This master's thesis examines the development of wind energy cooperatives (WECs) in the Netherlands between 1986 and 2014. It analyzes how their production capacity and membership has grown over three phases: an emergence phase from 1986-1996 under monopoly conditions, a consolidation phase from 1997-2012 in a competitive electricity market, and the introduction of a new business model from 2013-2014. The thesis finds that two main business models were used - one focused on local communities introduced by ODE, and one not tied to specific regions introduced by Windcentrale. WECs using the local model relied on geographical proximity for expansion, while those using the other model did not. A key development was the professionalization of some WEC