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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

#111

Post by _aavaa_ »

mabbo wrote: post #62
slashdev wrote: post #53

Earlier quoted context omitted.

As much as I’ve been rooting for nuclear, I think the ship has sailed. If newer advances can’t make it cost competitive with renewables plus some storage (I’ll get to that in a minute) then why would you ever deploy it. Renewables are really cheap and getting cheaper, so some combination of overbuild with storage is probably the winning formula. Storage is a little too expensive as lithium ion batteries, but there’s…

> So nuclear (including hypothetical nuclear fusion) will probably not acquire significant market share. Unless you can somehow make it cost competitive. Ontario is a great counter example. We have something like 60-70% of our power from nuclear, representing most of the base load. We're building more plants soon too. Electricity is cheap, and used to be even cheaper before it was privatized. And we have no nuclear w…

Ontario has cheap nuclear because it's nuclear fleet was build in the best possible time, the past.

Even china [0] renowned for pushing projects through and "getting stuff done" hasn't been able to push the price and construction time of nuclear down enough to make them cheap and easy to build.

[0]: https://cleantechnica.com/2023/02/06/renewables-in-china-tre...

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#112

Post by kakwa_ »

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 gains can even very well be detrimental to resource consumption.

Efficiency gains generally lead to lower cost, which in turn lead to higher demand. And this increased demand can very well be in excess of the efficiency gain.

This was observed as early as the 1860ies and theorized in concepts like the Jevons Paradox/Rebound Effect.

This doesn't mean efficiency gains are not desirable, but they must be implemented in conjunction with other factors like environmental policies.

https://en.wikipedia.org/wiki/Jevons_paradox

https://en.wikipedia.org/wiki/Rebound_effect_(conservation)

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#113

Post by AnthonyMouse »

jakewins wrote: post #100
AnthonyMouse wrote: post #97

Earlier quoted context omitted.

> If newer advances can’t make it cost competitive Did they ever get rid of the rule that prohibits nuclear from being cost competitive? Its opponents got it so if they ever found a way to make it cost less the money explicitly had to be spent on new safety measures. Which obviously not only makes it impossible to reduce the cost but also removes any incentive to try.

What legal jurisdiction are you saying this was a rule in? I’ve never heard of this

US.

https://www.nrc.gov/reading-rm/basic-ref/glossary/alara.html

Google doesn't want to find a more specific link right now, but you can see the implication from the definition: If you find a way to make nuclear cost less than something else, now it's economical to make it cost more in order to reduce radiation exposure, with no lower limit where you can stop.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#114

Post by _aavaa_ »

kakwa_ wrote: post #112
mustafa_pasi wrote: post #14

Earlier quoted context omitted.

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 gains can even very well be detrimental to resource consumption. Efficiency gains generally lead to lower cost, which in turn lead to higher demand. And this increased demand can very well be in excess of the efficiency gain. This was observed as early as the 1860ies and theorized in concepts like the Jevons Paradox/Rebound Effect. This doesn't mean efficiency gains are not desirable, but they must be impl…

It's true, but that isn't a given. For example, it won't matter how cheap and efficient LEDs are, people aren't going to keep adding them to their house.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#115

Post by rcme »

_aavaa_ wrote: post #109
rcme wrote: post #107

Earlier quoted context omitted.

It actually doesn’t have to do with transmission at all. Rather, when you pay for electrolysis, you’re paying for all the energy inputs. When you burn fossil fuels, you’re not paying for any of the energy inputs (hundreds of millions of years of solar radiation). So it’s not surprising that fossil fuels are cheaper even if they’re less efficient.

Firstly I don't see how that follows. You still need to pay to transport both the oil and the hydrogen from where you make it to where you use it. Most importantly, you're not (in most places) paying for the pollution of the atmosphere. E.g. Prices on carbon are nowhere near the level of societal harm that putting it into the atmosphere causes.

My point is that to produce hydrogen via electrolysis, you need to input energy. Due to thermodynamics, you can only ever hope to get 0.9 units for each unit of input energy.

With fossil fuels, you don’t need to input energy to get them. At least not in the same way. You can run a pump to pump them out of the ground. For each unit of energy that goes into the pump, you likely get 1000x units of energy out.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#116

Post by wffurr »

_aavaa_ wrote: post #99
wffurr wrote: post #41

Earlier quoted context omitted.

