In this paper we will pose the question whether a higher level of user participation could be used as a strategy to improve the development and dissemination of sustainable energy technologies. We will especially focus on user-led innovation processes with a high involvement of individual end-users. In our argument we will draw on several case studies in the field of renewable energy technologies-in particular solar collectors and biomass heating systems-and sustainable building technologies. Users in these case studies were involved in the design or planning processes, sometimes in a very selective way and with limited influence, sometimes very active and for quite a long period of time. Especially in the case of renewable energy technologies self-building groups were highly successful and resulted in improved and widely disseminated technologies. Based on the empirical results of our case studies we will critically discuss the potential of user involvement (especially in self-building groups) for the development and promotion of sustainable energy technologies and outline technological and social preconditions for the success of such approaches. (c) 2004 Elsevier Ltd. All rights reserved.