The mobility sector accounts for 25% (Rodrigue, 2017) of fossil energy demand globally. In most countries, if we breakdown emissions per sector, mobility constitutes a high percentage of the emissions. In mobility, there has been tremendous growth in the capabilities of battery-electric and alternative fuel vehicles in recent years however they still make up a small percentage of the overall number of vehicles available. Further to this, Pricewaterhouse Coopers (PWC) believe we will likely see a change in the economics of powertrains (PwC Strategy & Germany, 2018) allowing for further development and demands for particular fuel cell batteries to grow.
Due to the nature of the mobility sector accounting for a large proportion of CO2 emissions globally, the tightening of emission standards has increased the TCO of ICE with conventional fuels. At the same time, the cost degression witnessed with BEV and hybrid vehicles is likely to continue. To add to this, we have seen a demand for hybridisation over previous year especially for surface transport.
This is likely to continue, combining the advantages of chemical energy carriers with electric traction but there will be a shifting focus only so that energy carriers must be renewable in the future.
From a technical standpoint, there are still many mobility applications that require large volumetric or specific energy densities provided by oil, 64% (Surveyed experts based on the SWAFEA study) of mobility sector to be exact. Over all mobility applications, this occurs mainly for vehicles that need long range without refuelling/recharging, move heavy loads or need to be lightweight. Later in this chapter we will address particular areas of the mobility sector and show how the need for powerfuels and regulation supporting the technology is unique for all applications. Ultimately, the results from the analysis indicate that powerfuels constitute a large opportunity for de-fossilisation. In some applications there is no known alternative, hence powerfuels can help mitigate risks for market stakeholders in the wake of upcoming regulation.
For years now, aviation has been improving its energy efficiency and carbon footprint around the world. Despite high growth rates, aviation has accounted for more than 2% of CO2 emissions globally (European Commission, 2016). By comparison, the share was 2.92 percent in 2000. This is due to increasingly efficient flights ensuring that the absolute CO2 emissions in the aviation sector grow at a lower rate than emissions from other sectors. In 2015, intra-European flights accounted for 0.52 percent of total CO2 emissions in the EU, while in Germany the share of CO2 emissions from domestic flights was 0.3 percent of total German emissions (IEA, 2019b).
Worldwide aviation fuel consumption through jet fuel (kerosene) is estimated to be at 200 to 225 million tonnes (Surveyed experts based on the SWAFEA study). European fuel consumption makes up approximately one quarter of this figure at around 54 million tonnes (Surveyed experts based on Eurostat). At a conversion factor of 3.16 (This is the conversion factor used in CORSIA. The ETS currently uses a conversion factor of 3.15, but will in the future align with CORSIA) tonnes of CO2 per tonne of kerosene burned, this corresponds to a CO2 emission of about 650 to 700 billion CO2 worldwide, and about 170 million tonnes of CO2 from uplifts in Europe. If present growth processes persist, these emissions will double or triple by 2050 (ICAO, 2016). It is also important to recognise that there is some ground emissions from aviation, but those emissions only amount to 1 to 2% of flight CO2 emissions (There is no comprehensive report on these emissions, but the European Aviation Environmental Report 2019 states 2017-2018 direct emissions under the full control of the airport to have been 1.985 million tonnes of CO2. To this, some additional emissions by airlines and third party operators must be added, but these are not exactly known). What is also important to be recognised is that CO2 emissions are also dependent on the particular location of the plane whilst taking into account the altitude to which the emissions are being produced.
In 2009, airlines, aircraft manufacturers, air navigation service providers and airports worldwide agreed on a climate protection plan: to increase fuel efficiency by approximately 1.5 percent per year; to achieve carbon-neutral growth in air travel by 2020; and to halve net CO2 emissions by 2050 compared to 2005 levels. These goals will be achieved by implementing the following measures:
Already today: increase efficiency – reduce CO2 increase
Reducing the specific energy requirements of aircraft will cut fuel consumption and, in turn, CO2 emissions. The measures designed to achieve this improvement include technical innovations by aircraft and engine manufacturers, optimally coordinated operational processes on the ground and in the air, and implementation of the Single European Sky.
