Do I Need To Clean My Solar Panels?

One of the most common questions I hear on a daily basis is, "Do I need to clean the solar panels or do any maintenance?"  It would make sense that if a layer of dirt or dust is sticking to your panel, light will be blocked and won't make it to the solar cell, rendering it useless. I have good news for you. You do not realistically need to worry about cleaning your panels for several years in more than  99% of scenarios. I have installed over 700 systems in the last 7 years and while it is one of the most common questions I receive pre installation, I almost never hear about it after installation. This is because we have monitoring production data which verifies that production isn't substantially dropping more than the normal .25-.5% each each. Unless your system is visibly dirty and you see a drop in production, cleaning your panels will more often than not be more costly do clean than the value of the increased energy production you will see. 

Large ground mount commercial and utility scale systems are more oftentimes cleaned since small percentages in production drop is a more substantial amount of kWh and panels that are most likely on a ground mount out in the desert will experience more dust build up. 

A note about this topic is that PPA and Lease salesman will commonly use "maintenance liability" as a fear tactic to make you more attracted to the PPA or Lease option. In reality, Sunrun or the leasing company is NEVER going to come clean your panels or something like that in the event your system is not producing as much as they expected. If anything breaks it is under warranty. Sunrun PPA  salesman make it sound like there is going to tons of maintenance costs that you will have to absorb but it is simply not true when the truth is realized that the only potential time the system would need to be worked on is in the event of a warranty claim which would be taken care of with a purchased system.