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[P]
The car that runs on air

By skim123 in MLP
Wed Oct 25, 2000 at 04:36:31 AM EST
Tags: Technology (all tags)
Technology

Seems like those crazy South Africans have invented a car that runs on an air-powered engine. The upside? The car can travel 120 miles for ~30 US cents. The downsides are numerous however: after 10 hours of operating, you need to "power-up," which can take up to four hours (or longer, depending on your lung-strength <grin>). Also, the car looks like it has some sort of glandular problem. The car is expecting to cost around $10,000 USD and should be hitting showroom floors (at least in South Africa and France) in 2002.


I have to wonder if Americans would drive such a contraption. Since the gas price is not as high here as it is in other nations, I find it hard for people to endure such long charge-up times for such a short amount of driving time. Seems that if you wanted to best of both worlds - low fuels costs but no annoying recharging time (and a more sporty looking car) - you'd go with the Honda Insight.

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Poll
I would buy an air-powered car
o Yes 51%
o No 11%
o Only if the recharge/driving time rate were improved marketably 37%

Votes: 43
Results | Other Polls

Related Links
o car that runs on an air-powered engine
o Honda Insight
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The car that runs on air | 42 comments (41 topical, 1 editorial, 0 hidden)
Who compresses the air? (3.50 / 10) (#1)
by rusty on Wed Oct 25, 2000 at 01:51:01 AM EST

Not that I don't think this is a pretty cool idea, especially for reducing smog in urban areas, but of course this is not zero pollution. It runs on compressed air, and air doesn't just go around compressing itself cause we want it to. It's still electric-powered, the power just comes from some power plant somewhere, probably from merry glowing uranium cores.

I only point this out because people have a tendancy to look only at the small picture when considering things like vehicle emissions. "It's pollution free" won't happen till we have solar cars. I still think solar is the best chance at a truly low-to-no environmental impact energy source. We just gotta get more efficient about capturing it.

____
Not the real rusty

Sketchy (2.66 / 3) (#2)
by Commienst on Wed Oct 25, 2000 at 02:04:00 AM EST

"The car, which resembles a small minibus, is being promoted by the slogan "Simple, Economic and Clean", but details of how the vehicle will work remain sketchy. "
Like they said details are sketchy. My guess is the car compresses the air onboard while charging and stores it into the "scuba tanks".

[ Parent ]
Unless the electricity is produced by solar power (2.25 / 4) (#3)
by skim123 on Wed Oct 25, 2000 at 02:04:53 AM EST

Then you have completely clean cars.

I gotta wonder, if the universe starts contracting one day, might we have anti-entropy, and air just might start compressing itself?

Money is in some respects like fire; it is a very excellent servant but a terrible master.
PT Barnum


[ Parent ]
Probability Level... (1.25 / 4) (#9)
by rusty on Wed Oct 25, 2000 at 03:37:01 AM EST

2 to the 123873692 to 1 against and dropping.

;-)

____
Not the real rusty
[ Parent ]

Solar energy also not that clean (2.66 / 3) (#8)
by dabadab on Wed Oct 25, 2000 at 03:28:27 AM EST

"I still think solar is the best chance at a truly low-to-no environmental impact energy source."

Well, I have doubts about it. Solar cell manufacturing produces lots of dangerous by-products and it needs much energy - IIRC more than a solar cell is expected to produce during its lifetime.

Of course technology can improve - but in its current state I think nuclear energy is much more cleaner than solar.
--
Real life is overrated.
[ Parent ]

Hmm (2.00 / 3) (#10)
by rusty on Wed Oct 25, 2000 at 03:44:26 AM EST

By-products are bad, yes. Something to do with earth metals, I'm guessing? [hazy recollections from nuclear & particle physics classes...]

