In the early 2000s high expectations existed regarding the potential contribution of biofuels to the reduction of greenhouse gas emissions and substitution of fossil fuels in transport. In recent years sobering judgments prevailed. The major barriers for a further expansion of biofuels are their...

Rapidly growing fossil energy consumption in the transport sector in the last two centuries caused problems such as increasing greenhouse gas emissions, growing energy dependency and supply insecurity. One approach to solve these problems could be to increase the use of biofuels.

The discussion on the promotion of biofuels is ambiguous: on the one hand benefits like reduction of greenhouse gas emissions and increase of energy supply security are expected, on the other hand low effectiveness with respect to reducing greenhouse gas emissions and high costs are being...