Dirt-Repellent Coating For Solar Panels From Fraunhofer FEP

Fraunhofer FEP Discovers Roll-To-Roll Coating Process That Prevents Dirt Deposits On Solar Modules Under European Union Backed NewSkin Project

Dirt-Repellent Coating For Solar Panels From Fraunhofer FEP

The 1st image (l) shows coating with titanium dioxide, in the initial state (hydrophobic, water drops contact angle approx. 95°), and after irradiation with UV light (r) for 30 minutes (superhydrophilic, contact angle <5°). (Photo Credit: Fraunhofer FEP)

  • Fraunhofer FEP has introduced a new coating process using crystalline titanium oxide on ultra-thin glass that gives dirt-repelling properties
  • Applied using roll-to-roll process, the coating can ensure all dirt deposits are washed off by the hydrophobicity of the surface through beading raindrops
  • This process can enhance energy efficiency of solar panels and lower maintenance costs

Using roll-to-roll process to apply crystalline titanium oxide to ultra-thin glass, Fraunhofer Institute for Organic Electronics (FEP) has announced achieving hydrophobic surfaces that can repel dirt deposits on glass facades or solar panels as a pilot under the European Union (EU) funded NewSkin Project.

Such a process will enhance energy efficiency while also bringing down costs of maintaining solar panels, said the researchers.

“We are focusing on photoinduced hydrophilicity on surfaces here,” said graduate student Valentin Heiser from Fraunhofer FEP. “The ultrathin and lightweight glass can be applied subsequently to facades or directly incorporated into solar modules as a composite material – and even onto curved surfaces.”

The team explains, when the coating of titanium dioxide on ultrathin and lightweight glass is exposed to UV radiation, it changes the water repellency or hydrophilicity of the glass. When it is ‘unirradiated’ it forms water or becomes hydrophobic. On the other hand, when irradiated, it becomes superhydrophilic or becomes completely moistened.

Coating of titanium dioxide means no or very little dirt can be deposited on glass facades or solar panels since it is washed off by the hydrophobicity of the surface via beading raindrops. This also provides an antibacterial and sterile properties for the glass.

First coatings developed by the team—a 30 cm wide and 20 m long roll of thin glass, with a glass thickness of 100 micrometers—was coated with 30 –150 nanometers of titanium oxide, in a roll-to-roll system. This pilot plant for roll-to-roll coating of thin glass (FOSA LabX 330 Glass from VON ARDENNE) is located at Fraunhofer FEP.

Listing challenges in achieving scale for this significant research, the team cites the breakability element of this thin glass that reacts sensitively to thermal and mechanical stresses. To ensure titanium oxide lends hydrophobicity and hydrophilicity to the glass, it needs to be crystalline in nature which is produced using high temperatures.

Going forward, the team is now working on bringing together the best of titanium dioxide and thin glass in an ‘optimal and cost-efficient’ manner. Another partner of the NewSkin project, Uppsala University if now working on transferring the results to polymer films.

Fraunhofer FEP says it will also work on layer systems that can also work with visible light, and not just UV light for which it is considering production and embedding of nanoparticles or doping with nitrogen.

To discuss solar module innovations in the year gone by, and to see what’s coming next, TaiyangNews is holding 1-day Virtual Conference on Solar Module Innovations 2023—Looking Back and Forth on January 31, 2023. Registrations are free and can be done here.

About The Author

Anu Bhambhani

Anu Bhambhani is the Senior News Editor of TaiyangNews. Anu is our solar news whirlwind. At TaiyangNews she covers everything that is of importance in the world of solar power.

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