French Air-powered Car To Trials

[Rajiv]

Re: French Air-powered Car To Trials

I apologize unconditionally -- my bad -- It was totally uncalled for

It is pretty obvious that the energy density of compressed air, entropy, enthalpy included is much lower than gasoline. I do not think anybody is arguing on that account.

What makes compressed air viable (and the jury is still out on that) is that the tank to wheel efficiency of Compressed air is 4-6X that of a gasoline powered auto (1.5 to 2x of a hybrid) and allow for much lighter vehicles -- What MDI and Tata are betting on is that over the medium term, the price of oil and hence gasoline and diesel will shoot up -- battery costs will still limit EVs. In That scenario, Compressed air can make some sense as long as Electricity production can keep up. Other than in North America, auto trips are relatively short -- and at relatively low speeds and mostly confined to urban areas.

I think much depends on how well they are able to implement multistage compression -- in other words the other side of the equation -- delivering compressed air to the tank.

again my sincere apologies

[Sharky]

Re: French Air-powered Car To Trials

French Air-powered Car To Trials

Saying a car is powered by air alone is of course totally misleading. Maybe it works because French Air is super-powerful?

On the other hand, all cars are air powered. That is, they burn fuel in air. They actually consume much more oxygen by weight than gasoline or diesel, so technically it would be more accurate to call them air-powered than gasoline-powered. And certainly less misleading than the OP. Where does the energy come from to compress the air in the first place? Electricity, which comes from.... Nuclear? Are they really nuclear-powered cars? Cool. If so, I definitely want one. :rolleyes:

[flintlock]

Re: French Air-powered Car To Trials

The big picture? Like the fact that our underlying electrical infrastructure is incapable of providing the energy requirements of automobiles?

No, the big picture is what eludes those who tout each new revision of using old fashioned combustion to power a secondary power source. Most times either electric or pneumatic. That's the trouble with those who know nothing of engineering making policy decisions. They come up with inefficient and unusable ideas and waste billions trying to fit a square peg into a round hole.

Electric cars come to mind. If there has ever been a more wasteful use of natural resources I don't know what it could possibly be. On a first or second law basis. You start out with the efficiency of a coal fired power plant and then throw away a bit on your high voltage transport. Then you throw away ever larger chunks in your local grid, your household wiring, and finally an expensive and inefficient storage battery. Not to mention you have to put it all together in a package that would scarcely pass a 5 year old's soap box derby car as regards safety just to let it get out of its own way.

And in the end call it progress.

I'd a damned sight more rather see us go all the way back to external combustion engines powered with steam as go through that morass. At least with those you don't have to spend a half trillion updating the power grid to make it all work.

Thanks for bringing this up. I'm no engineer, but I am an electrical contractor, and it always seems as if people pushing electric cars were acting like the electricity they use is free. Like 100 million cars could all be charging overnight with no additional strain on the grid.

[kingcopper]

Re: French Air-powered Car To Trials

Please focus on the storage capabilities. Compressing air isn't free and it requires energy. So does every other battery. The difference to me is how cheap and enviromentally clean air tanks are. Compressed tanks of air that can be recharged for decades should be considered a good thing.

I think the rotary air compressed motor can have a great future as a back up generator at the household level if properly used. A home could theoretically contain underground air tanks that hold as much compressed air as is needed to generate electricity at night.

Maybe the next underground utility distribution network will be 12" pipes that carry compressed air from utility to home. Imagine that; above ground electric lines, underground water, natural gas, and air lines. Not too far fetched if you ask me.

Also, over unity electric generation is very possible in the near future and can be done almost off the grid; in northern climates! Couple unlimited energy storage via air tanks and highly efficient energy generation and we may very well achieve some semblance of energy independence.

[mr_fibuli]

Re: French Air-powered Car To Trials

The big picture? Like the fact that our underlying electrical infrastructure is incapable of providing the energy requirements of automobiles?

No, the big picture is what eludes those who tout each new revision of using old fashioned combustion to power a secondary power source. Most times either electric or pneumatic. That's the trouble with those who know nothing of engineering making policy decisions. They come up with inefficient and unusable ideas and waste billions trying to fit a square peg into a round hole.

Thank you - this is the problem - many people think there is a magic bullet that will solve all our problems and that the existing technological solutions are an arbitrary imposition by big business. Sadi Carnot figured out a way to prove that there is no such thing as a free lunch 200 years ago and yet it still generates heated debate!

There are many improvements that could be made to internal combustion engines yet to incrementally improve efficiency - camless engines etc. that would give a usable improvement to existing technology. If we really cared about improving mileage we could reduce the mass of the car and with good structural designs, airbags etc. safety would not be compromised.

Let's focus on practical improvements that we know will work - buy a toyota yaris instead of a prius if you want to use less fuel. The yaris gets almost the same mileage, does the same job, costs a lot less and uses less energy to make than the prius. It also has a longer life and has a lot lower heavy metal content.

[we_are_toast]

Re: French Air-powered Car To Trials

Sorry engineers, but you're not going to solve the problem of a rapidly depleting limited resource by twiddling the knobs of efficiency on an internal or external combustion engine that ends up using a little less of the same resource. At best it postpones the problem, at worst it deludes people into believing the problem is solved.

