Environmental life cycle assessment of novel PV systems for desert conditions

Abstract

Solar photovoltaic (PV) systems are currently seen as an affordable and mainstream renewable energy option to support energy decarbonisation, aligning with commitments of the UN Sustainable Development Goals (SDG 7). This technology prevails in high irradiance places such as deserts, where some of the largest PV systems are installed globally. However, harsh desert conditions reduce PV systems' efficiency and lifespan, among other negative effects. While research on designing PV systems that endure desert conditions is ongoing, little is known about the environmental impacts of these novel PV solutions. This study uses the life cycle assessment (LCA) methodology to assess the environmental impacts of four novel PV system designs (HJT 1–4) for desert conditions and compares them with three systems available in the current market (PERC, PERC+ and TOPCon). The functional unit of the study is ‘the production of 1 kWh of electricity AC, considering a PV system connected to a 570kWp grid in the Atacama Desert with a lifespan of 25 years’. The inventories were built using data from tested designs in the desert. 18 environmental impact indicators were included following ReCiPe method, and complemented with energy payback time (EPBT). Results show that the novel design (HJT 3) achieves up to 30% reduction in GWP100 per kWh of electricity generated compared to conventional monofacial PERC modules, and a 15% reduction compared to TOPCon modules, primarily due to higher efficiency and reduced materials consumption. The Balance of System (BOS) and installation stage shows the greatest impact on PV systems, contributing 46% on average across all environmental burden, followed by the wafer manufacturing (25% on average) and module manufacturing stages (18% on average). Across all impact categories, including EPBT, PERC is the worst performer, and HJT 3 and HJT 4 are the best performers, followed by TOPCon. This study validates the effort of performing environmental impact assessments on new designs, to ensure both technical performance and the environmental and economic sustainability of renewable energy systems.