this post was submitted on 24 Apr 2024
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Hiringa, with partners fuel supplier Waitomo Group and Australasia’s largest heavy vehicle fleet owner TR Group, on Tuesday opened three green hydrogen stations, with a fourth under way, within the North Island’s economic “golden triangle” of freight movement.

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[–] [email protected] 0 points 6 months ago* (last edited 6 months ago) (1 children)

The inefficiency.

If you need 100 kWh into the truck's electric motor to drive somewhere, with a battery electric truck you need to generate around 120 kWh at the power station. After transmission losses, transformer losses, charging and discharging the battery, etc you wind up with your 100 kWh.

If you're driving a hydrogen fuel cell vehicle, you still have an electric motor and you still need 100 kWh to reach your destination. But you need to generate something like 400 kWh to actually get 100 kWh into the motor, and that 400 kWh of generation and grid transmission is what you need to pay for. Turning electricity into hydrogen and back into electricity is incredibly wasteful.

[–] [email protected] 0 points 6 months ago

This is hydrogens main problem.

It just costs so much more to make it.

There are some places in the world where it can be drilled for, eliminating some of the costs of production, but then you have to store and transport it. Hydrogen can't be stored easily (just big metal tanks), it requires pressure vessels made of exotic composites to reduce leakage, or worse cryogenic tanks that take a constant energy supply to stay cold.

Unlike nitrogen which we store as a liquid easily at industrial scales, hydrogen would be a nightmare to liquefy and store as any kind of scale. Nitrogen is liquid at -77 C, put it into a big metal tank and you are happy. Hydrogen is liquid at 20K (-253 C), metals are (mostly) to brittle at this temperature to be safely used. So exotic composites are required again to make cryogenic storage tanks.

The energy required to liquefy hydrogen is ridiculous, taking something to 20K is difficult and energy intensive.

I could go on, but beyond very specific use-cases hydrogen is a non-starter from a cost perspective.