Crystallization, Cast Mono, Life Cycle Assessment (LCA), Sustainability, Photovoltaic (PV)
Summary / Abstract:
The economic and ecologic sustainability of using cast-mono silicon wafers in comparison to Czochralski silicon wafers for the production of PERC solar cells and their subsequent application in a photovoltaic system has been studied within a cost and carbon footprint analysis for the whole value chain. The cast-mono growth technology has been modelled based on a G8 industrial furnace system compared to a Cz-growth systems with 36” crucible size and recharging process. The carbon footprint and cost per wafer were evaluated for M6 and M12 wafer sizes. A PV system with cast-mono wafers shows a 9 % reduced carbon footprint for a use phase of 25 years with the assumed properties. On wafer level the cost profiles for both technologies show a cross over point at around 5-7 $ct per kilowatt hour of electricity with lower cost of cast-mono wafers in case of higher electricity prices. An increase of brick yield from actual approx. 53 % to over 60 % would result in a wafer cost decrease of up to 0,4 $ct per Watt peak thus enabling a competitiveness for the future wafer market.