Comparative life cycle assessment of photovoltaic systems: An evaluation of environmental impacts over time

The production of photovoltaic (PV) systems is subject to continuous technological development and geographical shifts in manufacturing, leading to changes in economic aspects and environmental impacts. This work focuses on evaluating changes in environmental impacts over time using life cycle assessment (LCA). Several existing LCA studies and life-cycle inventory datasets for multi-crystalline silicon (multi-Si), single-crystalline silicon (single-Si), cadmium telluride (CdTe), and copper indium gallium selenide (CIS) were compared, and the reasons for deviations were analyzed.

The comparison was carried out at the plant level for panel slanted roof systems, and the impact assessment results were compared to their counterparts from the ecoinvent v3.3 life cycle inventory cut-off database for individual datasets.

The study found that technological advances in PV manufacturing have reduced environmental impacts. The differences between cell types converged over time, with CdTe having the lowest environmental impact during production. However, this may be relativized when considering the lower life time of CdTe cells in a cradle-to-grave assessment. Single-Si has a higher environmental impact during manufacturing, but it is just about compensated for compared to multi-Si. If a dataset for PV must be selected without cell-type knowledge, multi-Si plants are recommended as a proxy. The analysis provides insights into the environmental impacts of different PV systems over time and highlights the importance of regular updates of life-cycle inventories and consistent modeling.