Report questions using renewably generated electricity to make e-fuels for aviation
The aviation sector is desperate to find some form of jet fuel that it can claim is low carbon, so it can justify continuing to fly ever more planes, transporting ever more passengers, against all logic of the carbon emissions generated. Hydrogen-fuelled and electric planes are not going to contribute in any meaningful way, for decades, if ever. That leaves SAF (Sustainable Aviation Fuel), one section of which might be “electrofuels” – ie. those generated by using surplus renewably generated electricity. But there are huge problems, due to the immense global demand for this electricity, which needs to be used for domestic heating and lighting, for all commercial buildings, all vehicles, trains etc etc. There just is not going to be much spare electricity, to (rather inefficiently) produce jet fuel. Now a new paper from a climate venture capital firm says this is not an efficient use of the electricity. “The figures show that a lot of renewable electricity is spent for scaling the production of synfuels which means it would be more efficient to use that electricity for other things like displacing coal generation or powering an electric vehicle.”
New Report Questions Electrofuels’ Efficiency In Decarbonizing Aviation
by Petya Trendafilova (Carbon Herald)
December 12, 2022
The World Fund – the European climate tech venture capital firm that invests in carbon removal startups with high potential, released a recent report featuring the state of electrofuels for aviation. It examines the emission reduction potential of synthetic fuels or “electrofuels” as a medium-term solution to decarbonize aviation.
The analysis evaluates the current impact of electrofuels within the aviation industry and also the consequences of deploying them on large scale in the energy system. It is divided into three parts – Part I of the report looks into electrofuels for the aviation industry, while Part II focuses on impact within the wider energy system and Part III of the report examines processes, challenges, and innovations related to the sector.
“How much carbon will be removed largely depends on how cost-effective it is compared to other mitigation options. This exemplifies that there are emissions reductions that likely will be more expensive than technological carbon removal,” said Robert Höglund an independent carbon removal advisor at Marginal Carbon, commenting on the analysis.
After examining the challenges of the aviation industry and available pathways of decarbonization, the only sensible answer turns out to be the use of drop-in fuels to replace conventional petroleum-derived hydrocarbons. Global aviation traffic is forecasted to double by 2040, and apart from syn fuels, other options for decarbonization are limited.
Battery electric flight can currently displace very short, low-volume flights, and replacing conventional aircrafts with hydrogen airplanes by 2040 is considered complex, expensive and time-consuming for now.
The report also critically examines electrofuels’ impact on the wider energy system. The KPI [Key Performance Indicator] used to evaluate it is the CO2 saved per MWh of renewable electricity. That literally means – does it make sense to use renewable energy resources to make synfuels compared to, for example, using them to displace gas generation or power a heat pump?
The figures show that a lot of renewable electricity is spent for scaling the production of synfuels which means it would be more efficient to use that electricity for other things like displacing coal generation or powering an electric vehicle.
The report also compares two pathways – using kerosene and offsetting its emissions with direct air capture versus using direct air capture for the production of synfuels.
Both processes require direct air capture powered by renewable energy, however, the synfuels process requires a lot more renewable electricity than kerosene and DAC [Direct Air Capture of CO2] . Scaling up the production of synfuels would also require vast quantities of renewable electricity generation, more needed in other places that can save much more CO2 per MWh of electricity.
One of the main conclusions of the report is that electrofuel production may lead to an adverse climate effect compared to a scenario in which DAC is used to compensate for emissions from kerosene. Still, more research is needed to confirm this conclusion as there are some factors that require more advanced knowledge.