Battery Vehicle Society

ChrisBarron wrote:The most prolific and cheapest way to get hydrogen is through water electrolysis. The energy required to compress the hydrogen to the required 5,000psi (and more) is massive.To produce 1kg of liquid hydrogen requires about 70kWh. That's enough to power the FCX for about 72 miles, and the Tesla for up to 300.
Chris

Nice examples Chris. It really does get under my skin when I hear hydrogen fuel cell technology being touted as some sort of panacea, a source of unlimited clean, free energy that's always just over the horizon.

What it effectively does is take a battery vehicle and add a very complex and unnecessary intermediate stage that is extremely costly, inefficient and environmentally harmful – simply to shore up the existing fuel production and distribution infrastructure.

It's natural that industry should want to protect its own, and I realise that a lot of people depend on these industries for a living. However this doesn't change the fact that it makes more sense to plug in at home than it does to use a great deal more electricity to electrolyse water, compress the resulting hydrogen into liquid, distribute it all around the country, and then mix it with oxygen again in order to generate electricity locally.

I've nothing against fuel cell technology as such, it's very clever and there are bound to be some valuable spinoffs from all the development work. But if a fraction of the R&D budget that has been spent on fuel cell technology had been invested instead in battery development it's likely we would be seeing batteries with twice the energy density we see today.

Please excuse the lecture, but it's much more therapeutic than shouting at the kids

I think the promotion of hydrogen is as much to do with the promotion of nuclear. A nuclear power station cannot be switched up and down to match the load requirements and so the excess energy has to go somewhere, hence develop a reliance on hydrogen and it will justify nuclear.

Night Train wrote: A nuclear power station cannot be switched up and down to match the load requirements and so the excess energy has to go somewhere,.

Don't know where you get that idea from but yes they can.

qdos wrote:

Night Train wrote: A nuclear power station cannot be switched up and down to match the load requirements and so the excess energy has to go somewhere,.

Don't know where you get that idea from but yes they can.

IMHO it's a misunderstanding. Civil nuclear plant is very poor at adjusting the level of output. It's very slow to respond and thermal cycling has a high effect upon it's reliability. As such it is common practice to run them at a fixed output level for "base load" which leads to a belief that is the only possibility.

Military reactors (ie subs) HAVE to be a lot more responsive, but that makes them a lot less efficent.

In practice this may mean that it's only economically viable to run civil plant at fixed output.

All of which excludes the concept of using chemical/thermal processes to split water into hydrogen.

I could go on about how there are only five plants in the world able to make certain critical civil reactor forgings, however the thread is really about top gear rather than nuclear power isn't it.

JonSpence wrote:I could go on about how there are only five plants in the world able to make certain critical civil reactor forgings, however the thread is really about top gear rather than nuclear power isn't it.

'tis indeedy

I think we all agree Hydrogen isn't in reality anything like efficient and that it's a pipe dream that's encouraged by the likes of 'G Dubyah' mainly due to the fact that his oil buddies are the boys who have the infrastructure to contain it and transport it as it's not too dissimilar to LPG really. It's certainly not something you can simply plug into at home or generate yourself.

qdos wrote:

JonSpence wrote:It's certainly not something you can simply plug into at home or generate yourself.

Err, I wouldn't make too many sweeping statements.

You might like to check ITM out. Here is an article about them in the mag "The Engineer".

http://www.theengineer.co.uk/Articles/3 ... r+play.htm

Personally I am not convinced enough to buy shares in the company, but it certainly is NOT true to claim that you can't generate it (produce it using water and electricity) at home.

Interesting stuff I will be interested to see what happens. Anyone likely to get one of these "Green Box" Hydrogen generators?

It's gone off topic again so in an attempt to get it back again the issues that Top Gear raised about electric vehicles was that currently you can't refuel a vehicle as quick as you can an ICE (please don't say swap out the batteries cos yes that's possible but it's not like simply opening the filler cap and pumping in petrol in 2 minutes for 300 miles range all with one hand)

I think the conclusion Top Gear came to was Electric motors in cars are not at all bad if only we could sort out a way to refuel them quickly like we can with a petrol car. Hydrogen seems to address that issue but they failed to say how much energy was required to obtain the hydrogen. They also failed to say how much pollution was generated in the production of enough petrol to do the same test in a Lotus Elise as the Tesla.

Bottom line is how convenient is it all and how much is it going to cost? Is it really likely Joe Public will buy one? Bit silly given that Top Gear is all about monstrous V8s with twin turbos these days but hey, it's entertainment.

qdos wrote:I think the conclusion Top Gear came to was Electric motors in cars are not at all bad if only we could sort out a way to refuel them quickly like we can with a petrol car.

It's not quite two minutes, but the Altair Nano cells are not far off: http://uk.youtube.com/watch?v=Rcbx57Azisw

woooh certainly getting there looks good enough for me!

I wonder how the power lines to a forecourt will cope with around 16 cars refueling simultaneously. Think how many cars go through a petrol station in 10 minutes

qdos wrote:woooh certainly getting there looks good enough for me!

I wonder how the power lines to a forecourt will cope with around 16 cars refueling simultaneously. Think how many cars go through a petrol station in 10 minutes

Yes, but, do you need forecourts anymore ? There is no tank to bury under the ground, nor any specialist pumps and nozzles. You just need a power outlet. Therefore, smaller and more plentiful fuelling station can be provided, and that means that each one only needs a smaller supply cable than one which would be required for a 16 car station. Power points at shopping areas would be part of the answer too.

I personally like the attractive benefits of battery changing stations, which give a complete refuel in under 1 minute, and suspect batteries can be dealt with appropriately at the convenience of the changing station's technicians.