A new methodological framework for Life Cycle Assessment (LCA) of future technologies is developed by combining prospective methods that are used to reflect technological change (like Technology Foresight and Experience Curves) with the traditional LCA approach. In contrast to traditional static LCA, a direct link between LCA tools and energy system modelling is established, enabling direct feedback loops between future energy system configurations and the life cycle inventories of individual energy technologies (dynamic LCA). Life cycle inventory data for the reference technologies (e.g. kg SO2-emissions per kWh) are combined with results from Research Stream 1b (providing external costs per unit of environmental intervention, e.g. €/kg SO2-emissions) to quantify external costs per kWh for each reference technology.