Any chance that economies of scale could reduce the total amount of energy consumed by solar cell production? Kinda like how the first Pentium chip cost 3 billion dollars to make, and the second one cost 2 cents (I'm making up these numbers out of thin air, so don't get all factual on me ;-) The point stands.). If enough solar cells were being produced, and production energy dropped below output energy, then you could conceivably use solar power to power the production plants. That would solve that problem.

FWIW, I agree with you that the only good bet currently is nuclear. Accidents are pretty rare (although they suck bad when they do happen), the actual operation of the plant is very low impact, but man those byproducts are a bitch. Is anyone working on any kind of "dump consumed fuel rods into the sun" kind of plan, or would that be a Bad Idea?

____
Not the real rusty
[ Parent ]

Nuclear waste (1.50 / 2) (#15)
by dabadab on Wed Oct 25, 2000 at 05:39:52 AM EST

Well, dumping nuclear waste into the sun is a promising idea as nuclear power plants use incredibly low amount of fuel but the current trend is - as I see it - is to store the stuff as it is a potential power source. Although current technology does not allow us to use it effeciently, research is on the way.
--
Real life is overrated.
[ Parent ]
Nuclear energy is a bust. (3.00 / 1) (#26)
by itsbruce on Wed Oct 25, 2000 at 10:40:10 AM EST

FWIW, I agree with you that the only good bet currently is nuclear. Accidents are pretty rare (although they suck bad when they do happen), the actual operation of the plant is very low impact, but man those byproducts are a bitch. Is anyone working on any kind of "dump consumed fuel rods into the sun" kind of plan, or would that be a Bad Idea?
Imagine if Challenger had been carrying a payload of nuclear waste. Hold that thought.

  • Nuclear power is dangerous

    Large-scale nuclear accidents may be rare but minor ones happen all the time - and are hushed up. The effects are insidious, hard to spot and last a *very* long time. The worst oil-based disaster of all time - Saddam burning the Kuwaiti oil fields - doesn't even begin to compare to Chernobyl. Three Mile Island nearly wiped out a city of millions.

  • Nuclear energy is expensive

    All the cheap energy propaganda put out by US and European governments was a lie. We've all been paying subsidies to the nuclear industry to create the illusion of cheap nuclear energy.

  • Nuclear power is desperately inefficient

    Nuclear fuel contaminates everything it touches. Containers, work clothing, everything. The industry generates a constant flow of this low-grade waste which itself has to be expensively disposed of (although a lot of it is criminally dumped in normal waste depositories).

  • Nuclear power spans have a short lifespan

    At the end of which the whole plant (let alone the pile) is one big lump of low-to-medium grade nuclear waste. This has to be carefully disposed of at a big cost - see the last item.

  • Uranium ore is a non-renewable resource

    Not only are we already dependent on too many non-renewable resources but radio-active decay means that all the ore and refined nuclear fuel becomes less useful over time even when you're not using it

The only reason we still have nuclear industries is the fact that it provides a relatively cheap source of plutonium for warheads.

--

It is impolite to tell a man who is carrying you on his shoulders that his head smells.
[ Parent ]
Nuclear Power (2.66 / 3) (#30)
by Alarmist on Wed Oct 25, 2000 at 01:04:17 PM EST

Large-scale nuclear accidents may be rare but minor ones happen all the time - and are hushed up. The effects are insidious, hard to spot and last a *very* long time. The worst oil-based disaster of all time - Saddam burning the Kuwaiti oil fields - doesn't even begin to compare to Chernobyl. Three Mile Island nearly wiped out a city of millions.

Um? As I recall from school, the radiation release at TMI was on the order of a few percents of a millirem at 1/3rd of a mile outside the plant. Chest x-rays give you much more radiation. How, exactly, did TMI almost kill millions? As for the idea that there are lots of minor incidents, I ask you for sources. I'm not doubting that they happen, but I want to look at your evidence myself.

