Environmental Impacts from Energy Use in Solar Photovoltaics Manufacturing

Solar energy have been considered as a clean, renewable and non-pollutive source of energy. However, the environmental impacts of solar energy are usually not considered and not well understood. Crystalline solar photovoltaic (PV) panels are the most popular form of solar energy in use currently. A cradle to gate life cycle assessment (LCA) was done for mono and polycrystalline solar photovoltaic (PV) panels. The raw materials, electricity and other inputs were considered in nine impact categories, up to the manufacturing stage. Results showed that energy input had the greatest environmental impacts among all inputs. Of all possible sources of energy input, coal use had the highest environmental impact. Increasing the proportion of renewable energy use in the manufacturing of PVs reduced the impacts across all categories. This implies that as more PVs are manufactured for use in the coming years, more carbon emissions will be expected, generating a carbon debt, unless a corresponding increase in renewable energy is use in manufacturing. This is also true for other environmental impacts, such as acidification, aquatic, terrestrial and human toxicities. However, certain processes in PV manufacturing, such as silicon ore refining has no known renewable energy substitute. The limits on the use of renewable energy in solar PVs manufacturing would limit the environmental benefits of using PVs and negatively affect decarbonization efforts.