The present study investigates renewable energy analyzing the last twenty years of worldwide scientific production and the dynamics of interest around relevant policies in this direction. Based on a review on the role of knowledge development in technology transitions, we coupled bibliometric and expert debate approaches to provide decision makers with a sound analysis of thematic and regional trends in the field. Results show that the level of activity of researchers in the field of solar energy is somewhat contrasted only by biomass and wind energy. Despite countries being embedded in a global virtual network, geographical differences still arise: while North America and Europe show isomorphism of national communities and a high diversification of vertical foci, emerging research communities (e.g. BRICS countries) reflect market strategies (e.g. China) and the natural environment (e.g. Brazil) with a higher directionality of researches. Our findings provide an overall picture on world-wide development of competences as a relevant variable which policy makers should ideally consider in detail when setting integrated research, industrial and energy policies and strategies. (C) 2013 Elsevier Ltd. All rights reserved.