Hi, K here revisiting solar panels from our previous series on photovoltaic systems. Recently, I noticed several systems set up, some by professional installers, with the solar panels at angles that are too steep for this latitude. So I figured I should write a post on the best angles for your panels to intercept the most sunlight.

If you’re in the northern hemisphere of the Earth, remember to always face your panels to the south. To figure out what angle to set them at, you need to consider the tilted axis of the Earth and the resulting seasons, and where you are on the globe. During the winter, the Earth’s northern hemisphere is tilted 12° away from the sun.  So the best winter angle would be your latitude + 12°. During the summer, the northern hemisphere is tilted towards the sun, and the best angle for the panels is your latitude – 12°. At these angles, the solar panels will intercept the most sunlight throughout the year. 

If, like me, you don’t want to change the angle throughout the year, you can set it at the winter angle. That way you maximize intercepted sunlight when days are the shortest. For the central U.S. (going north to south), the latitude is around 38°N. So the winter angle would be about 50° from the ground to the solar panels.

This panel placement may seem trivial, but it becomes really important during stormy days and the shortest winter days where every little bit of energy production counts. Remember, drawing your batteries down too low will irreversibly damage them.

Next blog post: Part 1: Preparing for winter (by Phoenix)