This international comparative study provides insight in the political-institutional conditions that have impeded and encouraged onshore wind power implementation in the Netherlands, England and the German state of North Rhine-Westphalia. The extent to which wind power, as a new energy technology, has become embedded in existing routines and practices (institutions) of society, differs between the cases. North Rhine-Westphalia, which is most successful in terms of installed capacity, is also most successful in terms of social acceptance of wind power. Wind power developments started in the form of grass-roots initiatives in which many citizens participated. Over time, in North Rhine-Westphalia, wind power became embedded as an environmentally preferable energy source, as a new economic sector, and as a socially acceptable alternative to conventional energy generation. In the other cases, the historical trajectories have been different and less successful.