Shadows crossing the panel: Throughout the day the sun moves across the sky and with it shadows move across the ground and potentially your solar panel. Shadows are very deceptive in relation to where they will be cast throughout the day. There are two ways to determine if a shadow will cross the panel: watch it throughout the day or use a solar pathfinder. As the sun gets lower in the sky during the winter months these shadows grow longer and vice versa during the summer months. We recommend watching the panel between 11AM and 3PM every hour on the hour, which is the optimal exposure window of solar radiation that a solar panel uses. Although this varies depending on your geographical location. For instance, if you live in a mountainous area the sun will set at an earlier hour than compared to a plain region. ANY form of shadow on the panel at all will cease the panel from operating correctly. 

Incidence of Angle to the Sun: You may receive light from 8AM to 5PM, but in the morning and evening most of the solar radiation needed to drive the solar panel is refracted off of the earth's atmosphere. A certain wavelength of light is needed to drive a panel to produce power and can only permeate the atmosphere when it has a more direct exposure in relation to your geographical location. During these times when solar radiation can permeate the atmosphere is known as solar exposure window. There is a connection between the incidence angle of the panel and the solar exposure window. If your panel's angle is too high, then not all of the light needed actually hits the surface of the panel. If your panel's angle is to low then most of light needed reflects off of the panel’s surface and isn't absorbed. A good rule of thumb is to angle your panel from horizontal to a degree of your latitude plus 15 degrees in winter or minus 15 degrees in summer.

Orientation: Orientation is important because the sun moves across the sky but not directly above. If you live in the northern hemisphere then the sun moves across the sky in the southern hemisphere. If you live in the southern hemisphere then the sun moves across the sky in the northern hemisphere. The sun stays more directly overhead the closer to the equator you live. Therefore for best panel orientation you will have to position your panel so that it faces true south (not magnetic) or true north, depending on which hemisphere you live.

In conclusion, be cautious of your panel’s placement by observing it during the recommended time for shadows. Keep in mind that as the seasons change so do shadows. Face your panel true south (not magnetic) if you’re in the northern hemisphere or true north (not magnetic) if you’re in the southern hemisphere and angle it so the energy is absorbed, not reflected.