Re: Chernobyl. Important facts to remember here are that the basic reactor design was unsafe and that the accident was caused by an unauthorized safety test that shut down too many of the safety features. Yes, it was a big huge mess, but that's what happens when you have idiots fooling around with dangerous things.

All the cheap energy propaganda put out by US and European governments was a lie. We've all been paying subsidies to the nuclear industry to create the illusion of cheap nuclear energy.

Sources, please? I'm genuinely interested.

Nuclear fuel contaminates everything it touches. Containers, work clothing, everything. The industry generates a constant flow of this low-grade waste which itself has to be expensively disposed of (although a lot of it is criminally dumped in normal waste depositories).

Yes, nuclear power does contaminate things. Yes, waste is often criminally disposed of. Does this need to change? Of course. Problems like this abound in every energy industry: oil- and coal-fired plants generate toxic exhausts, manufacture of solar cells involves the generation of dangerous waste products, windmills can disrupt local environments, hydroelectric plants can damage riparian ecologies, and so on. About the only one that is, to my knowledge, relatively clean is geothermal power, but it's fiendishly difficult to put into practice and very expensive. The waste generated by nuclear power, while dangerous, is not on the same order of magnitude as that generated by fossil fuel industries.

Not only are we already dependent on too many non-renewable resources but radio-active decay means that all the ore and refined nuclear fuel becomes less useful over time even when you're not using it

Also true. But the half-life for U-238 (the most common isotope) is about 4.6 billion years. The half-life for U-235 is about 703 million years. Clearly, the vanishing of all our uranium into lead is going to take some time. While I agree with you that we should be using renewable and cleaner resources, nuclear power (when properly used and checked) is the best shot we've got right now.

As for deaths attributable to nuclear power accidents versus something more common (like coal power operation), it's like comparing the deaths due to airline crashes and the deaths due to automobile accidents. More people die at once from the plane crash, but more people are killed annually while driving. (Not-so-fun fact: radioactive emissions in the exhaust from coal-fired plants kill about 50 people in the United States every year).

Fight the Power.


[ Parent ]

Some more information (none / 0) (#34)
by itsbruce on Wed Oct 25, 2000 at 06:17:38 PM EST

Um? As I recall from school, the radiation release at TMI was on the order of a few percents of a millirem at 1/3rd of a mile outside the plant. Chest x-rays give you much more radiation. How, exactly, did TMI almost kill millions?
By almost having a complete meltdown, something they came very close to. If that had happened, the top of the reactor would have blown, venting tons of radioactive steam followed by smoke laden with fission products (from the burning core) and finally the core would have melted it's way through the bottom of the reactor and into the ground, where its poisons would have spread rapidly through the water table (and let's not forget it sits in the middle of a river).

As it was, the incident was contained (as much through luck as judgement) but they came yay close (imagine I'm holding my thumb and forefinger very close together).

There's a good technical account of how it went here. The author seems to have no special agenda.

As for the idea that there are lots of minor incidents, I ask you for sources.

I don't know about American sources but N-Base is a huge resource of press cuttings, briefings and reports relating to the UK industry. As to specific incidents...

There was the Windscale incident in 1957, a fire in a plutonium production reactor. The government's main remedy was to change the name of the plant to Sellafield. The workers who took part in the clean-up were given minimum protection and, later in life when they started to die of it, were forced to sign gagging agreements before they were given compensation.

The Dounreay plant stores low-grade waste in a pit with pathetic saftey provisions. There have been several explosions in this pit over the years and erosion (the pit is close to a cliff!) threatens to dump the whole lot into the sea at some point in the near future.

Sources, please[re cheap energy lies and subsidies for the nuclear industry]? I'm genuinely interested.
(Sometimes "type='cite'" just stops working here)

In 1982 The British government imposed a 10% nuclear levy on all electricity bills, ostensibly to pay for the cost of decomissioning - PWR. This was scrapped on privatisation of most of the UK energy industry, but a new tax on non-nuclear sources of energy was imposed, effectively reintroducing it. There's a nice little summary of Britains disastrous nuclear experiment here.

