Environmental performance of solar photovoltaics across three generations: A cradle-to-gate comparison

Abstract

Solar photovoltaic (PV) systems are essential for low-carbon electricity generation. This study addresses current critical gap in comparative life-cycle data by conducting a cradle-to-gate life cycle assessment (LCA) of eight representative PV panels across three generations. By adopting a harmonized methodological framework, the analysis overcomes inconsistencies that hindered comparisons across prior studies, enabling robust cross generation benchmarking. Results identify that technological advances in first-generation solar PV panels have driven a consistent decline in environmental impacts across all six evaluated categories. Emerging third-generation technologies show improved environmental performance over established first-generation systems. This LCA modelling indicates a marked reduction in global warming (GW) impacts for first-generation PV panels, decreasing from 30 to below 25 g CO2 eq/kWh, primarily driven by improvements in conversion efficiency. Second-generation technologies achieve the lowest GW impacts (' 20 g CO2 eq/kWh), although their widespread deployment remains constrained by cost-effectiveness limitations. Contribution analysis shows that embodied energy in manufacturing and aluminum alloy used in encapsulation accounted for 30.6-41.7% and 10.5-26.9% of the total impacts, respectively, highlighting the dependence on non-renewable energy sources. Encapsulation emerges as a major contributor to mineral resource scarcity, while the use of chalcogenide compounds in second-generation absorber layers further exacerbates this impact. Sensitivity analysis shows that emerging tandem technologies must achieve operational lifetimes exceeding 15-year and reduce annual degradation rate below 2% to deliver a sustainability advantage over silicon-based modules. Overall, these findings provide actionable insights to guide sustainable PV manufacturing strategies and inform evidence-based decisions on future solar energy deployment.