Transitions between technological systems involve evolutionary processes. The past both shapes the current system and influences future options and pathways. Understanding the nature of energy transitions has become particularly important in light of the major changes that the world faces in the next century in the way that energy is sourced, converted and used. Policy-makers and decisiontakers need to understand the extent to which they can, or should, manage the transition. This paper proposes that a detailed study the patterns of change in a specific sector's past can improve our understanding of how it might evolve. A methodology is presented and applied to a case study of the prospective transition towards renewable raw material (RRM) use in the production of liquid fuels and organic chemicals in the UK. A process analysis of the historical transition to petroleum-based fuels and chemicals was used to shape a series of contemporary interviews that explored the perceptions and expectations of key actors in RRM and biorefining. The results show that the innovation system is already experiencing the socio-technical dynamics of regime disruption and competing designs. An empirical basis is offered for the the use of past transitions to inform scenarios for the future. (C) 2012 Elsevier Ltd. All rights reserved.