Why Are Solar Panels Tilted?

Have you ever seen a solar panel farm in real life? If you have, you may have noticed that they are not installed flat on the ground. Instead, they are slightly tilted upwards, facing wherever the sun rises, depending on their location. Solar panels can produce the most energy when they receive the most solar radiation [3]. To maximize this radiation amount, the solar panels must be directly perpendicular to the solar rays they receive [1]. The same is true for the opposite case, where solar panels produce the least output when solar rays are parallel to them.

There are several factors to consider when determining the optimal tilt angle for solar panels, but arguably, the most important one will be the geographic location of the site. One general rule of thumb is that the tilt of the solar panels must be the same as the site’s geographic latitude [2]. So, for example, in the case of the Philippines, which lies near the equator at 14° to 15°N latitude, it would be best for the solar panels to be tilted at an angle somewhere near or between those two values. 

Some systems implement programs that adjust the tilt of the solar panels according to the time of the day and year. These solar panel backtracking systems utilize motors and a tracking program that determines the sun’s location and computes the optimal angle at which the solar panels should be tilted. However, these systems are more expensive than the usual installations, and more parts require more maintenance than the usual setups [2]. 

That is why computing the optimal solar panel tilt is very important. It would allow us to receive as much energy as possible at a lower cost. Backtracking is only effective in areas where direct sunlight is much higher than diffuse sunlight. This lets them justify the extra costs of the solar farm. However, backtracking is just an option for most people. Fixed solar panel installations are enough for our case in the Philippines, and the extra costs would not be necessary.

References:

[1] B. G, “Why solar panels are installed at certain angle? ,” EcoSoch Solar, https://www.ecosoch.com/solar-panel-angle/ (accessed Jul. 27, 2023).  

[2] I. Negro, “How PV panel tilt affects Solar Plant Performance,” RatedPower, https://ratedpower.com/blog/pv-panel-tilt/ (accessed Jul. 27, 2023). 

[3] “What is the optimal orientation and tilt angle for solar panels?,” DualSun, https://dualsun.com/en/blog/installation-maintenance/optimal-orientation-tilt-angle-solar-panels/ (accessed Jul. 27, 2023).