46Risø Energy Report 3<strong>Hydrogen</strong> for transport5.4• vehicles can maintain full performance over 5,000operating hours; <strong>and</strong>• hydrogen costs fall to $1.50-$2.10 per gallon gasolineequivalent.The Fuel Cell Commercialization Conference of Japan(FCCJ) arrived at a similar estimate for the threshold costof fuel cells: ¥5,000 ($42)/kW, including auxiliary equipment.CRF prototypesIn projects funded by the Italian Ministry of the Environment,Fiat's CRF research centre developed twoconcepts for PEMFC city cars (Figure 24).Conclusions <strong>and</strong> recommendationsEstimations of the size of a future market for hydrogenpropelledcars have shown dramatic divergences <strong>and</strong>there is still no consensus concerning the near future.Although direct hydrogen fuel cells <strong>and</strong> pressurisedonboard hydrogen storage currently seem to have aleading position in the competition between hydrogentechnologies for transport purposes, it is still uncertainwhat the winning technology will be.The problem of cost effective <strong>and</strong> energy effectivehydrogen storage onboard vehicles is persistent <strong>and</strong>needs considerable scientific <strong>and</strong> technical attention ifwe want hydrogen vehicles to be comparable to conventionalvehicles concerning operation range.
Risø Energy Report 3<strong>Hydrogen</strong> in portable devices 475.5<strong>Hydrogen</strong> in portable devicesJUERGEN GARCHE, ZSW – ELECTROCHEMICAL ENERGY STORAGE AND ENERGY CONVERSION DIVISION; ULRICH STIMMING, TECHNISCHE UNIVER-SITÄT MÜNCHEN; ANDREAS KASPER FRIEDRICH, ZAE BAYERN; ROBERT FEIDENHANS'L, RISØ NATIONAL LABORATORYIntroductionFuel cells were originally intended for use in powerplants <strong>and</strong> vehicles. More recently, developers realisedthat it is possible to build much smaller un<strong>its</strong> <strong>and</strong> forlower prices per kilowatt than their larger relatives. Thishas led to strong interest in developing small fuel cells.Small fuel cells could replace batteries in portable electronicequipment (up to 100 W) <strong>and</strong> internal combustionengines in portable generators. The upper limit forportable generators is about 5 kW, mainly because of theweight of the fuel cell.The International Electrotechnical Commission IEC saysof fuel cells for h<strong>and</strong>-held or portable devices: “The fuelcell power unit may be intended for mounting in a dedicatedcavity in the device for easy removal, or maybe ast<strong>and</strong>-alone electrical power source system intended forconnecting to one or more devices with a wiring <strong>and</strong>connector means”[1].The main applications for low-power fuel cells aremobile phones, personal digital assistants (PDAs), laptop<strong>and</strong> notebook computers, cameras, medical equipment,military applications <strong>and</strong> other portable electronicdevices. In comparison to batteries, fuel cells can supplymuch more power per unit volume or weight, thoughthey have lower output voltages <strong>and</strong> are slower torespond to transients.Applications for fuel cells up to 5 kW include portablegenerators, uninterruptible power supplies (UPSs), auxiliarypower un<strong>its</strong>, power tools, light vehicles such as electrictrolleys, lawn mowers <strong>and</strong> roadside equipment.Fuel cell types that are suitable for portable applicationsinclude:• proton exchange membrane fuel cells (PEMFCs) usingpure hydrogen (H 2 -PEMFCs);• PEMFCs using hydrogen-rich gases from hydrocarbonor alcohol reforming (Ref-PEMFCs);• direct methanol fuel cells (DMFCs); <strong>and</strong>• high-temperature fuel cells such as solid oxide fuel cells(SOFCs) <strong>and</strong> molten carbonate fuel cells (MCFCs) usinghydrocarbons directly.cations. However, PEMFCs that are to be integrated intosmall electronic devices, need to be specially designed forminiaturisation.Fuel cells for portable applications have the advantagethat the cost per kW is much less important than forstationary <strong>and</strong> transport applications. They are usuallyonly required to have relatively short lifetimes, typicallyof the order 2,000 hours. This makes them suitable forrapid market introduction.Fuel cells do not create new applications for portableequipment, but they can improve the practical value ofexisting devices. As battery replacements, for instance,fuel cells can increase the operating time of electronic<strong>and</strong> electrical equipment. In portable generators theyeliminate the noise <strong>and</strong> emission characteristics ofinternal combustion engines.These advantages will only be taken up if the costs of fuelcells are comparable with those of the technologies theyreplace. As shown in Figure 25 this is already close to bethe case for portable equipment. In this marked sector itis therefore only necessary to solve the remaining problemsassociated with reliability, lifetime, volume <strong>and</strong>weight.ApplicationsLow-power applications in electronic devices(up to 20 W)Fuel cells for small electronic devices such as mobile <strong>and</strong>cordless phones, pagers, radios, portable CD players, taperecorders <strong>and</strong> battery chargers are known as “device-integrated”because the requirements set lim<strong>its</strong> on the fuelFigure 25: Costs at which fuel cells will become competitive in differentapplications (“4C” = camcorders, cellular phones, computers, cordlesstools).Cost/€/kW5.0004CPortableDMFCs are mostly used for small un<strong>its</strong> <strong>and</strong> devices inintegrated systems because they use a liquid fuel with ahigh energy density that is easy to distribute. PEMFCs arebetter for high-power systems because of their higherpower density. Applications of small high-temperaturefuel cells are limited to auxiliary power un<strong>its</strong> that are infrequent use, <strong>and</strong> therefore they will not be dealt withfurther in this chapter.PEMFCs for portable generators do not differ much fromthe large PEMFCs used in stationary <strong>and</strong> transport appli-5005005StationaryCar50 power/kW
Change language