Since the carport solar panels have no tilt, rain doesn’t do a good job of rinsing off the dirt they collect. (Also, our carports are situated across from a sand field, which doesn’t help the situation.) We cleaned these panels for the first time after they had been in operation for 15 months, and their energy output doubled overnight. When we cleaned them again eight months later, their output instantly increased by 36 percent. In fact, we found that cleaning these panels is the #1 way to maximize the energy they produce. As a result, we’ve added the carport solar panels to our spring cleaning checklist.
According to the article, tilted panels don’t see as much of a decrease in output assuming you have enough rain to clean the dust off them every so often. This probably doesn’t apply in San Diego.
