Willkommen.

Why does a photovoltaic or solar thermal should be cleaned?
That rain cleans the solar planels is not true. How do you like if your car dealer gives you the advice to keep clean your car, by adding it, to stand in the rain? Worldwide solar manufactures have been working on the development of high quality products. But acid rain, bird droppings, iron oxide, chemicals, dirt and many other pollution of the atmosphere finds ideal target on the photovoltaic and thermal solar modules.

The self-cleaning by rain or specially coated glass surfaces delays the deposition of dirt, but they are not in a position to bring miracles.  Self- cleaning glass can be rarely found in the construction of photovoltaic modules or solar collector application. So if solar modules would not be cleaned, they can be irreversible damaged and a reduction in efficiency would be the result.


How about clean with a sponge and household detergent?
During the Apollo 9 mission to the moon, one of  few cameras was defect. One of the astronauts tried to repair it with a hammer. To compare with these example it would be, than if you would not use special detergents or products. Conventional glass cleaners can significantly change the surface of the glass. In combination with a sponge the glass surface would be scratched. Correct glasscleaning  furthermore requires some precautions. (such as never clean glass surfaces in direct sunlight or if the glass is still hot)


How to clean a photovoltaic system or solar thermal system?
The challange is to clean the plant without touching the surface of the modules. It is very difficult because often the modules are inaccessible. The solution is using high pressure cleaners and special products. An additional equipment such as  30 metre long telescopic hose extensions and  spray guns could make the work easier on large eterior installations. This cleaning should be carry out by professionals who posses the necessary equipment and are convinces with the applicable safety precautions.


How often should a plant be cleaned?
The frequency of cleaning depends on the location and the climatic conditions in their region. If your plant is in the cathment area for migratory birds or directly next to railway facilities, it necessary has to be cleaned quite often.
As a rule you can take: in rural areas one cleaning per year should be enough. In urban areas two cleanings per year should be sufficient. Facilities in industrial areas and areas with serious air pollution requires regular attention. The cleaning of the modules does not only removes exesting dirt, it also complicates the desposition and accumulation of dirt on new plants.

If your modules looks like those on the photo next window, you should think about the need for clean thoughts. On these modules the rain brought sand which is accumulated on the modules.


How much energy(money) you lost every year?
In the first 1 or 2 years the failure to clean the plant would not be notice. Everything is new and in a good condition. On polluted plants the damage is not limited only by a reduction in effeciency-because less sunlight or infrared or ultraviolet radiation goes down on the cells or planels. It also brings a chemical reaction in the glass, the metal and
the silicon parts of the modules.

These reaction will result in further deposition of dirt and enhance the chemical reactions on and on. If no one stoppes this process, the result would be a no irreversible damage to the plant. Therefore regular cleaning is very importent, because it effectively protects against these effects. Various studies have shown, that after cleaning, plants have up to 15 % more energy output. The R. O. I.( Return of investment) is expressed in photovoltaic systems as well as solar thermal systems with the effeciency of energy yield. At today´s energy prices, 15% of energy is very much.


Does photovoltaic systems requires a different maintenance than thermal solar systems?
It doesn´t matter, whether you have a thermal solar system ( hot water) or a photovoltaic system ( electricity). Both types of systems are suspended on the same evironmental conditions, such as UV radiation, high temperatures and pollution. The maintenance of thermal solar systems require a cleaningof the glazing of the solar collectors or vaccuum glass tubes.

Particular attention in both-  photovoltaic and solar thermal systems – requires the maintenance of metal or aluminium parts. The most pollution is on the relationship of glass and metal leads. These areas are designated as “critical area”. Here deposites the most dirt and allows microorganisms to resume their destructive work.