RE: Detroit '09: Dodge Circuit EV

[andy_b]

XitUp said:

BigE1967 said:

Hydrogen may very well be the future of alternative energy, but electricity is here in abundance now. Another thing to consider is that electricity can be produced by using free power sources, wind, the sun, the ocean, as well as regenerative braking.

Great post apart from the highlighted bit.

honest question.... why isn't Hydrogen the future?

andy

[OJ]

GTRene said:

but to be honest, I would like the all electric in-wheel motors and the complete car of the Lightning even more...not only because it has more then 700hp

They have lots of issues. They're direct drive so have no step down gearing, meaning you get a comically high top speed but rubbish rest torque. About the same as pulling away in 2nd in a petrol Focus. Even a car weighing just over a tonne would struggle to get up a multi-storey car park ramp without a run up.

Also, they can only brake the car as fast as they can accelerate it, so braking performance is poor compared to discs.

And they're not particularly efficient at low speed so they overheat... which is a pain seeing as the cooling circuit has to be very complicated and robust.

Finally they're unsprung and thus are thrown about a lot, so they break.

None of these problems are insurmountable, and the motors are very immature at the moment, but that Lightning GT being available in a usable form any time soon is IMO a pipe dream.

[OJ]

andy_b said:

honest question.... why isn't Hydrogen the future?

andy

Difficult to store resulting in big, heavy tanks with not a lot of hydrogen in, and low energy content compared to fossil fuels.

Basically for a 2 tonne car (which would be a minimum with current tech), you'd need a 150 kilo tank that's a metre and a half long and three quarters of a metre wide to run a Fuel Cell car for 250 miles.

Although I personally disagree that it's not the future. The technology will develop and it will become feasible and more efficient eventually... just not as soon as everyone seems to think.

Arguably too much money is spent on it at a time where renewable infrastructure to create the hydrogen is required for it to be an ecologically viable solution.

Edited by OJ on Tuesday 13th January 08:25

[Monkey boy 1]

IMHO this is what the Europa should have looked like from the start.

[MrTappets]

I must say, with the exception of the front grille and paint job, i think that is much better looking than the standard Europa.

[XitUp]

andy_b said:

honest question.... why isn't Hydrogen the future?

andy

The laws of thermodynamics.
It takes way more energy to make hydrogen than you can get back from burning it or using it in a fuel cell.
Then you have the £billions that would be needed for new transportation and storage infrastructure.

[kambites]

XitUp said:

andy_b said:

honest question.... why isn't Hydrogen the future?

andy

The laws of thermodynamics.
It takes way more energy to make hydrogen than you can get back from burning it or using it in a fuel cell.
Then you have the £billions that would be needed for new transportation and storage infrastructure.

I suppose that depends on how it's done. You don't need to transport or store much hydrogen if your electricity infrastructure if up to the load, you could generate it relatively locally.

I don't know how the total efficiency between going, for example, "fossil fuel -> electricity -> grid -> hydrogen -> electricity -> kinetic energy" compares to burning the fossil fuel in the car, but I could believe it if I was told that either was more efficient.

From memory of the other bits, you'd need electricity -> hydrogen -> electricity to be about 80% efficient in order for using hydrogen to be more efficient overall. I have no idea what the real figure is though.

[XitUp]

It's far less efficient than most other forms of propulsion.

[OJ]

Monkey boy 1 said:

IMHO this is what the Europa should have looked like from the start.

+1

[spoonoff]

kambites said:

XitUp said:

andy_b said:

honest question.... why isn't Hydrogen the future?

andy

The laws of thermodynamics.
It takes way more energy to make hydrogen than you can get back from burning it or using it in a fuel cell.
Then you have the £billions that would be needed for new transportation and storage infrastructure.

I suppose that depends on how it's done. You don't need to transport or store much hydrogen if your electricity infrastructure if up to the load, you could generate it relatively locally.

I don't know how the total efficiency between going, for example, "fossil fuel -> electricity -> grid -> hydrogen -> electricity -> kinetic energy" compares to burning the fossil fuel in the car, but I could believe it if I was told that either was more efficient.

From memory of the other bits, you'd need electricity -> hydrogen -> electricity to be about 80% efficient in order for using hydrogen to be more efficient overall. I have no idea what the real figure is though.

Good post- this is why nuclear energy is the only real alternative at present, but the by products are not good. If they could crack nuclear fusion then that would provide virtually limitless, polution free energy.

[BigLepton]

kambites said:

There are a HUGE number of people for whom it would make a perfect mode of transport. The fact that you're not one of them doesn't take it "stupid".

Until you take into account the purchase price of somewhere between £60-90,000 and then it becomes no-ones perfect mode of transport. . . . . . .

[kambites]

In a moment of boredom I (very roughly) worked out the efficiency of my car on the motorway today.

Cruising at about 80mph (something like half throttle at 3500rpm) it's putting out about 35bhp (26kw).

40mpg = 8.8 miles per litre.

