According to the Department of Energy Efficiency, solar panels work when the suns energy is absorbed by photovoltaics (PV) cells, which are in the panels that you use.

When the panels receive more sunshine, they generate more power.

In Southern California, a lot of dust, dirt, pollution, bird poop, and other debris that rain doesn't wash away, covers your solar panels which results in less power being generated due to less sunlight reaching the PV cells.

Solar companies claim that you will save a certain amount of money on your home or business by adding solar panels, but that is based on the performance of clean solar panels.

When dirt, dust and poop cover your panels, it has a significant effect on your panels reaching that calculation.

This is why it is very important to have your solar panels cleaned at least every 3 months so you can maintain your return on your investment!