LAUSR

Abstract The competitiveness of conventional and advanced (second generation) biofuels is a critical issue for the implementation of a sustainable transport strategy. We model biofuel competition under different feedstock cost development scenarios, assessing what costs and cost developments can be expected for energy crops in Germany and how these feedstock cost developments affect the competitiveness between biofuels. Perennial poplar was found to be the least-cost energy crop, with non-perennial silage maize being strongly competitive at increasing feedstock price developments. Assuming increasing feedstock costs for the future, neither conventional biodiesel from rape seed nor advanced biodiesel were found to be competitive in the long run. Feedstock costs were found to overshadow all other factors, leading to costs for advanced biodiesel to be between 27.0 and 53.6€ GJ−1 in 2030, which is above most expectations. Of the advanced biofuels, only synthetic natural gas was cost-competitive under some circumstances, but biomethane from silage maize and bioethanol from sugar beet were the strongest options, as they combine high yields with high conversion efficiencies while avoiding the high upfront costs of advanced biofuels and the risk of switching to perennial crops. However, such a transition leads to less mobile feedstocks being used than presently and in the case of gaseous fuels requires stimulation of the demand side in order to function. The high dependence on and increasing relevance of feedstock costs is characteristic for the biobased renewables only and is detrimental and inhibiting for investments and research and development efforts, in contrast to for e.g. wind and solar photovoltaics, and must be considered when designing policy for any sector of the bioeconomy.