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This will be a game changer

Post in 'The Green Room' started by tony58, Jan 18, 2012.

  1. fossil

    fossil Accidental Moderator Staff Member

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    If you're talking to me, rest assured I'm quite well versed in the Laws of Thermodynamics. I made no implication whatever that this was some sort of a lossless system. Rick

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  2. begreen

    begreen Mooderator Staff Member

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    Batteries do not come for free either. Look at their cradle to grave costs from the mining of rare minerals, to construction, to use, to recycling. The Tesla S looks lovely, but at $65K (short range version) to $95K, it is built for the wealthy, not the average citizen. India has an abundance of sunshine so storing this energy as compressed air is a technology they can use now while waiting for battery technology to develop makes sense. As for safety, the idea is to get young families off of motorcycles where they often ride with 3-4 aboard. It's all relative. What works for them is not the same as for us. After all, how many 3 wheel tut-tut taxis do you see roaming NYC's streets? Safety, pffft. :)
  3. JRP3

    JRP3 Member

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    Which is why I suggested the SUNNEV as a better solution. India doesn't have so much electricity that it can afford to waste it in a compressed air system, frankly no country does. A wasteful system does not make any more sense for India than it does for us. As for batteries, short range NEV's can use common lead acid batteries, which are highly recycled, though lifetime costs would be lower with lithium. Further more lithium batteries do not have large amounts of rare earths in them, in fact most lithium formulations use none. The majority of materials in a lithium battery are plastic, aluminum, copper, and electrolyte, with small amounts of lithium. They are not particularly toxic either and are also recyclable. They are also very long lived in EV formats and use, and even after they have lost too much capacity for EV use they can have a second life in grid back up systems where energy density is less important. An EV battery pack might see 20 years or more of total use before it needs to be recycled.
    The Tesla 160 mile version is $57K by the way. As with any new technology initial costs are high but come down with increased volume.
  4. Jags

    Jags Moderate Moderator Staff Member

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    Well, it took about 6.5 seconds on google to debunk this statement. I will not bore anybody with the details, use your own search. There are some very large and efficient systems out there that in fact use compressed air for an energy storage medium.

    I got no dog in this fight. Just say'in.
  5. begreen

    begreen Mooderator Staff Member

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    I stand corrected. Did they just change their website? I was on it last week looking at pricing and I see some changes today. The 40K battery model will now be $49K (Dec 2012), but the 300 mile range 85K battery model starts at $69K and up to $97.9 for the full trimmed performance version. I'll take two so that my wife can have one also. Oh heck, throw in a couple for the kids to play with too.
  6. fossil

    fossil Accidental Moderator Staff Member

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    Tesla makes a couple of really beautiful cars. They're also complex, heavy, and very expensive. Tesla's never turned a profit. Tesla's managed to sell about 2100 vehicles in 9 years. Tesla and Tata aren't exactly in the same league...nor is this somewhat intriguing concept car from Tata aimed at the same demographic as Tesla's products (by a long shot). "Compressed air is a poor form of energy storage, period, end of story, do not pass go, do not collect $200." This is the kind of thinking that stifles creativity and innovation. I'm glad it's an attitude that's rarely found in the Engineering/R&D community. If you think a whole lot of research by some very bright individuals has not led to the development of this Tata "air car", then you don't know much about the Indian technical community. Rick
  7. begreen

    begreen Mooderator Staff Member

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    Yes, even if they cut the price by $10K the Tesla S is not going to compete with a Honda Civic or other average econobox. They do make beautiful cars, but I'm not sure I will ever own one, though it would be fun to try one out. Perhaps a more reasonable comparison will be the Mitsubishi iMiEV? I note that the MiniCat is designed to go 200-300km on a filling for a cost of about 100 rupees or about $2. The car is set to sell for under $13K and will have full safety features. Maintenance will be low with an oil change every 50,000km.
  8. JRP3

    JRP3 Member

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    If you had data you should share it. Maybe you are referring to large scale CAES systems for grid regulation, where they aren't trying to carry air in a portable container. It's relatively cheap compared to some large scale grid storage systems but round trip efficiency is poor. Trying to carry enough air around in a vehicle is a bit different. From Wikipedia:
    http://en.wikipedia.org/wiki/Compressed_air_energy_storage#Energy_density_and_efficiency
    That's not even addressing the power losses in compression and decompression to fill a tank and power a vehicle, and carbon fiber tanks are not cheap. So you've got energy density around lead acid battery levels, poor "charge" and "discharge" efficiencies, and the need for expensive high pressure tanks, which also pose a potential explosion risk from violent decompression in an accident. If that all sounds good to you have at it, I'd just like people to look at this with some facts and open eyes. Too many people see "Air car" and think "wow, it just runs on air, perfect". There are a lot of real problems with the concept that should not be ignored.
  9. JRP3

    JRP3 Member

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    No they've been quoting the same prices since it was announced, though it wasn't official until a few weeks ago. The $49K is including the $7500 tax rebate.
  10. JRP3

    JRP3 Member

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    Obviously Tesla is not trying to sell to the same market as Honda, they are targeting BMW, Mercedes, Porsche, etc. The 2012 production run is already sold out in advance.
    I'm going way out on a limb, (not really), and bet that the MiniCat will never get 200km of range, let alone 300km. I think the Midi car it's based on went about 7 miles, at maybe 30 mph. Has there been any independent testing of the MiniCat?
  11. fossil

    fossil Accidental Moderator Staff Member

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    Well, I'd like to see some data to support that statement. You don't give "people" much credit.

