hydrogen fuel cells… quick query :-)

Just been watching Top Gear (a repeat ‘Best of…’) and it had the Honda Clarity on, the first production car to utilise a hydrogen fuel cell, it’s only emission being H20… apparently a good thing right?

But a couple of things occured to me: 1) what happens when you have a million+ of these things in your city? Just how much water vapour is going to be going into the air? And 2) isn’t H2O vapour one of the most powerful greenhouse gases going? So how can pumping mega-tonnes of the stuff into the atmosphere be an OK thing?

Just curious 🙂

it’ll rain more

so city’s will have their own ‘rainforest’ microclimate?

Water cycle innit

so we replace the carbon cycle with the water cycle?

Of course, they keep very quiet about the fact that the most common source of hydrogen gas comes from *drum roll* burning fossil fuels.

/slaps forehead/

invent a condenser and make £££millions

But, all that extra water that isn’t in the oceans will prevent seas rising, see?

I think the plan for producing hydrogen will be power sourced from nuclear… no problem with that, I have no issue really with modern nuclear power plants, very efficient and safe really…

This will only have a chance of working if there is a shedload of nuclear/renewable electricity to generate the hydrogen (from water).

Also, the hydrogen will have to be very clean to stop poisoning of the catalysts.

Not in my lifetime I reckon.

I have no issue really with modern nuclear power plants, very efficient and safe really…

…just try selling that to the scientifically ignorant general masses who get their opinions from the equally dimwitted printed media.

yeah I know… it drives me spare: “remember Chernobyl…” and all that bullsh1t 🙄

I don’t quite understand why no one ever mentions the safety factor. How are they going to stop a the fuel tanks rupturing when the cars crash into each other?

our companies currently designing/building a large scale hydrogen plant (think oil refinery kinda scale) in Abu Dabi, but i agree it seems pointless all they’r doing is stripping the carbon from oil to produce hydrogen, which ultimately stil leaves you with the same two products (CO2 and H2O).

I think the plan for producing hydrogen will be power sourced from nuclear… no problem with that, I have no issue really with modern nuclear power plants, very efficient and safe really…

I agree about the nuclear plants, but using power to generate hydrogen and then turning that into electricity in a fuel cell is actually a very inefficient way of getting electricity from the power station to the vehicle’s motors. Anyway we already had this discussion on the old forums when that TG episode was on the first time.

Until they crack efficient mass production of hydrogen all this is doing is moving the source of CO2.
You don’t get ought for nowt…

I guess the question is where you source your hydrogen from, if you are splitting water to get your hydrogen then the release of water back into the water cycle shouldn’t make all that much difference in the grand scale of things. But the vested interest might be to source your hydrogen elsewhere.

With carbon being the demon du jour theres a lot of talk of extract hydrogen from fossil fuels (which are hydrocarbons), capturing the carbon and sticking it back underground. But just as the issue of emission of CO2 gets confused because people confuse the natural cycling of carbon with the introduction new carbon into the atmosphere, introducing ‘new’ water into the atmosphere potentially raises the same problems, its just that at present its an easy sell to suggest that an emission is ‘only’ water.

CO2 used to only be CO2.

I think its a non-advance. We’re too eager to be sold something that saves us having to make any real changes, we’re all ears for anything that allows us to just get on doing the same old thing without the guilt. Thats why Top Gear are so unquestioningly sold on it, because they are so deeply sold on all the fantasies of motoring. Its us, not fuel that needs to change.

Edit – I typed that too slowly. nmmmmm boosze

I have no issue really with modern nuclear power plants, very efficient and safe really…

Me neither. It’s just the tiny problem of the highly dangerous and effectively ever-lasting waste material that bothers me. And of course, you’d not catch me swimming downcurrent of seascale.

Never mind the funnding for a secondary distribution system.

Conks

Carbon cycle = hundreds of thousands/ millions of year ( talking mineral capture rather than plant/algal which can be re-released very quickly by us)

Water cycle = days

Plus if we get extra atmospheric water the cloud cover could actually cause global cooling via reflected sunlight. H2 powered skidoos anyone?

A change in technological human behaviour would be much better obviously but bob hope of that.

Nuc fusion research should be getting a serious boost IMO.

So how can pumping mega-tonnes of the stuff into the atmosphere be an OK thing?

The water vapour will stay low down in the atmosphere, where it’ll easily condense as rain or dew. The problem with the greenhouse effect is greenhouse gasses in the upper atmosphere.

At the moment H2 is produced via fossil fuels, but producing it on an industrial scale is likely more efficient than burning fossil fuels in a car. Economies of scale and all that. Plus, in the future H2 could be generated in a more renewable way – but that wouldn’t happen if the technology to power cars with it wasn’t there. Hence Honda et al’s research.

There’s actually a whole island in Japan where they are generating renewable energy from hydroelectric schemes, using this energy for hydrogen production to go into the fuel cell cars that they drive around in – it’s all on a small scale at the moment but the fuel cell would appear to answer a lot of shortcomings with battery powered electric cars. It’s only the cost of the hyrdogen storage/transport infrastructure that restricting it’s short term growth.

At the moment H2 is produced via fossil fuels, but producing it on an industrial scale is likely more efficient than burning fossil fuels in a car.

How exactly are you comparing the efficiency of two processes which don’t have the same endpoint? If you compare the whole process from fossil fuels via hydrogen, a fuel cell and electric motors to the wheels, then that’s certainly significantly less efficient than using a conventional ICE.