 Hydrogen 3
No, this is only marginally about the advantages and disadvantages of hydrogen buses. Nor is there any distinction between green and gray hydrogen. Two buses are being evaluated for their suitability as hydrogen buses.
Let's start with the 'Bus of the Year 2025,' the Solaris Urbino 18 hydrogen, which, in our opinion, best lives up to the label. Like all its class, it is first and foremost an electric bus, here even in its most conventional form.
This means they've removed the diesel engine and replaced it with a surprisingly powerful electric motor. Others, for example truck manufacturers, sometimes use at least two engines because they obviously have
difficulties finding such a powerful engine.
It's a 240 kW motor from Medcom in Warsaw, with which Solaris collaborates in Poland. The lithium titanium oxide battery, typical for fuel cell vehicles, is relatively small at 60 kWh.
Ballard is a well-known fuel cell manufacturer with whom Mercedes has also collaborated in previous years. It has 100 kW of power and a lifespan of >30,000 hours. If the engine needs more power, it draws it from the
battery.
Unlike a passenger car, it operates at up to 350 bar, which would mean less effort for gas stations serving this clientele. The tanks are located on the roof and are modular.According to the manufacturer, a range of over
600 km is possible when fully equipped.
Next, we'd like to introduce you to the eCitaro with fuel cell. Unlike the Solaris, the Mercedes has an electric axle from ZF, which is also different from the one in the eActros. Presumably, the low-floor bus concept was a key
factor here.
The all-electric and hydrogen-powered Citaro differ very little from each other. The 295 kWh is about half of the 588 kWh of the all-electric eCitaro. Essentially, you refuel with hydrogen, but you also need to recharge with
electricity at the depot to achieve maximum range.
You can even recharge electricity made from hydrogen, but that seems completely pointless to us. With the small amount of hydrogen—six tanks totaling 30 kg—the range naturally drops to 480 km, according to the
manufacturer.
The assumed 6.3 kg/100 km is surprising. Under unfavorable conditions, 40-tonners can reach twice that, while Mercedes' hydrogen bus also has a permissible total weight of 20 tons, but requires a much more complex
heating system.
Despite its extensive battery configuration, the Mercedes can still be considered lightweight, as the Solaris weighs 29 tons, albeit only as a solo bus. Nevertheless, this eCitaro would have to be described as a bus with a
hydrogen-powered range extender.
Or if you take a closer look, you'll discover that Mercedes is using a variant of the Toyota Mirai's fuel cell, not the Ballard one as before. And the 5 kg fuel tanks also seem to be borrowed from cars. What would you conclude
from this?
| 
