Photovoltaic solar panels are relatively new in the UK in any number. In North America, Europe and Australia as well as many other parts of the world photovoltaic solar systems have been installed for many years and so the need for solar panel cleaning has been realised.
When you first had solar panels installed you probably did not even consider the need to keep them clean. Most panels have a glass surface just like windows and so get dirty just like windows. In fact due to the position of the panels facing upwards they are more prone to bird dropping deposits and other debris settling on the surface.
Unlike windows the panels on your roof need to have a clean and clear surface to ensure they are working at their maximum efficiency. If they are not at their optimum performance it means they are not producing the amount of electricity that they could be.
The above image shows solar panels with bird droppings that do not wash off easily with just rain. This will affect the panels performance. To reduce the problem of bird droppings you can put a plastic mesh over your TV aerial to stop birds using it as a perch and messing on the panels below.
On the roof and angled skywards the panels will attract dirt, dust, soot, pollen, tree sap and salt crystals in costal regions creating a fine layer of grime. This layer reduces the amount of light reaching the silicon cells under the glass surface and reduces the panel's effectiveness. A solar panel that has never been cleaned could be producing almost a third less power than it otherwise could be. Some have reported a ten to fifteen percent loss of solar output due to dirty panels. Boston University in the States have done some research on this and claim that as little as a few grams of dust per square metre can halve their efficiency.
From the ground the panels may appear to be clean, just like your windows. Up close however you can see the grime that has built up from the dirt and pollution in the air. A more noticeable deposit that can be left on panels is bird droppings. These tend to completely block the light from areas of the photovoltaic panel and can considerable reduce its effectiveness.
Some people may try to clean them themselves although this is not recommended. Firstly it can be dangerous trying to reach your roof without the proper equipment. Secondly you may end up damaging the panels either accidentally or by attempting to clean them yourself.
It is recommended that you hire a cleaning company that provides a solar panel cleaning service that know how to clean solar photovoltaic panels properly. Do not just hire a window cleaner unless they have specific knowledge and experience in this area. They may end up at worst damaging the panels or not effectively cleaning the panels so you end up no better off.
Hire a company that has the proper solar panel cleaning equipment
A company who is experienced in cleaning PV panels will have the proper equipment. Using standard windows cleaning tools means that they will end up leaving soap residue behind and hard water spots as any water on the panels surface evaporates.
A professional cleaner will use a water fed pole system that can reach the panels on your roof from the ground. They will use a pure water system that uses de-ionised water and a soft head brush attachment so as not to damage the panels. No chemical should be used as these can cause damage.
In the UK this is something that we do not have much experience or knowledge with. Luckily solar panel cleaning services in other countries have been established for many years and many recommend getting them cleaned twice a year. Some suggest you get them cleaned every couple of months.
For the best results the first clean should be at the start of spring as the days lengthen and the amount of sun reaching the panels increases. Later in the summer they should be cleaned again. For the UK climate this seems to be the best solution.
If you have free solar panels installed or are thinking of getting them you should check with the installer to see if they pay for getting the panels cleaned. It is in their interest to keep them running at optimal efficiency.
During the summer there may be long periods where it does not rain and the summer is when photovoltaics produce the most electricity. When it does rain some of the loose dirt is removed but more is deposited in its place. Some types of soiling such as that from birds will remain for many weeks and even months if they are not cleaned.
The best way to prove this is to record the amount of power being generated before the panels are cleaned. Get the panels cleaned and then compare the new reading with the ones that you took earlier. It is best to do this on a sunny day where the weather is pretty constant as the sun disappearing behind the clouds intermittently is going to affect the results.
At the moment for residential installations the most practical and proven method is to just get them cleaned regularly. There are special coatings that can be applied to the surface of the panels which claim to prevent dirt from sticking. If you are going to go down that root you need to make sure you check with the panel manufacturer first.
There are other systems that are not really practical for residential systems such as spray systems built into the roof that regularly hose down the panel. There are even solar panel cleaning robots that can clean them. There is also a system that uses an electric charge to lift the dust of the surface of panels.
Your solar system represent a significant investment of capital. Allowing your solar modules to get soiled due to airborne particles, bird droppings, leaves etc. can greatly reduce your electricity output.
Additionally, by not cleaning your solar system at all, you may not only risk losing a significant amount of electricity output, but you may risk losing your modules too.
Indeed, certain airborne particles may be quite abrasive and scratch the surface of the solar modules, causing permanent damage when they are not removed. Other organic deposits (e.g. windborne dirt, bird and other animal droppings, urban pollution (e.g. soot from burning coal or diesel), as well as decomposing organic plant matter from leaves, pollen, etc., can become wet and cause potential corrosion.
