One of the most common questions we receive from both prospective and existing clients is whether or not solar panels require manual cleaning.
The answer to this question is no, you do not have to regularly clean your solar panels to avoid major performance loss. In Arizona, the rain received throughout the year is sufficient to remove natural residue build up on rooftop solar panels. Numerous studies have been conducted, including a recent investigation at the University of Arizona*, showing a minimal (2%) increase in annual energy production from frequent cleaning of panels.
If you do, however, decide to clean your solar panels, it is best to take proper precautions to avoid causing thermal stress to the modules. It is recommended that you rinse only with water, and avoid cleaning at times that will drastically effect the temperature of the modules. Always avoid splashing hot solar panels with cold water. It is best to wash during the early morning before the panels begin absorbing heat from daylight to ensure that a rapid temperature reduction is not sustained. A light rinsing with water to clear away natural debris and dust buildup is all that is needed to return your panels to their maximum efficiency, and further maintenance - such as scrubbing or wiping - is not recommended.
At TFS, we maintain pro-active data monitoring of all solar installations, allowing us to track system production and alert a customer to any issues or potential red flags in their generation levels. Data monitoring is also available on the client’s end as well, providing easy access to generation levels at home. While solar panels are very durable and require little to no cleaning upkeep, occurrences such as power outages can occasionally result in a need to manually re-establish connection between your home and your solar system, which our data monitoring allows us to keep aware of, frequently resulting in a prompt diagnosis, repair, and follow up before the client notices.
*University of Arizona study: http://uapv.physics.arizona.edu/publications.php