Comment by ssl-3
20 hours ago
Ignoring some of the other issues:
Imagine we have this electrolysis plant, splitting up water to produce the hydrogen we need for an area. That's fine.
But it needs fed electricity to keep the process going. Lots of it. It needs more electrical power to split the water than combining it again produces.
So it starts off being energy-negative, and it takes serious electricity to make it happen. Our grid isn't necessarily ready for that.
And then we need to transport the hydrogen. Probably with things like trucks and trains at first (but maybe pipelines eventually). This makes it even more energy-negative, and adds having great volumes of this potentially-explosive gas in our immediate vicinity some of the time whether we're using it individually or not.
Or: We can just plug in our battery-cars at home, and skip all that fuel transportation business altogether.
It's still energy-negative, and the grid might not be ready for everyone to do that either.
But at least we don't need to to implement an entirely new kind of scale for hydrogen production and distribution before it can be used.
So that's kind of the way we've been going: We plug out cars into the existing grid and charge them using the same electricity that could instead have been used to produce hydrogen.
(It'd be nice if battery recycling were more common, but it turns out that they have far longer useful lives than anyone reasonably anticipated and it just isn't a huge problem...yet. And that's not a huge concern, really: We already have a profitable and profoundly vast automotive recycling industry. We'll be sourcing lithium from automotive salvage yards as soon as it is profitable to do so.)
It’s not even the grid, by the time you’ve done the electrolysis you’d be better off just charging a battery.
Also, compressing and cooling a gas takes another huge hit at the efficiency. Electrolysis comes out at atmospheric pressures.
Oh and the platinum electrodes you need…
I’m also just now visualising a hydrogen pipeline fire… terrible terrible idea.
It's the everything, yeah. There's a lot working against using hydrogen as the local energy source for automotive propulsion in the world that we presently have.
Some advantages are that a fuel cell that accepts hydrogen and air at one end and emits electricity and water at the other can be lighter-weight than a big battery, and it can [potentially] be refueled quickly for long trips.
Some disadvantages: We need a compressed hydrogen tank -- which isn't as scary to me as it may be for some people, but that's still a new kind of risk we need to carry with us wherever we drive. And we still need a big(ish) battery and the controls for it in order for regen braking to do its thing (which hybrids have shown to be very useful).
And, again, the grid: If it were cheaper/better/efficient to move energy from electrical generating stations to the point of use using buckets [or trucks or trains] of hydrogen, we'd already be doing that. But it isn't. So we just plug stuff in, instead, and use the grid we already have.
A quick Google suggests that a regular 120v US outlet might charge EVs at a rate somewhere in the range of 3 to 5 miles per hour. So a dozen or so hours sitting, plugged in at home every day, is enough to cover most folks' every-day driving. There's far faster methods, but that's something that lots of regular people with a normal commute and normal working hours can already accomplish very easily if they have private parking with an outlet nearby.
For most folks, with most driving, that's all they ever have to do. It shifts concerns about refueling speed from "Yeah, but hydrogen is fast! I waste hardly any time at all while it refills!" to "What refueling stops? I just unplug my car in the morning and go. I haven't needed to stop at gas station in years."
The main advantages of hydrogen are real, but they just aren't very useful compared to other things that we also have.
Also, what pipeline operator is going to want to move hydrogen when almost all other products are more valuable?