The goal: fly carbon-neutral
In order to be able to fly CO2-neutral in the long term, we need to see the development of new airplanes, alternative fuels and drives, combined with the political support to make their use commercially viable.
On the way to the goal: compensate carbon growth
As global air traffic continues to grow by about five per cent per year, the reduction in specific fuel consumption is not enough to stop the increase in CO2 emissions. Therefore, at the UN level, the international CO2 offsetting system CORSIA was adopted by the Civil Aviation Organization ICAO. As part of CORSIA, growth-related CO2 emissions of international flights will be compensated by financing carbon offset projects from 2021 onwards. It should be noted that whilst it is clear that offsetting is helpful in the short run since it is a rather ‘cheap avoidance option’ for regulatory governing bodies and airlines, at the same time it does not foster technological progress for CO2 avoidance in the aviation sector.
The figure (left) illustrates that it is almost certain that the future growth of air traffic will overcompensate potential efficiency gains. Therefore, the large-scale use of renewable energy carriers (such as powerfuels) has to be seen as key pillar towards GHG-reduction within the aviation sector (Schmidt et al., 2016, p. 10).
The Aviation sector is very much characterized by the need for fuels that exhibit both volumetric and gravimetric energy density. Although there have been some tests with hydrogen (DLR) and hybrid (Siemens) or battery-electric (Flugrevue, EasyJet wants electric aircraft for short-haul flights, https://www.flugrevue.de/zusammenarbeit-mit-wright-electric-easyjet-will-elektroflugzeuge-fuer-kurzstrecken/) propulsion, for long-haul commercial flights there is consensus that there is no alternative to liquid hydrocarbon fuels for the foreseeable future.
Ideally, powerfuels could replace all fossil kerosene. The regional distribution corresponds to that of air traffic, i.e. the focus is on the US, Europe, the Middle East and Asia (Airbus, 2018). Air traffic growth is expected to be considerable over the next couple of decades, and fuel consumption is expected to grow correspondingly, albeit at a lower rate owing to technical improvements. Powerfuels fuels should be drop-in, hence should have no impact on operations. The alternative to powerfuels fuels are other renewable liquid fuels, like biofuels.
Powerfuels will need to be REACH registered and ASTM certified. However, these are minor issues compared to getting powerfuels production going. For example, some synthetic fuels (Fischer-Tropsch based) have already been approved according to ASTM D7566 and can now be used in blends of up to 50% with conventional jet fuels (Schmidt et al., 2016, p. 14), but other developments of powerfuels are still not ASTM approved. One particular mean in tacking this potential barrier is to build we build up a global standard and database for alternative sustainable fuels like NABISY (Bundesanstalt für Landwirtschaft und Ernährung, 2019) to allow globally produced kerosene to be counted towards a potential global emissions trading scheme.
Another factor to take into account regarding powerfuels in aviation is price. This may to some extent be industry specific, as aviation is facing rather high demand elasticity, particularly if such price increases are not global. Ultimately there needs to be a shift in environment to see prices become more affordable for commercial use.
In 2012 the maritime transport sector emitted about 796 million tonnes of CO2, which represented about 2.2% of global emissions (IRENA, 2017, p. 34). Due to the increasing role of global trade, emissions of this sector are expected to increase in the future. For example, in a scenario with no additional policies, CO2 emissions from global shipping are projected to reach 1090 Million tonnes by 2035 (23% growth compared to 2015) (ITF, 2018, p. 13). Consequently speaking, although global regulation on mandatory energy efficiency standards in shipping was introduced in 2013, various studies project shipping’s GHG emissions to grow if additional measures are not taken.
The large majority of GHG emissions attributed to the maritime transport sector originates from the combustion of fossil fuels within the ships’ engines. Therefore, potential abatement options to reduce emissions within the maritime transport sector either represent measures to reduce the fuel consumption of ships or focus on the substitution of fossil energy carriers with alternative fuels. The fuel consumption within the maritime transport sector can be reduced by technological and operational measures. Weight reduction (e.g. by replacing heavy steel by lighter material such as aluminium) and optimisation measures to scale down the friction of ships (e.g. slender hull design, hull coatings and air lubrication) fall within the first category. This also holds for the recovery of waste heat for on-board needs and the application of more efficient propulsion devices. The fuel reduction potential of these options are not easy to assess, as they highly depend on respective ship characteristics, but estimates of various scholars are mainly below 10%. Moreover, as the relation between ship size and emissions is not linear, economies of scale could be realised if larger ships were used (ITF, 2018, pp. 26, 29).
