Financed by the Swedish Wallenberg family and French banks, the company was founded on December 2, 1905 as Norsk hydro-elektrisk (lit.

The process required large amounts of electric energy, and for this, a power plant was built at the Svelgfossen waterfall near Notodden.

By the 1920s, Norsk Hydro's electric arc-based technology for manufacturing artificial fertilizer was no longer able to compete with the newly developed Haber-Bosch process, and in 1927 the company formed a partnership with the German company IG Farben in order to gain access to this process.

The Rjukan plant was the only location in Europe which produced heavy water, a component the Allied powers in World War II feared would be used as part of the German atomic bomb project.

The first steps towards light metal production came in 1940 when Hydro started construction of a magnesium carbonate plant at Herøya, but the German invasion of Norway stopped the plans.

[7] (The consortium included Thomas Fearnley, Orkla, Fred Olsen, Storebrand, Jens P. Heyerdahl, Klaveness & Co, Christopher Kahrs Kielland.

This gave Hydro the world's largest alumina refinery and aimed to "secure raw materials for more than a hundred years of aluminum production".

[10][11] In 1965, Hydro joined Elf Aquitaine and six other French companies to form Petronord to perform search for oil and gas in the North Sea.

Hydro soon became a large company in the North Sea petroleum industry, and also became operator of a number of fields, the first being Oseberg.

In 1995 Hydro merged its gas stations in Norway and Denmark with the Texaco, creating the joint venture HydroTexaco.

Hydro's fertilizer business was spun off as a separately stock-listed company under the name of Yara International on March 26, 2004.

[13] In recent years, Norsk Hydro has faced criticism for continuing operations in Russia despite international sanctions and geopolitical tensions following the Russian invasion of Ukraine.

In Norway, Hydro has plants in Magnor, Rjukan, Raufoss, Vennesla, Karmøy, Høyanger, Årdal, Husnes, Sunndalsøra, and Holmestrand.

[17] In 2010, Hydro acquired the Brazilian bauxite, alumina and aluminium production assets of Vale, an international mining and metals company.

To secure electricity for its aluminium production Hydro has signed a power purchase agreement with the Fosen Vind wind farm, which is scheduled to be fully operational in 2020.

[20] In February 2018 Hydro was forced to cut aluminium production by 50% in its plant located in Pará, Brazil (operated by the joint venture Albras).

A team of local researchers found a clandestine waste pipe and highly elevated levels of aluminum in its proximity.

[21] Hydro has since claimed that while some unauthorized spills had happened,[22] their own and independent reports showed no environmental pollution of the river but only a small change in pH.