Transport

Alternative fuels and power sources to reach zero-emission transportation

Perhaps the shift towards a sustainable economy will be most clearly visible in the transport sector. New possibilities to use biofuel, hydrogen, electricity or combinations of these will undoubtly re-shape the future highway environment, travel and transport dynamics and also the landscape itself. Many promising technologies are on the verge of being implemented on a large scale - making long-term sustainability an important research agenda.

Transport contributes by around 25% to the global GHG emissions and comparably in Norway by 33%. The higher share in Norway is primarily due to stationary power generation being fully covered by hydroelectric sources, and secondly due to Norway’s demography and the massive coastal traffic. In Norway road transportation alone contributes by 25% to the total domestic GHG emissions, and both road and maritime transport have experienced a significant growth over the last decades. With an annual domestic energy consumption in transportation of about 60 TWh and vast amounts of un-exploited renewable energy available the transport sector represents a key area for GHG emission reductions in Norway.

The predominance of fossil fuels in transportation is still high although fuels based on renewable resources have been introduced in some market segments. As part of the European Union’s ambitious strategy for reducing the CO2-emission, a new directive is being introduced in order to secure the supply of alternative fuels through a parallel development of refuelling infrastructure for natural gas, electricity, biofuels and hydrogen. It is foreseen that various fuels and propulsion technologies will dominate different segments of transport in the future. (See figure on the opposite page).

The European Commission’s overview of which fuels are suitable for various segments of transport. The proposal for the directive was launched January 2013, and the general approach was adopted by Member States December 2013.

In the directive natural gas is also included as this will provide environmental benefits with respect to emission of particulates and NOX when replacing diesel in some market segments, like in heavy duty vehicles and in maritime transport. This SFFE strategy will, however, focus on fuels which are purely based on renewable energy and will therefore only consider electricity, biofuels and hydrogen.

When evaluating these alternative fuels’ potential contribution to emission reductions it is important to include the availability of resources. Although biofuels according to the figure may be used in all market segments, biofuels should (due to limited availability) be reserved for segments of transport where there are no or few other alternatives, like in heavy duty transport over longer distances, maritime transport and aviation. Furthermore, to secure optimal utilization of renewable based electricity as well as biomass, it is crucial to realize that stationary power production and transport are competing for these same resources.

Technology status

Electric propulsion of vehicles is nothing new. At the turn

of the 18th century, more battery electric vehicles (BEVs) were sold than cars with internal combustion engines (ICEs). During the late 1960s the first fuel cell electric vehicle (FCEV) was demonstrated, in which the energy is stored as hydrogen and converted to electricity upon demand. Since the (re-)introduction of the hybrid electric vehicle (HEV) Toyota Prius in the passenger car market in 1997, most auto manufacturers now offer hybrid versions of some of their models. Moreover, bio-based fuels have been utilised for almost a century, although initially at low shares. Europe is currently producing significantly volumes of bio fuels and is targeting a 10% of biofuels in 2020.

Electricity BEVs are available from many auto manufacturers and are currently selling very well in Norway, totalling 20.000 vehicles registered by the end of 2013, related to tax exemptions and a wide range of benefits for BEVs and FCEVs. High sales are also expected in the next years. HEVs combine a conventional ICE with an electric drive-train and a small battery pack, thereby reducing fuel consumption significantly for city driving at varying load, for which regenerative braking represents the major part of these savings. HEVs now take more than a 50% share of Toyota’s sales in Norway. Plug-in hybrid electric vehicles (PHEVs) have a larger battery pack than HEVs which may be charged from the grid. The number of PHEV models on the market is increasing, but they are still selling in low numbers due to higher cost than cars with conventional ICE power trains.

Hydrogen Hydrogen powered FCEVs are technologically mature (see also the chapter Hydrogen applications) and will in the period 2014-2017 be introduced to the market by several leading auto manufacturers; Hyundai, Toyota, Honda, Daimler, Nissan and Ford. The number of vehicles is, however, currently limited to some hundreds globally. Several demonstration projects within public transportation (buses) are also in progress. Political engagement is increasing especially at regional level. Application of hydrogen as fuel in maritime transport has recently also received attention. Public support for establishment of hydrogen infrastructure is a prerequisite for FCEVs to take market shares.

road rail air water

natural gas

electricity

biofuel

hydrogen

urban medium long short medium long inland short routes maritime

European Commission’s overview of which fuels are suitable for various segments of transport. The proposal for the directive was launched January 2013, and the general approach was adopted by Member States December 2013.

Biofuels In Norway the agrarian crops growth rate is generally too low for profitable production of first generation biofuels, unless larger quantities of biodiesel is produced from rape seeds. Second generation bio fuels can, however, be produced from wood or marine raw materials like macro algae, which have a high potential in Norway.

According to Statistics Norway (SSB) the potential for utilization of Norwegian woods, biogas and seaweed as resources for biofuels all together cover 2300 million litres fuel annually. [1] As comparison, the fuel consumption for coastal traffic is 1800 million litres/ year and for the domestic air traffic 1000 million litres/ year. The total fuel consumption for transport in Norway in 2011 was 7700 million litres. [2] The resources for biofuel could hence, cover around 30% of the required fuel in Norway.

Challenges

Substitution of conventional crude oil based fuels with renewable alternatives like electricity, hydrogen and biofuels constitute viable options to reach zero-emission transportation. However, the varying degree of efficiency and competition regarding resources require that several technologies are developed in parallel to ensure sufficient supply of renewable energy for transportation applications. Introduction of one fuel or new propulsion technology alone will not solve the overall problem we are facing.

Driving range still limits the widespread deployment of BEVs for intercity driving, but the establishment of a network of super-chargers along the main roads is in progress, extending the use of BEVs to rural areas. Despite tax reduction based on CO2-emissions for PHEVs in Norway these are still more expensive than the corresponding vehicles utilising conventional ICE power trains.

Limited access to and high initial cost for hydrogen as fuel also constitute important challenges, which needs to be resolved before the FCEVs can be introduced in the market and represent a realistic alternative for the end user. Incentives for fuel-providers must be introduced in order to stimulate the investments in and profitable operation of hydrogen refuelling stations until these become commercially viable.

Introduction of biofuels to the current transport system is possible and requires limited changes to the infrastructure. However, the lack of cost efficient

conversion technologies for marine and terrestrial

R&D recommendations:

• Ensure commercially competitive biobased fuels, including biogas for all sustainable production paths through a combination of tax incentives and research activities. policy recommendations:

• Public support for establishing charging/refuelling infrastructure for electic vehicles and biofuels is needed to support deployment of sustainable transportation.

• Preserving the tax exemption incentives for zero-emission vehicles until their number exceeds 50.000 or until these are commercially competitive.

• A joint assessment with respect to availability of and demand for energy across stationary power production and transportation.

R&D recommendations:

• Develop more cost-efficient power cycles for low to medium temperature heat sources (100-250°C) based on benign working fluids.

• Increase the knowledge related to heat capturing technology in order to develop novel cost efficient heat exchanging technologies. policy recommendations:

• Develop industry cluster concepts to minimize emissions of waste heat.