The yet-unspecified turbine will be used to gain operational experience to help the development of future offshore projects.
Statkraft already operates a 150MW project on the island. It uses 20 2MW and 48 2.3MW Siemens turbines.
It was built in two phases with the first phase commissioned in 2002 and the second phase in 2005.
The 8MW turbine will be incorporated and operated from the existing wind project.
The 150MW project has been criticised by conservation groups in the past, including the UK's Royal Society for the Protection of Birds, after the deaths of four rare white-tailed eagles in 2006. Last year, Statkraft painted some of the turbines' blades black in a bid to prevent further bird deaths.
Norway's energy department said the installation of the 8MW would not affect the area's avian wildlife.
Statkraft is involved in the development of the 7.2GW Dogger Bank offshore development in UK North Sea waters.