| http://agmetalminer.com/2009/02/26/power-costs-the-productio...: "Although the newest smelters can be closer to 12,500 kWh per ton let’s say most smelters are consuming electricity at 14,500-15,000 kWh/ton of ingot produced." So, that is 12 to 15 kWH per kilogram. Compare that with http://www.rsi-silicon.com/media/SolarGradeSilicon_050611.pd...: "In making MG-Si, approximately 12 kilowatt-hours of electrical energy are consumed per kilogram of silicon produced." That already is in the same ballpark, for MG = metallurgical grade silicon. Getting from there at the purity needed for chip production is energy intensive. From the same text: "Energy consumption for the Siemens process is ~200 kilowatt hours/kilogram of silicon produced" Even correcting for a potential bias of the author (who has his own patented process that he claims to be more efficient and, I guess, that he wants to sell), I conclude that, per kg, production of silicon-grade silicon is way more energy expensive than production of aluminum. On the other hand, http://www.rsi-silicon.com/media/SolarGradeSilicon_050611.pd... seems to indicate that chip-quality silicon is overkill for solar cells. A dedicated factory for solar cell silicon would be more energy efficient than what exists now. |