Kemijoki Oy is the most important producer of hydroelectric power and related services in Finland. The company owns 20 hydropower plants, 16 of which are located in the River Kemijoki system, two on River Lieksanjoki and two on River Kymijoki. In addition, the company regulates the Lokka and Porttipahta artificial lakes, Lake Kemijärvi and Lake Olkkajärvi. The electricity produced at the power plants is sold at cost price to the company’s hydroelectric power shareholders.