Photovoltaic, or solar, panels are designed to endure for at least 25 years with normal use. There are still numerous solar panels operating at or over their designed capacity that were placed in the 1980s. 1 In addition to being very dependable, solar panels have seen a significant rise in lifespan over the last two decades. 2 Many solar manufacturers provide warranties that not only ensure their devices will work well for decades, but also provide a performance guarantee.
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Do not assume that since solar panels have a long lifespan that they will continue to generate power for another couple of decades after being installed on your roof. Just know that their energy output will drop by the amount that solar panel manufacturers think necessary to satisfy the demands of the typical American household.