Electric cars

[marinyork]

However, there is another approach in development based around high powered lasers. I think we'd be pretty unlucky if neither technology worked out.

On the topic of ICF, it's just taken a very long time. NIF is very impressive for the insane power of the lasers, HiPER for it's ingenuity. Despite this it's hard to see where it's going.

 

[tyred]

Electric cars will do absolutely nothing to solve the congestion issues in towns and cities which imo, is the biggest problem with conventional cars.

 

[marinyork]

I was reading an interesting article in New Scientist yesterday. It was about a new type of battery containing what the inventor referred to as Cambridge Crude (Cambridge in the US where the MIT is based). The liquid contains specks of lithium ion which holds the charge, and specks of carbon graphite which provides the electrical path. One advantage of this technology is that you could fill up your tank at a petrol station. There were still a lot of drawbacks of the technology, but there seems to be a lot of interesting developments in battery technology.

We need some materials breakthroughs. If we have to rely on rare earth elements too heavily in the electric or hybrid cars then we are in potentially big, big trouble.

 

[Piemaster]

I'm actually fascinated with the possiblities electric vehicles if designers can move away from just sticking an electric motor in the vehicles we use now. Think of a 4x4 (or 6x6, etc.) electric vehicle using 4 of Michelins active wheels or something similar.

 

[Dan B]

the cynic in me thinks that it is because viable nuclear fusion = virtually limitless cheap energy

The entertainment industry reacted to the prospect of virtually limitless free information by inventing copy protection (nowadays known as DRM) - perhaps I am even more cynical than you, but i see no reason that The Man couldn't manage a similar trick for free energy. Doesn't matter now much it costs to produce, if they won't hook you up to the supply unless you pay your fees they can carry on charging you 20p a unit.

And if fusing at home becomes a practical option (I found this link very interesting) they'll make it illegal, just as distilling spirits is. Health and Safety, inniy?

 

[slowmotion]

Except that the electricity for a Prius comes from its own brakes. All it does is recapture energy that would be wasted in a conventional car (slowing down) and use it to supplement a conventional petrol engine.

The recycled kinetic energy is generated from fossil fuel.

 

[XmisterIS]

Does anyone know how electric cars are heated?
I was working outside yesterday and when returning to the van I was cold and wet, its wonderful to get the heater on full blast and enjoy the 30+ miles home. Now if this had been an electric vhicle with an electric heater, would I have been reluctant to put the heater on run the batteries down even quicker and fail to get home. I suppose they could be fitted with auxiliary heaters such as fitted in lorry cabs with a small little tank for the diesel.

Heaters? Tsk! A few years ago (when we had that perishingly cold winter, snow drifts, etc) I drove all winter in my old car in which the heater had gone completely. Nothing a pair of gloves, a jacket, a wooly hat and a scarf couldn't fix! Heaters are for wimps!

(that being said, I sold the car for scrap in the spring ...)

 

[User482]

The recycled kinetic is generated from fossil fuel.

Which would otherwise be wasted. This isn't relevant to the discussion about electric cars displacing the impact of fuel combustion elsewhere - the Prius is just a clever way of making a conventional car more energy-efficient. Plenty of other conventional cars employ similar technology, albeit less obvious. For example, BMW's "efficientdynamics" is a mild hybrid.

 

[Night Train]

Does anyone know how electric cars are heated?

Some are electrically heated, which does reduce the range a bit but they can be preheated while charging to reduce teh load on the batteries when running. Others are fossil fuel heated with oil burners.

The DIY route is usually to use a ceramic heater, ripped out of a household heater, as they are self governing for temperature and so don't overheat if the fan stopped running.
Attempts have been made to recover heat from the motor and the controller but due to the relatively high working efficiency, 80-95% compared to 30% for internal combustion, there is very little spare heat to be had.

 

[jdtate101]

Fusion has been "two decades away" for how long now? I wouldn't hold your breath!

Better, I think, to prepare for cutting our usage, and if fusion power does come to fruition, then look at it as an unexpected bonus.

Not really, the ITER project in France:

http://en.wikipedia.org/wiki/ITER

This is the first full up test of a commercial scale design and is slated to start major power production tests in 2019, it's still only a large scale testbed, but should it work it will form the basis of future power plant design. Thus my two decades statement.

 

[User482]

Not really, the ITER project in France:

http://en.wikipedia.org/wiki/ITER

This is the first full up test of a commercial scale design and is slated to start major power production tests in 2019, it's still only a large scale testbed, but should it work it will form the basis of future power plant design. Thus my two decades statement.

No chance! It's extremely optimistic to think that they're going to start tests in 2019, and even if they do, it'll be at least 5 years before they can think about a commercial plant, and then at least another 15 years to design and build it. Allowing for inevitable delays and commissioning, I'd say my estimate of 40 years is about right.

 

[Red Light]

Except that the electricity for a Prius comes from its own brakes. All it does is recapture energy that would be wasted in a conventional car (slowing down) and use it to supplement a conventional petrol engine.

Some of the energy comes from regenerative braking but most of it comes from the engine charging the battery. The reason for its efficiency is primarily that it is able to use the much more efficient Atkinson cycle engine (rather than the normal Otto cycle) which has the disadvantage of low torque at low rpm which the electric motors make up for.

 

[Red Light]

Not really, the ITER project in France:

http://en.wikipedia.org/wiki/ITER

This is the first full up test of a commercial scale design and is slated to start major power production tests in 2019, it's still only a large scale testbed, but should it work it will form the basis of future power plant design. Thus my two decades statement.

ITER kicked off in 1985 and is expected to be running as you say in 2019. Which gives you an idea of the timescales you are dealing with to get it to the next stage beyond. I worked in magnetic and inertial confinement fusion in the late 70's and early 80's and its as far away to day as was being claimed then. And if it is made to work the one thing it will not be is free energy. Apart from about two thirds of the cost of electricity being distribution costs, the reactors themselves will not be cheap to build, run or maintain and there are significant radiological problems to deal with too.

 

[User482]

Some of the energy comes from regenerative braking but most of it comes from the engine charging the battery. The reason for its efficiency is primarily that it is able to use the much more efficient Atkinson cycle engine (rather than the normal Otto cycle) which has the disadvantage of low torque at low rpm which the electric motors make up for.

We have a Prius (mark 2) at work. According the dashboard computer, battery recharging is more often from slowing down and braking than from the petrol engine.

Your point about the Atkinson cycle engine is true, albeit a minor one: the Prius is at its least efficient when it's on "petrol only" mode, typically this is on motorways. One might expect fuel economy of 50-55mpg in this situation. By contrast, urban use, where full use is made of regenerative braking and the electric motor, one might expect fuel economy of 60 mpg or more.

 

[snailracer]

The electric cars available now are fairly efficient in comparison to their petrol equivalents, but that's because they are designed to be, to appeal to the eco crowd but also because batteries aren't very good.
Looking into my crystal ball, when electric cars become mainstream, batteries improve or are easily charged, those constraints won't apply - you will simply end up with the electric equivalent of gas guzzlers.