Is electric battery power a one-fits-all solution for transportation?
A recent article published by Financial Times deals with the challenges faced by shipping industry in order to reduce the toxic emissions produced by vessels, in particular sulphur dioxide and CO2. In order to be compliant with stricter and stricter rules concerning emissions, some shipping companies have so far invested in switching from high-sulphur fuel oil to marine gas-oil (which is almost 50 per cent more expensive), or in retrofitting vessels with scrubbers (but there are also questions about the longevity of this investment).
Also the airways industry is affected by the same issues concerning GHG emissions. In both cases, one of the solutions currently on the table is the introduction of electric battery-powered ferries and aircrafts.
As a matter of fact, high GHG emissions are a problem common to all transportation industries (except railways). However, while Battery Electric Vehicles (BEV) seem to represent the concrete — and unavoidable — future of the automotive industry, can we state it too for the airways and shipping sector? If not, is it possible to identify an alternative technology to internal combustion engines (ICE) that can be deployed in all the above mentioned industries? And why is it important to reduce GHG emissions produced by vessels and aircrafts?
Lowering GHG emissions
Considering the main sources of GHG in EU in 2015, it clearly emerges that transportation as a whole (i.e. considering both private and commercial transports) is not the major provider of GHG to the atmosphere (it represents 24% of overall emissions); rather the main pollutant is the “Fuel combustion and fugitive emissions from fuels” (55% of overall emissions). This is a broad category including emissions coming from fuel combustion not related to transportation activities.
Hence, even if BEVs were extensively adopted, they would not be able to eliminate all the toxic emissions coming from fuel combustion; moreover they would not eliminate all the GHG related to transportation, since it is unlikely for aircrafts or cargo ships to be powered only by batteries (at least in the medium-term) because of the bigger size and longer life that would be required to batteries. However, it is fair to report that CO2 releases coming from road transport account for about the entirety of CO2 releases in the transport sector.
Considering that the environmental benefits of BEVs will offset just a minor, though material, part of overall GHG emissions coming from fuel combustion, would not be reasonable to focus the attention — and economic resources — on possible alternative technologies that can be applied beyond the automotive sector?
Fuelling a solution
Ideally, this technology shall not be invasive as BEVs from the engineering point of view, but at the same time shall comply with CO2 reduction targets. In the light of this, the solution could be working on the fuel rather than the engine. An example of this approach is synthetic fuel.
It consists of fuel produced from CO2 provided by biomasses or air and hydrogen. Hydrogen is extracted from water through renewable energy, while the CO2 needed for synthesizing fuel is retrieved from biomasses, but in the future it will be directly collected from the air. Eventually a carbon neutral fuel is produced.
Through this process it is possible to synthesize petrol, diesel and kerosene. In other words it provides a carbon neutral fuel to the whole spectrum of transportation and ICEs. Research is in progress for lowering the costs of CO2 extraction from the air. In this way, it would be possible to scale-up the Carbon Capture and Storage process, which is fundamental for holding global warming to 2°C. Furthermore, existing filling-station network can continue to be used also with synthetic fuel and the same applies to the existing combustion-engine expertise.
Nevertheless, the process for producing synthetic fuel is still expensive and painstaking, and it requires more energy to produce the fuel than you can get back from burning it (i.e. it is energy sink). Therefore, without any sort of scaling-up and usage of renewable energies, the process would be ineffective in reaching any GHG emissions target.
Conversely, if the consensus is to move from ICE to a different source of power, hydrogen technologies shall be considered. Full Cells (FC) technology presents some advantages in terms of energy storage, charging infrastructure and travelling range. In regard to the first point, FC need only water or natural gas as raw material inputs. Hydrogen can be physically transported similar to gasoline or diesel, and the needed to refuel is close to that of ICE vehicles. Finally, the higher range provided by fuel cells makes this technology more feasible for long-haul lorries. However, the technology behind FC is still immature and expensive. There are still several issues which have not been addressed, including the cooling of hydrogen, its safe storage system and increasing hydrogen extraction.
Conclusions
Lowering GHG emissions cannot be procrastinated and reducing CO2 impact of vehicles is a mandatory milestone. Currently the most trustworthy technology is the one of BEVs, as it is confirmed by increasing investments from car manufacturers and governments. Nevertheless, BEVs exposes to some economic and social risks in terms of: supply shocks, child labour, environmental impacts of mining and jobs. In addition, BEV technology cannot be applied to the full spectrum of means of transports.
Provided that the convergence in the future will be to FC, it seems more logic to focus on a technology that would have fewer impacts beyond the environmental field, but that at the same time is able to ease GHG emissions. Therefore, in the wait for FC to be economically viable, current ships and aircrafts should be fed with carbon neutral fuel; a solution that may potentially apply also to all processes requiring fuel combustion and not related to transportation. In this sense, the most promising technology is the one of synthetic fuels, but it is still expensive and not economically sustainable. However these issues were common also to renewable energies and BEV, but thanks to massive investments and scale-up, they have been overtaken.
(Note: this article expresses my own idea and not the one of the companies to which I am related)
