Question: how much energy is needed to produce aluminum?
Answer: According to Alcoa, the world's largest producer of aluminium, the best smelters use about 13 kilowatt hours (46.8 megajoules) of electrical energy to produce one kilogram of aluminium; the worldwide average is closer to 15 kWh/kg (54 MJ/kg). Worldwide production of aluminium in 2010 was 41.4 million tonnes.