For one perspective on the US equivalent, see Too Cheap to Meter.

As for deaths attributable to nuclear power accidents versus something more common (like coal power operation), it's like comparing the deaths due to airline crashes and the deaths due to automobile accidents. More people die at once from the plane crash, but more people are killed annually while driving.
But a serious nuclear incident is a combination of both. It would be like a plane crash which caused regular car crashes for years afterwards.

--

It is impolite to tell a man who is carrying you on his shoulders that his head smells.
[ Parent ]
Information. (none / 0) (#38)
by Alarmist on Thu Oct 26, 2000 at 10:23:47 AM EST

Well, those links will kill most of my work day...(smirk). Thanks for the information. I'm very used to arguing with people who don't bother to cite things, so this is a refreshing change of pace.

WRT serious nuclear accidents, it's not something I'd want to have happen. That's why reactors should be designed with hyper-redundant, never-halt-or-catch-fire systems. Unfortunately, a lot of corner-cutting goes on that is simply criminal.

What I'd really like to see is a series of efforts to reduce power consumption (either by introducing more power-efficient products or by lowering consumer demand or both) and research into non-nuclear, non-fossil fuel power production. Alcohol-fired plants might be good for small applications (since alcohol's rather cheap), and solar and wind both work well in the appropriate places. I'm less in favor of hydroelectric dams, and I don't know enough about tide pools to be for or against.

Thanks for the citations. Maybe this will change my mind.


[ Parent ]

Chances? (none / 0) (#40)
by itsbruce on Thu Oct 26, 2000 at 04:41:04 PM EST

What I'd really like to see is a series of efforts to reduce power consumption (either by introducing more power-efficient products or by lowering consumer demand or both)
Human nature being what it is - and, more importantly, capitalism/consumerism being what it is, the more energy efficient we become the more we'll do with the energy we have. In fact, the more energy efficient you are, the greater incentive there is to generate more engergy, since you can make good use of even a small amount.
and research into non-nuclear, non-fossil fuel power production.
If only these technologies were given the same kind of funds that have been ploughed into nuclear research. Unfortunately, vested interests in traditional energy sources do their best to sabotage these whenever they can, Salter's Duck being a good example.

--

It is impolite to tell a man who is carrying you on his shoulders that his head smells.
[ Parent ]
Solar making solar making solar... (none / 0) (#33)
by Michael Leuchtenburg on Wed Oct 25, 2000 at 05:17:55 PM EST

It doesn't fix everything to power the solar panel plant with solar power. After all, you've still got that whole by-product thing, remember? So yeah, now it's viable as a source of energy (rather than a weird sort of battery), but then you need to dispose of the waste.

Disposing of the waste also takes energy, plus might be difficult given the general nature of toxic wastes. They're not easy to get rid of.

[ #k5: dyfrgi ]
[ TINK5C ]
[ Parent ]

Solar cars are never going to work (2.00 / 1) (#17)
by goonie on Wed Oct 25, 2000 at 06:12:21 AM EST

Even given a perfectly efficient motor (in fact, we're pretty close to that, even a standard electric motor is approximately 80% efficient, and the ones they use in solar challenges are like 99% efficient), and super-efficient solar cells (though there is a theoretical limit of about 27% efficiency and we can now do about 25%), the surface area of a car's roof is not big enough to collect enough energy to power any realistically constructed car with acceptable performance. Solar cars are a no-go, unfortunately.

Of course, if people stopped driving V8 petrol SUV's to do the shopping and replaced them with European-sized minicars (or even Accord-size conventional cars), you'd halve vehicle emissions, but that's too simple :-/



[ Parent ]
Agree, but... (3.00 / 1) (#32)
by rusty on Wed Oct 25, 2000 at 03:48:01 PM EST

I agree that solar powered cars are unlikely. But think bigger than that. Here, for example, we have an air powered car, which needs some initial energy to compress the air for it to run on. Ok, so electric will do that fine, but where does the electricity come from? Ah ha! Now soalar power can step in. I doubt the portable solar power will ever go anywhere, but then portable nuclear power (except for subs and aircraft carriers) never did either. If you centralize the main source of the power, then it doesn't have to be portable.

