Stornorrfors Hydroelectric Power Station () is a hydroelectric power station on the Ume River in Västerbotten County, Sweden. The city of UmeÃÂ¥ lies about 15 km southeast of the power station.
Prior to the construction of Stornorrfors, the Klabböle Power Plant supplied power to the city of UmeÃÂ¥ several kilometers downstream from Stornorrfors. Klabböle's power plant was commissioned in 1899, and supplied power to the city until 1958, when Stornorrfors began operating.
Stornorrfors is owned by Vattenfall (75 %; municipality of UmeÃÂ¥ 25 %) and operated by Vattenfall. It generates more electricity per year than any other hydroelectric power plant in Sweden and is the country's second largest by nameplate capacity, after HarsprÃÂ¥nget.
Stornorrfors Dam is a concrete gravity dam located about 4 km from the power station. A canal connects the reservoir with the power station.
The power station contains 4 (or 5) Francis turbine-generators. The total nameplate capacity is 599.4 MW. Its average annual generation is 2,256 GWh. The hydraulic head is 75 m. Maximum flow is 975 mó/s.
The first 3 machines with 131 MW each went on line in 1958. The turbines were manufactured by NOHAB.
The fourth turbine with 187 MW was commissioned in 1982. The turbine was manufactured by Kværner.