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Solubility of Solar Encapsulants – Improvement of Recycling Processes
S. Feldbacher, T. Dobra, I. Mühlbacher, G. Oreski, M. Aarnio-Winterhof
Photovoltaic Modules and BoS Components
Subtopic: Sustainability and Recycling
Event: 38th European Photovoltaic Solar Energy Conference and Exhibition
Session: 4DV.2.17
ISBN: 3-936338-78-7
0,00 EUR
Document(s): poster


Sufficient protection of solar cells is essential during lifetime of a photovoltaic (PV) module. Therefore, in addition to the front glass and backsheet, a polymer encapsulant is used to provide the functions of structural support, electrical isolation, and physical protection for the interconnected solar cells [1]. Currently, crosslinked ethylene-vinyl acetate (EVA) is the dominant encapsulant material [2] in PV modules. Recently, an interest in new encapsulant materials based on thermoplastic polyolefines (PO) has increased to overcome the issues of EVA [3, 4, 5] and also meets the challenges of newly designed sustainable photovoltaic modules. Wherein economic and ecological End-of-life management is taken into account, the enhanced solubility of PO compared to EVA is beneficial. Concidering recycling of PV modules, preferably all individual layers of the module undergo a separation process. Removability of the encapsulant materials plays a key role in enabling the recovery of the front glass and valuable materials from the interconnected solar cell. The feasibility of certain separation processes can be very much influenced by the composition of the encapsulant. Chemical separation through solvents as a first step in the recycling of PV modules with EVA encapsulants has been previously investigated [6, 7]. However mostly solvents which are regarded as harmful to humans and/or the environment were applied. For new PO-based encapsulant materials no information in regard to solubility is available. Therefore, green solvent guidelines were used, in order to identify more environmentally friendly and less harmful substances with similar proprieties to those solvents already proven to achieve high solubility in regard to polymers with low surface energy.