The Naked Scientists

The Naked Scientists Forum

Author Topic: What is holding back electric car technology?  (Read 143952 times)

Offline baker1

  • First timers
  • *
  • Posts: 1
    • View Profile
What is holding back electric car technology?
« on: 15/12/2008 02:47:57 »
anyone have any fresh ideas that might advance the electric car concept?
 
« Last Edit: 18/12/2008 18:14:47 by chris »


 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
Re: What is holding back electric car technology?
« Reply #1 on: 15/12/2008 07:12:48 »
Electric cars have too many snags. 
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Re: What is holding back electric car technology?
« Reply #2 on: 15/12/2008 07:25:05 »
Until electricity can be generated efficiently without the use of fossil fuels or nuclear reactors and stored in equally efficient batteries, I do not see electric powered transport as the answer to our problems  vis-à-vis CO2 and pollution.
 

Offline teragram

  • Sr. Member
  • ****
  • Posts: 122
    • View Profile
Re: What is holding back electric car technology?
« Reply #3 on: 18/12/2008 17:56:04 »
Don_1, "..... I do not see electric powered transport as the answer to our problems  vis-à-vis CO2 and pollution."

With the greatest respect, what is the answer?
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8645
  • Thanked: 42 times
    • View Profile
What is holding back electric car technology?
« Reply #4 on: 18/12/2008 18:48:43 »
Fewer people?
 

Offline techmind

  • Hero Member
  • *****
  • Posts: 934
  • Un-obfuscated
    • View Profile
    • techmind.org
What is holding back electric car technology?
« Reply #5 on: 18/12/2008 22:07:17 »
anyone have any fresh ideas that might advance the electric car concept?

Probably the biggest problem is that the energy density of batteries (ie stored energy compared to weight and to size) is low compared to petroleum.
In other words, you have to have a big, heavy (and expensive) battery to get you very far. Carrying deadweight around decreases performance for stop-start driving, and increases the energy requirements to climb hills.

We then have the small issue of practical power-connection (charging) for people who don't have private garages or driveways. Drag cables across pavements and leave overnight?
No viable battery technology can recharge in the few minutes taken to refuel with petrol (and no present domestic supply could provide enough instantaneous power/current to do so anyway).


I'll leave it as an exercise for someone else to calculate the energy in Joules (then kilowatt-hours) in 45litres of premium unleaded, and then calculate how many hours it would take to pull that same amount of energy out of the domestic 240V electricity supply limited by a 60amp company fuse...

Needless to say, if everyone swapped to an electric car overnight, we'd need some major upgrades to our electricity distribution infrastructure one way or another. I think we'd more than double our electricity usage.
« Last Edit: 18/12/2008 22:15:05 by techmind »
 

Offline Chemistry4me

  • Neilep Level Member
  • ******
  • Posts: 7709
    • View Profile
What is holding back electric car technology?
« Reply #6 on: 18/12/2008 22:56:41 »
No one wants to invent a viable one because they'll get assassinated by some oil company hired hit-man...
 

lyner

  • Guest
What is holding back electric car technology?
« Reply #7 on: 18/12/2008 23:21:08 »
It's much cheaper (and legal) to buy out inventors, actually. They are always doing it. When the time comes to jump, they'll all jump into the electrical pond - using the technology which they own already.
 

Offline LeeE

  • Neilep Level Member
  • ******
  • Posts: 3382
    • View Profile
    • Spatial
What is holding back electric car technology?
« Reply #8 on: 19/12/2008 00:29:02 »
The main thing that's holding back electric car technology is weight.  Then performance.
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
What is holding back electric car technology?
« Reply #9 on: 19/12/2008 08:36:17 »
Don_1, "..... I do not see electric powered transport as the answer to our problems  vis-à-vis CO2 and pollution."

With the greatest respect, what is the answer?

Fewer people?

Apart from BC's answer, I do not know. We need to travel less and supply our needs from our own locality. Since this is simply not possible in towns and cities such as London, New York, Paris etc. etc. we must continue to transport our requirements over great distances.

