Available online at www.sciencedirect.com International Journal of Hydrogen Energy 28 (2003) 735–741 www.elsevier.com/locate/ijhydene Full fuel cycles and market potentials of future passenger car propulsion systems J. Linssen∗, Th. Grube, B. Hoehlein, M. Walbeck Programme Group Systems Analysis and Technology Evaluation (STE) and Institute for Materials and Processes in Energy Systems (IWV-3), Forschungszentrum Julich! GmbH, 52425 Julich,! Germany Abstract The focus of the paper covers the current discussion on the contribution of fuel cell vehicles to so-called “sustainable mobility”. It evaluates whether advantages for the environmental situation and energy carrier supply can be expected from the already visible future characteristics of fuel cell propulsion systems in the transport sector. This contribution therefore determines full fuel cycle data for the energy demand and emissions as well as economic data. The di!erent paths of a hydrocarbon-based fuel supply are evaluated with respect to primary energy use and CO2 emissions from the fuel cycle. The technical systems analysis of fuel cell propulsion systems was realised with dynamic simulation models for driving cycles. The energy consumption and emission reduction potentials in the German passenger car transport sector were estimated for the introduction of fuel cell propulsion systems. Therefore scenario calculations were carried out to indicate how the results of the single analysis of technology and fuel supply concepts a!ect the German transport sector. The application of fuel cell electric vehicles in comparison to advanced internal combustion engine vehicles identiÿes a small CO2 emission reduction potential for the German transport sector depending on the assumed full fuel cycles. The reduction of limited emissions can be expected to be much greater, which can help to reduce local smog problems. ? 2003 Published by Elsevier Science Ltd on behalf of the International Association for Hydrogen Energy. 1. Introduction for stationary applications: natural gas • for mobile applications: natural gas, alcohols, liquid syn- • Fuel cell propulsion systems are still at the developing thetic hydrocarbons (in combination with on-board hy- and testing stage. They have to compete with propulsion drogen generation for fuel cell propulsion systems) systems like drive trains with advanced internal combustion engines (ICE), hybrid propulsion systems with high weights The trend of fuel cell development for mobile applications is and costs, as well as electric vehicles with the same disad- a!ected by the discussion about the “right” fuel, functional vantages of weight and cost due to the battery system. performance of the technology, cost reductions as well as With the application of hydrogen from non-fossil sources considerations about new added values. Di!erent require- fuel cells show advantages like low speciÿc energy demand ments at the fuel cell stack, system, fuel, onboard hydrogen and low or no speciÿc emissions in comparison to conven- generation and the entire vehicle have to be considered for tional internal combustion engines. fuel cell vehicles (see Table 1). In contrast to niche products, other energy carriers than Currently requirements at the cell, stack and system lead hydrogen will have priority for the medium-term energy to the use of low-temperature fuel cells with a polymer elec- market (next 10–20 years): trolyte membrane in vehicle propulsion systems. Therefore only PEFC (polymer electrolyte fuel cell) propulsion sys- tems are analysed for the evaluation of the full fuel cycles in the study. The calculations of emission and energy con- ∗ Corresponding author. Tel.: +49-2461613581; fax: +49-2461612540. sumption for di!erent full fuel cycles were subdivided into E-mail address: [email protected] (J. Linssen). vehicle and fuel supply considerations. 0360-3199/03/$ 30.00 ? 2003 Published by Elsevier Science Ltd on behalf of the International Association for Hydrogen Energy. PII: S0360-3199(02)00241-0 736 D.J. Linssen et al. / International Journal of Hydrogen Energy 28 (2003) 735–741 Table 1 The simulation results of the assumed vehicle class spread Requirements at fuel cell vehicles in Fig. 2 show a very wide range of fuel consumption for typ- ical vehicle classes. These classes are characterised by typi- Fuel cell solid electrolyte high power density cal vehicle parameters like weight, maximum power, maxi- mum top speed, minimum acceleration and so on. The high Stack heat dissipation (liquid cooling system) customer demands concerning acceleration and top speed in high power density the di!erent classes, especially in the large vehicle size, lead to a high weight of the FC vehicle. The reason for this is the System fast operational standby current high power speciÿc weight of the fuel cell propul- good dynamic behaviour (velocity of load sion system. The assumptions of the average customer re- change) quirements concerning basic weight, acceleration, top speed high degree of e#ciency for net electric and so on were made with the aid of registration statistics power generation