High purity silicon has always been the most costly component of crystalline silicon solar cells. The need to reduce silicon content for cost savings, however, has become acute during the current polysilicon shortage. High solar cell efficiency decreases silicon consumption and manufacturing cost because such cells generate more watts per gram of silicon.
High purity silicon has always been the most costly component of crystalline silicon solar cells. The need to reduce silicon content for cost savings, however, has become acute during the current polysilicon shortage. High solar cell efficiency decreases silicon consumption and manufacturing cost because such cells generate more watts per gram of silicon. This paper describes SunPower's efforts to decrease silicon consumption through a combination of efficiency improvement and wafer thickness reduction. Cell performance versus wafer thickness is described. The advantages of SunPower's back-contact design, with respect to thickness reduction, are reviewed. Manufacturing results on grams/watt progress and a future roadmap are presented.
By William P. Mulligan, Marie A. Carandang, Matthew Dawson, Denis M. De Ceuster, Charles N. Stone, Richard M. Swanson, SunPower Corporation.
What is the cost per watt of wafer after reducing the thikness and how much is the improvement in terms of cost per watt?