Crystalline silicon manufacturing progress

The increasing demand for renewable forms of energy is making photovoltaic products an important part of the energy supply future. The costs of producing photovoltaic modules have been significantly reduced during the last 10 years as manufacturing costs per watt have dropped from over $6 per peak watt to less than half of that value now. This paper summarizes progress in several aspects of photovoltaic manufacturing which have contributed to this reduction. Crystal growth improvements, both in yield and machine design, have reduced the energy consumption by a factor of 3 and improved silicon utilization by 40%. Wafer slicing process changes have resulted in 66% more wafers being produced for a given amount of silicon. Cell production improvements in both automation and improved efficiency have reduced the labor cost contribution by 40% per watt. Larger modules and better materials have added another 10% reduction in the cost to produce photovoltaics. These improvements have contributed to a better energy payback time, reducing it from over 5 years to approximately 3. Reductions in cost and improvements in energy efficiency have made photovoltaic products a commercially viable alternate energy source.