Israeli Researchers Produce Green Hydrogen with 90% Efficiency • Hacker News Board

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#121

Post by slashdev » Thu, Aug 17, 2023, 6:33 PM UTC

pjc50 wrote: post #58

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…

> I’m fond of pumped hydro, which we can do anywhere with a height difference Not really economical unless you've got some suitably-shaped geology to build most of the storage vessels out of. The lithium issues may be addressed by sodium-ion, which is now mature enough that you can buy it on aliexpress.

There’s sodium ion, molten sodium, iron air, probably various options with iron or aluminum. There’s literally dozens of promising battery chemistries for grid storage where weight and density don’t matter.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#122

Post by _hypx » Thu, Aug 17, 2023, 6:50 PM UTC

jandrese wrote: post #110

_hypx wrote: post #92

Earlier quoted context omitted.

Biofuels are fundamentally not green. You might as well suggest we use fossil fuels forever.

Biofuels today have issues, but there's no fundamental problem preventing them from being green. It's just a side effect of shoehorning them into our existing agriculture systems. In the future when we have more solar power than we know what to do with during the day it may become economical to run the Sabatier reaction with hydrolyzed seawater and atmospheric CO2 to make methane, which can be burned in a lightly mod…

That isn't biofuel. That's synthetic fuel.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#123

Post by kakwa_ » Thu, Aug 17, 2023, 7:25 PM UTC

_aavaa_ wrote: post #114

kakwa_ wrote: post #112

Earlier quoted context omitted.

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.

Indeed, this effect is not a given, specially if the resource is scarce to begin with.

But regarding your example, personally, I'm actually kind of "keep adding light bulbs" thanks to LEDs. I'm no longer using one central 75W incandescent bulb per room, but rather 4 or 5 Philips Hue lights (bulbs & led strips) in an indirect fashion. Hue bulbs & these new usages would not have existed without the LED efficiency gains.

This counter example, of course, has many flaws, firstly, it's only my specific situation, not an average case. The efficiency gains (energy and longevity) is only part of what enabled these new types of lights. And lastly, I think my energy consumption is still lower non-the-less. But it demonstrate how things might not be so clear cut.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#124

Post by WorldMaker » Thu, Aug 17, 2023, 7:26 PM UTC

rfgmendoza wrote: post #85

MrVitaliy wrote: post #46

Earlier quoted context omitted.

I'm hopeful for hydrogen use in aviation. Either that or some ridiculous breakthrough in battery tech, and the latter seems less likely than former.

flying machines and hydrogen has an spotless history without any tragedies whatsoever

Practically no one died in the Hindenberg disaster. There were more people injured than died. Most people involved just walked away from it. It was televised spectacle much more than a factual tragedy.

(It's a bit like saying we shouldn't use AC power because look what Edison did with those poor elephants. It's interesting anti-technological propaganda that made sense socio-politically at the time but isn't that useful to today's discussions.)

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#125

Post by ImJamal » Thu, Aug 17, 2023, 7:32 PM UTC

slashdev wrote: post #118

ImJamal wrote: post #80

Earlier quoted context omitted.

>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.)

Solar can produce on cloudy days, but can be greatly reduced. I've seen estimates at 10-25% of the normal rate on a very cloudy day. If there is no wind being generated at the same time it could cause issues.

Sure overbuilding might work, but only getting 10% of the solar and 0% of the wind would require such massive overbuilding it would probably not be practical.

I did mention interconnection. While it can help, there can be extreme weather over large parts of the country at one time. We have fires in Canada blocking out some parts of the North East. Imagine if there was a large fire happening in California and a hurricane in the south. As climate change continues that is only going to get worse blocking out solar in large chunks of the country.

The problem is determining the correct amount of storage. If we get 10% of the normal solar along with no wind for a week or two would there be enough storage? I'm guessing not.

It is good you agree that we need some diversity. So many people are radicals and say we don't need an alternative. I agree with your sentiment, but think we should also have nuclear not just natural gas. Nuclear is reliable and clean. Why use natural gas if we don't need to?

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#126

Post by slashdev » Thu, Aug 17, 2023, 7:53 PM UTC

ImJamal wrote: post #125

slashdev wrote: post #118

Earlier quoted context omitted.

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.)

Solar can produce on cloudy days, but can be greatly reduced. I've seen estimates at 10-25% of the normal rate on a very cloudy day. If there is no wind being generated at the same time it could cause issues. Sure overbuilding might work, but only getting 10% of the solar and 0% of the wind would require such massive overbuilding it would probably not be practical. I did mention interconnection. While it can help, th…

> I agree with your sentiment, but think we should also have nuclear not just natural gas. Nuclear is reliable and clean. Why use natural gas if we don't need to?

Because natural gas is cheap and nuclear is not. If you’re using tax payer dollars, you absolutely can be wasteful and choose the more expensive option. That may even make sense when you factor in the cost of the carbon dioxide pollution. We’re not there yet, but it could come back around, especially if you implement a high enough carbon tax, which I’ve always advocated for.

