Muoidejohka power plant

Muoidejohka is located on the south side of the Beiardalen valley in Beiarn municipality, Nordland county. The river flows into the Beiarelva river, approx. 40 km from the outlet of the Beiarelva river in Beiarfjorden. The waterway will include a combination of buried pipes, drilled holes and a tunnel. The Muoidejohka power plant will be realised through a collaboration between private landowners, Småkraft and Statskog Energi.

History

The Krokstrand and Hammernes farms are located in Beiardalen in Beiarn municipality. Together with Statskog, which owns large land areas in Beiarn, they have the waterfall rights in Muoidejohka river. The landowners were aware that the river could have a good potential for small-scale hydropower. Realisation of the value creation from the river has been the subject of several plans over the years. In 1944, a cooperative was formed with 68 members, the purpose of which was to obtain electricity for people living in Gråttånes in the Beiardalen valley.

Much of the power resources in the inner part of the Beiardalen valley had undergone development in the early 1990s, but the Muoidejohka was not affected by the development at that time. When the next construction phase was to begin in the late 1990s, the intent was for the Muoidejohka to be transferred to Glomfjord. However, there was such fierce opposition that the government brought the project to a halt in 2000, just before construction began. In his New Year speech in 2001, Jens Stoltenberg proclaimed that “the time for new large-scale hydropower developments in Norway is over”.

In 2004, a contract was signed with Småkraft, which assumed the risk, the work with the licensing process and the development itself. During the final inspection, it became clear that Statskog was the owner of the upper part of the waterfall. Statskog became an active co-owner of the project, and Muoidejohka Kraft AS became the project owner. NVE granted a licence in 2010. Excavators arrived in the summer of 2011, and in 2014, the power plant was ready to deliver its contribution in the form of new renewable energy and local business revenues.

With its natural stone walls and a glass façade, the station building has an attractive exterior and has been nicely adapted to the terrain by the confluence of the Beiarelva river.

The project

The implementation of the project has had its challenges along the way, including the pilot project with drilling in the mountain, a waterway through porous rock, costly access to the power grid and telecommunications network, and a harsh winter during the construction phase.
Collaboration with landowners has been good. Their contributions in the form of local knowledge, and their presence during the construction phase has enabled a smooth project implementation.

Technical information

Muoidejohka power plant has inflow from a catchment area of 14 km2. The minimum water flow in winter is 10 l/s, while in summer it is 100 l/s. The intake at elevation 622 and the power station at elevation144 give it a fall height of 478 metres. Power production is estimated at 18.2 GWh in a normal year. This corresponds with an electricity consumption for 910 households.

The Pelton turbine has 5 nozzles with a maximum flow rate of 1.50 m3/s, and it operates a 5490 kVA, 6600 v generator. All power is converted to 22 kV and delivered to the grid. The grid is reinforced to the Beiarn transformer, which is located about 20 km further down in the Beiardalen valley.

The intake dam was built with blasted pools and a low dam in reinforced concrete, and with a wall cast between the box dam and intake pool. The intake is well adapted to the terrain of the site, and appears to be a modest intervention.

The penstock is made of cast iron and leads from the shaft to the station, while the shaft has steel pipes. The diameter is 700 mm. The entire waterway leads either through rock in the mountain or is buried.

The 80 m2 power plant building is constructed in the familiar Småkraft style and stands on the ground, well integrated into the terrain. Outflow is led through pipes/channel into the river.

Technical data

Rainfall field

14.0 km²

Minimum water flow

Summer: 100 l/s

Intake elevation

625 m

Power station elevation

144,0 m

Drop height

481 m

Production

18,2 GWh
This corresponds to electricity 1138 households.