Oulujoki river system
Oulujoki is a 107 km long river in the Oulu province in Finland. Fortum has eleven hydro power plants in the Oulujoki river system: Aittokoski, Ala-Utos, Jylhämä, Leppikoski, Montta, Nuojua, Pyhäkoski, Pälli, Seitenoikea, Utanen and Ämmä.

Aittokoski hydro power plant
The Aittokoski hydro power plant, completed in 1960, is located along the Emäjoki river in Suomussalmi.
The output of the Aittokoski hydro power plant is 45 MW and the head is 30 meters. One Kaplan turbine. Average annual production covers the annual electricity use 6,000+ households with electric heat.