Go buy a pizza and look at the ingredients. Now think of where those ingredients came from; Wheat flour perhaps from America, tomatoes from Holland, sun dried tomatoes from Italy, olive oil from Greece, cheese from New Zealand, herbs from France, pineapple from Brazil, ham from Denmark, cardboard packaging from the UK and all put together in Germany.

How many thousands of miles has that pizza travelled???

This planet cannot sustain man's appetite.
 

Offline teragram

  • Sr. Member
  • ****
  • Posts: 122
    • View Profile
What is holding back electric car technology?
« Reply #10 on: 19/12/2008 20:28:45 »
"Electric cars have too many snags."  
"We then have the small issue of practical power-connection (charging) for people who don't have private garages or driveways. Drag cables across pavements and leave overnight?
No viable battery technology can recharge in the few minutes taken to refuel with petrol (and no present domestic supply could provide enough instantaneous power/current to do so anyway)."
"Needless to say, if everyone swapped to an electric car overnight, we'd need some major upgrades to our electricity distribution infrastructure one way or another. I think we'd more than double our electricity usage."
"The main thing that's holding back electric car technology is weight.  Then performance"   .........etc. etc.

So do we then just give up?, and admit that we cannot progress beyond the 19th century when it comes to transport technology?
I thought this was a science forum!!
Reading all this, the "fewer people" answer is the one we'll have to put up with.
 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
What is holding back electric car technology?
« Reply #11 on: 19/12/2008 22:56:07 »
"So do we then just give up?"

How do you solve all the problems then?..  Wave a magic wand.





 

lyner

  • Guest
What is holding back electric car technology?
« Reply #12 on: 20/12/2008 00:06:51 »
The charging time problem is far from intractable. I have a cordless drill with just two batteries. One charges whilst I am using the other and the system works on a continuous basis for all but the most intensive jobs. A third battery would cope with almost any circumstance.
A petrol station could be replaced by a battery swap station - no deliveries needed - just a whacking great mains supply cable and a vast number of  batteries on charge. The volume taken up would be somewhat more than the existing fuel storage tanks, of course, but change over would / could be quicker and a lot safer than pouring inflammable fuel all over your shoes instead of into your tank.
 

Offline DoctorBeaver

  • Naked Science Forum GOD!
  • *******
  • Posts: 12656
  • Thanked: 3 times
  • A stitch in time would have confused Einstein.
    • View Profile
What is holding back electric car technology?
« Reply #13 on: 20/12/2008 09:19:41 »
30-odd years ago on Tomorrow's World they said we'd all be driving nuclear-powered cars by 2000  :D
 

lyner

  • Guest
What is holding back electric car technology?
« Reply #14 on: 20/12/2008 11:25:02 »
Raymond Baxter was a Sports commentator, wasn't he?
 

Offline graham.d

  • Neilep Level Member
  • ******
  • Posts: 2208
    • View Profile
What is holding back electric car technology?
« Reply #15 on: 20/12/2008 14:14:04 »
You are all a bit negative I think. Electric cars do not necessarily mean batteries for a start. What about Hydrogen Fuel Cells for example? It is still an electric car with a relatively simple and efficient electric motor and it does not take longer to fill up with hydrogen than with petrol or diesel. London has a couple of Mercedes buses that work with such a design at the present time so it is a practical solution.

I can also say, from having tried out a Lexus hybrid for a couple of days, that even batteries, when combined with a petrol engine, certainly improve the fuel consumption. In the case of the Lexus, this was combined with very impressive performance too. It may not be wholly green, but it is certainly a step forward. I admit there wasn't too much room in the boot (trunk) though.
 

Offline teragram

  • Sr. Member
  • ****
  • Posts: 122
    • View Profile
What is holding back electric car technology?
« Reply #16 on: 20/12/2008 15:59:37 »
Thanks to graham.d for some common sense.
My next comments are these:-
My car can cover well over 700 miles on one “charge” (50litres).
This range capability is useful to me three or four times a year.
The majority of car journeys are I think within the range of even present day electric car technology.
We still are building and buying cars which can achieve ridiculously high maximum speeds (average speeds in U.K. towns are I think about 20m.p.h.) and are ridiculously heavy. Transport fuel demand could be reduced enormously (15-20%) by reducing trunk road speed limits from 70 (U.K.) to 50m.p.h., (be a lot safer to).
These are some of the points in response to “what could we do without new technology?”

