Although the glass on residential solar panels and commercial solar panels is extremely robust – much more so than regular glass – it is unfortunately still breakable. The glass on photovoltaic panels is designed to withstand rough weather and extensive use, but certain situations can compromise the module glass and, as a worst-case scenario, cause it to crack.
There is a range of mistakes that some solar owners tend to make when maintaining their solar system. One is attempting to clean their rooftop solar panels by themselves. Solar panel cleaning may seem like a simple task – one that you can do using just your garden hose. However, cleaning solar panels with a garden hose is one of the most common causes of damaged solar panels.
In the summer, solar panels get hot from the sun. Spraying cold water on them can result in what is called ‘thermal stress.’ Glass is by nature brittle, so when the glass experiences an extreme change in temperature, the material cannot accommodate fast enough – and it cracks.
It is rare to crack a solar panel in one single event (this is called ‘thermal shock’). However, over time many cycles of thermal stress can cause solar panel glass to crack in a phenomenon called ‘thermal fatigue.’ This thermal fatigue is a real threat to long-term panel performance and warranties. The best way to clean your solar panels is to do it at night as recommended by panel warranties when the panels are at their coolest to avoid thermal fatigue.
Even if you are happy to get up in the early hours of the day or late hours of the night to give your panels a good rinse, it is still recommended to avoid cleaning your panels yourself. Unfiltered water can damage the panels through lime-scale build up over time. On top of that, it is safest to avoid having people walk on your roof – whether it is yourself or someone else. The safest and most efficient professional solar panel cleaning is an automated cleaning system. An automated cleaning system means no people on your roof, scheduled cleanings at night while you are sound asleep, and clean, filtered water to protect your panels.
Not being aware of what can potentially make the solar panels crack can be intimidating and make some solar owners refrain from maintaining them all together. “Do I need to clean my solar panels” is therefore a question many solar owners have asked themselves. The answer is yes, solar panels absolutely need to be cleaned! Dirt will cause production to decrease significantly, so keeping the panels clean is important for optimal performance. In addition, panel manufacturers require that the panels be maintained in order for the warranty to be valid. But you should not clean your panels yourself.
Dirt on your panels can build up in only a few days, so to keep your panels clean and thus performing optimally, solar panels should be cleaned a few times a week. This of course depends on where you live and how dirty your panels get. Some geographical areas may require more frequent cleaning than others, but the rule of thumb is 1-2 times a week.