The starting point is that the current energy system is largely dependant on fossil fuels. This phenomenon, which is labelled as carbon lock-in by Unruh (2000), makes the breakthrough of renewable energies long, slow, and tedious. The most suitable theoretical approach to analyse the development, diffusion and implementation of emergent technologies, such as renewable energies, is the Technological Innovation Systems' (TIS) perspective as developed by Carlsson and Stanckiewicz (1991). This approach focuses on a particular technology and includes all those factors (institutions, actors, and networks) that influence its development. Recent research has identified several so-called System Functions that need to be fulfilled for a TIS to support successfully the evolution of a technology. In this paper we will use the following set of System Functions: F1: Entrepreneurial Activities, F2: Knowledge Development (learning), F3: Knowledge Diffusion through Networks, F4: Guidance of the Search, F5: Market Formation, F6: Resources Mobilisation, F7: Counteracting Resistance to Change (also Support from Advocacy Coalitions). By focusing on the System Functions the key processes that occur in a system which influence the development, diffusion and implementation of that technology will be identified and insight will be gained in the system dynamics. The System Functions are not independent but interact and influence each other. The nature of interactions whether they are positive or negative will influence the performance of the system respectively. Positive System Function fulfilment can lead to positive, i.e. virtuous cycles of processes that strengthen each other and lead to the building up of momentum that creates a process of creative destruction within the incumbent system (Jacobsson and Bergek 2004). According to the same reasoning, a system in decline is characterised by one or more vicious cycles, where the System Functions interact and reinforce each other in a negative way. The results from the case studies showed that different functional patterns occurred for the Biomass Innovation Systems. These can be divided into virtuous and vicious cycles. In the case of virtuous cycles a successful diffusion of the respective technologies occurred (for example biomass digestion in Germany and biomass co-firing in the Netherlands), whereas low diffusion is observed for the technologies (for example biomass digestion, biomass gasification and stand-alone biomass combustion in the Netherlands) where vicious cycles dominated the system. Furthermore, the findings show that biomass technologies go through long-term trajectories (10-30 years) of development, diffusion and implementation. However, the Dutch government only provided short-term policies and removed all support when the technical problems were not solved within this short term. In order to accelerate the diffusion of biomass energy technologies a long-term and stable guidance by the government is needed where time and space for trial and error are provided, where a market is formed and where entrepreneurs pack together to lobby for better institutional conditions for their technology