[Andy]

Agreed that when you have electricity initially, going the H2 route does not make sense from an efficiency perspective. I will argue however that if you can get direct to H2 without the electricity intermediary at any where near 10% or better efficiency and obviously no electrolyzer use, we have a different situation. In this case we have a portable (O.K not as portable as gasoline etc. but way more portable) fuel than electricity with inherent storage advantages.

Agreed also that storing H2 is diffficult but it is not impossible. Compressed composite gas tanks already exist that do a reasonable job keeping the H2 in on scales that can even be seasonal. Check out Dynetec etc. for their products.

Another thing you are overlooking is that with direct solar to H2, a lot of the H2 can be produced on site or nearby rendering long distance transportation unnecessary. In other words, just like PV, this technology is most powerful when envisioned in a distributed production scenario.

[Denny]

This could be the coolest thing of the century, if its got a good return on energy invested. If it just does a tiny trickle of hydrogen compared to the catalyst "investment", then its no biggie. It wodl also be good to now hopw many cycled the catlalyst is good berfore it needs replacement.

I always wonder when apparently scientific articles don't delve into the common sense question of how much you get out for how much you put in.

[PeakOiler]

I've done it.

As part of my undergraduate research work at UT, we took some zeolite-L, embedded colloidal platinum within the zeolite, added various ruthenium bipyridinium derivatives as the chromophore, and added a sacrificial electron donor in a flask of water and irradiated the solution artificially with a tungsten lamp (with various cut-off filters to simulate sunlight). (Although we could have taken the setup outside to use the sun, it's best to do those research experiments in the lab.) We watched hydrogen bubble out of the solution. We drew gas samples from the headspace of the flask with an air-tight syringe, injected the gas on a GC, and sure enough, very pure hydrogen...It was pretty cool.

My main job was to synthesize the ruthenium bipyridinium derivatives. The professor I worked for at UT included my name as a "co-author" in a few articles for my contributions, some which were published in a few journals, including the Journal of the American Chemical Society and the Journal of Inorganic Chemistry.

Main problem: The reaction was not reversible. The key was to "tune" the chromophore by using different, or a combination of various ligands to the ruthenium, so a sacrificial electron donor wouldn't be needed. Ideally, water itself would provide the electrons and also be the electron acceptor. This research has been going on for decades, and yet the "breakthrough" has not yet occured.

Then there's the problem of scaling. Not enough platinum and ruthenium exists in the world. Zeolite-L is an artificial mineral as well.

[PolestaR]

Agreed that when you have electricity initially, going the H2 route does not make sense from an efficiency perspective. I will argue however that if you can get direct to H2 without the electricity intermediary at any where near 10% or better efficiency and obviously no electrolyzer use, we have a different situation. In this case we have a portable (O.K not as portable as gasoline etc. but way more portable) fuel than electricity with inherent storage advantages.

So lets say you save 10% compared to using electricity to electrolyze water (and for this example assume these light->h2 converters operate at the same efficiency as light->elec converters, which they don't atm). So you have H2 gas, then what do you do with it? Are you using it in a fuel cell or an ICE? If it's the former it's expensive as all hell and rather limited in it's current applications, and only then converts 40-70% of the energy back you got from it. If it's the latter, then it's even worse efficiency wise, but at least it's cheap to run.

Whereas if you put the electricity you generate into a battery or a capacitor you will get 90% of the energy back (to make it easy for you, compare the 70% you get back from the best and expensive fuel cell + the 10% efficiency gain). Which comes out better? Just to help you, storing electricity in a battery or capacitor is cheaper, and more efficient.

Another thing you are overlooking is that with direct solar to H2, a lot of the H2 can be produced on site or nearby rendering long distance transportation unnecessary. In other words, just like PV, this technology is most powerful when envisioned in a distributed production scenario.

See above. Why would I want distributed H2 when I would be able to drive my electric car further with the same amount of sun?

[Andy]

Pstar, as good as batteries are, they are not as good as chemical fuels especially for long term storage. I do not envision H2 powering vehicles at all. As you nicely pointed out, way too inefficient!!!!

But, in the context of a power supply heavily slanted towards renewables, particularly the variable ones, H2 represents potential smoothing storage technology. It is there to cover the odd time when you need buffer energy for example during winter when solar + batteries are not enough. It, like the other chemical fuels affords us to obtain a power flux especially for heat that batteries cannot match in specific applications. It allows us to use every last drop of renewable energy available rather than having to throw out excess if that occurs. Batteries simply are not there where that is concerned.

