Earlier this evening I heard a radio show from back home in Iceland where there was a person who said that it did not pay for the environment for Iceland to produce electricity for aluminum factories because it took so much power to move the bauxite (the ore that aluminum is finally extracted from) to Iceland and then move the final product away from Iceland again.
Now this is something that I can relate to but is it true? Alcoa says it can produce 1 ton of aluminum from 4 tons of bauxite and it takes about 15 kilowatt hours to produce 1 kg of aluminum according to wikipedia. So to produce 1 ton of aluminum with clean energy in Iceland it costs 15 megawatt hours and lets say that if it was produced by unclean energy in the country of the mine then the difference should just be the transport of the bauxite and aluminum. So for this to be economically and environmentally viable then it cant be more expensive to move the ore back and forth from Iceland then 15 megawatt hours per ton. I don't know how much energy it goes into moving 1 ton of stuff by sea or how it scales (that is, how much energy it takes to move 1 ton, and how much energy it takes to move 10 tons). It would be interesting to find out.