The energy agreement for sustainable growth, includes an objective to have 6000 MW installed wind energy capacity on land in the Netherlands by 2020 and emphasizes the important role wind cooperatives can play in achieving that objective. Currently, the 25 Dutch wind cooperatives have a minor influence with the 4% wind energy capacity share they have installed. However, sufficient information on what influences their success is lacking. It is challenging to understand in what way wind cooperatives can be stimulated to play a more prominent role in achieving the objectives of the energy agreement without understanding the success of wind cooperatives. Therefore, the following main research question was defined: What are the key determinants of the success of Dutch onshore-wind cooperatives, and in what way do these determinants influence their success? An explorative research approach was designed, starting with a literature research. That research was followed by an empirical research, to identify what determinants are perceived to be important by actors in practice. Face-to-face semi-structured interviews with wind cooperative representatives and experts, were used as data collection method. The determinants were retrieved from the empirical data, via coding global interview transcripts. Data analysis resulted in a list of 74 validated determinants. The most important determinants and the relations between them were used as a basis for a tentative conceptual model. Determinants relating to collaboration, interaction with stakeholders and sharing knowledge and expertise prove to be most important. Wind cooperative are recommended to enhance knowledge and expertise sharing via the organisations that are already established. Besides that, wind cooperatives seem to have different perceptions regarding lobbying, therefore it is suggested that wind cooperatives discuss what approach is most appropriate in which situation. Policy makers are recommended to provide more specific guidelines for participation plans, and to raise awareness for the existence of (wind) energy cooperatives among citizens. If the government aims to let wind cooperatives play a more dominant role, the government should also think of measures to make land positions available for cooperatives. Further research is recommended to focus on validation of the determinants and the relations between them, towards a conceptual model.