It is portable (less so than gasoline or propane etc. but more so than batteries). The only way in my opinion to have a 100% renewable economy is to have at least some fraction (10 - 20%) of the energy available in the form of a storable fuel for emergency situations. Otherwise we are stuck with using fossil fuels to carry out that role. Batteries simply can't do it.

[Andy]

Another thing PStar. Based on my understanding of current battery technology including Li and UltraCaps etc. , batteries are not cheaper (in a strict storage sense) than fuel containers, even when the containers are made of carbon fibre.

Do not get me wrong. I am a staunch proponent of battery electrics owing to their superior efficiency. I mean, solar panel charging battery electrics could be cost competitive already versus gasoline. But I am saying there are things that batteries cannot do as well as chemical fuels like provide large heat fluxes needed in industry etc.

[PolestaR]

Pstar, as good as batteries are, they are not as good as chemical fuels especially for long term storage. I do not envision H2 powering vehicles at all. As you nicely pointed out, way too inefficient!!!!

How long term is relevant? Ideas for using batteries of electric cars as distributed "plug in" storage solve a lot of the issues of storing electricity, provided the fleet was big enough. And it's distributed.

But, in the context of a power supply heavily slanted towards renewables, particularly the variable ones, H2 represents potential smoothing storage technology. It is there to cover the odd time when you need buffer energy for example during winter when solar + batteries are not enough. It, like the other chemical fuels affords us to obtain a power flux especially for heat that batteries cannot match in specific applications. It allows us to use every last drop of renewable energy available rather than having to throw out excess if that occurs. Batteries simply are not there where that is concerned.

It is portable (less so than gasoline or propane etc. but more so than batteries). The only way in my opinion to have a 100% renewable economy is to have at least some fraction (10 - 20%) of the energy available in the form of a storable fuel for emergency situations. Otherwise we are stuck with using fossil fuels to carry out that role. Batteries simply can't do it.

It depends doesn't it, you have to weigh up the costs of the inefficiency of storing H2 over electricity, then the inefficiency of burning/using the H2 to get power again. Looking at the numbers I have in efficiency terms ALONE, suggest that going batteries/caps for storage is a much better idea,when you factor in the costs of hydrogen it is even more favorable.

[cornucopian dream mode on]
Please tell me why you would go H2 for anything, when you get less power in the end and it costs more? You think they can't just build more batteries for storage in a similar fashion to them just building bigger H2 storage tanks? Either way the best solution at the moment is to burn FFs or use nukes in the off peak renewable situation, if you had that much RE in the first place. By the time FFs run out they would have better capacitor technology you would think. And capacitors with million+ recharge cycles and big capacities easily blow off every alternative when it comes to energy storage.
[cornucopian dream mode off]

It's all irrelevant anyhow because the collapse is going to kill most of us before any of this takes place, which I think you are probably in denial about.

[wisconsin_cur]

The Economist

Not if ITM Power has anything to do with it. This British firm, based in Sheffield, thinks that hydrogen is still the fuel of the future. It differs from others who cleave to that view in that it also thinks that instead of being delivered by an expensive, new infrastructure of pipes and storage tanks, the gas will be brewed at home by car owners using water, electricity and ITM’s proprietary technology.

The brain behind this idea is Donald Highgate, a polymers expert, who made his name in the 1970s by developing soft contact lenses. The polymer he has come up with this time is used to make what are known as proton-exchange membranes. These, depending on how the device containing them is set up, can act as the guts of a fuel cell or as its opposite, turning water and electricity into hydrogen and oxygen.

That process is known as electrolysis, and normal commercial electrolysers are chunky units placed next to power stations to produce industrial quantities of hydrogen for the chemical industry. They rely on platinum, a metal that costs twice as much as gold, to catalyse the reaction.

Existing fuel cells intended for cars are not quite so greedy. They use some platinum, but also involve membranes made of a polymer called Nafion. However, these membranes cost $500 a square metre.

ITM’s new material costs a hundredth of that, and no platinum is involved. Moreover, its superior conductivity allows the use of a thicker, more robust membrane that will last longer than one made of Nafion. The firm has also patented a simple, one-step manufacturing process: the liquid polymer is poured into a bag before being cured, a bit like an injection-moulded waffle.

Making hydrogen at home, using one of these membranes, gets around the problem of a lack of hydrogen filling stations. In

[jlw61]

I hope it's true. However, there is one thing that will prevent the widespread use of it in the home.

Government.

Government must have it's taxes and thus people will not be allowed to own their own hydrogen manufacturing plants thus the costs will remain high and the taxes will continue to pour in.

