Mitigating the uncertainties in life cycle assessment of photovoltaic cells

Life cycle assessment (LCA) of photovoltaic (PV) electric power generation investigates the energy requirement over the whole manufacturing and operational phases. Existing LCA results of PV have been based on process LCA method which considers the material and energy flow on physical level. This method has an obvious shortcoming of limited boundary. Many processes over the life cycle of PV are excluded from the process LCA, such as producing chemicals, manufacturing facilities and equipment, services and transportation. This paper proposes a step-by-step hybrid LCA method to mitigate the error induced by process LCA of PV. Besides the energy requirement analyzed by process LCA, there are energy requirements analyzed by economic input-output (EIO) LCA.