Life-cycle assessment of China's multi-crystalline silicon photovoltaic modules considering international trade

We performed a life-cycle environmental assessment of China's multi-crystalline silicon photovoltaic (PV) modules associated with international trade. The study distinguished domestic and imported raw materials for PV modules within the framework of a life-cycle assessment based on traditional processes. Domestic process data were collected from typical PV companies in China and the literature. Imported raw material data were obtained from international trade databases and life-cycle inventory primary databases. The results indicate that it is necessary to consider the international trade of raw materials in life-cycle environmental impacts of PV modules produced in China when considering the shift of environmental impacts between countries associated with international trade of material and products. Multi-crystalline silicon PV production and PV module packaging are important manufacturing processes within the context of environmental impacts of the manufacture of PV modules in China. This assessment also reveals that production of multi-crystalline silicon PV modules in the country has emitted significant amounts of greenhouses gases (GHG). For example, over 2.21E+07 tons of CO2eq were emitted in 2010, of which 94% were from Chinese domestic industries and only 6% from imported raw materials. Regarding the export of PV modules, 82.4% of GHG emissions in China were from imports of PV modules by other countries. This result implies that while the export of Chinese PV modules supplied a large amount of clean energy to the world, it also caused significant environmental impacts in China.