Solar panels are known to be an efficient and environmentally friendly source of energy. That, and seeing big savings on electricity, are the main reasons they are so popular today. 

But not many people are familiar with the ins and outs of solar panels. Which leads to a lot of questions.

Maybe you already know that a solar panel has cells that allow it to absorb solar energy coming from the sun. The absorbed energy will then be converted into an electric current, mostly alternating current. 

But what if the solar panel itself is dirty? Will that hurt its ability to absorb light from the sun and make the panels less efficient? Or will it still function like brand new if you just leave it be? 

If you’re wondering, do solar panels need cleaning, you’re in the right place!  

Do Solar Panels Need Cleaning?

Solar panels generally do not need to be cleaned. However, yes, it usually is a good idea to clean your panels every now and then. Keeping them clean can help them maintain their efficiency. 

Much like a shade, dirt can get in the way between your solar panel and its source of energy, the sun. When this happens, less light is able to reach the solar cells, affecting how efficient they convert light to electric power. 

It is unavoidable for a solar panel to get dirty. The most common types of dirt that get on the solar panel and affect their efficiency are: 

  • Bird droppings
  • Pollen 
  • Dust
  • Ash 
  • Calcium
  • Limestone
  • Soil
  • Sand
  • Silica

Air pollution creates a form of dust that can affect a solar panel’s performance. How much your panels efficiency is affected depends on a few factors such as the type of solar panel as well as the type and amount of dirt. 

How Much Does Dirt Hurt Solar Panel Efficiency?

This all said, usually dirt doesn’t cause that big a drop in panel efficiency. The average decrease of solar panel efficiency due to dust and dirt ranges from 1.5 percent to 6 percent. But in places where pollution is higher, dirt can decrease the efficiency of solar panels by up to 50 percent! 

However, some reports show the effect is much less than this. One study by the University of San Diego suggests that less than 0.05 percent of the solar panel’s output is decreased due to dirt and dust. 

However, efficiency is not the only concern when it comes to dirt. Dirt can also harm the solar cells themselves. Traditional solar cells shaded by accumulated dust and dirt will act as a resistance to the power generated by other solar cells. 

As a result, the shaded cells can heat up and damage other cells. It’s really not that common of an issue, but it can occur.

How To Keep Your Panels Clean

If you live in an area that gets a lot of rain, you are in luck! Even a fairly light rain will wash the dirt off your solar panels. 

But sometimes dirt is stubborn enough so that it will take more than rain to get them clean.

You can try cleaning the solar panels themselves. However, experts recommended paying a professional to do it. That said, you have to decide if that is worth the cost or not. It may be that you will not save enough in improved efficiency to cover the cost of a professional cleaning.

Cleaning your solar panels by yourself can be tricky. But if you want to give it a go, there are a few recommended ways to handle it.

One is to simply use a hose and bucket of soapy water. If you need more than that, then you can try a VERY soft sponge.

You do not want to use anything abrasive that could damage your panels in any way. You should also avoid using high pressure sprayers that could also damage panels. 

Lastly, since panels can get very hot when in the sun, it’s best to clean them early in the morning or on a cloudy day.