____
Not the real rusty
[ Parent ]
Economy of scale? (3.00 / 1) (#22)
by interiot on Wed Oct 25, 2000 at 09:00:51 AM EST

Perhaps economies of scale becomes an issue here?

On one hand, you've got a 100HP engine that produces the pollution. And you have the catalytic converter to clean some of the particles from the air.

In the other situation, you've got much larger stations that produce compressed air. Because there's almost no weight requirements (you don't have to drag the engine or scrubbers with you) and because the pollution for many cars is combined in one place, better and bigger scrubbers can be used to filter out a greater percentage of the pollution overall. The larger the station, the greater percentage of the pollutants could be removed.

[ Parent ]

Efficeincy (none / 0) (#36)
by Hillgiant on Wed Oct 25, 2000 at 06:37:10 PM EST

+A centalized power station can have a natural gas powered steam turbine that constantly operates at peak efficeincy.
-A car almost never operates at peak efficeincy (not even on the freeway really, if the power train assumes 55mph and you are doodling allong at 75mph)
Higher efficeincy means less fuel consumed, more complete combustion, and less pollution.

Also, with a single emmissions source you can devote more energy (and capital) into reducing the already low emmisions.

-----
"It is impossible to say what I mean." -johnny
[ Parent ]

I would drive that contraption (3.00 / 6) (#4)
by Commienst on Wed Oct 25, 2000 at 02:12:42 AM EST

To me your downside is really weak. I do not know many people who drive more than 10 hours a day. Do you?

"But the manufacturers envisage that fleet owners could install their own air stations, where a fill up could take as little as three minutes."

I am assuming by "fleet owners" they meant gas stations or something of the sort. That would really make this car ideal if you could go to "gas station" and fill up with all the electricity you need in 3 minutes.

Good point (2.00 / 2) (#5)
by skim123 on Wed Oct 25, 2000 at 02:15:41 AM EST

To me your downside is really weak. I do not know many people who drive more than 10 hours a day. Do you?

Come to think of it... no. Well, truckers maybe... wouldn't it be funny to see an 18-wheeler version of this car? :-)

Good point...

Money is in some respects like fire; it is a very excellent servant but a terrible master.
PT Barnum


[ Parent ]
What about those little tire inflators? (3.00 / 2) (#13)
by Anonymous 6522 on Wed Oct 25, 2000 at 04:40:57 AM EST

Why couldn't you just go to a gas station and use the little compressed air thing that you usally inflate you tires with? Instead of paying for fuel, you could get it for free.

[ Parent ]
You didnt read the article! (none / 0) (#16)
by Commienst on Wed Oct 25, 2000 at 06:12:12 AM EST

Shame on you.

[ Parent ]
Yes I did read it (4.00 / 1) (#41)
by Anonymous 6522 on Fri Oct 27, 2000 at 12:13:26 AM EST

The article make no mention of using tire inflators to fill up you car

[ Parent ]
Winter driving (3.25 / 4) (#6)
by korvemaker on Wed Oct 25, 2000 at 02:35:20 AM EST

My first question: how does it handle temperature extremes? Given the idea of Mexican and South African plants, presumably it'll do decent in summer. But what about winter? Is it going to be a pretty yellow snow break when it's -40, or is it going to keep on going? Any insights?

