Solar Panel Degradation: What It Actually Means for Your Energy Bills
A solar panel installed today will not produce the same output in year twenty as it did on day one. That’s normal, and it isn’t a sign of a faulty system. It’s called degradation, and every panel on the market experiences it in some form. The number that matters is how much it degrades each year and whether the installer chose panels and mounting conditions that keep that number low. Get that wrong and a system that looked good on paper can underperform its projected returns by a noticeable margin over 25 years. What Is Solar Panel Degradation? Solar panel degradation is the gradual drop in a panel’s power output caused by exposure to sunlight, heat, humidity, and mechanical stress over years of operation. The silicon cells, the encapsulant layer, the wiring, and the junction box all age slowly, and each contributes a small amount to the overall loss. Manufacturers account for this in their warranties. A typical performance warranty guarantees around 90% of rated output at year...