Unveiling the environmental footprint of photovoltaic systems: A life cycle assessment across technologies and configurations

Rapid global PV (photovoltaic) expansion driven by global decarbonization goals requires comprehensive life cycle environmental evaluation. This study applies a harmonized life cycle assessment (LCA) to seven representative PV modules across six installation scenarios, enabling consistent comparison at both module and system levels. Results indicate that cadmium telluride (CdTe) achieves the lowest environmental footprint, followed closely by perovskite-silicon tandem (PST) module at 23.28 Pt per kWp. Despite high conversion efficiency, PST module presents specific marine eutrophication and toxicity risks arising from heavy metal use. Conversely, polycrystalline silicon (Poly-Si) module exhibits the highest burden due to energy intensive manufacturing. Notably, system level analysis reveals that Balance of System (BOS) components contribute 48% to 70% of total environmental damage, acting as the dominant environmental driver. Rooftop systems consistently outperform ground mounted alternatives, with human health identified as the main impact category. These insights indicate that reducing the PV environmental footprint relies on a coordinated strategy that optimizes module technology while minimizing BOS material intensity. • Environmental impacts of seven PV modules and six installation scenarios are systematically assessed. • Contributions from modules and BOS components are quantitatively compared. • Toxicity risks from heavy metals in Perovskite-silicon tandem modules are identified and evaluated. • Targeted optimization strategies for modules and BOS are proposed for rooftop and ground systems.