Interesting: Germans switch on "artificial sun" to separate hydrogen from water vapour

Surely the only viable way to split water is electrolysis ???

You can also focus sunlight to heat water to power turbines - there's a massive tracking array of mirrors in Spain (?) that do this.

Of course a *real* artificial sun is made by fusing hydrogen atoms together into Helium, with the unimaginable release of energy available in nuclear reactions.

" ? but scientists hope that in the future natural sunlight could be used to produce hydrogen in a carbon-neutral way."

I think its just a research project. Actual implementations would use sunlight.

En el artículo , Jethro_uk escribió:

California?

It begins to dissociates into hydrogen and oxygen above 3000c - so maybe that's what they are trying. It can't be easy separating H2 from O2 and water vapour (plasma?) in that environment.

Thermodynamics says it takes exactly the same amount of energy to split a water molecule however you do it, but maybe this method is more efficient than boiling water to power a steam turbine to spin a generator to produce electricity to hydrolyse water.

I think the Spanish one heats molten salt, rather than producing steam, so iy can store the energy and deliver it at night (either that or they've hidden the diesel gennys better than that other spanish scheme).

I think several of these 'solar furnace' arrays are in financial difficulties, and aren't producing as much power as was claimed in their various prospectuses. They also cause significant harm to bird life. Any bird that flies through the concentrated beam of sunlight is instantly incinerated and falls to the ground leaving a trail of smoke. The ground in front of the central collector is littered with partially incinerated corpses.

En el artículo , Chris Hogg escribió:

Funnily enough, I've just re-watched Danny Boyle's "Sunshine". :)

I was going to suggest scarecrows, but that would be a bit mean.

Wind farms also kill birds, though I have no idea of relative numbers.

The trouble is it's not efficient. Most hydrogen is produced from hydrocarbon fuels, releasing the carbon as carbon dioxide. Only around 2-3% comes from electrolysis because it's much more expensive.

What on earth are they up to? Kind of reminds me of the huge amount used by some of those laser driven fusion devices popular a few years back, until they realised the real issue is containment and energy extraction. Brian

ogg

Both these sound like another level in angry birds I haven't come across.

What does "generate climate friendly fuel" really mean? Grow stuff?

Spliting water to get Hydrogen is a non-starter. When you burn the hydrogen you can only get back what you shoved in to split the water. Losses mean the overall system needs an external energy source bigger than the useful energy you get. May as well try and use that energy source directly a skip the water to hydrogen conversion loses.

What we need to do is work out what green plants did millions of years ago. ie how to convert CO2 and H20 into sugar and oxygen at normal temperatures and pressures with just a bit of sunlight. Or better still get at the process at the point were there is free hydrogen kicking about before it's combined with the carbon.

I think one of the problems is the rapid drop-off of energy captured as soon as the mirrors start to get dusty. So you need a regular regime to ensure all x000 mirrors are clean. Which costs.

There is still some work going on - quietly - in microbiology, looking at direct fermentation of cellulose (i.e. grass and green biomass). There are some bugs/yeasts/microbes that can ferment cellulose to alcohol (which is then immediately available as a fuel). The problem is they are sloooooooowwwwwwww. The need speeding up by a factor of 100, at least.

It's a field my brother was working on in the US ... it then bleeds into medicine and modern pharmacology, as it seems the "clock" that cells work to is ... well just not known. It will have a genetic solution, undoubtedly.

The problem is (seriously) that the end goal of loads of keen gardeners composting their green waste directly to car fuel doesn't have a nearly enough complexity trough for all the snouts that will want to fit into it. The same reason why despite the best use of UK solar energy to heat your water via roof panels, everyone rushed into these s***ty PEV panels that are bleeding the grid dry.

They want to power hydrogen cars. They need to make it look green. They will probably try and use solar to do it. If they can do it on a micro scale and get everyone to fit a solar collector that produces hydrogen and some way to collect it up they will be OK, however, they have no chance of that!

You can speed it up by scaling it up so that isn't the problem. All you need is a few million litres going at once rather than a few thousand litres.

I suspect there are other problems that are stopping it.

kicking

Not the same as photosythesis, which I get the impression is a bit like a bubble bee. The theory says bubble bees can't fly, but they do. The theory says photosynthesis isn't possible, but plants do it. They are getting there ISTR that it's down to molecular shapes and possibly moving molecular shapes that strip electrons from the oxygen.

Or have a bigger tank. B-)

And the Domestic RHI insists that Solar Thermal is domestic hot water only. Bung some solar thermal panels onto a heat bank that does anything other than hotwater and you can't get the RHI for them. So much for any "Incentive" to use less fossil based energy.

The solar thermal here does noticeably reduce the amount of oil we burn over the summer period.

I can't recall the exact details, but in an (excellent) BBC4 documentary about quantum mechanics, Jim Al Khalili explained that photosynthesis and the sense of smell appear to rely on some quantum trickery. The series ended with a suggestion that evolution itself - in the area of genetic combination - has picked up on the quantum world ...

What an extraordinary statement.

If the world - the One True World -is Quantum, how can one 'pick up on the quantum world'.

Even if its just a human model the only thing that can 'pick up on it' will be a human being.