Solar Panels Paint a Better Black

FRIDAY, AUGUST 1, 2014


Swiss researchers have created a coating for solar thermal panels that is greener than current coatings and may last as long as the panel itself.

Using a stronger black coating made of three different materials, the researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland, say they may be able to extend the life of the coating to the 25-year life of the panels.

The New Coating

Traditional solar panels are coated with black chromium, which can be toxic, the Daily Fusion reports.

But black is the key element of thermal panels, as it absorbs 90 percent of the energy it receives.

Martin Joly, of the Laboratory of Solar Energy and Building Physics, developed a nanocrystalline coating that boasts exceptional resistance to high temperatures, better light absorption than chromium, and less toxicity.

Joly’s multilayer composite can withstand temperatures of 680 degrees Fahrenheit. The layers are cobalt, for corrosion resistance; manganese, for blackness; and copper, for thermal conductivity,

“The durability of our materials at temperatures exceeding 360 °C could also be of interest to thermal power plants,” Andreas Schüler, head the research team, told the Daily Fusion.

Under the current method, light and heat deteriorate the black chromium coating, making the thermal panels less efficient.

The Process

To cast the elements into layers, the researchers had to work in full scale.

Achieving this meant building their own machines. 

EPFL

Researcher Martin Joly developed the new thermal coating process that applies cobalt, manganese, and copper in layers.

“When researching nanoparticles, you normally use samples. For us, we set the challenge to coat two-meters-long stainless-steel tubes,” Schüler said.

Each layer was deposited by dripping, then heated by induction to evaporate the carbon to fix the elements.

This process is rapid and more energy efficient than current methods—so much so that the researchers are seeking to patent it.

   

Tagged categories: Coatings Technology; Energy efficiency; Research; Solar; Solar energy

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