> Hyundai ix35 fuel cell tank cutaway. Source and permission: greenmotor.co.uk
The picture above says to me: hydrogen vehicles are always going to be a cludge. Just look at that fuel tank! It’s an aluminium core surrounded by hundreds of layers of some plastic or other - and that’s just one of two tanks in the Hyundai ix35 demonstrator, totalling 144 litres.
I just don’t know. As you know from my previous post, I would love fuel cell cars to succeed, but the challenges to producing a sensible vehicle system and ecosystem are many, and devilishly detailed.
Challenges are what engineering is all about, and whilst I, and no doubt most engineers involved in fuel cell development, could imagine some funky carbon-fibre-clad magnesium tanks reducing bulk, their colleagues in finance will be confiscating their coffee cups until costs are driven down and infrastructure is driven up. Now, I know that separating engineers and their coffee is counterproductive, even under the best collaborative conditions, achieving both will take a few decades more.
Anyway, the article that prompted this post, in the German emobilitytec magazine, about this self-same Hyundai ix35 raised some interesting points:
- The ix35 has two H2 tanks (1 at 100 l + 40 l) totalling 144 l
- Fully tanked, the fuel weighs just 5.6 kg at 700 bar.
- Yes, that’s 700 bar.
- Consumption is 0.94 kg H2 per 100 km.
- The car includes a 24 kWh battery (same as in the new e-Golf), half charged.
- This is because fuel cells need time to warm up (so the ix35 starts up as electro car) plus time to run down after switching off the vehicle - so the battery needs to soak up the additional charge 100 kW power, Max 124 kW with fully loaded battery, providing a decent 300 Nm
- Good for up to 600 km.
So, power, torque and range are decent, and whilst the volume of fuel being held is large, at least its weight is low. Additionally, you don’t need pumps to get the hydrogen from tank to stack, so on the tank side of things, things are relatively simple. If you discount the difficulties in sealing up the piping between tank and stack under all operating conditions.
That stack itself remains a complex, expensive and still rather fragile mystery to me. And we still need to the extract hydrogen from the environment as sensibly as possible.
Development continues, if not apace. As the European HyFive infrastructure and 110 fuel cell vehicle project shows, industry and politics can combine to prod things forward little by little.
