Solar Panel Cleaning.
Why should we clean our solar panels?
We know that dust, dirt, pollen, bird droppings and other debris can negatively affect solar panel efficiency.
Google conducted a ground breaking experiment at their 1.6 MW solar farm in Mountain View, California. They found that cleaning the solar 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 satisfying 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 us to neglect solar panel cleaning?
It is reasonable to assume that solar panels can loose 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 we clean our solar panels?
In most places, there`s more pollution in the winter, which is why the 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. However, some places do require extra attention:
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.
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.