How to clean solar panels
- The first thing you want to do is to check with your solar panel manufacturer. They might have specific recommendations for cleaning.
- Solar panels can become incredibly hot in the midday sunshine. Either clean your solar panels in the morning/afternoon or pick a relatively cool day.
- First, try your garden hose to see if it alone does the job. If a lot of dust and dirt have accumulated you might need to clean more thoroughly.
- Fill a bucket or spray bottle with warm water and soap – no other special equipment is needed.
- Clean the surface of the solar panel with a soft cloth or sponge. You do not have to clean the wiring underneath.
Why should I clean my solar panels? We know that dust, dirt, pollen, bird droppings, and other debris can negatively affect the solar panel's efficiency and can even lower your power production up to 20%.
Google conducted a groundbreaking experiment at their 1.6 MW solar farm in Mountain View, California. They found that cleaning the solar panels was “the number one way to maximize the energy they produce.” Cleaning solar panels that had been in operation for 15 months doubled their output of electricity.
The same study also found that rain is not a satisfactory way of cleaning solar panels. Solar panels that were cleaned professionally had a 12% higher output of electricity compared to those cleaned by rain.
How much money would it cost me to neglect solar panel cleaning? It is reasonable to assume that solar panels can lose 15-25% of their efficiency if not cleaned properly. This literally means that they will generate 15-25% less electricity, which you now will have to source from the utility company at their price rates. This easily adds a couple of years extra on the payback time.
How often should I clean my solar panels? In most places, there`s more pollution in the winter, which is why spring is a good time to do an annual cleaning. Solar panels that are cleaned once and twice a year produce 3.5% and 5.1% more electricity respectively than those that are left uncleaned.[3] However, some places do require extra attention:
In the southwest region of the U.S., where rainfall is limited for several months at a time, the accumulation of dirt is far greater. Solar panels that are installed near sources of pollution such as freeways, factories, and airports need to be cleaned more often. Other special cases to consider include autumn and winter, where the removal of leaves and snow is important for optimal performance.
Another thing to note is that rainwater has an easier time cleaning solar panels that are tilted (as opposed to flat-mounted solar panels).
Here`s the best piece of advice when it comes to frequency: Monitor changes in the power output of your solar panels before and after cleaning. Experiment with different time intervals. Take note and evaluate what works.
Cleaning solar panels is not really that much different than cleaning a typical window. It is not very time-consuming either. Neglecting to clean your solar panels is not much different than throwing money out of the window. Self-cleaning solar systems are available for those lazy folks out there that are willing to spend the extra buck.