Solar panel cleaning

Professional solar panel cleaning

At Rope-Tech we clean solar farms and large commercial installations — on the roofs of production and warehouse halls, office buildings, carports and industrial sites. We also look after smaller rooftop systems, including those on apartment buildings and houses with difficult access. We are based in Łódź and serve the Łódź region locally, but on larger contracts we work throughout Poland and across Europe. Our advantage is rope access — we don’t need scaffolding or lifting platforms, which on roofs carrying a PV installation are often either impossible to position or disproportionately expensive.

A solar installation differs from ordinary glazing in one respect: it is there to earn. That’s why we treat module cleaning as a technical service rather than a housekeeping job. Before we come out, we ask for the monitoring data and establish whether the drop in generation really does come from soiling — or from shading, an inverter fault or a damaged module. On solar farms we treat cleaning as part of the maintenance plan for the installation, not as a one-off service.

How much energy can dirty panels cost you?

The scale of the losses depends on the location, the weather, the tilt of the modules, the type of soiling and the way the installation is built. That’s why no single figure fits every site.

Fine dust, washed off regularly by rain, may have little effect on generation. In that case, preventive cleaning won’t always pay for itself.

Stubborn deposits from road traffic, industry, construction work or agriculture can matter far more, particularly during long dry spells.

Localised soiling — bird droppings, leaves, lichen or resin — can shade a module unevenly. That may reduce output, activate bypass diodes and, in certain conditions, lead to localised overheating.

This is why, before we propose cleaning, we look at the type of soiling, the installation’s surroundings and, where available, the monitoring data. On larger sites, cleaning can form part of the operation and maintenance plan, but how often it is needed should follow from the actual working conditions.

How we clean — the method, and what we never do

With PV modules, what matters most is what you must not use. Our procedure:

• Deionised water. We usually work with water purified by reverse osmosis, which contains very little mineral content. That limits the streaks and deposits left behind as it dries. We set the water parameters with the module manufacturer’s instructions in mind.
• Controlled pressure and the right tools. Excessive pressure or the wrong angle of spray can damage seals, connections or the module surface. That’s why we match the cleaning parameters and the type of brush to the documentation for the specific product. We use soft tools intended for delicate surfaces.
• Agents that meet the manufacturer’s requirements. We don’t use abrasives or aggressive solvents. If water alone isn’t enough, any use of a cleaning agent is decided case by case, based on the module manufacturer’s instructions and the type of soiling.
• The right time of day. We don’t clean hot glass — the temperature difference between a heated module and cold water risks thermal shock. We work in the morning, in the evening or under cloud cover.
• No load on the modules. We don’t walk or stand on the panels. Point loading can cause microcracks in the cells or other damage that isn’t always visible during a routine look-over, but can affect how the module performs over time.
• Preparing the installation for the work. How the installation is shut down and made safe is agreed in line with the equipment instructions and the procedures in force on site. We take into account that modules exposed to light can still generate voltage on the DC side.