How much electricity does aluminum smelting require per kilogram of metal?

The amount of electricity required to produce aluminum through the Hall-Héroult process has decreased significantly due to technological advancements. In 1940, the production of one kilogram of aluminum required 19 kilowatt-hours of electricity. By 1990, the most efficient cells had reduced this consumption to approximately 13 kilowatt-hours per kilogram of metal produced.1

Because electric current is a major cost factor in aluminum processing, producers have historically sought out inexpensive sources of hydroelectric power to support their operations. It is worth noting that recycling scrap metal is far more energy-efficient, requiring only about 5 percent of the energy needed to produce primary aluminum from bauxite.12