Furthermore, fuel consumption could be influenced by the mode ships are operated. The most promising option here is to reduce ships’ speed, which could yield an estimated CO2 reduction potential of up to 60% depending on the speed decrease. However, slower speeds automatically come with the need of more ships to keep the transport service frequency stable. This would yield to an increase in investment cost (ITF, 2018, p. 28).
It is not controversial that to meet the 2° climate target, a strong de-fossilisation of all sectors, including shipping is required. As the reduction potential of the measures descripted above is limited, it is obvious that alternative fuels will play an important role for the reduction of GHG emissions in the maritime sector (Lloyds’s Register Marine and UCL Energy Institute, 2014). In this regard, the most promising fuels within the shipping sector are:
With respect to our definition (see chapter 2), hydrogen, ammonia and methanol represent powerfuels, if their energy content is based on renewable electricity.
Batteries are tested in ferries (Siemens, ABB), but for long-distance shipping there is the need for higher energy density in both weight and volume. This is further exacerbated by the high power rating of marine motors up to 80 MW. Therefore, from today’s perspective there are large improvements in terms of battery capacity needed, in order to represent a broad option for the maritime transport industry. Additionally, the electric vessel was shown to be the least profitable alternative fuel options (Lloyds’s Register Marine and UCL Energy Institute, 2014).
In contrast, biofuels are sometimes seen as the most profitable zero-emission solution (Lloyds’s Register Marine and UCL Energy Institute, 2014). Already today they can be produced in such quality, that they are compatible with existing marine engines. Nevertheless, studies highly question whether the supply potential for biofuels will be sufficient to cover the needs of the global shipping fleet (ITF, 2018, pp. 32–33). In regards to hydrogen, it can be used in fuel cells or as substitute (either completely or partly as blends) for heavy fuel oil (HFO) in combustion processes. For, example a fifty-fifty-mixture of HFO and hydrogen can reduce CO2 emissions by up to 43% per tonne-kilometre (Bicer & Dincer, 2018).
When addressing ammonia, the reduction potential is of similar size (Bicer & Dincer, 2018). Ammonia is a hydrogen carrier, which has the advantage of higher energy density compared to hydrogen. It can be used in fuel cells or directly in combustion engines. However, within the shipping industry it has not been tested yet and there exists no operational ship powered by ammonia today (ITF, 2018, p. 35). However, MAN Energy Solutions announced an engine in early 2019 (Ammonia Energy: www.ammoniaenergy.org/man-energy-solutions-an-ammonia-engine-for-the-maritime-sector/). Finally, methanol also represents an alternative fuel option that has already been tested within the maritime transport sector. For example, there is a large methanol-powered passenger and car ferry that is operating between Germany and Sweden. However, the methanol supplied there is produced from natural gas (ITF, 2018, p. 36). Further, MOL operates an methanol-powered methanol carrier since 2013 (Ammonia Energy, 2019).
Given the variety and diversity of the shipping industry, it is obvious that there will be no one-size-fits-all option to reduce GHG emissions of this sector. However, it was shown that powerfuels such that hydrogen, ammonia and methanol represent promising alternatives to HFO and thus huge opportunities for the maritime transport sector.
Whereas powerfuels are promising, their practical application within the shipping industry is still very limited to pilot projects. This can be mainly attributed to the fact that they are not yet cost competitive compared to HFO. For example, a study by Lloyd’s register estimates that throughout different scenarios none of the above mentioned alternative fuels options will be more profitable than a HFO reference ship in 2030 (Lloyds’s Register Marine and UCL Energy Institute, 2014). This indicates that market forces are insufficient to induce a broad fuel switch and thus highlights the importance of regulation.
