Svelgfoss Power Plant was commissioned in 1958. It gets its water from the Tinnelva river, which is part of the Skien watercourse.
The original Svelgfoss I from 1907 was once Europe’s largest and the world’s second largest power plant, second only to the plants at Niagara Falls. Svelgfoss I was developed to secure power for Norsk Hydro’s first saltpetre factory in Notodden. Later, Lienfoss Power Plant was commissioned in 1911 and Svelgfoss II in 1915. These three power plants have now merged into the new Svelgfoss Power Plant. The waterfall height is 70 metres.
The power station has two generators with Francis turbines. The installed output is 96 MW.
The owners are Norsk Hydro ASA with 70.8% and the Hjartdøla Group (Skagerak Kraft) with 29.2%.