80 = m/h
8.8 = m/l
=> 8.8l = m, 80h = m
=> 8.8l = 80h
=> l = 9.1h

So that's using 9.1 litres per hour.
=> 0.00253 litres per second.

Petrol contains about 37 MJ per litre

So: 0.00253 * 37000000 = 93,610 Watts, or 93.61kw


26/93 = 0.28

So my K-series engine, when cruising on the motorway, is something like 28% efficient. Can't be hard to beat that, surely?

[kambites]

BigLepton said:

kambites said:

There are a HUGE number of people for whom it would make a perfect mode of transport. The fact that you're not one of them doesn't take it "stupid".

Until you take into account the purchase price of somewhere between £60-90,000 and then it becomes no-ones perfect mode of transport. . . . . . .

Yeah true. It's not commercially viable as anything other than a curiosity for the rich at the moment, but that's how the internal combustion engine powered car started out too.

[qube_TA]

wooooody said:

qube_TA said:

Looks awesome but it's too tiny for anyone over 6' to fit in, has no storage and you have to leave it plugged in overnight.

Not for me thanks.

Being elise based, it'll be fine for those over 6'. Just not over 6' and fat though.

Nah, I'm 6'7", weigh 16St, my legs are too long to get underneath the steering wheel onto the pedals and the car isn't wide enough to spread and put my knees either side of the wheel. I can just about squeeze into the passenger seat but it's fairly awful. The car needs to be about 6" longer so as it is it's useless.

TBH even if you do fit in an Elise or cars of that size I can't see how you could ever live with them as every day cars.

[kambites]

qube_TA said:

TBH even if you do fit in an Elise or cars of that size I can't see how you could ever live with them as every day cars.

Plenty of us manage.

[OJ]

qube_TA said:

Nah, I'm 6'7", weigh 16St, my legs are too long to get underneath the steering wheel onto the pedals and the car isn't wide enough to spread and put my knees either side of the wheel. I can just about squeeze into the passenger seat but it's fairly awful. The car needs to be about 6" longer so as it is it's useless.

I'm 6'4' and of a similar weight, and I'm just about alright in one with my legs straightish and a skid lid rubbing against the roof. If I were an inch taller I wouldn't fit

[OJ]

kambites said:

In a moment of boredom I (very roughly) worked out the efficiency of my car on the motorway today.

Cruising at about 80mph (something like half throttle at 3500rpm) it's putting out about 35bhp (26kw).

40mpg = 8.8 miles per litre.

80 = m/h
8.8 = m/l
=> 8.8l = m, 80h = m
=> 8.8l = 80h
=> l = 9.1h

So that's using 9.1 litres per hour.
=> 0.00253 litres per second.

Petrol contains about 37 MJ per litre

So: 0.00253 * 37000000 = 93,610 Watts, or 93.61kw


26/93 = 0.28

So my K-series engine, when cruising on the motorway, is something like 28% efficient. Can't be hard to beat that, surely?

Firstly I personally would have done it this way ...

26kW for an hour at 80mph and 40mpg is 26kWh and 2 gallons of fuel.

2 gallons is 9.092 litres

95 fuel is 39.5MJ/L

39.5 * 9.092 is 359 MJ which is 99 odd kW

which gives 26% efficiency

That still sounds a bit optimistic as it happens.

Before you've got into any supply line efficiencies, a fuel cell might be 60% efficient (absolute top whack with current tech), but it has to go through a 75% efficient motor which goes through a 90% efficient driveline just like any car, and you're back down to 40% efficiency.

And don't forget you've got at least 150 kilos of Fuel Tank, 150 kilos of fuel cell and most likely another 150 kilos of batteries to haul around, so you'll be using up more energy than your 130kg IC engine just to cart it all around.

[kambites]

I wasn't really trying to say that electric cars were better. I was merely pointing out that petrol cars are crap.

ETA: I have to admit that I was surprised the figure came out to high too. I was expecting 15-20%.

Edited by kambites on Tuesday 13th January 14:27

[carl_w]

Is it really that much of a surprise? For sure, an ICE isn't as efficient as an oil-fired or coal-fired power plant, but they're essentially doing a similar job to extract energy by burning fossil fuels. If you miniaturize that power plant and put it at the point the energy is required (i.e. near the wheels of the car) then you save all of the conversion and transmission losses, and you can store the fuel in a handy format until it's needed. IIRC Edison was totally convinced that Benz's plan to generate the energy on-board was the way to go.

[carsnapper]

Whilst I do not endorse or agree with everything he says, (and plainly disagree on occassions)I think his experience with the Tesla is a fair reflection of where this technology is currently at. I only just found this article tonight.

http://www.timesonline.co.uk/tol/driving/jeremy_cl...



Give it 30 years though and we'll all be nipping around in them, especially when they drop to the same price of an equivalent IC engined car in terms of initial financial outlay, running costs & repair and good overall economy, without the battery issues outlined by lots of us already.