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Hydrogen vehicles in Denmark left without fuel as all commercial refuelling stations shuttered
(www.hydrogeninsight.com)
Hydrogen never really made sense for cars, the infrastructure and storage is too expensive. But I wonder if it'd work for trains that haven't been fully electrified with overhead cables yet. You'd need much less infrastructure at just a few locations.
On the other hand, my city is trying hydrogen bus.
There is a single refilling station needed.
Oh that's a good idea too. If the hydrogen and electricity is green, it'd have less of an environmental than batteries.
It isn't. The amount of green hydrogen is a fraction of a fraction a percent of all hydrogen. The rest is all made from natural gas and the CO2 is released into the air. It's a green washed fossil fuel.
But if they're making the stations, they can use or manufacture green hydrogen. It just a matter of the political will.
But if they’re making the stations
But they’re not. See: this article. They’re not profitable, and if they ever were, it was propped up by greenwashing a byproduct of natural gas production.
The article didn't link. Also, not profitable compared to what? Because running at a slight loss to decrease ghg emissions would still be worth it. Are there fully electric battery alternatives to use instead?
I’m referring to the article posted in this post. Stations are being shut down because they aren’t profitable. It doesn’t have to be compared to anything. If they can’t make hydrogen cheap enough, they can’t sell enough and they can’t sustain the business mode.
The cheapest way to make hydrogen now is as a byproduct of natural gas production which is not as eco-friendly as anybody would hope.
Hydrogen for consumer use is a boondoggle and waste of time. BEVs are here and work great on existing infrastructure (for L2 charging at least). I drive an EV and exclusively charge it at home. No special station required.
Absolutely. That's what I said originally. Consumer use never made sense. But busses or trains might still make sense since they'd have much more centralized infrastructure.
"Green hydrogen", is also incredibly inefficient in its own right. Approximately a 70 percent loss of energy compared to 15-20 percent for battery storage. It would literally be just as efficient to burn natural gas in a power station (with a 50+ percent efficiency, modern power turbines are very efficient) and use that power to charge a battery. The entire "hydrogen economy" has been a pipe dream by either complete morons or fraudsters (probably both). (Hydrogen aeroplanes might actually work, but that is by combustion and jet engines are already very efficient).
Today, green hydrogen is essentially an expensive, low-efficiency battery.
That could change with future work on making more efficient hydrolysis, but today, the numbers really don't work out on green hydrogen vs alternatives like lithium ion or overhead wires for busses.
But a hydrogen battery has much much better specific energy than lithium ion. So you can have a much longer range.
Hydrogen is very light, so the energy per kilogram is quite high.
However, hydrogen is also naturally not very dense. Hydrogen at 1 atmosphere has a tiny fraction of the energy of a similar volume of batteries. Pressurized hydrogen is similarly dense to a battery, and liquid hydrogen is about twice as dense.
So to make hydrogen dense, you need a very thick, heavy tank to hold the pressurized hydrogen. That significantly cuts into your weight advantages.
Add to that, fuel cells are very inefficient at converting hydrogen to usable electricity.
Maybe I'm missing other conversion factors, but hydrogen has a volumetric energy density of 9MJ/L which is about 2.5kWh/L compared to about 1.7kWh/L for the newest Tesla batteries. So hydrogen is more energy dense than batteries even by volume.
Aren't those the numbers for liquid hydrogen?
Oh maybe. That would make extra complications. Looks like low pressure gas is 0.5 kWh/L which is more in line with what you were saying.
Nope. They tried hydrogen trains in Germany and are not buying more of them.
How do battery operated work? Are they short rage trains? Or do they have like a car full of batteries? And how do recharge times work? Can they recharge just in the stations? If it works for them, great. And it sounds like it is. It just seemed like there were several problems.
Battery locomotives don't have enough range to be useful solo, but they're a handy to add on to an existing train to give it regenerative braking and improve it's efficiency.
You want practically zero emissions train, you build overhead catenary wires. But that's decades old tech that just works, it's not sexy futuristic stuff.
Hear me out… SOLAR FREAKIN RAILWAYS
I was saying it seems to make sense to use hydrogen as an intermediate step before you can put in all the infrastructure for overhead wires. If Germany is just using electric engines plus diesel engines now, instead of hydrogen engines, then there's still emitting a whole lot more than they would otherwise. Even if it is cheaper.
There's no way Hydrogen in Germany would be more green than diesel. It'd just be greenwashing. You'd need to make electricity to make hydrogen, store it and transport it, then turn it back into electricity (that's how a hydrogen engine works, not by burning it). In the mean time, Germany is increasing it's production of dirty energy, so the hydrogen production would have to be done with dirty energy. There's no way that process is more efficient than just using diesel directly.
It might be better somewhere else, but not in Germany.
You don't need to use the standard grid energy. You can use off peak power rates in areas with a lot of wind, so it'd use the otherwise unusable energy. Or you could disconnect from the grid entirely. But the power source is absolutely a concern.
What would the co2 trade off look like between diesel and hydrogen? Diesel you'd have a constant co2 per mile, whereas hydrogen would have higher kwh efficiency, but high conversion inefficiency, then some percentage of the energy emits co2 at a certain rate. I don't have time to crunch the numbers now, but I would be surprised if hydrogen was more ghg intensive.
Or you could disconnect from the grid entirely.
The off peak usage, sure. This though? How would that be green? You could spend the same money to install solar, wind, whatever and take dirty energy off the grid. That's the point is you need to use energy to make it, when instead that energy could remove dirty energy. It's greenwashing. It's not removing demand for dirty energy, its just increasing overall energy demand.
Increasing energy use compared to diesel? If you count the energy in the diesel, I'm pretty sure hydrogen would use less. But I think what matters over all is the total co2 emitted per mile, including generation.
I don't know, have you seen those wires above the rails? They always look sexy and futuristic to me, especially the high speed rail ones 🥵
Irish Rail is trying this. There was an article posted about it yesterday!
I'm from Denmark and I've never even heard there were Hydrogen cars around here.
Edit: but then again, I don't drive a car, so maybe Im just not the target audience.
Big L for them.
this post was submitted on 21 Sep 2023
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