Middøla power plant

The dam and intake are constructed of cast-in-place concrete with intake grates downstream of the dam slab that utilises the coanda effect. According to the watercourse licence, minimum water flow past the dam and intake of 50 l/s must be released all year round.

The pressure pipe is 2700 metres long and consists of ductile cast iron pipes and Ø900 mm fibreglass reinforced pipes. In addition, a 15-metre pipeline bridge was built across the Middøla river. There is a 2-bend along the pressure pipe and 4 t-tubes for access into the pressure pipe.

A Pelton generator with 6 nozzles has been installed in the power station with a maximum flow rate of 1.9 m³/s. The power station consists of a machine room, control room, transformer and high voltage room, and the building is constructed with pre-cast concrete elements.

The power plant was built by the local Notodden company Tinfos AS.

Contracting parties during the construction included:
– Bystøl, in charge of engineering
– Fadum Tekniske, supplied the turbine and electromechanical equipment
– Brødrene Dahl, supplied pipes and components for the dam and intake
– Brødrene Alseth, contractor with responsibility for all ground and concrete work
– A-til-Å Entreprenør, contractor with responsibility for the superstructure of the power station

The power plant was later sold to Norsk Grønnkraft AS (which later merged with Småkraft AS). It is now owned by Småkraft AS.

Technical data

Rainfall field

29.3 km²

Minimum water flow

Summer: 50 l/s

Intake elevation

530 m

Power station elevation

255,0 m

Drop height

275 m


12,0 GWh
This corresponds to electricity 750 households.