The amount of energy in 45 litres of petrol is about 1,700MegaJoules, but the petrol engine converts about 1,200MegaJoules of that into waste heat, 500MegaJoules into motive power. Diesel engines are of course superior, but not astonishingly so.
If the motive power was supplied by electric motors, only about 170MegaJoules would be wasted,
In response to the original question:-

Electric motor technology is advancing encouragingly, see Siemens e-corner, Flightlink PML, (both in wheel motor technology, NO COMMENTS ABOUT UNSPRUNG WEIGHT PLEASE).
Battery technology also, see Altairnano in California (application of nanotechnology to battery development).
The possibility of motors such those above means that a car would have no gearbox and clutch (needed in conventional cars because the I.C. engine is so ill-matched to the load requirements) and no differential, all of which contribute to poor efficiency. They are perfectly suited to energy recovery on braking (not a fantastic amount unless you’re in a race, but useful)

I find all the negative attitudes to the need for drastic new methods of transport and energy to be extremely discouraging and I repeat "I thought this was a Science Forum"
 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
What is holding back electric car technology?
« Reply #17 on: 20/12/2008 17:09:50 »
It is a science and engineering forum and not a science fiction forum.

Batteries.... You need at least a ten fold increase in energy stored per weight.  You need cheap safe and long life batteries.   
 
Unless domestic electricity supplies are beefed up by a factor of several times (very unlikley to happen) home charging will always be slow.  Even charging on an industrial scale will never be fast.  Battery swapping seems to be the only alternative and at current battery weight and bulk it is not really on.

People want  versatility..  They may do the same short journey day after day but they will want to go and see their granny etc etc now and again which involves an extra 10 miles.   A 50 mile range will mean you won't risk going more than 20 miles from home. 

Look at the G-wiz.  You have to take range figures etc with a bucket of salt. 

 

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • Posts: 11978
  • Thanked: 4 times
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
What is holding back electric car technology?
« Reply #18 on: 20/12/2008 17:11:26 »
In fact 'fewer people' is the viable answer:)
This is what we need to consider.

Any way, there are a lot of short term solutions energy wise:)
If we would 'permanent' them though the power(s) 'that be' would have to change.
As our society would change.

Less central control.
more diversification with lesser possibilities to 'supervise' us.
Unless we accept a 'police state'.
Which wouldn't surprise me:)
 

Offline LeeE

  • Neilep Level Member
  • ******
  • Posts: 3382
    • View Profile
    • Spatial
What is holding back electric car technology?
« Reply #19 on: 21/12/2008 17:03:57 »
One issue with batteries and fuel cells is that they store an enormous amount of energy and if they're damaged there's a risk of all that energy being released at once in an explosion.  This doesn't sound too different from the case with petrol but while petrol will burn it won't explode in atmospheric air.  It explodes in the cylinders but this is only after it is atomised and mixed with air in the right combination.  In this respect petrol is safer than batteries or fuel cells.

Hydrogen fuel, carried separately and used in a fuel cell type convertor, might be the best option.  As with petrol, Hydrogen won't explode in atmospheric air unless the mixture is right, although it will of course burn, but it's problematic stuff to carry around.  It's molecules, being so small, will leak out of fuel tanks very quickly unless they're made and maintained to a high standard.
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
What is holding back electric car technology?
« Reply #20 on: 21/12/2008 17:20:41 »
There is a great deal of emphasis on electric cars here, i.e. personal transport. If you really want to do something which will be of some benefit to the environment, forget electric cars, in fact, forget ALL forms of personal transport which need more than your own body power. Then tackle the wider problem of the transport of provisions.