Allowing dirt to build up, can also lead to local overheating inside the solar modules, so called hot spots. Hot spot heating occurs when a single cell in a series string generates less current than the module, because the cell is shaded (as a result of dirt build up) or otherwise damaged. Hot spots are parts of your solar modules where heat is produced instead of electrical power. These hot spots not only decrease the energy efficiency of your solar modules but they can also reduce the their life time significantly.
It is clear that the economic benefit of increased production and preserving the lifetime of the panels greatly outweighs the cost of periodic maintenance of the PV modules surface.
Soiling of solar module surfaces is a complex phenomenon varying by climate, environment and location. A surface in a dry desert-like location will be subject to electrostatically attracted inorganic materials, a surface in a coastal area will be subject to salts and rain driven dirt, and a surface in an industrial and cooler location will be subject to organic windblown dirt, deposits from evaporated rain and atmospheric pollutants from fossil fuels.
Generally, soiling of an exposed outdoor surface (such as a solar module) will be a mix of organic and inorganic solids. Some of these solids will be windborne whilst others will be deposited from evaporated liquid (rain water, dew, fog).
In very dry and desert like environments, most of the module soiling may be inorganic windborne solids (dust and dirt particles) that are electrostatically attracted to the solar module’s glass surface as a result of dry winds. Additionally, some of this dust may consist of abrasive inorganic minerals (e.g. silica) which may scratch and damage the surface of the modules.
In more cooler and wet environments, most of the module soiling may be organic deposits including windborne dirt, bird and other animal droppings, pollution (soot from burning coal or diesel), as well as decomposing organic plant matter from leaves, pollen, etc. When these materials become wet, they may be spread over the panel surface and further bond to it, causing potential corrosion and leaching of irons. In coastal areas, there may be salt deposits on the panel’s surfaces resulting from water spray and rain driven dirt.
The frequency by which solar modules should be cleaned is of course dependent on the location and environment in which they are placed.
However, the presence of heavy industry nearby, coastal areas and heavy bird populations may warrant more frequent cleaning to assure optimal output and maintenance of your solar modules.
For solar modules placed in more dry and desert like environments (subject to more dust) it is recommended to have the solar panels cleaned on a more periodic basis (e.g. on a monthly basis).
Rainfall alone does not suffice to properly clean and maintain your solar modules. Rain can remove some dust and dirt off the solar modules as a result of their smooth surface and tilted position. However, rain cannot deal with all dust and dirt and it is not an effective means to remove the contamination from bird droppings, chemicals, acid rain and other air pollution. Additionally, rain may itself leave mineral deposits on the solar modules after evaporation. Consequently it is highly recommended to use a proper and specifically designed cleaning product like Solcleaner, which provides an all-in-one solution for all kinds of contamination.
Although PV systems and their output have been well studied and statistically measured over the last 25 years, the effects of module soiling on performance have only recently been the subject of scientific analysis.
It is a scientific fact that any object or element preventing photovoltaic cells from being exposed fully to the sunlight will decrease their output. International scientific research shows that the yield of solar panels is reduced by 3% to up to 15% on an annual basis as a consequence of soiling!
A study of the Netherlands Organization for Applied Scientific Research (TNO) has showed a decrease in energy production of 4,4% to up to 7,7% in 1 year caused solely by pollution. A 12 year lasting scientific research study by Mr. H. Haberlin proved a similar result. According to the Solar Electric Power Association (SEPA), photovoltaic electricity output will decline approximately 10% due to accumulation of dirt, dust, and other residues. Further research by the US based Solar Electric Power Association (SEPA) indicates that PV electricity generation will decline 15-20% in areas where bird droppings, urban pollution or dust from farming operations are common.
Individual dealers have even reported losses as high as 25% from some customers who neglected to ever clean their solar modules.
When you first had solar panels installed you probably did not even consider the need to keep them clean. Most panels have a glass surface just like windows and so get dirty just like windows. In fact due to the position of the panels facing upwards they are more prone to bird dropping deposits and other debris settling on the surface.
Why do solar panels need cleaning?
Unlike windows the panels on your roof need to have a clean and clear surface to ensure they are working at their maximum efficiency. If they are not at their optimum performance it means they are not producing the amount of electricity that they could be.
The above image shows solar panels with bird droppings that do not wash off easily with just rain. This will affect the panels performance. To reduce the problem of bird droppings you can put a plastic mesh over your TV aerial to stop birds using it as a perch and messing on the panels below.
