We estimate the production cost of aluminum today as 4.5 times that of steel: around $2700/t for aluminum and $600/t for steel. We divide the production cost of steel and aluminum into four main categories: energy, raw materials, capex, and labor/other. In broad terms, the cost of aluminum is dominated by electricity and capital costs, while the cost of steel is low and dominated by raw materials and labor. Energy is half the cost of aluminum, while it is only one quarter the cost of steel (Figure ). These production cost estimates are high compared to market prices of $2500/t for aluminum and $700/t for hot-rolled steel coil in North America, per the London Metal Exchange. Reasons include the following: production cost estimates are for relatively high-cost labor markets in the United States and Western Europe, energy costs assume industrial-average electricity prices 14 rather than negotiated rates, estimates are based on material demand requirements from scientific literature and may be subject to error, and margins are low for primary metal production.