Passenger cars account for a significant share of emissions worldwide, emitting approximately 3.5 Gt of CO2 per year. This constitutes 45 % of all transport emissions and approx. 10 % of the global GHG emissions (IEA, 2018a). Despite strong progress in recent decades, car manufacturers are increasingly under pressure by both consumers, general public and regulators to further reduce local and GHG emissions.
Vehicle manufacturers are looking at addressing the issue by making the manufacturing process, as well as the final product for consumers more carbon neutral. Further, the last years have seen increased efforts in the development of affordable and reliable electric vehicles (EV’s). Besides, stakeholders are increasingly addressing a shift to other, more sustainable modes of transport.
Over the next decade, it is predicted that in addition to Internal Combustion Engine (ICE) vehicles, there will more than likely be plug-in hybrid electric vehicles (PHEV’s), fully battery-powered electric vehicles (BEV’s), and fuel cell electric vehicles (FCEV’s) running on hydrogen (PwC Strategy & Germany, 2018, p. 5). Studies have shown that system costs are lower for BEV cars in a driving range considered short to medium, however if the range is considered medium to long in distance, FCEV’s have a lower system operation cost (National Organisation Hydrogen and Fuel Cell Technology (NOW), 2018, p. 5). Liquid powerfuels can be a viable option to reduce GHG emissions in the existing vehicle stock.
Car manufacturers that are currently in the production phase of Hydrogen fuel-cell based cars include:
In addition, car manufacturers are also involved in pilot synthetic fuel production projects, for example the Audi e-gas plant in Werlte and the Audi e-diesel plant in Laufenburg.
Most manufacturers addressing several of the potential abatement options mentioned above. The replacement of hydrogen from fossil origin in refineries by renewable hydrogen could be one of the first measures to reduce well-to-wheel emissions.
There is no current regulation to help incentivise power fuel driven cars. Through efficiency measures, we have seen the reduction of GHG emissions and fossil fuel use. Due to each type of technology having specific parameters influencing their affordability and accessibility, the overall price of each technology is symbiotic of one another individual markets:
Whilst there has been a shift towards electric heavy vehicles in recent years, trucks and buses continue to be dominated but internal combustion engines that are powered by fuels. In urban agglomerations, public transport also causes high CO2 emissions. In most developed countries, the buses used in public transport are almost exclusively diesel vehicles (Strategieplattform Power-to-Gas, 2018a). It is also common knowledge that there is a direct correlation between the burning of fuels and CO2 emissions. Additionally, heavy vehicles are aligned with notions of long distance travel and high transport capacities, climate-friendly fuels with high energy density are necessary. There is a necessity for powerfuels as we continue to see a demand for the usage of heavy duty vehicles. According to the IEA, heavy duty vehicles emit approximately 2 Gt of CO2 per year. Which accounts for 29% of all transport emissions worldwide and 6% of global GHG emissions (IEA, 2019a). 2017 in Europe saw two key phenomena occur; first the amount of new car registrations increased to a record high of 15.2 million. This was the highest total we have seen since 2007 (ICCT, 2017, p. 2). Second, average emissions levels for new passengers increased by 1g/km now taking the total 119 grams per kilometre (ICCT, 2017, p. 3).
As previously mentioned in the cars chapter, manufacturers are looking at developing both electric and hydrogen fuel cell batteries. Most of the technologies currently available are feasible and available for distribution trucks but further research and developments are being made to make the technology more efficient. From an operational costs, the potential for battery electric heavy-duty long-haul trucks is limited because of a limited range without significant payload penalty. Therefore, installing overhead catenary wires along express highways is proposed.
The Ports of Los Angeles and Long Beach in the USA are planning to electrify highways for drayage operations (CE Delft & DLR, 2013; SCAQMD, 2015a). However, if electric heavy-duty vehicles for which the electricity is supplied by overhead catenary wires are to reach a significant share of overall freight transport services, a grid of overhead wires across the whole EU would be required (Deutsche Energie Agentur & Ludwig-Bölkow Systemtechnik, 2017, p. 34). Only a few member states, among them Germany and Sweden, are discussing overhead catenary wires as a source of electricity for heavy-duty vehicles. In addition to natural gas/LPG and hybrid drive systems as well as direct electrification, the use of powerfuels will make an important contribution to reducing traffic-related emissions in the future.
