In 2009 Østfold Energi, together with Nord-Trøndelag Elektrisitetsverk, purchased Siso and Lakshola power plants in Nordland county.

This acquisition brings Østfold Energi’s share of Norway’s total hydropower production to around 1.7 per cent.

Østfold Energi is co-owner of Kvalheim Kraft DA who owns and operates the windmill park Mehuken in Sogn og Fjordane on the west coast of Norway.

The company also holds ownership of Zephyr (33%), Norsk Grønnkraft (25%), Kvalheim Kraft (33%), Rygge sivile lufthavn (15%) and Hafslund (4.5%).

[2] In April 2017, Orkla, Thon Holding AS and Østfold Energi have entered into an agreement with the investment company Jotunfjell Partners for the sale of Rygge Sivile Lufthavn AS.