger slope that faces west by southwest.
L shaped roof
This is a complicated roof. You should select the slope nearest the bottom that faces south by southwest.