Int. J. Technology, Policy and Management, Vol. 11, Nos. 3/4, 2011 307 Copyright © 2011 Inderscience Enterprises Ltd. The role of policy in the evolution of technological innovation systems for photovoltaic power in Germany and the Netherlands Véronique Vasseur* and René Kemp International Centre for Integrated Assessment and Sustainable Development, University Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands E-mail: veronique.vasseur@maastrichtuniversity.nl E-mail: rene.kemp@maastrichtuniversity.nl *Corresponding author Abstract: In this paper, we examine the role of policy in the evolution of technological innovation system and diffusion of solar photovoltaic (PV) panels in Germany and the Netherlands. PV power development and diffusion have been actively supported in both countries; however, Germany has a well- developed technological innovation system and a successful industry, whereas the Netherlands has not. The focus of this paper is on the dynamic relationship between policy developments and technology innovation systems developments. Within both countries policy has changed over time but the German feed-in law provided an element of continuity which the Dutch policy lacked. The creation of a successful industry for PV in Germany can be attributed to the greater consistency and continuity of the German policies. Keywords: technological development; regulatory framework; diffusion of PV. Reference to this paper should be made as follows: Vasseur, V. and Kemp, R. (2011) ‘The role of policy in the evolution of technological innovation systems for photovoltaic power in Germany and the Netherlands’, Int. J. Technology, Policy and Management, Vol. 11, Nos. 3/4, pp.307–327. Biographical notes: Véronique Vasseur is a PhD Researcher at ICIS (International Centre for Integrated Assessment and Sustainable Development, Maastricht University), The Netherlands. She focuses on how users can contribute to the development and diffusion of sustainable energy technologies now and in the future. She graduated as a Master of Science with a major in Innovation Management. René Kemp is a Professor of Innovation and Sustainable Development at ICIS (International Centre for Integrated Assessment and Sustainable Development, Maastricht University) and Professorial Fellow at UNU-MERIT in Maastricht, The Netherlands. He is an expert on eco-innovation and sustainability transitions, two fields which he helped to develop. He is a Member of the editorial board of the journal Environmental Innovation and Societal Transitions, Editor of the Springer book series Sustainability and Innovation, Member of the scientific board of ARTEC, University of Bremen and Advisory Editor of Research Policy. He has over 200 publications in the field of