An electric 42 ton truck??? I don't think so.
 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
What is holding back electric car technology?
« Reply #21 on: 21/12/2008 18:08:38 »
I gather the Tesla Roadster has been tested by Clarkson on Top Gear and the prog is on tonight on BBC2.  Sounds like Tesla objected to the findings.  For one thing there is some argument about the charging time of 16 hours versus 3.5 hours.   I would have thought that 3.5 hours is simply not possible with British domestic (or any other in the World) supplies and 6 hours would be more like it.
 

Offline teragram

  • Sr. Member
  • ****
  • Posts: 122
    • View Profile
What is holding back electric car technology?
« Reply #22 on: 21/12/2008 18:50:54 »
The original question was -
"anyone have any fresh ideas that might advance the electric car concept?"
I think I am the only one to have attempted to answer this so far. Most of the replies seem to be merely concerned with stating the problems of electric cars. Any mention of electric cars seems to frighten a lot of people. Why don’t we remember the problems with conventional cars?

"One issue with batteries and fuel cells is that they store an enormous amount of energy and if they're damaged there's a risk of all that energy being released at once in an explosion."

Developments on Li-ion batteries seem likely to address this problem. Also, is being in a fireball any better than being in an explosion?

If every experimenter or engineer just accepts all the problems stated, and didn't bother doing any development, then alternatives will never appear. This applies to every other technological endeavour. I remember the appearance of transistors spawning the argument "transistors will never replace valves". We now have phenomenally powerful computers in almost every home.
Incidentally, this is not an invitation to open the debate here on whether valve audio amplifiers are better than transistor ones.

There is no science fiction here, we just have to change our lifestiles.
 

Offline techmind

  • Hero Member
  • *****
  • Posts: 934
  • Un-obfuscated
    • View Profile
    • techmind.org
What is holding back electric car technology?
« Reply #23 on: 21/12/2008 20:36:14 »
"So do we then just give up?"

How do you solve all the problems then?..  Wave a magic wand.

Well, forgive us for being negative, but the thread title appears to be
"What is holding back electric car technology?"
so that could be expected to direct the tone of many of the replies.


Fundamentally, moving an individual around in a steel cage/contraption with 5 to 10x the mass of the occupant is going to be inefficient because you have all that deadweight.

Although it doesn't come with creature-comforts, the bicycle is a far lower-energy method of getting around. It's a shame that inconsiderate car drivers often make cycling on our roads an unpleasant and hazardous activity.

Mass-transit systems (buses, coaches, trains) are far more fuel-efficient than private cars too - but have their drawbacks in terms of limited routes, limited frequency of service, sharing space with strangers etc etc. On the other hand, if more people used them then the logistics of frequency and routes becomes helped by economies of scale.

Electric cars could probably be 2-3x (thereabouts) more energy-efficient than petrol cars - but far greater savings could be achieved by considering wider options for transport.

Another possibility is if we all owned much smaller 1-2 person cars as local runabouts (electric or otherwise), and adopted the mindset of hiring larger cars just on the rare occasions when we actually need to cover longer distances or carry bigger loads.


Electric cars would have some advantages, but shouldn't be viewed as a magic bullet. The solution to excessive energy use is not purely more technology, but technology alongside some changed lifestyle expectations.
« Last Edit: 21/12/2008 20:41:16 by techmind »
 

Offline Pumblechook

  • Hero Member
  • *****
  • Posts: 569
    • View Profile
What is holding back electric car technology?
« Reply #24 on: 21/12/2008 21:00:34 »
I think Top Gear got it about right. A great car but only for as long as the batteries have juice.  The programme will be viewable on BBC i-player.

Electric car manufactrurers and fans do themselves no favours by quoting silly figures that tests and calculations reveal to be bogus.


I don't see how electric vehicles can be more energy efficient than petrol ones.  After all the batteries are only a means of storing energy from some other source and there are losses all the way from the power station to the battery.  Maybe less than half of the mechanical energy produced by the turbines reaches the driving wheels of a vehicle.

You could say electric vehicle users are (deluded) polluting, parasitic tax dodgers if you wanted to be unkind but there is some truth in that.
 

The Naked Scientists Forum

What is holding back electric car technology?
« Reply #24 on: 21/12/2008 21:00:34 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums