27 marzo, 2019 0 By admin

Regular cleaning of photovoltaic panels allows you to maximize the absorption of solar radiation, optimize installation costs and extend the life of your system.

The importance of constant cleaning.

The importance of cleaning ordinary and extraordinary photovoltaic panels should not be underestimated. To avoid damaging the implant and ensure that operations are performed safely, it is recommended to avoid “do it yourself”. Always get in touch with industry professionals. 
Given that the initial cost is around € 9,000 that is recovered in 10 years, it is worth keeping them in the best possible conditions. If the plant is not cleaned frequently, its performance decreases by up to 30%.

Power plant prices
1 kWp – 20 kWp 130 – 200 €
21 kWp – 40 kWp 210 – € 280

Save on cleaning your photovoltaic panels.

If you want to install a photovoltaic system that has a long-term guarantee and a cleaning service included, we recommend you contact more experts and evaluate different estimates. 

What is the average cost?

Many companies offer, together with the installation of the panels, a cleaning package in addition to the guarantee for the next 25-35 years, 10 years for the  investors  . Otherwise, you should consider that the average cost varies between 40 cents and € 2 per square meter. For residential systems that are on the roofs and are difficult to reach, you need an elevator or a mechanical arm and can reach a figure between € 15 and € 40 per square meter. 
In the table above, you can find the average costs in total.

Why is it necessary to clean the photovoltaic panels?

The presence of dust, dirt and various residues can decrease the performance of your  photovoltaic panels by   up to 30%. The research conducted by the US Department of Energy. UU (DOE, for its acronym in English) has recently shown that only dust reduces efficiency by up to 7%. To this must be added the reduction in yield due to the deposition on the photovoltaic surface of: dry leaves, bird droppings or other materials. 
Even rain, which partly washes the panels, paradoxically brings fragments and causes water stains that significantly reduce the overall efficiency of the plant. All this makes it more difficult to absorb sunlight and produce energy, which reduces performance.

When do you plan to clean your plant?

It is usually recommended to do it a couple of times a year, preferably in spring, before the period of greater irradiation, and in autumn. 
We recommend that you periodically monitor the amount of energy it produces. Also check the conditions you are in, at least twice a month. If possible, compare it with similar ones in your area. 
When you see that the efficiency decreases, check the conditions of your system frequently. In case of doubt, request an inspection or opinion from specialized personnel.


More frequent cleaning

The cleaning of a photovoltaic system is part of the routine maintenance work and the frequency depends mainly on the position of the plant and the requirements indicated in the manufacturer’s warranty. 
It should be more frequent for those installed near:

  • port or near the sea (presence of sand and salt);
  • industrial area (due to soot and various residues);
  • chimney of a fireplace / stove;
  • windy area (transport of debris, dust and dirt);
  • A plant (accumulation of foliage, bark and resin).

Also keep in mind that those above the roofs of the sheds, with an inclination of between 10 ° and 15 °, get dirtier than those on the ground with an inclination of more than 45 °.

How are the panels cleaned?

Experienced companies use demineralized water or water deprived of impurities and external substances to clean the photovoltaic panels, so that dirt is better retained among its own molecules and is eliminated naturally. 
In general, they use rotating pressure brushes that can also be combined with hot water and create a pressure / depression effect on the panel, completely eliminating dirt in the glass cavity. 
It is an ecological cleaning system that avoids the use of polluting chemical products, which must then be rinsed and double the cleaning time.

A specialized company usually offers a service that includes:

  • Cleaning of the components and of the whole system.
  • visual inspection to verify any internal deterioration of the seal of the sealed panel;
  • control of wiring and electrical connections;
  • voltage control


And for industrial photovoltaic panels?

Companies and industries are also investing more and more in photovoltaic, solar and heat energy. In this way, they gradually reduce energy costs and the fixed costs of management and production. 
In the case of an industrial plant, it is impossible to carry out these operations without the assistance of a company specialized in maintenance and cleaning. In fact, they are often large and require special care, in addition to the organized intervention of expert companies. It can also be difficult to reach them without specific tools, such as telescopic rods.

Any advice for “do it yourself”

If you decide to trust in DIY, you should act early in the morning because the dew softens the debris that has been deposited.

The cleaning kit 

In the market there is no shortage of panel cleaning kits that generally include:

  • telescopic rod;
  • Ionic resin filter to produce about 1,000 liters of purified water.
  • Adjustable angle adapter to reach any inclination;
  • flexible hose
  • Brush with specific soft fixed bristles.

The indicative cost is € 400, without the filter and only with the brush the price drops to € 70.


The best soap is one that does not require rinsing, without persistent active substances. It is usually very concentrated and must be diluted in water. If you want to use a normal detergent, wash it well, otherwise there will be residues that will prevent the system from working properly.

Helpful tips

  • do not rely on just cleaning the rain because it is shallow and often leaves water stains and debris;
  • Contact professionals to avoid the risk of damage:
  • Avoid household detergents, diluents based on aggressive substances or pressure instruments;
  • keep the performance of your system constantly monitored;
  • remember that specific equipment is often required.

To avoid risking damage, contact a specialized company or the company that installed it. In this way, all operations will comply with the security rules provided and you will have insurance coverage in case of damages. Larger and more experienced companies often provide this service along with the guarantee.

The cleaning of photovoltaic panels on their own is obviously cheaper, the only problem is access to the roof. If it is not easy, the only solution is to contact specialized companies that use a special aerial platform.