Sometimes you need to sacrifice efficiency or temporary cost benefits in order to transcend to a more sustainable technology. The days of fossil fueled based transportation are coming to an end, and any effort to revive it is as useless as trying to revive the FIRE economy. With distributed electricity production, better battery technology, and a new power grid, I'm putting my money on more electric based transportation.

[Penguin]

Re: French Air-powered Car To Trials

Well that is a whole different discussion. When you throw efficiency and economic concerns, at least short to medium term ones, overboard and are concerned with long term viability and national security issues then things weigh out differently.

Personally I was disgusted with the stimulus bill for throwing only a hummingbird sized funding bird down the throat of a saber toothed tiger sized problem with the underlying grid. It was a poor showing. Very poor.

Nuclear plants (even revamped coal fired ones) pushing electricity down a revamped and updated electric grid is one thing. Plugging current electric car offerings into your household wiring is a whole different ballgame. You have to actually plan these things out. I see nothing that tells me the right questions are even being asked.

Hybrids are great ideas. Diesel hybrids are even better. High speed small bore turbo diesels are wonderful creations that can make an immediate upgrade to our auto efficiencies. Solar supplemental power on a traditional car is another really good idea. We could reasonably make pretty good gains to give us some breathing room to make the necessary changes pretty quickly.

Legislation pointed towards a long term goal of energy independence is a precursor to doing anything more that this prior to an actual energy induced meltdown.This is the hand we have been dealt. We are the Saudi Arabia of coal, we have nuclear power knowhow, and we have a knowledgable and energetic workforce. The ball is in the courts of those who shape policy. And as far as I can tell they aren't even asking the right questions.

Will

[mr_fibuli]

Re: French Air-powered Car To Trials

Sorry engineers, but you're not going to solve the problem of a rapidly depleting limited resource by twiddling the knobs of efficiency on an internal or external combustion engine that ends up using a little less of the same resource. At best it postpones the problem, at worst it deludes people into believing the problem is solved.

Sometimes you need to sacrifice efficiency or temporary cost benefits in order to transcend to a more sustainable technology. The days of fossil fueled based transportation are coming to an end, and any effort to revive it is as useless as trying to revive the FIRE economy. With distributed electricity production, better battery technology, and a new power grid, I'm putting my money on more electric based transportation.

That is a different question - brings up a lot of other issues that nobody wants to address - too damn many people in the world, if there were only 1B people the strain on resources and the environment would be a lot less. The current human population (and growing) is the least sustainable thing humans are doing and one of the most difficult to reverse short of a Chicxulub asteriod strike..... Viewed this way our profligate use of energy is a symptom of a problem not the problem itself.

In the near term we need to reduce our use of precious fossil fuels, reduce our environmental footprint and this will be most effective if we make some hard decisions instead of looking for easy ways out. Electric cars, compressed air cars etc don't fundamentally change our use of energy just how we use it.

[flintlock]

Re: French Air-powered Car To Trials

I've always thought that overpopulation combined with increasing medical technology is the real threat to mankind. It's unsustainable. Cure cancer? Great, now what do you do with all the geriatrics you just "saved". Warehouse them in all the empty McMansions perhaps. Housing bubble solved. Please forward this to the Nobel prize committee.

[mr_fibuli]

Re: French Air-powered Car To Trials

I've always thought that overpopulation combined with increasing medical technology is the real threat to mankind. It's unsustainable. Cure cancer? Great, now what do you do with all the geriatrics you just "saved". Warehouse them in all the empty McMansions perhaps. Housing bubble solved. Please forward this to the Nobel prize committee.

Our long term goal should be fewer people living better lives. Most of the overpopulation is in places where people can't afford to live decently.

How do you accomplish this goal though? The only people who have attempted to address it seriously are the Chinese - not sure I'd like that imposed and it has not been all that effective.

This is one problem that no democratic politician will touch with a 10' pole as we have an underlying assumption that more people, living as long as possible is an ideal state of affairs.

Until we address that head on we'll always be dancing around the issue pretending it isn't there because we either haven't questioned it or don't know what to do about it.

[GRG55]

Re: French Air-powered Car To Trials

...The discussion here seems to have deteriorated to ad hominums and jokes -- without having any understanding of the science or technology underlying the air car -- remember, the concept of enthalpy is poorly understood by most high school graduates and even most undergraduates.

Rajiv: An increasing number of the threads seem to have become forums for people to let off a little steam...something that is probably needed more than previously as things become increasingly volatile and uncertain in many people's lives. Beats the hell out of those [thankfully] few threads where things momentarily fall into personal insults.

Now if you think enthalpy is a difficult concept to get across to students, just imagine trying to get them to grasp the concept of entropy...


GRG55's three laws of entropy:

1. No matter what you do, shzt happens and everything in the universe always falls apart.
2. Everything falls apart faster, under pressure [including compressed air pressure]
3. The financial system always falls apart at the speed of light, but never any faster or slower than that.

[Rajiv]

Re: French Air-powered Car To Trials

I agree with you. But it is early days as yet -- things are likely to get worse before they get better.