On the roof and angled skywards the panels will attract dirt, dust, soot, pollen, tree sap and salt crystals in costal regions creating a fine layer of grime. This layer reduces the amount of light reaching the silicon cells under the glass surface and reduces the panel's effectiveness. A solar panel that has never been cleaned could be producing almost a third less power than it otherwise could be. Some have reported a ten to fifteen percent loss of solar output due to dirty panels. Boston University in the States have done some research on this and claim that as little as a few grams of dust per square metre can halve their efficiency.
From the ground the panels may appear to be clean, just like your windows. Up close however you can see the grime that has built up from the dirt and pollution in the air. A more noticeable deposit that can be left on panels is bird droppings. These tend to completely block the light from areas of the photovoltaic panel and can considerable reduce its effectiveness.
How to clean solar panels?
Some people may try to clean them themselves although this is not recommended. Firstly it can be dangerous trying to reach your roof without the proper equipment. Secondly you may end up damaging the panels either accidentally or by attempting to clean them yourself.
It is recommended that you hire a cleaning company that provides a solar panel cleaning service that know how to clean solar photovoltaic panels properly. Do not just hire a window cleaner unless they have specific knowledge and experience in this area. They may end up at worst damaging the panels or not effectively cleaning the panels so you end up no better off.
Hire a company that has the proper solar panel cleaning equipment
A company who is experienced in cleaning PV panels will have the proper equipment. Using standard windows cleaning tools means that they will end up leaving soap residue behind and hard water spots as any water on the panels surface evaporates.
A professional cleaner will use a water fed pole system that can reach the panels on your roof from the ground. They will use a pure water system that uses de-ionised water and a soft head brush attachment so as not to damage the panels. No chemical should be used as these can cause damage.
How often should I clean my solar panels?
In the UK this is something that we do not have much experience or knowledge with. Luckily solar panel cleaning services in other countries have been established for many years and many recommend getting them cleaned twice a year. Some suggest you get them cleaned every couple of months.
For the best results the first clean should be at the start of spring as the days lengthen and the amount of sun reaching the panels increases. Later in the summer they should be cleaned again. For the UK climate this seems to be the best solution.
If you have free solar panels installed or are thinking of getting them you should check with the installer to see if they pay for getting the panels cleaned. It is in their interest to keep them running at optimal efficiency.
Won't the rain wash the dirt off the panels?
During the summer there may be long periods where it does not rain and the summer is when photovoltaics produce the most electricity. When it does rain some of the loose dirt is removed but more is deposited in its place. Some types of soiling such as that from birds will remain for many weeks and even months if they are not cleaned.
Does cleaning a solar panel really improve its efficiency?
The best way to prove this is to record the amount of power being generated before the panels are cleaned. Get the panels cleaned and then compare the new reading with the ones that you took earlier. It is best to do this on a sunny day where the weather is pretty constant as the sun disappearing behind the clouds intermittently is going to affect the results.
Is there a way to prevent my solar panels from getting as dirty?
At the moment for residential installations the most practical and proven method is to just get them cleaned regularly. There are special coatings that can be applied to the surface of the panels which claim to prevent dirt from sticking. If you are going to go down that root you need to make sure you check with the panel manufacturer first.
There are other systems that are not really practical for residential systems such as spray systems built into the roof that regularly hose down the panel. There are even solar panel cleaning robots that can clean them. There is also a system that uses an electric charge to lift the dust of the surface of panels.
Why do I need to clean my solar modules?
Your solar system represent a significant investment of capital. Allowing your solar modules to get soiled due to airborne particles, bird droppings, leaves etc. can greatly reduce your electricity output.
Additionally, by not cleaning your solar system at all, you may not only risk losing a significant amount of electricity output, but you may risk losing your modules too.
Indeed, certain airborne particles may be quite abrasive and scratch the surface of the solar modules, causing permanent damage when they are not removed. Other organic deposits (e.g. windborne dirt, bird and other animal droppings, urban pollution (e.g. soot from burning coal or diesel), as well as decomposing organic plant matter from leaves, pollen, etc., can become wet and cause potential corrosion.
Allowing dirt to build up, can also lead to local overheating inside the solar modules, so called hot spots. Hot spot heating occurs when a single cell in a series string generates less current than the module, because the cell is shaded (as a result of dirt build up) or otherwise damaged. Hot spots are parts of your solar modules where heat is produced instead of electrical power. These hot spots not only decrease the energy efficiency of your solar modules but they can also reduce the their life time significantly.
It is clear that the economic benefit of increased production and preserving the lifetime of the panels greatly outweighs the cost of periodic maintenance of the PV modules surface.
What kind of soiling are solar modules subject to?
