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. On 19 June 2013, the company Follsjå Kraft AS was founded by local landowners in cooperation with the Notodden company, Tinfos AS.
Because of the historical heritage in the area, extensive archaeological investigations were carried out, which cost a total of over NOK 1 million. Traces of hunter and gatherer groups were found, dating all the way back to the Stone Age, and near the intake you can see the remains of older industrial history in the form of timber chutes, old dams and retaining walls. In addition, nearly half a million Norwegian kroner has been spent on biological research on fishing, freshwater pearl mussels, moss, lichen and other fauna. Preservation of the important freshwater pearl mussel has been, and still is important in connection with the development, and for the operation of the power plant.
Construction on the facility began on 18 March 2014, and the power plant was completed in record time. The power plant was completed as early as 30 January 2015, approximately three weeks ahead of schedule. In 2016, Norsk Grønnkraft AS (which later merged with Småkraft AS) purchased the power plant, and today, Småkraft AS owns about 82% of Follsjå Kraft AS. Local landowners are the remaining shareholders.