for the current vehicle population in Germany. Table 2 in- provision of electric power in vehicle standby mode dicates some assumed characteristic vehicle parameters. small standby losses The characteristic vehicle and fuel cell data of the small high vibration insensitivity and shock resis- methanol fuel cell vehicle in Fig. 2 are not identical with tance those of the vehicle in Fig. 1 (di!erent approach for required minimum risk potential driving power of the propulsion system). As mentioned be- low-cost solutions for the periphery fore the currently high weight of fuel cell propulsion systems in comparison to ICE drive trains leads to greatly increased Fuel high energy density (high radius of opera- fuel consumption by large vehicles. Presently small vehicle tion) classes therefore seem to be the only meaningful market. long-term availability Besides the application of fuel cells in combination with future target: non-fossil fuel electric motors for vehicle propulsion systems, the e#ciency On-board hydrogen high fuel variability advantages of fuel cells may lead to increasing acceptance generation high dynamic behaviour of an electrical energy supply for vehicles. These auxiliary little impairment of e#ciency for net electric power units (APU) generate electric power in an e#cient power generation way (e.g. premium-class vehicles with high electrical power requirements) even in periods of vehicle standby. Vehicle high acceleration (power storage facility) In order to complete the full fuel cycle analysis the results su#cient radius of operation of the vehicle analysis have to be combined with di!erent recovery of brake energy and storage facility fuel supply paths. (stop and go) 3. Fuel supply 2. Vehicle analysis The introduction of new fuels should achieve the goals of fuel availability, generation, transportation, infrastruc- The technical analysis of fuel cell propulsion systems was ture, cost, safety and homologation requirements. The carried out with the dynamic simulation model SIMBA [1]. primary energy use and the CO2 emissions of di!erent With this model it is possible to determine the energy de- hydrocarbon-based fuel supply paths were determined with mand and emission data for the entire vehicle system in dif- the emission-balancing model KRAKE [3]. The starting ferent driving cycles. The consideration of the energy and point for di!erent fuel supply paths is the primary energy power management and the allocation of the fuel cell vehi- carriers crude oil and natural gas. The results for the di!er- cles to di!erent vehicle classes were the subject of further ent fuel supply cycles show a widespread dependence on the investigations (see Figs. 1 and 2). selected ÿnal energy carrier and the assumed production and Fig. 1 compares the results of the vehicle simulation in transportation paths (see Fig. 3). The supply of new fuels the study for the methanol fuel cell vehicle with results from like methanol and compressed or liqueÿed hydrogen may other studies [1,2]. Besides the methanol-fuelled vehicle a leads to signiÿcantly higher CO2 emissions except for CNG variant with compressed hydrogen is also simulated. The in comparison to the reÿnery path of gasoline and diesel. parameters of the simulated vehicles re$ect those of compact As part of a study by Research Centre Juelich [4] cost passenger cars. The results are therefore not representative of estimations for new fuel infrastructures were compared with the whole passenger car population. The calculations show a the aid of data currently available on investment costs for oil possible reduction of energy demand by the introduction of tankers, pipelines (remote and local) and ÿlling stations. The electric storage facilities for the methanol fuel cell vehicle supplementary expenditure for the new fuel infrastructure with PEFC. and thus the costs show a large range from a negligible D.J. Linssen et al. / International Journal of Hydrogen Energy 28 (2003) 735–741 737 fuelf cell propulsion system driving cycle with electric storage facility (improvement of dynamic 132 behaviour) ECECEECE 114 133 fuel cell propulsion system without storage facility; reference[2] 117 EUDCEUDC 106 121 fuel cell propulsion system 121 with gas storage facility; reference [1] EDCNEFZ 109 125 ECE: city cycle (Economic Commission 0 20 40 60 80 100 120 140 for Europe) E / (MJ/100 km) Methanol EUDC: extra urban driving cycle EDC: European driving cycle Fig. 1. Dynamic simulation of a methanol fuel cell propulsion system (compact class vehicle): results and comparison with literature sources. driving cycle EDC 300 250 7 quivalent) ä ] 250 5 157 [l/100km 176 200 3 150 112 Energiebedarf (benzin 1 EDC consumption energy 137 0 [l/100km] equivalent) (gasoline großgroß 100 95 large Fahrzeug- mittel 50 medium größenklasse Energiebedarf Energiebedarf im NEDC [MJ/100 km] vehicle class 0 kleinsmall energy consumption EDC consumption energy [MJ/100km] CH - PEFC - 2 MeOH - PEFC - PEFC Elektrofahrzeugfuel cell vehicle PEFC fuel cell vehicle (comp. hydrogen) Elektrofahrzeug (methanol;(Gasspeicher with) gas storage facility) Fig.