Soiling of solar module surfaces is a complex phenomenon varying by climate, environment and location. A surface in a dry desert-like location will be subject to electrostatically attracted inorganic materials, a surface in a coastal area will be subject to salts and rain driven dirt, and a surface in an industrial and cooler location will be subject to organic windblown dirt, deposits from evaporated rain and atmospheric pollutants from fossil fuels.
Generally, soiling of an exposed outdoor surface (such as a solar module) will be a mix of organic and inorganic solids. Some of these solids will be windborne whilst others will be deposited from evaporated liquid (rain water, dew, fog).
In very dry and desert like environments, most of the module soiling may be inorganic windborne solids (dust and dirt particles) that are electrostatically attracted to the solar module’s glass surface as a result of dry winds. Additionally, some of this dust may consist of abrasive inorganic minerals (e.g. silica) which may scratch and damage the surface of the modules.
In more cooler and wet environments, most of the module soiling may be organic deposits including windborne dirt, bird and other animal droppings, pollution (soot from burning coal or diesel), as well as decomposing organic plant matter from leaves, pollen, etc. When these materials become wet, they may be spread over the panel surface and further bond to it, causing potential corrosion and leaching of irons. In coastal areas, there may be salt deposits on the panel’s surfaces resulting from water spray and rain driven dirt.
How many times per year do I have to clean my solar modules?
The frequency by which solar modules should be cleaned is of course dependent on the location and environment in which they are placed.
However, the presence of heavy industry nearby, coastal areas and heavy bird populations may warrant more frequent cleaning to assure optimal output and maintenance of your solar modules.
For solar modules placed in more dry and desert like environments (subject to more dust) it is recommended to have the solar panels cleaned on a more periodic basis (e.g. on a monthly basis).
Isn’t rain alone sufficient to clean my solar modules?
Rainfall alone does not suffice to properly clean and maintain your solar modules. Rain can remove some dust and dirt off the solar modules as a result of their smooth surface and tilted position. However, rain cannot deal with all dust and dirt and it is not an effective means to remove the contamination from bird droppings, chemicals, acid rain and other air pollution. Additionally, rain may itself leave mineral deposits on the solar modules after evaporation. Consequently it is highly recommended to use a proper and specifically designed cleaning product like Solcleaner, which provides an all-in-one solution for all kinds of contamination.
What is the scientific effect of dirt build up on solar module performance?
Although PV systems and their output have been well studied and statistically measured over the last 25 years, the effects of module soiling on performance have only recently been the subject of scientific analysis.
It is a scientific fact that any object or element preventing photovoltaic cells from being exposed fully to the sunlight will decrease their output. International scientific research shows that the yield of solar panels is reduced by 3% to up to 15% on an annual basis as a consequence of soiling!
A study of the Netherlands Organization for Applied Scientific Research (TNO) has showed a decrease in energy production of 4,4% to up to 7,7% in 1 year caused solely by pollution. A 12 year lasting scientific research study by Mr. H. Haberlin proved a similar result. According to the Solar Electric Power Association (SEPA), photovoltaic electricity output will decline approximately 10% due to accumulation of dirt, dust, and other residues. Further research by the US based Solar Electric Power Association (SEPA) indicates that PV electricity generation will decline 15-20% in areas where bird droppings, urban pollution or dust from farming operations are common.
Individual dealers have even reported losses as high as 25% from some customers who neglected to ever clean their solar modules.
Aztec solar installations have been in the solar business for 10 years now. We are expanding our range to cover cleaning of solar PV panels, as well as our usual solar hot water services. We can carry out cleaning of your solar PV system from as little as £99. Please contact us for further details. As you can see below all the manufacturers recommend cleaning on a regular basis, for a higher output.
You can contact us on 07939052647
Recommendations from manufacturers
Suntec
Sharp
Solar Clean/Abwischen
Why do solar panels need cleaning?
How to clean solar panels?
How often should I clean?
Won't the rain wash the panels?
Does cleaning improve its efficiency?
Is there a way to prevent my solar panels from getting as dirty?
Why do I need to clean my solar modules?
What kind of soiling are solar modules subject to?
How many times per year do I have to clean my solar modules?
Isn’t rain alone sufficient to clean my solar modules?
What is the scientific effect of dirt build up on solar module performance?
How to clean solar panels?
How often should I clean?
Won't the rain wash the panels?
Does cleaning improve its efficiency?
Is there a way to prevent my solar panels from getting as dirty?
Why do I need to clean my solar modules?
What kind of soiling are solar modules subject to?
How many times per year do I have to clean my solar modules?
Isn’t rain alone sufficient to clean my solar modules?
What is the scientific effect of dirt build up on solar module performance?
