Authors: Ramirez, Arantza; Adamietz, Lukas; Bruhm, Hartmut; Czinki, Alexander; Diaz, Fabian; Beck, Gesa; Kashif, Syed Majazuddin; D’Souza, Alan.

Institute of Applied Resource Strategies at the SRH University of Applied Sciences, Berlin; Aschaffenburg University of Applied Sciences, Aschaffenburg; IME - Process Metallurgy and Metal Recycling Institute and chair at RWTH Aachen University.

The goal of this project was to develop an environmentally and economically feasible process to recycle thick film (c-Si) solar panels based on a delamination process. Thus, a four-step delamination process was developed. First, the backsides of the modules were subjected to a mechanical pre-treatment, in which the surface of the back sheet was milled in a specific pattern. This pre-treatment allows a homogeneous distribution of the chemical solvent in the next process step to dissolve the EVA encapsulant at room temperature. The modules were then subjected to machine-assisted mechanical separation, involving a wire cutter at room temperature. After a cleaning step, it was possible to obtain the glass intact, with virtually no change to its quality (e.g. composition and transparency) and an EVA/Si mixture.

As part of the project, there was a techno/economic assessment made, which included a market research, MFCA and LCA. The method proved to be feasible technically; however, current conditions in Germany don’t allow for it, as there is no demand for the intact flat glass. Considering 18 indicators, the ReGCell process was determined to have a significantly smaller impact on the environment, when compared to traditional glass manufacture from raw materials. The process could be reworked to become profitable and to allow for the recovery of valuable materials.

The authors acknowledge the financial support from the German Federal Environmental Foundation (Deutsche Bundesstiftung Umwelt DBU) for the project “ReGCell” (project number 34987/01).