Give a man a fish and you feed him for a day. Teach him to use the Net and he won't bother you for weeks.
Problems with this (2.40 / 5) (#7)
by scheme on Wed Oct 25, 2000 at 02:51:17 AM EST

I'm not sure about you but I don't really want to be sitting near the tank of compressed air that this car needs to have in order to run. Given the specs of being able to run for 10 hours, the tank must be really big or the air is pretty compressed. In any case, the tank would make a pretty good bomb. Any rupture in the tank due to metal fatigue, a collision, corrosion, etc would basically cause the tank to explode probably spew metal fragments all over the place.


"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity." --Albert Einstein


You dont know the facts man (1.00 / 1) (#18)
by Commienst on Wed Oct 25, 2000 at 06:26:09 AM EST

I am sure that is what people said about the first automobiles "I do not want to be near that thing when it crashes, the gas I'll explode". For all you know the car has a huge battery and compresses the air as it needs it storing the excess in the tanks. I doubt in a country like France where they drive so fast and have such high vehicle safety standards the air tank would turn out to be a shrapnel bomb waiting to happen or they would not have started producing it.

[ Parent ]
Uh.. No (3.00 / 1) (#28)
by scheme on Wed Oct 25, 2000 at 11:24:01 AM EST

or all you know the car has a huge battery and compresses the air as it needs it storing the excess in the tanks

I don't think so. If you already have a battery why not use it to directly drive the car using a motor instead of using it to compress air and then using the air to drive the car. From reading the article it seems like the car has a tank of compressed air.


"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity." --Albert Einstein


[ Parent ]
Hydrostatic Testing (3.00 / 1) (#24)
by interiot on Wed Oct 25, 2000 at 09:25:01 AM EST

Most high-pressure industrial tanks, SCUBA tanks, fire extinguishers, etc. require periodic testing to make sure there aren't microscopic cracks that could lead to an explosion. Usually they use hyderstatic testing, where they put the tank in water and pressurize it to 166% of its maximum pressure. If it doesn't leak or explode, it's probably safe at normal pressures for another year or two.

AFAIK, this has resulted in such tanks being very safe for a myriad of uses, so I suppose it would also work for these cars.

[ Parent ]

Maybe not (2.00 / 1) (#27)
by scheme on Wed Oct 25, 2000 at 11:21:09 AM EST

Testing does find problems that occur over time but would everyone take it in for testing? Also hydrostatic testing doesn't do to prevent problems due to collisions between cars.


"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity." --Albert Einstein


[ Parent ]
Mandatory Testing and Collisions (3.00 / 1) (#31)
by interiot on Wed Oct 25, 2000 at 01:55:28 PM EST

Would everyone test their tanks? Probably not, but that's usually handled by your favorite choice of government action (or inaction if you're libertarian and if random explosions aren't likely to hurt other people). Or perhaps technologic measures. In any case, I don't think it's a harder problem than other similar problems.

Collisions between cars are a problem with gasoline as well. One would think they could be protected to the extent that gas tanks can be protected.

[ Parent ]

Compressed Air Car (3.33 / 3) (#11)
by Suanrw on Wed Oct 25, 2000 at 03:46:14 AM EST

So we add compressed air to the list of stored energy sources: chemical batteries, fly wheels, hydrogen fuel cells, liquid petroleum (gasoline), compressed petroleum gases (propane, natural gas).

Safety issues. That's a good question about the pressure in the tanks. I am not as concerned about pressurized air as pressurized flamable gases, unpressurized flamable liquids and corrosive chemicals.

Operating temperature. I think the only component you need to worry about is CO2. That would only be an issue if you are extracting the gas so fast that your tank is cooling off. That might limit your range in cold climates.

Technology requirements. I think this is fairly low, and globally available. Gas compression technology is already wide spread, in the beverage industry, medicine, welding, pipelines.

Pollution. Start by using clean air. Is the compessed air already available, but discarding while bottling compressed oxygen, or CO2? I think a large compression plant (w|c|sh)ould be more efficient (and thus less polluting) that many small internal combustion engines.

I like this idea. I'd like to see it have a chance to prove itself.

