Yes, there are, and they are called self-cleaning panels.
We all know that the high solar radiation in deserts makes them suitable for installing solar panels. But deserts are also dusty which does not bode well for solar panels. Did you know that just four grams of dust per one square meter of a solar cell’s surface can reduce its energy output by 40 percent?
This is why cleaning of solar panels is done on a regular basis. But cleaning can be time-consuming, expensive and may even corrode the panel frame in extreme cases. Often, water can be the reason why solar panels get dirty. Water traps particulate matter, which in turn sticks to the panels once the water evaporates.
As a solution to this problem, researchers have created different versions of self-cleaning panels over time. There are nano-hydrophobic coatings that have been developed to keep panels clean for a longer period. Their water-repelling property is core to its cleaning ability. Some of these solutions also prevent algae formation and bird feces from sticking to solar panels.
In another effort, a team of researchers from MIT and Masdar Institute of Technology is currently developing a low-cost super coating that enhances the self-cleaning, abrasion-resistance, self-healing, anti-reflection and anti-static properties of solar cells. A multi-property solution like this sounds ambitious which also means it is challenging.
Self-cleaning panels, if commercially available, can reduce O&M expenses to a considerable extent which eventually means better returns on investment.
For most solar plants, the best way to reduce a decrease in energy generation due to dust is to perform regular cleaning of the panels.
What is usually done to abate the issue of dust (soiling) on panels?
Solar panels are generally self-cleaning, but in particularly dry areas or where panel tilt is minimal, dust and other substances such as bird droppings can build up over time and impact on the amount electricity generated by a module. Hence, cleaning of these panels become and imperative need. The frequency of cleaning depends pretty much on the amount of dust and dirt the panels are exposed to. Several interactions with project developers make Solar Mango suggest a cleaning pattern of once every two weeks for optimal output. To clean a solar panel requires more than a once over with a feather duster- only a good wipe with water does the job. Typically solar facilities use distilled water for washing the panels to avoid mineral scale deposits that might interfere with capturing the Sun’s rays.
So, what should be the frequency of cleaning solar panels?
Based on our research and interactions, we would say it is best to clean the solar panels once every two weeks. This could be especially useful for small rooftop solar installations that are located in dusty areas. If a fortnightly cleaning is challenging for any reason, ensure you clean the panels at least once a month. It is appreciated that there is a cost attached to cleaning solar panels – either a tangible monetary cost or cost in terms of time consumed. But done at optimal frequencies, we at Solar Mango feel that solar panel cleaning provides good returns on this investment.