Life cycle assessment of silicon solar panels manufacturing in the United States

This work discusses the life-cycle impact associated with manufacturing silicon monocrystalline (c-Si) and multi-crystalline (mc-Si) photovoltaic (PV) panels in the United States compared to China. It has two significant contributions. First, the impact of importing panels manufactured in China to install in the US is compared with domestic US manufacturing using a database modeling approach. Second, the life cycle analysis is improved by using specific electricity and material inventory based on disassembled Suniva panels for which the actual material inventory has been compiled. The results from the U.S. lifecycle assessment using standard lifecycle inventory shows that modules entirely made in China or assembled in U.S. from Chinese solar cells have a similar carbon footprint. However, the complete manufacturing of panels in the U.S. reduces the carbon footprint by 13 to 22% because of the difference in the energy mix and the reduction in transportation. By incorporating the data from dismantling and digesting modules, the use of metals in small quantities is accounted for, unlike previous studies, and allows for a more complete environmental comparison. Evaluating the metal use in PV modules shows the metal usage in the U.S. manufactured c-Si module is four times higher than other scenarios.