So that's why all this puff about the 'hydrogen economy'

[The Natural Philosopher]

[Tim+]

Paywalled...

Tim

[Tim+]

Hmm, 8kW from the fuel cell. My EV has a 150kW motor. Don?t think this car is gonna exactly fly along.

Tim

[Andy Burns]

Turn off javascript

[Paul]

You're confusing issues of "peak" versus "average" consumption.

When you breeze along the motorway at 100km/hour, it might take 20HP (~14kW) to handle wind resistance. You can then forecast how long the battery would last on your BEV, knowing that the wind resistance is what is eating at your battery.

I agree that fuel cells have piss-poor output characteristics. They're not "strong-like-bull" as electrical devices go.

But, you have the ability to fit Lithium batteries as a buffer to the fuel cell system, or if feeling particularly rich, you could fit UltraCaps to the car. The UltraCaps can provide bursts of 3000 amps if needed. This means you'll be able to burn donuts in the parking lot, do brake stands while waiting in traffic and so on. Your tires will be worn out and shot in no time.

But, with your electrical buffer, you can only refill the buffer at the 8kW rate. That means your "average" rate of consumption is capped. Burn one donut, wait two hours for your recharge. Then burn another donut. Boring.

Another way to think of this, is pretend they made a solar-powered car. Weak as piss solar array on the car roof. Recharge time ? A week maybe, or a month. Obviously, solar panels on the roof of the car cannot put out 8kW. Solar would be weaker still. But the buffering principle remains - if you could sit off the road for a week, you might be able to drive for a minute or two.

The hydrogen, you could still pull over to the side of the road, while the fuel cell continues to charge the Lithium system. When you come out of Harrods, your car has charged itself, and without using any of that grid power you don't have a lot of.

The fuel cell car then, will need a very low drag coefficient. You won't be driving an F150 with a load of brick in the back. You won't be pulling a motor home with it.

The Lithium batteries are still key to this, because they're needed for dynamic braking and harvesting the kinetic energy in the car while attempting to stop. That means less of that precious H2 will be needed to pull away when the light changes.

Ballard Systems in Vancouver, designed a transit bus that runs on fuel cells. When the driver stomps the "gas", a cloud of steam comes out of the back of the bus. It can be done. I wish I could find the video of the first time one of these buses pulled away... The available vids now are crap.

That's not the problem with the hydrogen economy. It's making the hydrogen that's a problem. Not enough electrolysis to make it sustainable... The sleazy ways to make hydrogen, are still losers.

Paul

[Jethro_uk]

It did cross my mind, reading a couple of discussions recently that there must be some snouts headed to a trough.

Oh well, fools and their money etc.

[misterroy]

Thanks, turned off javascript and it works with the Herald too.

[The Natural Philosopher]

8 Kw is around 10 bhp

Enough for 50 mph perhaps.

Most small cars cruise at around that figure.

I would add a battery as well for peak power demands.

But it underlines my point that all this maybe and could be crap falls to pieces when real numbers are inserted.

"When the flag drops, the bullshit stops" "Money talks, bullshit walks"

[Tim+]

That did the trick. Thanks.

Tim

[Tim+]

Oh I agree that with batteries and/or supercaps (and it does have the latter) one could extract a lot more short term power.

It?s still a bicycle-wheeled two seater with no luggage space with a top whack of 60mph relying on a fuel that?s near as dammit unobtainium. I can?t ever see demand being huge.

Tim

[Andy Burns]

I think both the hydrogen power cars available in the UK do use the fuel cell to charge battery as well as run the motors direct.

The Hyundai dealer in Leicester is offering test drives of the Nexo, despite the nearest hydrogen filling point being an 80 mile round trip to Derby, that's 20% of a tank gone before you start.

Plus wanky phrases like each hour of driving purifies enough air for 42 people to breath.

[Jethro_uk]

I still think we've reached peak private car. For all sorts of reasons.

[Roger Mills]

I don't know about this particular car, but I think that fuel-cell powered cars have a future.

At the moment they are prohibitively expensive because they're only made in penny numbers. Demand is low because of the high price and because of the lack of re-fueling infrastructure. If that vicious circle can be broken, they'll really take off because they have a much higher range than BEVs and are much quicker to re-fuel. We could even see refilling stations producing their own hydrogen from renewable energy - both helping to save the planet and eliminating distribution costs. The fact that the electrical energy which you get from the fuel cell is only about 50% of the energy used to produce the hydrogen may then not matter.

[Tim+]

That *sounds* like it out to be a huge selling point, but in practice, the vast majority of journeys are short ones.

Assuming you don?t have to drive miles to find a refuelling point. I have one at my home and very handy it is too. ;-)

Or better still, don?t waste that 50% and just stick the electricity straight into a BEV.

Of course BEVs can?t do everything a liquid/gas fuelled car can but they?re here NOW, they work and provide an excellent mode of transport for many people.

Tim

[Tim Streater]

You done the sums on that, then?

Petrol station at our local Morrisons has 12 slots for cars to load up with fuel. Lets say 6 average. A litre of petrol is 10kWh (thereabouts), so a car putting in 40 litres and occupying the slot for 10 mins, that's 2400kWh in an hour, so 2.4MW continuous, 5MW peak. Or if the efficiency of converting wind volts to H2 is 50%, 5MW average, 10MW peak. How many of those giant windmills will that require? And where would they go?

[The Natural Philosopher]

ROFLMAO! There's a levitating Gloucester Old Spot and a Wessex Saddleback! Pass me the Purdey!

[Chris Hogg]

They wouldn't last long - sliced into bacon rashers as soon as they hit one of the millions of whirling turbines.

[tim...]

can't see a model that bundles insurance is going to be viable

it will mean that the people used to paying 200pa for insurance will subsides those who pay 2000pa

[tim...]

Oh I missed that bit

Where's the market for such a car?

a city runaround has to be capable of taking the kids to school

otherwise it's useless

[tim...]

but do the vast majority of cars only do short journeys?

Having to have two cars to solve that problem isn't going to be a great use of resources