Sorry, not invented by "crazy South Africans& (3.00 / 3) (#14)
by jalbinet on Wed Oct 25, 2000 at 05:11:37 AM EST

but crazy Frenchies ! Our national 70ies slogan (petroleum crisis) : "we don't have petroleum, but we have ideas !" ("On n'a pas de pétrole, mais on a des idées !")

Would Americans drive one? I would. (2.66 / 3) (#19)
by katravax on Wed Oct 25, 2000 at 06:52:34 AM EST

To answer the question directly asked by the poster, I have to wonder if Americans would drive such a contraption, I have to say I would, in a heartbeat. I would buy one for its obvious benefits at first, and hope that the company succeeded, because the features (like recharge time and capacity) are only going to get better with time.



I would buy it..... (1.50 / 2) (#20)
by plastik55 on Wed Oct 25, 2000 at 07:02:52 AM EST

.....if it didn't look like a cross betwen a taxi cab, minivan, and iMac. Ugh.
w00t!
[ Parent ]
So what you're saying (2.33 / 3) (#21)
by katravax on Wed Oct 25, 2000 at 07:09:54 AM EST

is that appearances are more important than content? Style is more important than substance? You want to do the right thing but only if it doesn't make you look silly? I think it's this attitude that keeps us doing the same dumb things over and over again. Considering the inexpensive price, you can pay a few hundred for a paint job, yes?



[ Parent ]
no... (1.66 / 3) (#23)
by plastik55 on Wed Oct 25, 2000 at 09:14:34 AM EST

By the time I'll be in the market for one, someone will have made one with a modicum of stylistic sense.

Chill.
w00t!
[ Parent ]
Of course, it's only moving the pollution... (3.50 / 2) (#25)
by itsbruce on Wed Oct 25, 2000 at 09:50:37 AM EST

to the place where the energy needed to compress the air is generated - but that's still way more efficient and much cleaner than electric cars (nasty toxic batteries). And centralising energy production makes it easier to move to cleaner energy sources altogether.

As a Brit, I'm sorry we stopped making steam cars. We were good at steam (practically invented it) and steam power doesn't care how you generate the heat. In contrast, the design of the internal combustion engine is inextricably bound up in the chemical nature of its dirty fuel - any attempt to clean it up makes it less efficent (so it has to burn more fuel and so ad infinitum).

--

It is impolite to tell a man who is carrying you on his shoulders that his head smells.
Steam..... (none / 0) (#35)
by Hillgiant on Wed Oct 25, 2000 at 06:30:22 PM EST

If I recall correctly... there are a couple major drawbacks to steam power for automobiles:
1) They are heavy. Lots of plumbing for the heat exchanger and (if I remember my thermo class) operate at relatively high pressures. Sure the otto cycle uses high pressure too, but that is confined to a small area, whereas the steam cycle is fairly high pressure everywhere.
2) They take a while to heat up. Imagine waking up a half hour earlier to "build up a head of steam" before tooting down the road to work.

-----
"It is impossible to say what I mean." -johnny
[ Parent ]

recharging time (2.50 / 4) (#29)
by boxed on Wed Oct 25, 2000 at 11:33:45 AM EST

The four hours is when you hook a normal air pump up to a normal wall socket. This number should be compared to the time a recharge takes for a normal battery powered car. The preferred method of recharging though is by hooking up to a container of pre-compressed air. This will reduce the recharge time to 3 minutes. Something I would gladly accept for the payoffs.

Odd really. (3.00 / 1) (#37)
by Hillgiant on Wed Oct 25, 2000 at 06:53:04 PM EST

{ot} Really guys, one of these days I'm going to have to log in from work to get in on these topics earlier {/ot}

Isn't it odd that the only motor discussed on the company's web site (I found it at work, but can't seem to find it now =/ ), was internal combustion. Not compressed air as you would expect. Mind you the idea of a separate combustion chamber is really clever and should greatly reduce emmisions. However I think the limiting the frictional losses would be a beach. Think about it, you have twice the number of pistons.

