Solar Photovoltaic Panel: Review of Life Cycle, Recycling, and End-of-Life

Abstract

Solar photovoltaic (PV) energy is considered to be a promising sustainable renewable energy solution and has the potential to replace conventional fossil-fuel technology. Globally, it is expected that PV technology will reach 4,500GW installed capacity by the year 2050. However, with the increased installations of PV panels, PV waste has been on the rise in recent years. The global cumulative PV waste is estimated to reach 8 million tonnes in 2030, and 70 million tonnes by 2050. The increase in PV waste is bound to cause a novel environmental challenge. Current research has focused mainly on improving the efficiency of PV panels, and the use of various materials in the manufacturing of PV panels. Very few Life Cycle Assessments (LCAs) have been recorded on the management of EoL of PV panels due to inadequate information on the subject, and the long lifespan of PV panels. This research work analyses the EoL of solar PV panels, addresses New Zealand’s current EoL management of solar PV panels and also systematically reviews and compares potential environmental impacts resulting from the three methods of solar PV panel recycling, i.e., physical, thermal, and chemical. The potential environmental impact results reviewed were obtained from different LCA studies. The potential environmental impacts that were considered in this review were global warming potential (GWP), acidification potential (AP), ozone depletion potential (ODP), and photochemical ozone formation potential (PCOFP). The comparative analysis revealed that more than one recycling method was used to achieve complete panel recycling. Physical or manual recycling had the least potential environmental impacts for all the reviewed LCAs. This was followed by the thermal recycling method that had considerably low potential environmental impacts compared to chemical recycling. The potential environmental impacts of physical recycling (which included shredding and hammering) and thermal recycling were similar because they both used electricity for parts of the recycling process. The chemical recycling method had the highest potential environmental impact, especially on GWP, AP, and PCOFP, mostly due to the chemical upstream processes. For the separation techniques, physical separation techniques produced low potential environmental impacts compared to chemical separation techniques because of the mass of chemicals used in chemical etching.