Hydrogen Fuel Cell Bus Technology State of the ... - NEXTHYLIGHTS

Hydrogen Fuel Cell Bus Technology State of the Art Review
Finally, the concept designs of hybridised fuel cell buses are broken down in their key
structural components in order to understand the architecture of the technology.
1.2 Hydrogen-fuelled Internal Combustion Buses
Hydrogen-fuelled internal combustion engine buses (H2-ICE) have also offered a
significantly lower fuel economy than hybridised fuel cell buses 4 . In addition their
exhaust is not strictly pollution-free, as some NOx is inevitably produced in the
combustion process. Table 1, below, summarizes the performance of recent H2-ICE
trials in comparison with hybridised fuel cell buses.
Table 1 Performance of hybrid fuel cell buses in comparison with non hydrogen-fuelled
internal combustion engine buses.
Fuel Economy
(kg of hydrogen consumed
per 100km)
Range
(assuming a 40kg hydrogen
storage capacity on-board)
In-service Pollution
(toxic emissions from
exhausts)
H2-ICE Hybridised Fuel Cell Bus
15 – 21.6 kg/100km
180 – 260 km
Traces 5 of NOx
Source: Hydrogen Bus Alliance, HyFEET:CUTE, stakeholders interviews.
8 – 15 kg/100km
250 – 450 km
The observed availability of H2-ICE buses in demonstration projects is comparable with
traditional diesel buses (~90%) and their capital costs are significantly lower than the
current generation of hydrogen fuel cell buses. As a result, developers have considered
pursuing H2-ICE-type designs as a transition to fuel cell buses. However, in recent years
the major engine manufacturers (Ford and MAN) who were pursuing the technology
have pulled back from H2-ICE, which has led to a shortage of viable engines for H2-ICE
based buses.
4 This fact has been proved by the HyFLEET:CUTE demonstration.
5 The high temperature within the combustion chamber promotes the chemical reaction
between the oxygen and nitrogen present in the air, producing oxides of nitrogen (NOx).
None
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