Towards a successful re‐use of decommissioned photovoltaic modules

Abstract

AbstractSince massive numbers of photovoltaic (PV) modules are expected to be discarded in the next decades, it is important to think about end‐of‐life management for those PV modules and to include re‐use next to recycling. However, the re‐use of decommissioned PV modules is a quite complex subject since there are requirements from technical, economic, environmental and legislative point of view. An evaluation of possible applications for second‐hand PV modules showed that currently, the use of these PV modules in high‐income countries is only interesting for specific applications. These are the replacement of some defect modules to repair PV systems (that usually still receive feed‐in tariff) or the replacement of all PV modules for either a low‐cost extension of system lifetime or the repowering of severely underperforming systems. For low‐income countries, second‐hand PV modules are interesting to build new small to medium size PV systems (often off‐grid). The typical decommissioned PV module is a crystalline silicon glass‐backsheet module from a utility power plant. Most PV modules originate from plants that have been partly damaged by severe weather or from repowered plants that did not receive feed‐in tariff (anymore). Currently, technical requirements to qualify potentially re‐usable PV modules for re‐use are lacking. In the legislation also, a clear criterion for a PV module to be considered functional is needed, since it is not an easy yes/no situation like for a typical electronic device. In this paper, guidelines for a low‐cost quality inspection and cost‐effective PV module repair are given. It is proposed to set a clear performance threshold at 70% of the original power for a PV module to be not considered as waste. With this paper, we aim to open the dialogue on a commonly accepted re‐certification protocol and threshold values. Currently, the worldwide re‐use market size is estimated to be around 1 GWp/year, of which 0.3 GWp/year is originating from Europe (mainly Germany, with Italy rapidly coming up). Many second‐hand PV modules are shipped to developing countries without recycling facilities which might create the risk of disposal on the longer term. To create a healthy and sustainable market for second‐hand PV modules, it will be important that evaluation standards for potentially re‐usable PV modules become available and that the existing electronic waste legislation will be adapted for energy‐generating products like PV modules.