Norsk Hydro ASA operates two businesses: aluminum and energy. It is a supplier of aluminum and aluminum products, and serves markets, such as automotive and transport, building and construction, consumer goods, general engineering, packaging and printing. In its energy business, it produces hydropower and solar energy. Hydro’s power production is primarily used to supply its aluminum operations with electricity. Hydro operates 17 hydroelectric power plants with an annual production of nine terawatt hours. In December 2006, VM Materiaux bought back Quartz from Hydro.