Shading of Solar Panels in an Array
Placement of Solar Panels
If you want to place a solar array behind another array, you would need to ascertain whether the front array will cast a shadow on the rear array.
There is a trigonometric formula to calculate how far the shadow of the front array will be cast at midday during the winter solstice.
Winter of course is when the shadow is the longest and longer in the morning and afternoon than at midday.
But to calculate the length of the shadow at any time of day and from that to calculate how far behind the front array you need to be gets very complicated, mathematically speaking.
You would need to calculate how far south (in the southern hemisphere) the eastern corner of the front array casts on the rear array in the morning and how far south the western corner of the front array casts on the rear array in the afternoon, taking the width and placement of both arrays into consideration.
To help to figure this out, we have produced a series of tables covering latitudes from the northernmost tip of Queensland down to Tasmania.
How - NOT - to
Having a row of cells shaded will reduce the power output significantly.
Here's an illustration to help you understand the tables.
Download Shadow Tables
WinterShadow is series of tables with the for various latitudes.
- WinterShadow 42 degrees
- WinterShadow 38 degrees
- WinterShadow 36 degrees
- WinterShadow 34 degrees
- WinterShadow 32 degrees
- WinterShadow 30 degrees
- WinterShadow 26 degrees
- WinterShadow 22 degrees
- WinterShadow 18 degrees
- WinterShadow 14 degrees
- WinterShadow 10 degrees
We also created on for thelatitude of Nimbin.
Effect of Shade
The demonstration "Effect of Shade on Solar Panels" was developed and is hosted by Barry Miller.