The impact of silicon feedstock on the PV module cost

The impact of the use of new (solar grade) silicon feedstock materials on the manufacturing cost of wafer-based crystalline silicon photovoltaic modules is analyzed considering effects of material cost, efficiency of utilisation, and quality. Calculations based on data provided by European industry partners are presented for a baseline manufacturing technology and for four advanced wafer silicon technologies which may be ready for industrial implementation in the near future. Iso-cost curves show the technology parameter combinations that yield a constant total module cost for varying feedstock cost, silicon utilisation, and cell efficiency. A large variation of feedstock cost for different production processes, from near semiconductor grade Si (30 €/kg) to upgraded metallurgical grade Si (10 €/kg), changes the cost of crystalline silicon modules by 11% for present module technologies or by 7% for advanced technologies, if the cell efficiency can be maintained. However, this cost advantage is completely lost if cell efficiency is reduced, due to quality degradation, by an absolute 1.7% for present module technology or by an absolute 1.3% for advanced technologies.