I think you can get potentially very long term energy storage via pumped hydro, so I expect that would help as well. But natural gas can also be fired up occasionally on those very cloudy days when the wind is also not blowing. The pollution might not matter if you offset it via other means or you use green hydrogen or ammonia or something to that effect.

Since we already have a lot of natural gas power plants, we might not need to build any more, just maintain the more efficient ones in working order.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#127

Post by someplaceguy » Thu, Aug 17, 2023, 8:12 PM UTC

_aavaa_ wrote: post #108

someplaceguy wrote: post #26

Earlier quoted context omitted.

> Efficiency has a huge impact on the cost/economics It doesn't have nearly as much impact as other factors, such as abundance of the material, how easy/practical it is to work with it (which influences both demand and supply), whether mass infrastructure for it already exists (although this is more relevant in the short-term rather than long-term), etc. These factors impact the economics of an energy source much mor…

But the efficiency of something goes directly into the economics. If you need need to build out a grid to power your cars, you'll 3x as much energy at the source to get the same amount of energy into the tyres.

Which might mean very little compared to the other factors.

3 x 10 cents, which could represent a fixed amount of an abundant and easy-to-work-with energy source (therefore cheap) which has 33% efficiency (hence the 3x cost factor), still costs much less than say, 1 x 5 dollars, which might represent the same amount of energy provided by a scarce and/or hard-to-work-with energy source (therefore expensive), even if this energy source is 99.999% efficient (hence the 1x factor).

As an analogy, let's say you live in a community on an isolated island and you need to eat.

You can satisfy your hunger / nutrient / energy requirements with 1 coconut or with 5 apples (which means we're assuming one apple is only 1/5th as nutritious/efficient as one coconut in this example).

Which fruit serving will be cheaper? You can argue "if you eat apples you will need 5x more of them, therefore they will be more expensive!".

But of course, that might not matter one bit.

The problem is that maybe on the island there might only be 10 (reachable) coconuts but there might be 10,000 reachable apples, so the 5 apples would be much, much cheaper than 1 coconut.

Or perhaps there are also 10,000 coconuts but there are no knives on this island so they would be very hard to open and eat. Therefore you wouldn't be able to find coconuts at the market because nobody would want to pick them and sell them, since nobody would want to buy them despite everybody wanting to eat fruit every day.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#128

Post by slashdev » Thu, Aug 17, 2023, 9:06 PM UTC

jakewins wrote: post #102

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…

Rooftop solar in Australia is now cheaper in some jurisdictions than transmission per kWh. Meaning, if I tried to build a nuke or any other centralized generator and I gave the electricity away for free, rooftop solar would still be cheaper per kWh because consumers don’t need to pay to maintain transmission infrastructure.. Of course, only when the sun is shining. But it’s an incredible Lego block we’ve got to play…

> Rooftop solar in Australia is now cheaper in some jurisdictions than transmission per kWh

That is mind blowing to me. There’s definitely an argument to be made for decentralizing the grid.

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#129

Post by efitz » Thu, Aug 17, 2023, 10:09 PM UTC

efitz wrote: post #93

rfgmendoza wrote: post #84

Earlier quoted context omitted.

nuclear isn't cheap if you are thinking about the cost to build out a new plant under current design. but the per kw cost is relatively low as i understand it since the fuel is so efficient and its getting cheaper as new reactor designs get cheaper and safer

I wonder how much of the cost of nuclear is regulatory and lawfare related rather than intrinsic.

Why was this downvoted?

Re: Israeli Researchers Produce Green Hydrogen with 90% Efficiency

#130

Post by ben_w » Fri, Aug 18, 2023, 8:21 AM UTC

rcarr wrote: post #106

pjc50 wrote: post #49

Earlier quoted context omitted.

> few nuclear power plants, electricity should be ridiculously cheap Nuclear has never managed to be cheap. The really big nuclear buildouts always had a national security subsidy: either for energy security (France), or for nuclear weapons (US, UK, USSR, China, and also France). This is partly why non-weaponizable reactor designs never became popular either. > They obviously don't like that, which is why they keep p…

When I say nuclear, I don’t mean as the primary fuel source, but as a few strategically placed plants to serve as back up until large scale battery storage gets sufficiently commonplace until it is no longer needed. Eventually every house will have its own large battery and solar panels on its roof. In combination with grid battery storage, increased panel efficiencies and huge amounts of solar and wind farms eventua…

> and then we can just pipe energy from the equator to where it’s needed.

Superconductors aren't the limiting factor for that, on paper we can already make a 40,000 km long 0.5Ω power line for costs comparable to current annual fossil fuel mining (Chinese annual coal alone is expensive enough for the aluminium).

The problem is geopolitics and that it's a megaproject.