l'Actualité du Solaire

In France, the French Alternative Energies and Atomic Energy Commission (CEA) has developed a process for recycling end-of-life photovoltaic panels. To recover the silicon and silver, their process uses_CO2 in a supercritical state.

Silver represents more than 30% of a panel's value. "The whole point of recycling is to guarantee maximum purity of this valuable material so that it can be reused.

The process uses supercritical_CO2. This is a state of carbon dioxide that has properties intermediate between a liquid and a gas. It is reached when the_CO2 exceeds its critical point at 31°C and 73.8 bars of pressure. In this state, the_CO2 seeps into solids, particularly the polymer encapsulating the solar cells. When the researchers depressurise the polymer, the_CO2 contained in the encapsulating polymer transforms back into its gaseous state, causing the polymer to expand and foam. This deformation causes the different layers of the PV panel to separate, enabling them to be recovered individually.

https://www.pv-magazine.com/2023/10/12/frances-cea-developing-tech-to-recover-silicon-silver-from-end-of-life-pv-panneaux/

PV Magazine, 12 October 2023

Editor's note Brazilians have proposed a comparable method based on supercritical water. We reported on it in issue 458:To recycle end-of-life panel components, all you need is supercritical water!