Electric Vehicles

[josmith]

a few quick calculations will show the aircar up as a scam.<p>[ January 22, 2003: Message edited by: josmith ]</p>

[hlreed]

A steam engine without the steam. What horsepower is required to pump up the air. Compressed air is a lossy system, good for power tools but a car?
Nature is a tough mother. Not possible to fool.

[jbsteele]

Someone mentioned earlier that the electric car just moves the polution to another place... well that it a Good Thing. It's saner to concentrate the problem at one central plant where it can be dealt with by professionals than scatter it around among thousands of cars haphazardly maintained. Seems to me the greenies are ignoring the impact (sorry) of the huge battery packs on the environment. I'd hate to see all that lead flying around... or nickel & cadmium for that matter. <p>I like the idea of fuel cells... but where's the hydrogen going to come from? If we have to set up a hydrogen fueling infrastructure.. why use expensive fuel cell tech anyway? An internal combustion engine can run cleanly on hydrogen.<p>just ranting....
Jim

[natcsparky]

Hybrid Electric Cars have a future, but (I know this because we have built one) there are still issues. One is as Dean and others have brought up, the battery and the lack of a good replacement for lead acid, nickle metal hydride or Lithium Ion (like I want that in my car). The battery technology is limited by exactly what Dean brought up about other loads. Now vehicles are going to 42 volts so that electric steer, electric brakes can happen. This makes the reality of a true EV difficult to imagine. Hybrid technology looks promising on the surface, but when you consider that these very expensive battery packs will need replacing in 2 years? AND when you add the enviromental impact of recycling all of that heavy metal, the advantage of hybrid technology becomes less. Ultra-capacitors are promising as they have little environmental impact, are perfect for regenerative braking and are very good at supplying high current transients (standing on it at the light). The weakness is the amount of power (Amp Hours) UCAPS can deliver. When coupled with batteries UCAPS extend the battery life, and make the dynamics of the powertrain more flexible. Used alone with an engine powered generator, UCAPS can perform pretty well, but system tuning is required, due to the limited staying power of the charged cap. Fuel cells are perfect for space, as they really like a clean environment. Down to earth applications are more troublesome, but I have every confidence that fuel cells will be in our future. So what do we use for now. Toyota has been relatively successful and when UCAPS become less cost prohibitive, they will make the hybrid vehicle a very reliable alternative to the ICE alone. <p>I, like Dean, do not see a magical battery source coming down the road anytime soon, strange to think that the same lead acid batteries (albeit with improvements) that were used at the turn of the (last) century are still the "best" choice today.

[hlreed]

Rick
You said:
"Fuel cells are perfect for space, as they really like a clean environment. Down to earth applications are more troublesome"<p>I thought fuel cells could be filtered. Do you mean dirty air kills them? What is the main problem?

[natcsparky]

Harold,<p>The main problem is that impurities can cause premature failure of internal parts. I do not pretend to be an expert on this, but at a conference recently, the issue of impurities injested by the fuel cell showed that in some cases, material commonly found in the air can cause oxidation in concentrations of 5 PPM. Filtering does work, as there are several fuel cells performing now, but it is a large concern for all of the ongoing product manufacturers as they look to the fuel cell to augmnent their power plants on vehicles.

[hlreed]

Thanks Rick
I had hoped they would have made better membranes by now. I have not looked at fuel cells in a long time. I guess what we need is a breakthrough in making membranes.
I have had too much experience with batteries.
There is a new buzz on super caps or something like that. Charge and discharge.
Calling them super sells them I guess.

[natcsparky]

No Problem Harold,<p>The Super or Ultra Capacitors are having an impact and will probably help with dynamics on EV and hybrid powertrains within a few years. Right now the costs are too high, and there are problems with some of the UCAPS emitting cyanide when overcharged, not something I want to be around.

[hlreed]

Wow!
What are those things made of?

[L. Daniel Rosa]

There are mid-tech and low-tech options as well. Unfortunately the first I'll mention I don't have written evidence of.<p>I'd heard of a trio of high-schoolers that converted a gas powered car to a gas-pneumatic hybrid and downsized the engine to make room for the air tank. The engine was on an automatic controller that would switch between idle and some speed (I wasn't told) that was the best horsepower*hours per unit of fuel for the engine. The driver controlled the valve from the pressurized air tank to the air motor driving the transmission. So I'd heard, the efficiency could approach 90 miles per gallon.<p>Now on to what I've some supporting evidence for. For gasoline engines parked in rural areas, a Kalle gasifier may be appealing. http://www.artech.se/~joacim/gengas/kg_eng.html<p>As for diesel, there is always McDonalds.

[unknown_entity]

Well there's alot of stuff in electronics thats pretty nasty. I'm not fafiliar with the super caps but i wouldn't be suprised if they contained cyanide.<p>Old Xformers & Caps = PCBs
Solder = Lead
Doping in silicon = Arsenic
(not sure whether its in P or N type)
Car Batterys = Lead <p>There's probably alot more these are just the ones that come to mind.<p>I've only read about fuel cells but they seem to be a cleaner source(Hydrogen + Oxygen in) = (Water and voltage out)

[natcsparky]

Harold,<p>UCAPS come in two varieties (right now), acqueous and non-acqueous. The acqueous capacitors are safe from a hazardous material point of view. They use a pottasium based electrolyte and some lead. The non-acqueous based capacitors use something called StarLyte ACN which is based on Ethanenitrile, ethyl nitrile or Methyl cyanide. This is a hermetically sealed unit, but is designed to "releive" pressure under extreme overcharge events. This results in the emission of toxic vapors. There have been people injured by this (lucky to be alive), I do not know of any deaths at this point. The non-acquesous capacitors have the advantage of higher density capacitance per LB and respectable cubic densities. The acqueous based capacitors have the advantage of higher cubic specific power with but at a higher weight (i.e. lots of liquid electrolyte). They are available in modules up to 500 FARAD at 28 Volts (made up of 20 10000 Farad modules in series). Impressive technology to say the least.

[bwts]

Reguarding aircar skeptics (it may be a scam I dont know I dont happen to have an aircar to know for sure) the air is pumped into the containing tanks at a low temperature thus giving the capacity needed to generate enuff horse power to move the car.<p>Reguarding the issue of displacing pollution (for both electric and air powered cars). There are ways of generating electricity without using fossile fuels.<p>B)

[hlreed]

Mr. B
It is a matter of temperature. The aircar or air motor exists in every repair shop as an aircompressor. It takes more power to pump up the presure than is released by the pressure. There is no gain as in combustion. I expect the aircar milage is about 10 feet per tank.

[josmith]

The amount of energy that the aircar people claim is needed to charge the air tank isn't enough to power a
car for 10 hours even if it were recovered at 100%. <p>That amount of energy isn't enough to compress the volume of air at the pressure they refer to.<p>As Harold pointed out this is basically a steam engine, which uses air rather than steam as a working fluid. A steam engine still needs an outside source of heat to expand the fluid. No such source of heat is available on the aircar.<p>The description of the engine’s cycle implies that the heat generated by compressing one cylinder of ambient air will provide the heat to expand the compressed air. This is like saying that adding a bucket full of cold water to a cup of boiling water will yield a bucket of boiling water.<p>Unfortunately people tend to believe what they want to believe.