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Took me 6 months to figure out my solar panels were shading each other
I installed three panels on my roof in Denver last spring but my energy output stayed flat no matter the weather. After 6 months of checking inverters and cleaning dust I finally noticed the roof vent pipe cast a shadow that hit the middle panel right at peak sun. Has anyone else discovered a simple layout issue that wasted months of your time?
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kevin_sullivan5d ago
Three panels on one string? Sounds like you might have wired them in series. That makes shading way worse because one shaded panel drags the whole string down.
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grace5655d agoTop Commenter
Is it really that big of a deal though? I have three panels on one string and they work fine most of the time. Sure, if a leaf covers one panel the whole string slows down, but it doesn't happen often enough to worry about. Plus series wiring keeps the voltage up, which helps with long cable runs to the inverter. I think people get too hung up on this shading thing when their setup isn't even in a shady spot to begin with.
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leor374d ago
Series wiring three panels is fine for voltage but one bad panel kills your whole production. People always say "it works most of the time" until they get a single afternoon of shading and their system drops to zero. That string stops making power completely when something blocks one panel. Parallel wiring avoids that problem entirely by letting each panel work independently. You lose a little on voltage but you don't lose everything when a shadow hits. Just depends if you want reliable production or just acceptable most days.
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