The purpose of this model is to break down the most likely contribution of photovoltaic silicon to overall solar panel costs. The model starts from quartz, which is smelted into silicon metal, purified into polysilicon, upgraded into mono-crystalline poly-silicon and ultimately used in solar cells.
We estimate silicon explains $0.1/W of the cost of a $0.3/W panel. There is no way silicon producers are making economic returns below $12.5/kg mono-crystalline polysilicon prices.
If environmental costs are reflected as well, then PV-silicon price could double. Specifically, the average kg of PV silicon in a solar panel is most likely associated with 140kg of direct CO2 emissions.