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Discussion Starter #1
So I'm very naive on this.

The upside is range vs BEV.

The downside is that hydrogen isn't (mostly, currently) produced "cleanly".

Is that it in a really over-simplistic nut shell?

I see people saying it's about "big oil" and whatnot, but to be honest if "big oil" got off oil and in to another revenue stream that's clean(er), surely that's a win/win?
 

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Ask yourself how you make hydrogen?

Electrolysis? - No, it is far too inefficient and expensive.

So how? - Well, by processing Natural Gas and 'removing' the CO2.

And where does that CO2 go? - Up into the atmosphere (where it makes the world toasty warm!)

Any other issues? - Yes, this processing takes loads of extra energy.

Where does all that natural gas come from? Well, this is why Shell, BP, Exxon etc. love hydrogen!
 

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But just as the majority of UK electricity is "dirty" but COULD (should) be "clean", isn't the same said of hydrogen?

You can't get "hydrogen panels" on your roof for home generation though, that's one thing I'm certain on. :D
 

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Isn't it basically about efficiency. Even if you could make Hydrogen from from electricity generated by renewable sources by hydrolysis, you would be better using that electricity directly to power cars as the losses from hydrogen production are far greater than losses from electricity transmission and storage in batteries.
 

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Also, the "500 mile range!" You read for a fuel cell car are about as realistic as the "124 miles range!" For a Leaf, maybe even less so as they're not on sale they don actually need to go through NEDC testing...

As an example, the Hyundai tuscon fuel cell car has an EPA range of 265 miles, exactly the same as a Model S 85kwh.
 

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Also, the new Toyota FCV (which looks very nice in the flesh, btw!) has a range of 700km on the jc08 cycle. You can do your own conversion if you wish but I believe it will deliver an EPA range of about 260 miles.
 

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Great diagram to convey the argument about efficiency in a quick but factual way, thanks Matt.
And that is the best it gets to be if no natural gas or fossil fuel involved. Then there's the platinum or whatever it is in the fuel cell.
 

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Anecdote alert.

I was chatting to my next door neighbour at about 6.30 on Saturday morning (I think he always gets up at that time. For me, it was an unusual treat...). He does something on the design side of the motor industry and owns a fleet of Alfa Romeos with personalised number plates.

He was asking me how the car was going. I said how wonderful it was, as I always do, before the usual caveats about the infrastructure. He then went on to say that the programme to introduce hydrogen fuel pumps is advancing nicely and that they will all be solar powered, the hydrogen being manufactured on-site from a water supply and therefore requiring no massive transport network.

My scientific knowledge could be neatly inscribed on the inside of a benzene ring so I'm in no position to shout "Bullshit!" and wouldn't anyway because I don't want to fall out with my neighbour, but there we are. Hydrogen electrolysis is coming to a petrol station near you at some unspecified stage in the future. Provided the sun shines.
 

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Anecdote alert.

I was chatting to my next door neighbour at about 6.30 on Saturday morning (I think he always gets up at that time. For me, it was an unusual treat...). He does something on the design side of the motor industry and owns a fleet of Alfa Romeos with personalised number plates.

He was asking me how the car was going. I said how wonderful it was, as I always do, before the usual caveats about the infrastructure. He then went on to say that the programme to introduce hydrogen fuel pumps is advancing nicely and that they will all be solar powered, the hydrogen being manufactured on-site from a water supply and therefore requiring no massive transport network.

My scientific knowledge could be neatly inscribed on the inside of a benzene ring so I'm in no position to shout "Bullshit!" and wouldn't anyway because I don't want to fall out with my neighbour, but there we are. Hydrogen electrolysis is coming to a petrol station near you at some unspecified stage in the future. Provided the sun shines.
Yeah fairly confident that that's bullshit. Given these are vehicles that have ~250 miles range, we can assume they get ~80kwh out of their fuel cells, so about 160kwh of hydrogen. If we take the diagram above as correct (and skip the transport stage) that's 249kwh of sunlight per fill up. So to fill one vehicle you need something like 30kw of panels. 5 minute fillups means a max of 288 fillups per day per pump. That's a mere 8,640 kw of panels, or 34,560 of the 250 watt panels you typically see on peoples rooftops. Per pump.
 
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Like most people here I am no expert but you don't have to be a rocket scientist to see that the figures just don't stack up... regardless of how you look at it.

If they could make the figures work then they would be developing much faster and if it was better than battery EVs then the manufacturers would be making them.

I remain a huge H2 sceptic I am afraid :)
 

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Yeah fairly confident that that's bullshit. Given these are vehicles that have ~250 miles range, we can assume they get ~80kwh out of their fuel cells, so about 160kwh of hydrogen. If we take the diagram above as correct (and skip the transport stage) that's 249kwh of sunlight per fill up. So to fill one vehicle you need something like 30kw of panels. 5 minute fillups means a max of 288 fillups per day per pump. That's a mere 8,640 kw of panels, or 34,560 of the 250 watt panels you typically see on peoples rooftops. Per pump.
Very well put @Edd Beesley, but my minds eye imagines the massive amount of bubbles rising from the water tank which would be needed to supply one car, never mind a days worth of filling cars.
You also forgot the power required to compress the hydrogen to over 5000 psi and to think I thought petrol was dangerous in an accident.
According to Wikipedia, hydrogen requires a larger storage tank than the equivalent energy for petrol.
Not looking good is it and yet the hydrogen economy is touted by nearly all as the future.
 

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Discussion Starter #17
Is one attraction weight? We know that big batteries = big weight, but what about a hydrogen fuel cell? You may get better energy returns from a battery, but if that energy is used to lug around a much heavier load because of the battery, then is there a "tipping point" or comparison with that taken in to account?
 

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I like the diagram that @Matt Beard posted but it is mildly out of date, high pressure electrolysis has come a long way in recent years, (compressed before electrolysis) this is much more energy efficient and could be done at the roadside filling station eliminating H2 transport, (transport the electricity instead) even with these improvements (maybe 100% improvement) it still falls short!

My main gripe with H2 as a fuel is it's energy density Per Litre, H2 has excellent Energy density per KG but is pretty poor per Litre, any H2 car would need 2x as many litres of fuel, to match gasoline range, and if that is extremely high pressure those tanks are likely to be round! not neat boxes under seats!
 
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