If there is anything that makes me wish for a true crash (and I really do not want one, but sometimes I get the urge to wish for a political reset) it is the realization that if something does save us, it will simply mean a continuation down the political road that we are on.

[wisconsin_cur]

I hope it's true. However, there is one thing that will prevent the widespread use of it in the home.

Government.

Government must have it's taxes and thus people will not be allowed to own their own hydrogen manufacturing plants thus the costs will remain high and the taxes will continue to pour in.

If there is anything that makes me wish for a true crash (and I really do not want one, but sometimes I get the urge to wish for a political reset) it is the realization that if something does save us, it will simply mean a continuation down the political road that we are on.

Maybe the company can make sure it breaks every ten years so that we keep on buying more and then pay taxes on that purchase...

at least until the Japanese start making them

[coyote]

What I don't understand is why this would be any better than simply using a plug-in electric vehicle. For the average commuter, I mean; I suppose hydrogen might be more convenient for long-distance driving. But for the average Joe schlepping ten miles to work, what's the advantage of this setup over a wall socket?

[gnm]

Not if ITM Power has anything to do with it. This British firm, based in Sheffield, thinks that hydrogen is still the fuel of the future. I

HYDROGEN IS NOT A FUEL!

-G

[WisJim]

What I don't understand is why this would be any better than simply using a plug-in electric vehicle. For the average commuter, I mean; I suppose hydrogen might be more convenient for long-distance driving. But for the average Joe schlepping ten miles to work, what's the advantage of this setup over a wall socket?

No advantage. Even available lead acid batteries are as efficient as the fuel cells that are available, figuring that you start with an energy source, either charge a battery or make hydrogen, then either discharge the battery or run the hydrogen through a fuel cell to use the energy later. There are losses in charging and discharging a battery, and similar losses in generating, storing, and running hydrogen through a fuel cell. And fuel cells cost many times (hundreds or thousands of times) more than lead acid batteries. The jury is still out on other newer battery technologies.
I have been hoping that hydrogen, both making it using renewable energy sources, and using it again in fuel cells to use electricity later, would be a viable technology to replace my batteries in my home power system within the next 10 years, but I don't see it happening, not at the rate that they are making progress now.

[mos6507]

What I don't understand is why this would be any better than simply using a plug-in electric vehicle.

The big advantage of is hydrogen tanks are cheaper than batteries. Batteries are more efficient, but they are expensive and need regular replacement. This really adds to the total cost per mile of driving. When you look purely at the cost, you could make a case that a hydrogen ICE is cheaper than a BEV, despite the efficiency losses of splitting watter into hydrogen.

[Dezakin]

What I don't understand is why this would be any better than simply using a plug-in electric vehicle.

The big advantage of is hydrogen tanks are cheaper than batteries. Batteries are more efficient, but they are expensive and need regular replacement. This really adds to the total cost per mile of driving. When you look purely at the cost, you could make a case that a hydrogen ICE is cheaper than a BEV, despite the efficiency losses of splitting watter into hydrogen.

And its simply much more efficient if you get the hydrogen to react it with CO2 to make DME, gasoline, diesel or some other liquid hydrocarbon so you dont have to deal with a low volumetric energy density fuel.

[Dezakin]

Not if ITM Power has anything to do with it. This British firm, based in Sheffield, thinks that hydrogen is still the fuel of the future. I

HYDROGEN IS NOT A FUEL!

-G

Of course its a fuel, and for some niche applications (space travel comes to mind) its the best fuel. Its often noted that its not an energy source, but we're not exactly running short of energy.

[yesplease]

Where have you been? We're expecting peak sunlight any time now.

[mos6507]

And its simply much more efficient if you get the hydrogen to react it with CO2 to make DME, gasoline, diesel or some other liquid hydrocarbon so you dont have to deal with a low volumetric energy density fuel.

How is that done?

[yesplease]

Supposedly we use fission to get plenty of Hydrogen, and along with a lot of Carbon Dioxide and get methanol, which can then be converted to gasoline.

[newbonic]

One use case postulated by ITM is of someone with solar Pv or a wind turbine, or such like (i.e. micro generating renewables). The electrolyser will store unused output as compressed H2, which can be subsequently burned in an ICE or a domestic fuel cell.

Their website cites other use cases for their electrolysers and fuel cells.

I don't see any fundemental reason why it can't be scaled to generate H2 from unused off peak wind or wave output, for peak demand electricity generation. It could transform the economics of renewables, and aid the switch to BEVs (while also using dual fuel ICEs with their domestic electrolysers powered by fossil fuels and H2).

There will be no single silver bullet for the looming crisis but at least there are some credible alternatives nearing industrial scale production.