No one says that weaning air transport off its dependence on fossil fuels will be easy. For those with any doubt about the scale of the challenge, however, a new report from the UK’s Royal Society provides sober reading material, concluding that no single path to achieving net zero carbon exists and that the avenues now being explored are all fraught with technological and practical difficulties.
The "Net Zero Aviation Fuels: Resource Requirements and Environmental Impacts" paper published on February 28 focuses on four sustainable alternatives to jet-A fuel: hydrogen, ammonia, synthetic efuels, and biofuels. A working group led by Cardiff University’s professor Graham Hutchings assessed these options against the following considerations: the equivalent resources that would be required to replace fossil fuel, a lifecycle analysis and non-carbon-dioxide environmental impacts, likely costs, and modifications and replacement needed to implement the option.
Among the more startling conclusions in the context of the UK industry is that the country would have to allocate huge areas of agricultural land to support biofuel production or more than double its renewable electricity supply just to support the greening of aviation. “We need to be very clear about the strengths, limitations, and challenges that must be addressed and overcome if we are to scale up the required new technologies in a few short decades,” concluded professor Hutchings.
The difficulties regarding the availability and accessibility of sustainable feedstocks for biofuel production head a list of the report’s main conclusions. The working group stressed that some of the science related to the various options isn’t yet sufficiently understood. It called for more research and development in areas such as the efficient production, storage, and use of green hydrogen, ammonia, and efuels.