Recyclability of solar panels

Producing electricity using solar panels is better for the environment than using coal-fired power stations. That’s a no-brainer. But the service life of a solar panel is only 20 years, and then where does it end up? Miro Zeman, head of the Electrical Sustainable Energy department, has been researching solar panels for almost 30 years and explains how solar panels are recycled. 

“The most significant component of 90% of solar panels is silicon,” says Zeman. “Silicon is made from sand, which is the most common element on earth after oxygen. So we don’t have to worry about that running out any time soon. A solar panel also contains metal electrodes; metal is somewhat scarcer than sand. We are looking for solutions to replace the metal parts with carbon layers which can conduct electricity just as well. Another disadvantage of metal is that it needs to be protected against oxidation caused by exposure to air. That’s why the solar cells in a solar panel are fitted between glass plates. Glass primarily consists of silica or silicon dioxide, which is also made from sand.

At the moment, around 2% of all the world’s electricity is produced by solar panels. “We want to get that up to 50%,” says Zeman. “This percentage is rising because it is getting cheaper to generate electricity from solar energy and in some places it is even the cheapest form of usable energy: 1 KWh supplied by solar panels in the Netherlands now costs less than 8 cents. This is because the production of solar panels has increased massively in China, which makes them cheaper.” Zeman is pleased with this development.

‘As yet it is not commercially interesting to recycle solar panels’

“At the moment we are using a lot of primary, fossil sources to generate usable energy. They are certainly not circular and they are depleting rapidly. On the other hand, renewable sources, such as solar and wind, are circular.” 

And, according to Zeman, solar panels can actually be recycled. “As yet it is not commercially interesting, but there are many initiatives underway to push forward with recycling using thermal, mechanical and chemical separation methods. We expect considerable progress to be made here in the coming years. This is already being done on a small scale in Japan and Europe, for example, where 96% of silicon solar panels are recycled.”