Cleaning your solar panels will increase their efficiency.
Solar panels usually require a small maintenance service because they don’t have moving parts, but if they get dirty, you need to clean them up in order to keep the solar energy production at full capacity.
Keeping the solar modules clean is vital if you want the system to work at the maximum capacity because dirty panels will always have a reduced production of clean electricity even if the sun is up and shining.
Cleaning the solar modules is a service that can be done by yourself if you have a nice flat rooftop with easy access (plenty of room to walk between the panels), otherwise you can leave that to the pros in order to avoid a possible accident.
Solar panel cleaning at home
For you as homeowner and the payer of the bills it is very important to have the solar PV system working at full capacity.
Your solar PV (photovoltaic) system cannot convert into clean electricity more than 21% of the sunlight received (if you have a good system), so it is vital for you to have clean panels all the time to fully benefit from the technology that you paid for.
Before cleaning the panels, you need to check a few things:
1. You need to clean the panels if they are dirty and if you see a drop in energy production
Dirty or covered panels will always produce less power because the sunshine is obstructed from reaching the panels by the dust, sand, dirt, bird droppings, leaves, branches, snow, etc. that could land on the panels.
You always need to visually check your panels (if possible) to avoid any drop in energy production.
2. Before starting, always read the manufacturer manual to see if there are any specific recommendations for the cleaning service
There are solar manufacturers that have specific recommendations for cleaning the panels.
They may advise you to not use certain chemical substances or tools to avoid any damage made to the panels.
3. Always wash the solar modules during the morning or late in the evening
You don’t want to see water beads drying on the glass of the panels, and you also don’t want to spray cold water on very hot panels because they could break.
4. Use sturdy shoes with good grip when climbing on the roof
Walking between the panels on a rooftop that is wet or slippery could be very dangerous for you, so always wear good sturdy shoes that stick well to the roof to avoid any slippage.
A hat that protects your head from the sun and also provides shade is also welcome.
5. Cleaning the panels requires only water, soap and a few tools
If your solar panels are only covered by leaves or branches it is enough to remove them to solve the problem.
However, if the panels are covered by dust, dirt and bird droppings, you will need besides water, a scrub brush and some soap.
To get water, you need to pull the garden hose up on the roof.
The scrub brush used to clean the panel needs to have soft bristles to avoid any scratches on the panels, and also a long pole.
A wide squeegee with long pole is also a useful tool when cleaning the panels.
6. How to clean the panels
In a bucket with some water, put a little soap only to get some bubbles and to be able to clean any sticky dirt or droppings from the panels.
The first thing to do is to take the hose and spray some cold water on the panels starting from the top (do the cleaning only in the evening or early in the morning), this will cool down the panels.
When the water flows down from the panels be careful not to slip and fall from the rooftop.
Be aware of where your feet are all the time, especially when working on the roof.
Take the scrub brush and put it in the soapy water from the bucket and then start to rub the panels looking for any bird droppings or sticky dirt sitting on the panels.
Brush the panels very well and remove any dirt (even using your fingernails if needed), and after that take the hose again to rinse the soap off the panels.
To finish cleaning the panels, take the wide squeegee and starting from the top to the bottom remove all the water from the panels.
7. How often you should clean the panels?
You can clean your solar panels once a year (you don’t need to wash them more often), don’t forget that the rain is also cleaning them (sometimes even better than you).
Cleaning the solar modules only once a year it means that they require only a small maintenance service.
However, don’t forget that a clean solar panel will always perform at maximum capacity, while a dirty one will have a diminished energy production.
8. What is the difference between a clean solar panel and a dirty one?
After numerous tests made by different individual homeowners, a solar panel (both poly and monocrystalline) can lose about 20% of its generation capacity if it’s dirty.
Multiply this percent with the installed power of your PV system and you will realize that you need to keep the panels clean all time, to avoid any loss in power production.
Cleaning large solar panels at solar farms
Large solar farms cannot rely only on people to clean the panels because there is a very large number of panels involved within the farm, and because using a cleaning robot that is self-sufficient is more practical and more efficient.
Such a robot doesn’t need water to clean the panels (this is vital in very arid areas of the planet), the robot relies only on fast swinging microfibres that are brushing the dust down from the panels.
The robot is called E4 and is produced by Ecoppia, a privately held company with the headquarters in Asia & the Middle East.
The robot is self-sufficient because it uses its own solar panels to generate energy and operates at sunset and overnight to not interfere with the energy production.
A clean solar panel is more efficient than a dirty one, which means that for solar farms keeping the panels clean is a vital condition to ensure that the solar power plant operates at maximum output.