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Picture of Josha Kneiber, Geschäftsführer hyCLEANER

Josha Kneiber, Geschäftsführer hyCLEANER

Water pressure and water volume for cleaning large PV systems

Problem: Poor cleaning due to incorrect water usage

Operators of large photovoltaic systems face a recurring technical problem:

  • Many cleaning methods use too little water or utilize high-pressure cleaners – which may seem powerful for solar modules, but can damage the sensitive glass surface.
  • Pure low pressure on smooth PV surfaces can cause abrasion from dirt particles without a sufficient water volume, instead of dissolving them.
  • Furthermore, height differences and long hose distances lead to water pressure losses that reduce the cleaning effect.
  • Incorrectly sized hoses further reduce water throughput and thus the cleaning performance.

→ Studies on PV cleaning techniques recommend adjusted water volumes and suitable pressure to optimize cleaning efficiency and module protection.

Solution: Low pressure + sufficient water volume + correct hose technology

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1. Pre-cleaning and main cleaning with water

For optimal results, pre-cleaning and main cleaning with water is recommended, ideally with osmosis water:

Osmosis water is free of salts, minerals, and residues, offering a gentle yet effective cleaning without additives.

The filtered water creates a flushing effect that gently dissolves dirt without rubbing.

Benefit: Gentle removal of dirt, lower risk of scratching, and less post-cleaning required.

2. Low-pressure range instead of high pressure

Solar cleaning robots work effectively in the low-pressure range (approx. 2–4 bar) – this is roughly the same as a standard tap connection. Low-pressure cleaning ensures the surface of the modules is not damaged. Benefit: Gentle cleaning without risk to module glass or seals.

3. Consider water pressure losses and hose diameter

Pressure losses are caused by: Height differences: Rule of thumb: ~1 bar pressure loss per 10 m height Long hose lengths and small internal diameters: reduce water throughput hyCLEANER recommends supply hoses with an internal diameter of at least 10 mm for the solarROBOT series to ensure sufficient water flow. Benefit: Constant water pressure and higher cleaning effect across the entire system.

Advantages of the correct water strategy

Challenge Solution Result
Dirt rubs instead of dissolving Osmosis water + sufficient water volume Less abrasion & cleanliness
Pressure losses Correct hose + pressure planning Uniform cleaning
Module risks Low pressure instead of high pressure No surface damage
Dirt rubs instead of dissolving
Solution
Osmosis water + sufficient water volume
Result
Less abrasion & cleanliness
Pressure losses
Solution
Correct hose + pressure planning
Result
Uniform cleaning
Module risks
Solution
Low pressure instead of high pressure
Result
No surface damage
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ABOUT THE hyCLEANER EDITORIAL TEAM

Picture of Josha Kneiber, Geschäftsführer hyCLEANER

Josha Kneiber, Geschäftsführer hyCLEANER

The hyCLEANER editorial team brings together internal subject matter experts from various company departments – from practical application and technical development to sales and customer consulting. Together, they pursue the goal of presenting complex topics related to the cleaning of photovoltaic systems, glass surfaces, and facades in an understandable, practical, and compact way. The content is based on many years of industry experience, technical expertise, and insights from daily use in the field.

Areas of expertise:

PV cleaning | Glass and facade cleaning | Cleaning robotics | Industrial cleaning

Last technically reviewed: 2026-06-17