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Israeli Researchers Produce Green Hydrogen with 90% Efficiency

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Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#11

Post by cassepipe »

ben_w wrote: post #4

Interesting; I wonder if similar approaches will help make the fuel cells cheaper as well as hydrogen? Even if not, even if vehicles remain fully electric (which is my assumption): > The scientists said gray, black, and brown hydrogen release 9 to 12 tons of carbon dioxide for each ton of hydrogen produced. Yet, they correspond to 95% of all hydrogen currently produced worldwide for agricultural and industrial needs.…

Does this solve your problem ? : https://addons.mozilla.org/en-US/firefox/addon/overlay-remov...

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#12

Post by _aavaa_ »

> When it is genuinely green, it is obtained through electrolysis, a process that is only 70% to 80% efficient. That's not bad compared to internal combustion engines (ICEs), but fuel cell detractors use that to bash them anyway. Scientists at Tel Aviv University plan to kill that argument with a method that is over 90% efficient in generating green hydrogen.

This is highly disingenuous. The problem isn't just that electrolysis isn't 100% efficient. It's that the electrolysis and the compression and the transmission and the distribution and the fuel cell all have efficiency problems, and are all much more expensive that the alternative (straight electric).

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#13

Post by taylodl »

"Hydrogen storage would still be a problem unless the gas was transformed into synthetic fuel. Hopefully, another scientific breakthrough could address that as soon as possible. We also have another idea floating around that may help solve that."

This statement at the end of the article leads me to believe any widespread distribution of hydrogen is at least 10 years off. It'll be interesting to see if Toyota is vindicated after all! Realistically speaking, this seems like a good solution for long range trucks.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#14

Post by mustafa_pasi »

_aavaa_ wrote: post #12

> When it is genuinely green, it is obtained through electrolysis, a process that is only 70% to 80% efficient. That's not bad compared to internal combustion engines (ICEs), but fuel cell detractors use that to bash them anyway. Scientists at Tel Aviv University plan to kill that argument with a method that is over 90% efficient in generating green hydrogen. This is highly disingenuous. The problem isn't just that e…

The obsession with efficiency is disingenuous too. The two limiting factors are generation capacity and cost/economics. Efficiency by itself says nothing. In the early 1900s, gas was less efficient than electricity too, but for a whole century gasoline powered transportation was more feasible. Aviation is still only feasible with kerosene despite it being less efficient than electric propulsion.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#16

Post by causi »

jncfhnb wrote: post #3
matthewfelgate wrote: post #2

[flagged]

How so

Too many efficiency losses. Let's compare a BeV and a hydrogen vehicle. starting with a fully renewable source of electricity. For the BeV, we lose 5-6% over transmission lines, 5% of that converting AC to DC, another 5% on losses charging the battery, then another 10% at the electric motor. That's ~75% efficiency from your starting electricity to your wheels.

With hydrogen, you lose 30% to electrolysis, another ~25% to transportation, 50% converting the hydrogen back to electricity, then 10% at the electric motor. That's a power to road efficiency of 20-25%.

So this big advance is improving the electrolysis efficiency from 70% to 90%. That's a big advance, but it still only improves your overall efficiency from 20% to 30%, well below the BeV level.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#17

Post by hkt »

_aavaa_ wrote: post #12

> When it is genuinely green, it is obtained through electrolysis, a process that is only 70% to 80% efficient. That's not bad compared to internal combustion engines (ICEs), but fuel cell detractors use that to bash them anyway. Scientists at Tel Aviv University plan to kill that argument with a method that is over 90% efficient in generating green hydrogen. This is highly disingenuous. The problem isn't just that e…

100% this. Few people have been able to answer the question of "how does it compare to a heat pump that has a SCOP of 4?" without me having to fight the urge to roll my eyes.

By the time (highly explosive) hydrogen gets into people's homes I'd be surprised if it was even 20% as efficient as a heat pump.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#18

Post by aredox »

_aavaa_ wrote: post #12

> When it is genuinely green, it is obtained through electrolysis, a process that is only 70% to 80% efficient. That's not bad compared to internal combustion engines (ICEs), but fuel cell detractors use that to bash them anyway. Scientists at Tel Aviv University plan to kill that argument with a method that is over 90% efficient in generating green hydrogen. This is highly disingenuous. The problem isn't just that e…

I concur: Hydrogen is a "bad" fuel in terms of practicality: it's extremely reactive and it leaks easily.

To make a parallel with rocket science: there are extremely efficient liquid chemical propellants, much better than what is in use today, like Chlorine Trifluoride, that nobody uses anymore because they are just too dangerous to work with.

Or the fact that hydrogen airships will never come back: nobody will ever, ever switch from helium despite the cost and lift difference.

Hydrogen has its uses (e.g. steel plants). Transportation is not one of them.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#19

Post by bkor »

mustafa_pasi wrote: post #14
_aavaa_ wrote: post #12

> When it is genuinely green, it is obtained through electrolysis, a process that is only 70% to 80% efficient. That's not bad compared to internal combustion engines (ICEs), but fuel cell detractors use that to bash them anyway. Scientists at Tel Aviv University plan to kill that argument with a method that is over 90% efficient in generating green hydrogen. This is highly disingenuous. The problem isn't just that e…

The obsession with efficiency is disingenuous too. The two limiting factors are generation capacity and cost/economics. Efficiency by itself says nothing. In the early 1900s, gas was less efficient than electricity too, but for a whole century gasoline powered transportation was more feasible. Aviation is still only feasible with kerosene despite it being less efficient than electric propulsion.

Efficiency has a huge impact on the cost/economics, something that you've highlighted. If significant more energy is needed, it'll likely be more expensive. Hydrogen is sometimes only a third as efficient as other solutions. It's pretty logical to assume it'll be

> In the early 1900s, gas was less efficient than electricity too

I think you mean gasoline instead of just gas. Hydrogen requires huge amounts of energy before it's easy to transport, which is what you responded to. In any case, in the early 1900s, gasoline had a huge amount of stored energy. It was a matter of using it efficiently, you're comparing apples to oranges. With Green Hydrogren too often people say that some technological improvement will solve the drawbacks. While ignoring that for e.g. hydrogen it's not so easy, for other options it is/was.

Same for the often suggested "solution" of using surplus energy. A factory that doesn't work 24/7 is more costly. Aside from that I understood that hydrogen is best produced continuously for it to be efficient.

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