Merikoski hydro power plant

The crown jewel of our energy production is the old Merikoski hydro-electric power plant, which has produced environmentally friendly electricity in downtown Oulu since 1948. The Merikoski power plant produces approximately 10% of our annual electricity capacity.

In terms of architecture, the Merikoski power plant is a gem. The facility and the surrounding area are among the city's most beautiful spots. A competition was arranged to choose the architects for the power plant and the area of the rapids. As a result the power plant was designed by architect Bertel Strömmer from Tampere, while the residential area of Toivoniemi was planned by architect Alvar Aalto.

The power plant project had been underway for a quarter of a century before the decision to build it was finally made in 1939. The Winter War, however, put the plans on hold. Construction works were started in 1940 just before the Continuation War broke out. After various ups and downs the power plant was finished in 1954.

Merikoski hydro power plant

  • Electrical output 40 megawatts
  • Three hydroelectric generator sets
    • First generator set connected to the grid in 1948
    • Second generator set connected in 1950
    • Third generator set connected in 1954
  • The generator sets and the power plant building were renovated completely in 1993–1996.
  • Backwater height was increased to 11 metres in 1997.
  • The Merikoski fish ladder was built in 2003.
  • Generator sets 1 and 3 were modernised in 2004–2005.
  • Production record: 294 gigawatt-hours (2015).
  • In autumn 2014, a light art installation was built to the Merikoski segment dam to celebrate Oulun Energia's 125th anniversary.

The Merikoski Fishway: Enabling the salmon to swim upriver

Finland's longest fishway – and the only fishway in the Oulujoki river – was built to circumvent the Merikoski power plant in 2003. Thanks to the fishway, salmon and other migratory fish can reach a 40-kilometre stretch of the river above the Merikoski power plant up to the next power plant in Montta, and swim to the Muhosjoki and the Sanginjoki rivers, tributaries of the Oulujoki river. 

On the map