Brussels, 25 January 2011
Alternative fuels for transport
Transport has been the sector most resilient to efforts to reduce CO2 emissions due to its strong dependence on fossil energy sources and its steady growth despite the considerable efficiency gains that have already been made. Emissions can be reduced by improving energy efficiency, transport efficiency, and effective transport demand management. But the ultimate solution to decarbonising transport is the substitution of fossil fuels by CO2-lean energy supply to transport.
What is the current situation of transport in relation to fuel supply and climate protection?
Transport fuel supply today, especially road transport, is dominated by oil. Combustion of mineral oil derived fuels gives rise to CO2 emissions and, despite the fact that new vehicles emit significantly less CO2, emissions from transport have increased, representing today almost 20% of total European Union greenhouse gas emissions. The EU objective is an overall reduction of CO2 emissions of 80-95% by the year 2050, with respect to the 1990 level.
On the other hand, oil production is expected to start declining in the coming decade and reach depletion by 2050. Substitution of oil therefore needs to start as soon as possible and increase rapidly in order to ensure the security of energy supply.
How is the Commission addressing this situation?
The Commission is currently revising existing policies and launching new strategic initiatives for more sustainable transport in the EU. In the context of the so-called initiative on clean transport systems, the Commission established in March 2010 a stakeholder "expert group on future transport fuels", with the objective of providing advice to the Commission on the development of political strategies and specific actions aiming towards the substitution of fossil oil as transport fuel in the long term. The Commission has also launched a study on clean transport systems for a quantitative assessment of scenarios potentially capable of fully meeting the long-term energy demand with sustainable and secure transport systems. The objective of the Commission is to develop a consistent long-term European fuel strategy for transport, in a communication foreseen for the end of 2011.
Is there a single-fuel solution covering all transport modes?
A single solution covering all transport modes could be technically possible with liquid biofuels and synthetic fuels. But feedstock availability and sustainability considerations constrain their supply potential. Thus the expected future energy demand in transport can most likely not be met by one single fuel. Fuel demand and greenhouse gas challenges will require the use of a variety of primary energies. There is widespread agreement that all sustainable fuels will be needed to meet the expected demand.
What are the alternative fuel options for substituting oil in transport?
According to the report of the Expert Group on Future Transport Fuels, the main alternative fuels for propulsion in transport are the following:
Electricity/hydrogen, and biofuels (liquids) as the main options
Synthetic fuels as a technology bridge from fossil to biomass based fuels
Methane (natural gas and biomethane) as complementary fuel
Liquefied Petroleum Gas (LPG) as supplement
Which options of alternative fuels for the different transport modes?
Road transport could be powered by electricity for short distances, hydrogen and methane up to medium distance, and biofuels/synthetic fuels, LNG and LPG up to long distance.
Railways should be electrified wherever feasible, otherwise use biofuels.
Aviation should be supplied from biomass derived kerosene.
Waterborne transport could be supplied by biofuels (all vessels), hydrogen (inland waterways and small boats), LPG (short sea shipping), LNG and nuclear (maritime).
Electricity and hydrogen solutions
Electricity and hydrogen are universal energy carriers and can be produced from all primary energy sources. Both can in principle be made CO2 free, depending on the energy mix for production. Propulsion uses electric motors and energy can be supplied via three main pathways:
Battery-electric, with electricity from the grid stored in batteries. Application is limited to short-range road transport. The development of cost-competitive high energy density batteries and the build-up of charging infrastructure are the highest priority. Power transfer between the grid and vehicles requires new infrastructure and power management.
Fuel cells powered by hydrogen, used for on-board electricity production. The development of cost-competitive fuel cells, on-board hydrogen storage, and strategic refuelling infrastructure is of highest priority. Hydrogen production, distribution and storage require new infrastructure.
Overhead Line / Third Rail for tram, metro, trains, and trolley-buses, with electricity taken directly from the grid without the need of intermediate storage.
Biofuels could technically substitute oil in all transport modes, using existing power train technologies and existing re-fuelling infrastructure. First generation biofuels are based on traditional crops and animal fats. They include biodiesel, bioethanol, and biomethane. Advanced and second generation biofuels are produced from ligno-cellulosic feedstock and wastes. The production of biofuels from both food and energy crops is limited by the availability of land, energy and co-product yields, and sustainability considerations. Second generation biofuels are limited by the availability of raw materials.
The development of feedstock potential and of optimised production processes is the highest priority. A supportive policy framework at EU level and harmonised standards for biofuels across the EU are key elements for the future uptake of sustainable biofuels.
Synthetic fuels, substituting diesel and jet fuel, can be produced from different feedstock, converting biomass to liquid, coal to liquid or gas to liquid. Hydrotreated vegetable oils (HVO) are of similar nature. Di-Methyl Ether (DME) is another synthetic fuel produced from fossil or biomass resources via gasification, requiring moderate engine modifications. Synthetic fuels can be distributed, stored and used with existing infrastructure and existing internal combustion engines. They thus offer a non-disruptive option to replace oil-based fuels, with the perspective of further improved system performance with engines specifically adapted to synthetic fuels.
The development of industrial scale plants for the production of synthetic fuels derived from biomass is a key priority, while efforts should be continued to improve the CO2 balance.
Methane can be sourced from fossil natural gas or from biomass and waste such as biomethane. Biomethane should preferentially be fed into the general gas grid. Methane-powered vehicles should then be supplied from a single grid. Additional refuelling infrastructure has to be built up to ensure widespread supply. Propulsion uses internal combustion engines similar to those for liquid hydrocarbon fuels. Liquefied methane (LNG) could be a possible option where high energy density is required. Harmonised standards for biomethane injection into the gas grid and the build-up of EU-wide refuelling infrastructure are the highest priority.
LPG (liquefied petroleum gas) is a by-product of the hydrocarbon fuel chain, currently resulting from oil and natural gas, in future possibly also from biomass. LPG is currently the most widely used alternative fuel in Europe, powering five million cars and accounting for a 3% share of the fuel consumed by passenger cars. The core infrastructure is established, with more than 27,000 public filling stations.
Are EU policies required for the harmonisation of alternative fuels?
All main alternative fuels should be available EU-wide with harmonised standards, to ensure the free circulation of all vehicles throughout the EU. Incentives for the main alternative fuels and the corresponding vehicles should be harmonised EU-wide to prevent market distortions and to ensure economies of scale supporting rapid and broad market introduction of alternative fuels.
How can energy policies and transport policies co-operate supporting alternative fuels?
The main alternative fuels considered should be produced from low-carbon, and finally from carbon-free sources. Substitution of oil in transport by these main alternative fuels leads then inherently to a decarbonisation of transport if the energy system is decarbonised. Decarbonisation of transport and decarbonisation of energy should be considered as two complementary strategic lines, closely related, but decoupled and requiring different technical approaches.
Report of the European Expert Group on Future Transport Fuels:
See also IP/11/61