Tilt and Azimuth Reference
How far is this roof from the ideal tilt and direction for your city?
Data: No standard tables used. Shows how far the roof is from north and from the latitude tilt. No output percentage until a published table is built in. About standard editions
This tool shows how far a roof is from north and from the latitude tilt. It no longer shows an output percentage: the old figure came from a simplified model we could not source. Actual output depends on shading, weather, panel type and other site factors.
Site Parameters
Location
Roof Pitch
Roof Orientation (Azimuth)
0° = North (optimal for Australia), 180° = South
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This page is kept out of search results until its orientation figures can be taken from a published table.
Questions
- What tilt does the tool treat as ideal?
- Your latitude. That is the usual rule of thumb for the most energy over a full year, for example about 19 degrees in Townsville and about 38 degrees in Melbourne. The tool shows how far the roof pitch is from it.
- Which way should panels face in Australia?
- North, because the sun sits to the north in the southern hemisphere. The tool measures how far the roof faces from due north, from 0 to 180 degrees, and groups it as north, north-east or north-west, east or west, or south of east or west.
- Why is there no output percentage?
- Earlier versions showed one, but it came from a rough formula that badly understated east and west roofs. Published loss tables give much higher figures. Until a sourced table is built in, the tool shows only the tilt and direction difference.
- Are east or west roofs worth using?
- They produce less over a year than a north-facing array, but they move generation to the morning or the afternoon. That can suit a site that uses most of its power at those times.
- My town is not in the list. What do I enter?
- Pick Custom Latitude and enter it as a negative number, because Australia is south of the equator. For example, enter -23.5 for Emerald.
- What about a very flat roof?
- Below about 10 degrees, panels hold dirt and rain does less to wash them. The tool suggests tilt frames, which also bring the angle closer to the latitude.