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A Practible Electric Car?

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The kinetic energy of a 60 mph, 3500 lb car is about 570 kJ. That's the energy stored in 0.45% of a gallon of gas. Unless all you're doing is starting and stopping, the regenerative braking retrieves very little of the energy consumed on a trip.

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MIT, Prof. Mitchell from GM and Frank O. Gehry are developing a city concept car. The city car will have high tech wheels with embedded electric motor and suspension.

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60 mpg? what is green about that? A 4 seater that gets 30 mpg is as efficient, safer, weatherproof, and has a top speed of 90 mph or more.

Ridiculous.

The MIT car is even worse.

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Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
Well said Greg. I wasn't impressed by the figure either, I believe certain european or Japenese sub compacts may be at a similar value with 4 seats.

Of course in most cars all 4 seats aren't used so saying a 4 seater that gets 30mpg is as efficient as a 2 seater 30mpg is a simplification.

 
I guess it depends what you mean by efficient. By that logic an 8 passenger SUV at 15 mpg is equally as efficient as the Go Car. Of course there's usually just one or two passengers, and the mileage doesn't go up to 60 mpg with just two passengers. (Never saw cars rated in person miles per gallon before.)

I wasn't trying to say the thing is the "wave of the future" or phenominally amazing, just pointing out a (relatively) efficient vehicle that's on the road. I was also wondering how that was street legal, considering the DOT wouldn't certify the Smart Car due to safety concerns, but thats another thread.

As for the OP, the car looks great. Don't see how it overcomes the established problems with electric cars, though (range and battery reliability/volatility). My thought on the shifting of emissions issue: isn't it true that point source energy production is preferable because of higher efficiency and use of heavy equipment like scrubbers and the like to reduce emissions? (OK, the nasty stuff is still there, but its not air emissions at that point)

Also, I don't see the modern world getting away from providing electricity to homes -ever-, so isn't it logical to assume that the electrical generation technology will continue to improve and evolve? And if so, doesn't it make sense to develope electric cars to anticipate that eventuality?
 
Yes, the emissions are concentrated, but the companies are fighting the scrubbing tooth and nail. And the sources are converting to coal and water. While coal is relatively plentiful in the US, it's not a particularly clean burning fuel.

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Oz has 200 years of coal. The recent paper on it suggests that nuclear is more expensive than current coal power, but cheaper than clean coal, with CO2 sequestration.

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Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
The caveat is that most coal reserves are calculated on the CURRENT consumption, which in the US, is almost entirely used for electricuty. A drastic shift to electric cars would crank up the consumption of coal considerably, since hydro is pretty much maxed out already. This would have to be coupled with a drastic increase in the number of coal-fired generator plants, which will substantially add to the ecological cost of converting to electric cars.

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It's OK, the UK has plenty of coal left after the government pretty much shut down the coal mining industry in the 80's/early 90's.

Wouldn't be so easy to restart production etc but there you go.

Plus there are numerous other ways to produce electricity, some need further development others just have large up front costs with the current technology.

That said in the medium term I think a plug in (possibly series) hybrid would have been a better idea, though ewh it does look pretty cool.
 
So the coal is there for the foreseeable future, agreed. Andybody have any comments on how much more efficiency we can squeeze out of the plants and/or how much we can or will clean the emissions from these point sources?

As for CO2, I've got a plan. Its very complicated. It involves an extremely complex carbon sequestration device.

It's called a tree. Plant many. Cut them down after about 20 years and plant some more. Repeat. Use them to make things out of *wood*. The engineering historians may be able to shed some light on how that was once done.
 
How long does a structure last, typically? 30 years? 100 years? What happens to the wood in that structure then? Unless you can recycle it into something permanent then all you've done is taken it out of the carbon cycle for an additional 30-100 years. Not enough to make a difference IMO.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
You bury it in an old coal mine of course:)

More energy efficient might be to use it for fuel but then as you say, you're returning most of the CO2 to atmosphere.
 
Well short of Kenat's idea (which actually could work), think of it this way: by increasing the amount of products made of wood you've created a carbon "warehouse". Carbon flows into the warehouse, and eventually out of the warehouse. Once you reach steady state (full warehouse) flow in equals flow out. This might seem like you've gained nothing. However, for every pound (or kilo, whatever you crazy foreigners use) of carbon in the warehouse there is one less pound of carbon in the atmosphere. This can't solve the problem if we keep dumping carbon into the atmosphere, of course. But given a big enough warehouse (lots and lots of wood products), it could definitely buy us time, and maybe a quite a bit of it.

A properly maintained wooden structure can last 100 years, easily; maybe more with modern moisture control techniques. Other, more disposable products may have a life span of a few months to a few years. But each item increases the inventory of the "warehouse".

Have I fallen prey to some logical fallacy here? Feel free to poke holes in the argument.
 
The fallacy is that there are already carbon warehouses, e.g., the fossil fuel deposits. The problem is not that we don't have a carbon warehouse, it's that we're releasing ever increasing amounts of carbon from those warehouses.

The CO2 in the atmosphere cannot be readily re-warehoused, not without burning a whole bunch of energy to get there. How are you going to get the atmospheric carbon into wood without cracking the CO2, which requires at least as much energy as was released when the carbon was originally combusted?

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Your logic seems to work YoungTurk.

Lets build lots of HMS Victory's. Must be one of the oldest wooden structures around still in fairly good repair (yes I know a lot of her has actually been replaced over time).

Of course we still might be better burning most of that wood/vegetation in place of digging up new fossil fuels. Now if we can get the wood or other vegetable matter to grow faster than we can combust or otherwise turn it into useful energy we can start building victory's or burying it.

I propose a new unit. The Victory. An amount of sequestered carbon equivalent to that in the HMS Victory.;-)

 
But if we eat cows and other herbivores faster and kill the pesky termites (hence helping preserve the 'victories') this would probably adequately compensate.
 
Photosynthesis, sure, but how much energy are you going to burn to plant and maintain the 10 billion trees needed to warehouse the carbon? Don't forget fighting the forest fires and the pests, and relocating the people that havwe already encroached into the areas that would be reforested.

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