This question is part of the Super Big Solar Panel FAQ from Solar Mango, where expert answers to over 100 important questions on solar panels are provided.


Good question.

At Solar Mango, we frequently visit both rooftop and ground mounted solar farms, and we have seen how the simple act of cleaning the solar panels has been a rather inconsistent act.

In some well maintained solar farms, we have seen that they clean the solar panels at least once in a month, some times a bit more frequently than that.

Now, there are blokes who claim that solar panels need little or no cleaning. Their reasoning is that, firstly, frequent rains will any way clean most of the dust and dirt, and secondly, the amount of generation lost due to dirt and dust on the glass might not be significant effort to put in major efforts into cleaning.

Well, at this point of solar power plant evolution, there are not too many data sets to prove or disprove the above claims for all conditions.

What we however know is that there are many regions worldwide which get rains only for one or two months in a year. It is difficult to accept the reasoning of panels being cleaned by rains, for these regions at least.


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On the extent to which generation could be lost owing to dirt and dust cover, Solar Mango has the opportunity to analyse this at close quarters for one of our business acquaintances who had an industrial rooftop solar installation near New Delhi, India.

In one of the worst cases of solar power plant maintenance, we saw how a rooftop solar power plant had not been cleaned AT ALL EVEN ONCE for one and a half years after it was installed. Naturally, it had generated about 25% less overall during this period than a nearby rooftop solar power plant of equal capacity, but which was cleaned regularly.

Sure, this is a data set from just one solar power plant installation, but if it stands to reason that there will be a reasonable amount of generation loss if the solar power plant were not cleaned at all for months together.

All these make it clear that regular cleaning of solar panels is a critical activity

So, what should be the frequency of such cleaning?

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.

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