Zero Pollution Motors: Air to Stay?

jack (OaTs): The only source of compressed air I am familiar with is ... well, an air compressor. The ones I know run off of electricity. I think I have seen gas operated ones also.

Are there "good" efficient air compressors out there that I don't know about?

Are there any redeeming qualities for this idea (other than the batteries mentioned above) ?

"Are there any redeeming qualities for this idea?"

Short answer: No.

Compressed air must be cooled down in order to dry it and facilitate storage, so there's already energy loss there. Add to that the fact that as the air is used up, the pressure is reduced, reducing the stored potential energy, and....well, you get the picture.

jack (OaTs): The only source of compressed air I am familiar with is ... well, an air compressor. The ones I know run off of electricity. I think I have seen gas operated ones also.

That's how they work alright. The MDI one can potentially use both (grid power when stationary, gasoline when moving).

Are there "good" efficient air compressors out there that I don't know about?

Depends on your definition of "good". Some are less inefficient than others.

Are there any redeeming qualities for this idea (other than the batteries mentioned above) ?

For the compressed air car, no. Seriously, after researching the principle, concept and the actual product I have not found any redeeming qualities, even if they DON'T include the onboard gasoline-powered air compressor that compresses the air when the car is driving down the road.

No that's not quite true, the compressed air car is better than the scam cars marketed as running entirely off Hydrogen gained exclusively from an onboard gasoline-powered water electrolyser, only in the fact that a high energy fuel (such as gasoline or grid electricity from coal, gas, hydro, nuclear, etc) is converted to a better lower energy fuel (compressed air) (as apposed to a few bubbles of hydrogen).

jack (OaTs), that's a new one.

"jack (OaTs), that's a new one."

They say the oats is cheaper if it's been run through the horse first!

Yes, compressed air does have a redeeming feature in hot climates only.

The expanding air does work, gets cooler and therefore has to absorb heat from the environment between expansion stages. At the final stage, the emerging air is at atmospheric pressure but cooler than ambient. That's 'free' air conditioning!

In a cold climate, this is a liability because the radiator ices up and you don't get any heating for the car.

So ideally, a car owner should compress air at night, cooling the air by heating hot water for his house, then run the car by day but only on warm days.

sounds like you work for the oil compainies, well the air car as well as other alternitive powered vehicles are coing SOON and the big oil companies cant stop it not even with propagannda, I look forward to there demise, yes the oil companies are going the way of the dinosoars, and they brought it on themselves, with there greed and over priceing gas!!!!!!!

I get that a lot from people that don't bother to read my previous threads. Among other things I do research and development in alternative and cutting-edge energy storage, transmission and distribution technologies, along with commissioning multi MW size wind farms.

Please do some research first before commenting, and see MY previous positive and negative comments regarding the oil companies (I also do work for them AND the oil refineries and I believe I know just a little bit more than you regarding the subject).

For an air vehicle to be worth buying, you need a cheap source of energy to compress the air.....

Normal Electricity, at normal prices from the mains is simply not cheap enough (in most countries) as pumping losses for compressed air are very high......the heating effect is an obvious example of this.....

I am willing to bet here, openly, that there will be no great breakthrough for the masses with pressurized air UNLESS a new cheap method for producing it is found!!! Fusion power is a possible answer, if and when!!

For people with their own waterfall or windmill, it is possible that they can take advantage of their cheap power source and use air for driving, but it will never be any good for the masses.....

Please bet against me and be so kind as to give a best aproximate "date" for such things.......as near as you can please. I say basically never.......without Fusion or similar!

Has to be a "guest" doesn't it.

And of course professionals with collectively hundreds of years of hands on experience once again get denigrated for not going all ga ga over psuedoscience.

If you had to chase airstarted machines all around a mine site at all hours of night and actually had to fix the things you would just like the Boy Named Sue, come away with a different point of view.

I believe you are right in saying that compressing the air is inefficient. It is also true that the air cools as you use it up to run the car which lowers the pressure in the storage tank. However, there may be some advantages out there that we can look at for an air car. For this purpose I will be comparing air (and air hybrid) versus electric car (and electric hybrid).

1. The initial cost of an air storage tank should be considerably lower than traditional or lithium batteries for the same power.

2. The storage tanks are much much lighter than batteries which helps with fuel economy and may help offset some of the inefficiency in conversion of electricity to compressed air versus electricity charging batteries directly.

