aventron (formerly Kleinkraftwerk Birseck AG) was founded in November 2005 by Elektra Birseck Münchenstein (EBM). Two additional Swiss utility companies subsequently joined KKB: Energie Wasser Bern (ewb) in 2010 and Stadtwerk Winterthur (SWW) in 2013.
The two river power plants, Laufen and Dornachbrugg on the Birs river, were the foundations of the future aventron. In 2010 aventron entered the French market through the purchase of seven small hydro power plants. After increasing its capital, the company was listed the same year on the Bern eXchange (BX). The strategy was pursued successfully with further acquisitions in the solar and hydro sectors in 2011 and 2012.
The 2013 financial year saw the company acquire a further small hydro power plant in France, the construction of several large photovoltaic installations in Switzerland and the entry into the wind segment with the construction of a windpark in the Loire-Atlantique region of France.
2014 was a year of expansion and diversification with the opening of three further country holdings in Germany, Italy and Norway and the acquisition of power plants in those countries.
At the end of 2015, aventron was operating a portfolio of small power stations in the hydro, wind and solar sectors, controlling a capacity of 160 MW.
With its ten year anniversary in december 2015 the company decided to change its name to aventron.
In 2016 aventron completed its largest capital increase to date with over 131.9 millions swiss francs consisting of cash contributions of 57.6 millions and contributions in kind over 73.8 millions.
In 2017 and 2018 aventron steadily acquires further power plants, especially in the hydro segment Norway and the solar segment Italy. In August 2018 a capital increase over 94.3 millions is completed with 35.4 millions in cash and 58.9 millions in contributions in kind. The portfolio of power plants reaches a capacity of 476 MW year end 2018.