While I think this design could be converted into a compressed-air-expasion-type device, wouldn't an airmotor be better? The idea of using the motor to compress the air on board is (IMO) dumb. Look at power tools. The appeal of pnematic tools is that you do not have to carry the compressor around in your hand, just an airmotor and some way of turning ir's rotation into usefull work. An electric tool on the other hand requires you to have an electric motor, which are generally much heavier.


-----
"It is impossible to say what I mean." -johnny

A note on efficiency and a few other things (none / 0) (#39)
by scott@b on Thu Oct 26, 2000 at 02:22:31 PM EST

Compressing air can be quite effecient as a way of storing mechanical / kinetic energy. Consider a hydro plant or windmill. Both get the energy input as simple mechanical roation as the first step. Then this is used to turn a generator to get electric power. Some distance away we may comvert the electricity back to mechanical enegry with an electric motor, or stash it in a battery (electric => chemical => electric) and later on use the motor to convert it. Electric motors can be nicely efficent, batteries are pretty goo, but each conversion has some losses.

Now suppose we use that original mechanical energy to drive the pumps to compress air. The air gets hot, energy that would be wasted if it just was leaked out to the general environment (the air gets cold when you expenad it in the motor). However, if you use that heat to drive low temperature boilers and turbines (usually using some other liquid than water) you can save some of it And/or you can use it as a low grade heat source, heating a working fluid to warm habited spaces, fish ponds, or greenhouses.

Now the tanks are a concern. You'd want to dry the air first, and dsut filter it, to help reduce corrosion problems. I believe that tank design has progressed to the point that they are pretty save these days, using multi-layer fiber windings over an inner shell. The fibers hold things together even if the inner shell is broken. It's still a lot of energy stored in a small space, you need that to make vehicles practical. At least air won;t poison you, catch on fire and possibly exploded, or dissolve whatever it happens to land on lick some storage batteries.

CO2 in the iar isn't a problem, it's too small of a percentage. Neither is cold weather, at least in most of the world you don't get cold enough to make any difference even after the air has exanded and cooled itself. Oxygen is usually made at the same time as nitrogen, being two streams out of the compressor/cooler/airmotor/fractionation-column rig that typically is used. I suspect that the consumption of the N2 and O2 are pretty well balanced, without a huge surplus of N2, except at specialized smaler uses such as hospitals.

And you could even pump air through pipes (pipelines) like oil and gas. This might work better in metropolitan areas where a large compressor station could provide air to outlets for a few km surrounding. Long runs might have too much loss in friction.

It would be nice to see some hard numbers - weight of the tank and engine, efficiency of the engine. How good are the various compressor options - the little "at home" unit, a gas\\\air station size compressor, and a big hydrodam powered plant where the compression heat could be recovered.

Steam cars had problems, and were big and ugly. Technology has gotten better, the cars would be a little more acceptable. The vented steam on some designs was a problem, tending to dampen things that got too close. The high pressures are there partly because of thermodynamics, heat engines get higher efficiency when the temperature change is larger.

And finally, I believe that compressed air was used to power a few automobiles in their early days - just about everything was tried. But it is good idea for countries with smaller economies and no local automobile industry, they might get a jump on the big companies and at least produce a good chunk of their local needs.

Boy's Life air car (none / 0) (#42)
by Asperity on Thu Nov 02, 2000 at 09:13:50 PM EST

They used to have an ad for the plans to build an "air car" from common household stuff like a vacuum cleaner in the back of every "Boy's Life." I always thought it looked kinda cool, but never sent away for it.

Not that this is the same car (if it is, it'd be pretty damn cool), but did anyone ever order those plans? Did they work? I was always curious.

The car that runs on air | 42 comments (41 topical, 1 editorial, 0 hidden)
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