When Bent Blehr made his acquisitions in 1811, there were already three mills below the old intake dam where the Fulldøla river flows out from Follsjå lake. The last mill was built in the 1960s, and only the brick foundations now remain. In 1811, a sawmill for the farm was built, which was last used in the 1970s. Materials from this were used to build several of the cabins built at the entrance to Follsjå Kraft AS.
In the early 20th century, Sam Eyde and his company bought up all the rights to the utilisation of the watercourse, and the Årslifoss power plant was built in 1915 downstream of the Fulldøla river.
There was thus a long history of utilising the watercourses when landowners around the Fulldøla river and Follsjå lake began their work to develop a small-scale power plant. The landowners stood together through a time-consuming and difficult process, where many considerations had to be made due to the unique characteristics of Fulldøla and Follsjå.
On 12 December 2012, the final licence was granted to develop the power plant. The licence includes the right to regulate Follsjå itself and to exploit the waterfall along Fulldøla. 19. On 19 June 2013, the company Follsjå Kraft AS was founded by local landowners in cooperation with the Notodden company, Tinfos AS.
Due to the historical heritage of the area, extensive archaeological surveys were carried out, costing a total of over 1 million NOK. Remains of hunting and nomadic life dating back to the Stone Age were found, and near the intake, traces of the old industrial history can be seen in the form of timber flumes, old dam structures, and guide walls. In addition, approximately half a million NOK has been spent on biological surveys related to fish, freshwater pearl mussels, moss, lichen, and other fauna. In particular, the conservation of the important freshwater pearl mussel has been and remains vital in connection with the development and operation of the power plant.
Construction of the facility began on 18 March 2014, and the power plant was completed in record time. By 30 January 2015, approximately 3 weeks ahead of schedule, the power plant was finished. In 2016, Norsk Grønnkraft AS (later merged into Småkraft AS) acquired the power plant, and Småkraft AS currently owns approximately 82% of Follsjå Kraft AS. The remaining shareholders consist of local landowners.
