Do you have questions on our study? Or are you generally interested in the search for alternative fuels for aviation? Would you like to know what the main challenges for introducing alternative fuels or energy in aviation are? Whether it’s introduction is reasonable at all?
Yes, generally speaking, kerosene is currently the best fuel for aviation, as the aircraft, the engines, the fuel system and the suppliers have been build around it. However, there are various reasons why it is worthwhile looking for alternatives: The security of supply of kerosene and the problems of high and volatile oil prices as well as the environmental impact of aviation are the most dominant one. Especially with regard to the latter reasons, alternative fuels might have a huge benefit compared to newly developed technologies: A new fuel that could be used in the existing fleet offers a huge leverage for emission reductions. Imagine: A new fuel, that has a lower environmental impact could be – without major changes – used in all the aircrafts which are currently serving global demand. The environmental impact even of the older aircrafts could then be reduced. This is an emission reduction potential which is far beyond the impact of many other new technologies, as a lot of these could only be implemented in new aircraft.
The substitution potential of biomass derived fuels is a very complicated measure. It depends on the underlying land, the plants in focus and the processes how to make fuels out of the plants. The science community is currently still working on these issues. A simple answer to this question is therefore not available. A very recent study of the OECD  estimates that the global substitution potential of biofuels for the transportation sector could be around 23% in the year 2050. However, there are still many open questions: What would be the impact on water supplies? How could it be prevented that the production of biomass has a negative impact on food supplies or puts additional pressure on rain forests? And even if these questions can be solved: Where will the biomass be used later on: As biodiesel for the cars? In stationary plants for energy production? Or as a biojet fuel (in aviation)?
 Dornbusch, R. and Steenblik, R., “Biofuels: is the cure worse than the disease?”, Round Table on Sustainable Development, Paris, 11-12 Sept. 2007, Report Number SG/SD/RT(2007)3