Today's solar photovoltaic modules have a lifespan of around 30 years. It is estimated that, by 2050, Europe alone will have to deal with more than 10 million tons of end-of-life or defective panels. The most widespread solution for disposing of modules today is to shred them and use them as backfill in the construction industry. An alternative thermal treatment to separate the silicon cells from the photovoltaic module is energy-intensive and harmful to the environment. Finding new recycling solutions to recover metals such as silicon, silver, and copper is therefore essential.
CEA-Liten scientists have developed a recycling method that uses a diamond wire to cut through the photovoltaic cells, separating the glass front face from the polymer-based back face. Using a laboratory-scale version of the new process, it took just a half hour to separate the two surfaces—which are only a few hundred microns apart—of a typical one-square-meter panel. The recovered glass can then be recycled using a separate process. A hydrometallurgical treatment can also be used to separate and recover the various metals from the powder produced during the cutting process, so that they can be reused as well.
A European project will shortly be starting to develop industrial-scale equipment capable of processing several modules per hour. This equipment will use a reel-fed diamond wire so that its wear can be monitored. Solutions that cool the polymer to improve its cutting behavior are also being investigated.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.