Best Practices: Solar Panel Cleaning
A Necessary Maintenance To Optimize System Performance
By Diana Vu
March 10, 2020
Some of the most frequently asked questions we receive involve the maintenance and cleaning of solar panels. Why? How often? With what tools? Is rain sufficient?
Yes, it’s important to keep your solar panels clean. Your solar panels must be exposed to sunlight to produce power. Rooftop solar panels get dirty primarily from wind-blown dust and pollen. Just like dust gathers on your window sills and shelves, debris from the environment is constantly building up on your panels and decreasing their efficiency. Agricultural areas, where pollen, dust, and other airborne particles are common are even more susceptible to potential production issues.
Benefits of cleaning
We highly recommend getting a cleaning with an annual inspection and cleaning to keep your solar system operating at peak performance. We also suggest hiring a professional to perform the cleaning for your system. Safety is the main concern, since getting on your roof without the proper safety gear and experience is extremely dangerous.
A trained professional will also be able to spot potential issues that affect the health and performance of your system as well as assess any damage to the system to recommend the next steps. Cracks, hot spots, delamination, and nests can greatly affect production. In some cases, issues that arise from homeowners cleaning panels themselves can result in voiding your warranty.
Determining how often you should clean your panels
How often solar panels should be cleaned depends on several factors. Your location and climate play a major role. For example, areas where there is steady rainfall do not need to be cleaned as regularly. Another factor to consider is the amount of wind-blown dust in your area. Also keep in mind the pitch of your panels, since steeply tilted panels will stay cleaner longer than horizontal panels.
Believe it or not, the type of water, soap, and brushes mean everything when it comes to solar panel care. Using a de-ionized water system gives a spot-free finish that is long-lasting and more resistant to becoming dirty. Hard water deposits can leave residue and build-up over time, which will eventually affect your system’s production. Pressure washers should never be used, as the pressure could damage your panels and roof shingles.
For panels that are tilted at around 5 degrees or less, the use of a squeegee will ensure that no water is left behind on the panels. Leftover water could leave a puddle of muddy debris along the lower edge of the panel, and once dry, can accumulate a thick layer of dirt along the lower row of cells. Depending on the design of the system, this can cause a decrease in output.
Though we strongly recommend using a trained professional, the choice is up to you. At Solar Negotiators, we’re here to be a resource for you so you can make the best decision for you and your family. For homeowners who decide to clean their panels themselves, here’s a quick video of what we feel are the biggest DO’s and DONT’s when it comes to cleaning your own panels, or check out the list below.