Most hydrogen is made from fossil fuels, and has a lot of emissions during manufacturing. But even green hydrogen, which is made by using carbon free generated electricity to split water into hydrogen and oxygen doesn’t make sense.

If you’ve build new renewable power it’s more efficient to use it to charge batteries than to use it to generate hydrogen.

There might be a case for compressed hydrogen, In vehicles where batteries are too heavy like aircraft.

But for road vehicles, batteries are more effective at reducing emission.

If you’re building any new renewable power, you’ll reduce more emissions by using it to displace coal power, the to generate green hydrogen.

Some day when we’ve eliminated fossil fuel based electricity generation, Green hydrogen might start to make sense. But anybody trying to do it right now is not being as helpful as they could be.

[–] CrimeDad@lemmy.crimedad.work 1 points 6 months ago (1 children)

You're not really describing a problem with hydrogen powered vehicles. You're describing the problem with the way we've been trying to generate power free of greenhouse gas emissions. As long as the policy makers keep myopically insisting that we only do it with certain renewables, it doesn't matter if battery electric vehicles are actually more efficient or not. So, on balance, the relative inefficiency of a hydrogen powered fleet is more than made up for by avoiding a massive stream of battery waste that everyone seems to be ignoring.

[–] dgmib@lemmy.world 2 points 6 months ago (1 children)

Yes you’re correct. I will qualify my previous statement as hydrogen powered road vehicles don’t make sense for now.

The problem at the moment is that electricity generation is not carbon free and in most countries not even close.

Unfortunately the transition to a carbon free electric grid is being significantly retarded by policymakers that are, as you say, myopic. As a result it will be at least two more decades before hydrogen makes sense.

The carbon footprint of lithium battery manufacturing, is small compared to the carbon footprint of electricity generation. Until that changes significantly lithium batteries will continue to be a better choice than hydrogen fuel cell.

Hydrogen may make sense in a future where we’ve eliminated all fossil fuel electricity generation and there’s an abundance of carbon free electricity that can be used to create green hydrogen as a form of energy storage. Though by the time that point comes, we may have developed battery technology or some other energy storage technology that doesn’t carry the same carbon footprint that lithium ion does today.

[–] CrimeDad@lemmy.crimedad.work 3 points 6 months ago

I'm not so concerned about the carbon footprint of battery manufacturing as I am with the broader externalities associated with the battery lifecycle. This article is a few years old, but it provides a relevant, sobering assessment of the problem. Hydrogen powered vehicles make sense now because they avoid that problem. They're also a better choice for anyone whose driving needs would outpace overnight charging of a BEV at home (or anyone with a living situation that precludes it). The current policy of exclusively transitioning the fleet to BEVs is at best a kludge for bad energy policy.