Anything that blocks sunlight from your solar panels, such as tree branches, dirt and leaves can reduce your energy output. The Solar Electric Power Association (SEPA) states that energy output can be decreased by about 10% due to dirt and other residues. In areas with heavy bird droppings, pollution, dust or pollen, the efficiency can decrease as high as 15-20%. Sun City Solar recommends you clean your solar panels as part of your regular home maintenance. Clean panels will also maximize your investment and allow you to use all of the energy output available.
For convenience, hosing off the solar panels should get them clean enough to improve efficiency. However, if cleaning the solar panels requires more than a hose (for bird droppings and such), you will need to manually clean the solar panels with a brush and water.
To clean your solar panels manually, here are some factors to consider:
- It is recommended you NOT use soap and use SOFT water where possible. Hard water (with a high mineral content) can eventually build up heavy deposits.
- Never climb onto the array – use a soft brush with an extension pole. Boat cleaning brushes (around $30) are the best. Boat cleaning brushes are designed not to scratch and offer flow-through handles which deliver water right to the bristles.
- If chemical cleaning is required, use a detergent that will not damage aluminum. Many domestic detergents can damage panel frames and clamps.
- For large arrays, a commercial window cleaning system is advised. These brushes can extend up to 30′ and will deliver deionized water directly to the glass surface to remove dirt and leave no deposits.
- Never power wash the solar panels. The high pressure may dislodge wiring or damage the shingles around the roof mounts.
Solar panels benefit from natural cleaning from rain which usually removes most of the dirt and grime. How often you clean your panels is determined by the weather in your part of the country. For areas with less dirt, it is recommended to wash them around 1-2 times a year.
There is no set time to wash your solar panels, but you may want to include the maintenance with other seasonal chores, such as cleaning the gutters or washing windows. Clean solar panels will definitely improve your energy output and put more money in your pocket. Call Sun City Solar Energy and, for a nominal fee, we will be happy to wash your panels for you.