These are some good solar panel services in California Window And Solar Panel Cleaning by Vin Ruiz. SPD Solar Cleaning & Services. Aikyum Solar LA Elite Window Cleaning. LA Solar Cleaners. Solar Panel Cleaning By Brandon Miller. Cimco Solar Cleaning. The average cost for cleaning solar panels is around $150. Depending on various different factors like roof slant, solar system size, size of your house, etc, companies charge between $4 and $10 per solar panel. Some charge a flat rate within a range of $150 to $350. Annual inspections are typically $150 before the cost of cleaning.