Know Your Solar: Angles Matter

Solar panels work based on a principle called the Photoelectric effect. As sunlight hits the solar cells in the panel, it excites electrons and causes them to move. This movement of electrons is the electricity we collect. To increase the amount of solar energy we collect, we have to position our solar panels where they can absorb the most sun.  

But the sun is constantly moving!  

If you have a fixed roof-mounted panel, you roughly get about five hours of decent exposure when the sun is directly over the panel. Overland Solar panels are designed to be easy to maneuver. All you need to do is follow these simple steps to optimize and collect solar energy from sunrise to sunset:

  • At night: Point the panels towards where the sun will rise at an angle before you go to sleep
  • Mid day: Move the panels to be directly under the sun
  • Mid afternoon: Readjust the panel to continue getting direct light as the sun sets.

By moving the panel throughout the day, you continually get direct light and can expect to get more than 12 hours of direct sun in the summer and about 8 hours of sun in the winter.  

A direct comparison has estimated panels that track the movement of the sun throughout the day can receive 10% (in winter) to 40% (in summer) more energy than fixed panels.  

To put this in terms of solar systems you may be considering, the Overland Solar 90 Watt panel will provide more power to batteries than a large 200 Watt fixed roof system!

Now, to get really fancy, you can calculate the direction and angle the solar panel should face for complete optimization.  We like the “Solar Electricity Handbook” site that has a nifty calculator.

For a quick and dirty guide:

  • In the Summer, take your approximate latitude and subtract 15 degrees.
  • In the winter I suggest keeping the panel at 45 degrees in the US.
  • I have a cheap angle finder from Home Depot with a magnetic base for about ten bucks.