Life cycle assessment of Solar PV system-an update of life cycle inventory based on Chinese industrial data
Abstract
The thesis conducted a life cycle assessment (LCA) of electric generation by crystalline silicon-based photovoltaic system. LCA is an essential tool to evaluate the environmental impacts and potential advantages quantitatively. The life-cycle assessment is carried out based on a 3kWp slanted roof photovoltaic (PV) system with single-crystalline and multi-crystalline silicon panels and evaluates the environmental impact in terms of carbon equivalents global warming potential (GWP) if one unit of electricity is generated from the system. The thesis constructed a life cycle inventory (LCI) specifically for crystalline PV produced and installed in China. LCI considers mass and energy flows over the whole production process starting from raw silica material to the final electricity generation as well as end-of-life management, considering the latest technological facts and local electricity scenarios.
The LCA results calculated through Brightway2 using the IPCC method are 37.02 and 38.7 kgCO2eq/kWh for single- and multi-crystalline silicon PV, respectively. Contribution analysis were conducted for each process and sensitivity testing was done for parameters found with several possible values. The results show that the most critical parameters are the elctricity input mix and PV cell efficiency. Recycling and treatment was also found to be worthwhile to avoid environmental burdens and further recover parts of the embodied energy in the PV system.