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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

#31

Post by ben_w »

ComputerGuru wrote: post #24
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.…

> On a separate topic: this is the second site in a row where the full-screen "we respect your privacy click here to agree" banner won't actually let me scroll down to any of the buttons. https://chrome.google.com/webstore/detail/behind-the-overlay...

> https://chrome.google.com/webstore/detail/behind-the-overlay...

Safari on iPhone.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#32

Post by sitkack »

mustafa_pasi wrote: post #21
bkor wrote: post #19

Earlier quoted context omitted.

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 be…

>Efficiency has a huge impact on the cost/economics Not in the way that you think, no. For all intents and purposes, we have limitless energy. The problem was never that we don't have enough capacity, because we can scale capacity as much as we want. The only thing that is required is that energy generation (i.e. $/kWh) is cheap enough, and this seems feasible with solar and wind and maybe fission and later one fusio…

You would have to solve the problem of getting soggy toast from the exhaust steam.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#33

Post by mustafa_pasi »

thadjo wrote: post #30

I'm seeing a lot of people here assuming that the purpose of green hydrogen is for fuel cells / automotive transport, but I don't see many people in this space talking about that anymore (except Toyota). Instead there is a lot more interest in using green hydrogen for industrial purposes or as a key building block for cleaner fuels like methanol. Currently green hydrogen is expensive to make and sucks to transport. B…

I agree with this. I think there will still be niche products using liquid fuels. Like for example "explorer" or "offroader" type vehicles that require higher energy densities. And aviation of course. But commuter transportation will be using direct current or batteries.

But the two chief uses will be in industrial processes that use hydrogen directly, in chemical processes that use hydrocarbons directly, and in energy storage applications where you need to store large quantities of energy for weeks or months or years.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#34

Post by jncfhnb »

causi wrote: post #16
jncfhnb wrote: post #3

Earlier quoted context omitted.

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%…

That’s hardly a “scam” though. The use cases are simply different. Batteries are good. Transportable fuel is also good.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#35

Post by ben_w »

causi wrote: post #16
jncfhnb wrote: post #3

Earlier quoted context omitted.

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%…

Efficiency is important when energy is expensive; I can easily believe that other issues dominate.

Not that any of those other issues mean "and in conclusion: hydrogen, hydrogen, hydrogen!", it's just that people care about sticker price and safety as well.

(On the "wanting safety" front: the memetic destruction of the Hindenburg and the way people conflate chemical and atomic hydrogen bombs is a point against hydrogen fuel).

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#36

Post by bushbaba »

thadjo wrote: post #30

I'm seeing a lot of people here assuming that the purpose of green hydrogen is for fuel cells / automotive transport, but I don't see many people in this space talking about that anymore (except Toyota). Instead there is a lot more interest in using green hydrogen for industrial purposes or as a key building block for cleaner fuels like methanol. Currently green hydrogen is expensive to make and sucks to transport. B…

Or as an renewables energy storage for use in leaker plants.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#37

Post by micv »

thadjo wrote: post #30

I'm seeing a lot of people here assuming that the purpose of green hydrogen is for fuel cells / automotive transport, but I don't see many people in this space talking about that anymore (except Toyota). Instead there is a lot more interest in using green hydrogen for industrial purposes or as a key building block for cleaner fuels like methanol. Currently green hydrogen is expensive to make and sucks to transport. B…

There's been talk of replacing the natural gas used directly for heating in the UK with hydrogen. I have absolutely no idea how viable that will actually prove to be but it seems difficult.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#38

Post by rcarr »

Obviously hydrogen has it's uses, but a large part of me feels the energy industry is stalling for time. Oil and gas is basically a subscription model, whereas electric cars and heat pumps are buy once, upgrade in x years or when broken model. With enough renewable energy and a few nuclear power plants, electricity should be ridiculously cheap and if they've got the space, the consumer can even generate their own. That's more money and self-enpowerment for the consumer, and far less for the energy companies. They obviously don't like that, which is why they keep pushing for hydrogen to keep people dependent.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#39

Post by mrpopo »

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.

Not really, increasing energy efficiency is at the heart of many climate solutions. Clean energy is still scarce, and in the places where it isn't, for instance Germany, there is backlash against it. Not to mention that they aren't even close to being 100% renewable-powered (wind+solar 30%), not even close to have 100% EV market penetration (about 2%), not even close to have the theoretical capacity for a grid to power 100% EVs, and you would like to adopt a less efficient technology that would require to double the clean power needs compared to EVs...

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#40

Post by wffurr »

arijun wrote: post #22
aredox wrote: post #18

Earlier quoted context omitted.

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,…

I was curious about Chlorine Trifluoride as a propellant, and I found this quote of John D Clark on the Wiki page (hypergolic means it will ignite spontaneously): > It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engine…

Ignition! - a history of rocket fuels - from which this quote originates - is freely available online and an excellent read: https://library.sciencemadness.org/library/books/ignition.pd...
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