Shade: The Enemy of Solar

Shade is a natural enemy of solar power. Although trees are aesthetically pleasing and provide shade to cool the home, they have detrimental effects on your solar system’s production. There are solutions to keep that shade from blinding your solar panels.  You can eliminate the shade altogether or minimize its effect. If trees are the issue, the easiest short-term solution is to remove the tree or eliminate the shade by trimming them. With other situations including chimneys, vents, and other roofs the best solution is to minimize the effect of shade with a microinverter.

A solar system needs direct sunlight for optimal performance. Shade will jeopardize that performance. In simple terms, shade means there is less sunlight reaching your panels. On a more technical level, it involves how many fewer photons can reach the shaded solar panels and less photons reaching any single solar cell means less electrons that are generated and transferred on.

That’s where a microinverter is preferable, as it will reduce production loss by minimizing the effect of shade. The newer microinverter technology allows each panel to perform independently of the panel right next to it. By placing a microinverter onto the back of each panel, the panel(s) covered by shade will be the only one(s) experiencing a production loss, while not bringing down the production of neighboring panels. With microinverters, the inversion of the electrical current from DC to AC happens on the roof increasing panel efficiency.

Alternatively with a single inverter, shade cast on a single solar cell will not only affect the production of its respective panel, it will have a significant effect on the output of the entire string of panels. The reason is when panels are wired to a single inverter, they are on a closed circuit system and will only perform as well as the lowest-performing panel. The shaded cell will have a reduction in the number of electrons it can generate and send from one side to the other. Because they are not passing as many electrons to neighboring panels now, production on the entire string comes down.

There is no simple equation to determine how shading on a portion of a panel can proportionally effect the production of your system. However, with a Clean Solar evaluation at your home, we can forecast sun and shade patterns on your roof for the entire year. Eliminating shade altogether may not be an option, but with microinverters, you can optimize solar electricity production from the solar system on your roof.