The Best Location and Orientation for Solar Panels

How well solar lights perform depends largely on how much power they get from the sun. We all hope the sun shines strong all year round to keep the lights bright every day, however, sometimes things are just out of our control. So, what can we do to get them as much power as possible no matter what weather it is? That is, to set them at the best place in the best way.

Best Location - No Shade, No Shine
Solar panel converts solar energy to electricity when it is set in the sun. For the best performance of solar lights, their solar panel should be exposed to direct sunlight without being shaded by anything like trees, eaves, roofs, etc. If the solar panel is in shadow, partly or completely, solar energy will be blocked, hence less power to be transferred to the battery. Long-time undercharge will result in shorter working duration at night and even permanent failure when damage to the battery is irreversible.

Another concern is other light sources around the solar panel. Most solar lights work in a dusk-to-dawn way as the solar panel connects to a photosensor. They stay off when the sensor detects high brightness and turn on when the environment goes very dark. If the solar panel is in the reach of other light at night, the solar lights will not turn on themselves in nighttime.

For solar fixtures that come with detachable solar panel, it’s best to set somewhere high like up on or along roofs or eaves, preferably with no trees or anything higher around the spot. For solar lights designed to install at lower locations, like step lights, it is inevitable for them to be shaded partially or momentarily. Just make sure they’re not fully covered by shadow throughout the entire day.

Bad Examples:
1.Although solar panels in below pictures are set up high, there’re something higher around it — the tree behind and the protruding roof, which makes the locations imperfect.

2.With a super strong light behind, this environment is too bright to trigger the step lights on.

Best Direction - Face South
In the northern hemisphere, south-facing solar panels trap most energy throughout the year. Why it has to be the south? The sun moves east-to-west so facing either direction would end up a west-facing panel shaded in the morning and an east-facing one being in shadow as the afternoon comes. Then leave us no choice but the south and north. In the US where most territories are above the tropic of cancer, the sun is always at the south all over the year. That's why facing south work best whether it is summer or winter.


Best Angle - Tilt 30-45°
The best tilt angle of solar panel roughly equals the latitude of the installation location. If you live in California at 36°N, for example, the solar panel should be tilted about 36°towards the south. Yet, not all solar lights can be set this way, like those dock lights that lie flat on the ground. When the sloping position is not available, laying them horizontally facing up to the sky is the best alternative. Never goes with a 90° vertical installation or even face downward as the below images show.