3. The life of traditional batteries is very limited (lithium batteries are better but more expensive), a storage tank containing compressed air could concievably last much longer and be cheaper to replace if it did fail.

4. Electric cars use electric motors (often on two or four tires). These are very expensive to replace if they fail. An air motor has the advantage of being relatively simple in construction and therefore (theorectically) cheaper to repair and maintain over the life of the car.

5. I have not done much research into this, but I believe it would be significantly cheaper to mass produce an air powered car versus an electric powered car (the electric batteries especially being a big ticket item).

Both a pure electric vehicle and a pure air powered vehicle have very limited ranges and require extended periods to refill their batteries / tanks. That is why hybrids are much more attractive to the average consumer. Most people are familiar with hybrid electric vehicles (like the Prius). A hybrid air powered vehicle would burn gasoline or another fuel to either compress additional air or heat the air in the storage containers to raise the pressure in the tanks. This greatly increases the range of the vehicle between fill-ups.

Converting electricity to compressed air is inefficient. A large portion of this is energy is lost when the compressed air heats up. However there is no reason why we could not at least look at making this more efficient. There are existing, established technologies that can use heat differentials to produce power (electricity). It would be a simple matter to recapture some of this heat energy to produce more electricity, thus raising the efficiency of the method.

On another note, the price of PV solar systems is coming down and has been for some time. With some of the government incentives out there the price makes sense financially to install on a home or business, but it is reasonable to believe that the price for PV solar will someday soon reach financial feasibility without incentives. If we are using solar power to create electricity for ourselves, then it seems reasonable to want to use this power for our automobiles. Given the choice between air and batteries, I think we should look at the overall picture (initial cost, maintenance costs, cost of fuel and fuel effieciency) and weigh these costs comprehensively to see which choice may be better.

This poster shows little knowledge or common sense, or even a slight understanding of the problems he is talking about.....

Definitely not an Engineer!!

That is not quite right. Have a look at the numerous threads on CR4 regarding "MDI", "air motor", "Air car", etc. Many of us have gone in to great depth explaining the advantages and disadvantages as well as most (if not all) of your questions and points above.

The simple answer is compressed air is a hopeless energy carrier to begin with even before considering any of the many other disadvantages (such as poor energy conversion using electricity to create air). As for increasing the efficiency of conversion this is limited by natural laws and so a few percent increase doesn't help.

Have a look at the other threads on CR4 for more information as there is plenty there.

Love the comments.

Good to see that at least here nobody is getting the wool pulled over their eyes.....

Compressed air would still appear to be one of the best scams in the world......for uneducated people at least!

The air power concept is as old as the hills. It was tried with trains, and did have some usefulness in mines. But I suspect you'd run into the same problems with cars that they had with trains.

Here's a little history on air powered trains:

http://www.dself.dsl.pipex.com/MUSEUM/TRANSPORT/comprair/comprair.htm

Bricktop,

Compressed air is certainly used as a non ignition causing power source underground in coal mines, but the end user plugging in a pump doesn't have to think of the size of the compressor on the surface that is pumping its heart out to power the small pump.

Even if there was some efficiency in the system, anyone who has spent half of each shift running around site with a compressor in the back of the ute to get all the air start machines going will know the reciever tank is always empty when needed and the control valves are all stuck from condensation.

Even a fully charged reciever tank only gives you one shot at starting. If it is no good as a starter it will be worse as a primemover.

Pollution free be damned, air starters are lubricated by diesel injected into the air and air motors used as prime movers can be little different.

It is just another "Jolly Green Jerkoff".

In one of the videos on their website, they use the term, "Perpetual Motion," as if they finally solved the puzzle. That's more than enough to raise my eyebrow...

Bear with me, I have a un-thought out Idea.

If one was to use a windmill to compress air/refrigerant and use the heat for heating, the pressurized by product would be a low cost residual one could use for power, or cooling and maybe both.

Given you would need to be in a better than average wind area to even be considering it. The heat would need to be stored for use when wind was low.

Just an errant thought

Brad

I've been following this MDI site since the late 1990's and thought it was a hoax.
That said I'd love to be proven otherwise.

You guys seem to know a lot and I get annoyed at Govts not researching enough in a replacement for oil. What can you forsee when oil does run out? (Mineral not Bio)

Has anyone yet built a generator that makes good use of the tides?

Can Hydrogen be used for fuel? Could it be created at Wind Farms and transported to cities if so?

Would love to hear some Guru feedback.