You would use hydrogen to produce methane to then burn in people's existing as furnaces using the existing natural gas distribution infrastructure. That seems to be Terraform's plan. Still seems better to me to convert as much housing as possible to heat pumps, which seem much better fit for purpose than on-site combustion. I think green hydrogen has a lot more potential as a precursor to liquid fuels for e.g. aviati…

If you're going to convert it into methane and burn it you'll make a fuel cell's ~37% round trip efficiency look massive. turning it into methane to burn it is trying to solve last century's problem. People need way to stay warm not things to burn .

I think their point for syngas (or better yet synthetic liquid fuels) is that solar will be so cheap that the efficiency won't matter.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#117

Post by slashdev »

mabbo wrote: post #62
slashdev wrote: post #53

Earlier quoted context omitted.

As much as I’ve been rooting for nuclear, I think the ship has sailed. If newer advances can’t make it cost competitive with renewables plus some storage (I’ll get to that in a minute) then why would you ever deploy it. Renewables are really cheap and getting cheaper, so some combination of overbuild with storage is probably the winning formula. Storage is a little too expensive as lithium ion batteries, but there’s…

> So nuclear (including hypothetical nuclear fusion) will probably not acquire significant market share. Unless you can somehow make it cost competitive. Ontario is a great counter example. We have something like 60-70% of our power from nuclear, representing most of the base load. We're building more plants soon too. Electricity is cheap, and used to be even cheaper before it was privatized. And we have no nuclear w…

Ontario is a great example where no no nuclear projects have been built or proposed at a competitive price. I stand by my assertion that nuclear is dead in the West until shown contemporary numbers to the contrary.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#118

Post by slashdev »

ImJamal wrote: post #80
slashdev wrote: post #53

Earlier quoted context omitted.

As much as I’ve been rooting for nuclear, I think the ship has sailed. If newer advances can’t make it cost competitive with renewables plus some storage (I’ll get to that in a minute) then why would you ever deploy it. Renewables are really cheap and getting cheaper, so some combination of overbuild with storage is probably the winning formula. Storage is a little too expensive as lithium ion batteries, but there’s…

>If newer advances can’t make it cost competitive with renewables plus some storage (I’ll get to that in a minute) then why would you ever deploy it. Because it can work rain or shine. Wind or no wind. What happens if we have no wind and have a lot of clouds for a few weeks in an area? The storage is limited and nuclear can still produce. Yes, I understand other areas can likely pick up the slack, but nuclear doesn't…

Solar still produces on cloudy days.

The answer is a combination of storage, overbuild, long distance interconnections, and diversification ( which mostly means we keep some natural gas plants around, not new nuclear.)

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#119

Post by _aavaa_ »

rcme wrote: post #115
_aavaa_ wrote: post #109

Earlier quoted context omitted.

Firstly I don't see how that follows. You still need to pay to transport both the oil and the hydrogen from where you make it to where you use it. Most importantly, you're not (in most places) paying for the pollution of the atmosphere. E.g. Prices on carbon are nowhere near the level of societal harm that putting it into the atmosphere causes.

My point is that to produce hydrogen via electrolysis, you need to input energy. Due to thermodynamics, you can only ever hope to get 0.9 units for each unit of input energy. With fossil fuels, you don’t need to input energy to get them. At least not in the same way. You can run a pump to pump them out of the ground. For each unit of energy that goes into the pump, you likely get 1000x units of energy out.

I get what you mean. That will really depend on where you get the oil from. Some places need a lot more downstream processing (looking at alberta oil sands) to get something useable than others (the middle east).

Whether you want to consider that analogous to the electrolysis step or to another one is not clear since the processes don't map one to one.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#120

Post by slashdev »

TylerE wrote: post #60
slashdev wrote: post #53

Earlier quoted context omitted.

As much as I’ve been rooting for nuclear, I think the ship has sailed. If newer advances can’t make it cost competitive with renewables plus some storage (I’ll get to that in a minute) then why would you ever deploy it. Renewables are really cheap and getting cheaper, so some combination of overbuild with storage is probably the winning formula. Storage is a little too expensive as lithium ion batteries, but there’s…

22% of US power is generated via nuclear. Is that not significant? More than renewables, almost as much as coal.

That was built in the past, I’m talking purely about future potential for nuclear.
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