The use of powerfuels primarily on lines with a high vehicle load factor are an needed supplement to the direct the use of powerfuels is a sensible supplement to direct electrification, especially on routes with high vehicle utilization. Powerfuel-based drives currently have longer ranges and significantly shorter refuelling times than Electric Vehicles.
The technological barriers are similar to the ones mentioned in the cars chapter however, further barriers have been identified from a fuel cost perspective. From a commercialisation standpoint, the cost of hydrogen varies between $10 to $15 per kilogram. Whilst the efficiency of hydrogen is a positive in comparison to diesel or petroleum fuels, improvements still need to be made in terms of advancing power density, capital costs and efficiency (Advance Clean Tech News, Hydrogen Fuel Cell Future Is Promising for Heavy-Duty Trucks, 31 October 2018 https://www.act-news.com/news/hydrogen-fuel-cell-vehicles/). Further to this, whilst there is existing infrastructure for fuelling stations already present, each fuelling station would now need additional infrastructure and increase operational and safety costs in order to fulfil the requirements to refuel heavy-duty vehicles.
In 2015, the global energy-related CO2 emissions of the rail sector mounted to 336 million tonnes CO2, thus making up a share of 4.2% of global transport emissions. Although declining since 2005, the share of fossil oil products (diesel) in the global railway fuel mix still represents a significant fraction of 56% (IEA & UIC, 2017, p. 22). This can be attributed to the fact that on the global level, the majority of railway tracks is not electrified. This holds particularly for emerging economies (as of 2016 62% of tracks are electrified in China, 45% in India, 24% in Africa and less than 10% in South and North America) (IEA & UIC, 2017, p. 23). However, even in industrialized countries, a large part of rail traffic is not electrified, but runs on diesel.
For example, in Germany, about 40 percent of the rail network are not electrified and necessitates the operation of diesel locomotives. This holds particularly for local passenger and freight transport routes where electrification – from an economic point of view - is not worthwhile (Strategieplattform Power-to-Gas, 2018a). Their joint annual diesel consumption mounts to more than 400 million litre diesel with associated emissions of about one million CO2-equivalents (BMUB, 2017, p. 37).
Theoretically, the full electrification of train traffic combined with the use of electricity of renewable energies is an abatement option for the rail transport sector. However, building overhead lines is very expensive and requires substantial infrastructure investments. Depending on the utilisation rates of the respective tracks, these high infrastructure costs could make an electrification economically unfeasible.
This is often the case for local network sections with limited utilisation. As a reference, the share of diesel locomotives on total rail transport service is only 8% in Germany) (Bundesministerium für Verkehr und digitale Infrastruktur (BMVI), 2018, p. 44). Furthermore, emissions could be reduced by improving the fuel consumption of trains. Examples for potential measures are braking energy recovery or weight reduction. Nevertheless, these measures will only lead to limited reduction in GHG emissions, as long as the combustion engine is further fed with fossil-based fuels.
The use of alternative propulsion technologies such as hydrogen fuel cells represent a promising abatement option for non-electrified rail transport, if electrification is (economically) not feasible. In case, the used hydrogen has been produced based on renewable electricity, such hydrogen trains do not emit GHG emissions or other pollutants at all.
The first pilot projects have already proven the suitability of this technology for the rail sector. The Coradia iLint hydrogen fuel cell train that has been developed by Alstom can serve as example here, as it is the first regular operating train that is powered with hydrogen. In 2018, two pilot trains equipped with fuel cells that convert hydrogen and oxygen (from the ambient air) into electricity took up commercial service and have been operating on a regional connection in Lower Saxony (Germany) since then (https://www.alstom.com/press-releases-news/2018/9/world-premiere-alstoms-hydrogen-trains-enter-passenger-service-lower).
A challenge lies in the production, transport, storage and supply of hydrogen. With full compensation of railway associated diesel demand in Germany alone, 120,000 tonnes of hydrogen will be needed. This would probably require an installed electrolysis capacity of 1 to 1.5 GW (Strategieplattform Power-to-Gas, 2018a). Furthermore, from a logistical perspective, the use of so-called on-site electrolysers would be an option - these generate the hydrogen directly adjacent to the railway infrastructure.