Bjordalen is a power plant located in Hjartdal municipality and is linked to the Skien watercourse.
The power plant was commissioned in 1960 and utilises a 50-metre waterfall between the lakes Skjesvatnet and Breivatnet. Water is also taken in from Heiåi river. The power plant has a Francis turbine and an installed output of 2.9 MW.
The capacity of the transfer tunnel is limited, which can result in water being lost during busy periods. The water supply from Skjesvatnet lake to the power station is partly conveyed through pipes above the ground. This requires flow-through of water during low-temperature periods to avoid freezing. It is therefore important to keep production going in the power plant throughout the winter.
The power plant underwent significant refurbishment in 2017.
Bjordalen Power Plant is wholly owned by Skagerak Kraft.