    Hmm...you don't give the Indian engineering community much credit, either. Maybe you never had a college professor who came from India. I had a couple. Impressive, to say the least. I'm quite confident that the "real problems" have not been ignored.

    Not everyone needs or can afford the very best of anything & everything...including portable energy storage. Sometimes "good enough" is the best choice. I doubt you'd find any knowledgeable person who would argue that advanced battery technology is not superior to compressed air. But, is it the necessary and most cost-effective solution in every case? I don't think so. The world's big enough for a wide range of technologies & solutions to challenges...and the vast spectrum of needs vis-a-vis available resources demands a smorgasbord of choices. Rick
  12. JRP3

    JRP3 Member

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    I've been following this technology for quite a while, I've seen many people who think this only runs on air. The title of this very thread is overly enthusiastic and it's obvious a number of people posting have not really dug deeply into what is involved. I'm not slighting the engineers in India, but no engineer can change the laws of physics, and many very smart people have pursued projects destined to fail. (Plenty of people have tried perpetual motion projects because they were able to get 99% efficiency while ignoring the fact that 101% efficiency was impossible.) A compressed gas can only have so much gravimetric and volumetric energy density, and the only way to increase that is to increase the pressure, and the only way to increase the pressure is to use more electricity, or gas or diesel with a petroleum powered compressor, which would be even less efficient. There is no engineering that's going to change the way a gas compresses and decompresses. A regular 7.5hp 150psi air compressor would take 230V and 25 amps, 5,750 watts, and that's just for 150 psi. If that runs for an hour that's 5.75kWh's of electricity, how much electricity would a 4000+psi compressor need for a few hours fill time? Plus you lose a lot of that energy as heat in the compressor, and you lose more of it again in the air motor in the car, since it's basically just the reverse of a compressor.
    Worth reading: http://www.triplepundit.com/2011/09/tata-motors-air-car-minicat/
    And don't get too excited by the CO2 comparison numbers of the Air Pod to the Tesla Roadster, since the Air pod is basically a golf cart and the Roadster can do 0-60 in under 4 seconds and has over 200 miles of range.
  13. jharkin

    jharkin Minister of Fire

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    I gotta say I'm with fossil on this one. I grant this is nowhere near a game changer, but in certain markets it could be a good solution. Sure compressed air takes a big efficiency hit compared to batteries but there are ways to reduce that and some cases where its not such a big deal. The big losses are the heat generated in compression - those grid storage schemes use vast underground cavers to make the compressed volume so big that you don't need much pressure differential and thus minimize the heat issue (I have a friend working on this fora grid storage firm in NH working on this). Or you find someway to do useful work with the heat in a high pressure application. The fact that they quote $3 fill ups and that the tailpipe air comes out at below freezing temps tells me that that they got at least a usable level of efficiency out of the air driven engine.

    I mentioned earlier and Ill say it again - don't forget that with this scheme they don't have to haul around 1000 lb of batteries!!! That saving alone lets them make the system much lighter and requiring far less input energy.


    One other thing... Ill get on my podium for a minute... anyone who pins all their hopes on just one alternative (EV) writing off the rest IMHO does not understand the truly massive scale of the problem we face. We are a civilization that is almost totally dependent on the black gold... 80 million barrels of it every day... 29 billion every year. Its a staggering number that gets even scarier if you put it in gallons:

    1,226,400,000,000 gallons of crude oil consumed.

    every single year.

    People need to wake up to the fact that we simple are not going to be able to magically convert a couple billion cars to EV overnight... or maybe ever. We probably will find there just isn't enough lithium in the ground to make that many batteries. Thats the reason why we keep holding on to oil even though we know its days are numbered... its easy... the alternatives are all hard.. and none of them will scale to the level that we use oil.. ever. Our only hope for the future is to make use of a combination of all the available alternatives along with major reductions in energy use (efficiency and just making due with less).

    So lets not toss the baby with the bath water. Lets make a go at actually solving this thing. Lets prove the doomers wrong that we can get out of this mess we have backed ourselves into.
  14. fossil

    fossil Accidental Moderator Staff Member

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    Certainly an important consideration for a vehicle in downtown Mumbai.
  15. JRP3

    JRP3 Member

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    The only way we can get ourselves out of this mess is by not only pursing viable technologies but also by not wasting time on technologies that are destined to fail. Wasting electricity is not a viable way forward. Also, a car the size and specs of the Minicat would not need 1000lbs of batteries at all. This thing barely does 60 mph and it will not get the range they claim, (and have not demonstrated.)
  16. JRP3

    JRP3 Member

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    Are you purposely trying to miss the point? Or am I not being clear? Comparing the emissions profile of a vehicle with the performance of a golf cart to an extreme sports car is not exactly apples to apples. Might as well compare it to a bicycle.
  17. fossil

    fossil Accidental Moderator Staff Member

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    I never said a word about emissions profiles, but I certainly agree they're not meaningfully comparable. Nor are the needs that the two very different vehicles are intended to serve. I really think I'm about done here in this thread. Thanks all. Rick
  18. begreen

    begreen Mooderator Staff Member

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    The range thing... is your 'going out on a limb' opinion, as stated in your previous post. You could be right, or wrong. We'll see. I respect Tata and don't think they will bring this car to market unless they feel it offers a real solution. Let's wait and see.
  19. jebatty

    jebatty Minister of Fire

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    I find it interesting that the shortcomings of the air motor are presented as negatives. If, and only if, the gasoline engine was the new kid on the block, I venture to say that it would be panned to death.
  20. woodsmaster

    woodsmaster Minister of Fire

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    4350 psi is a lot. imagine if you crashed or severed a line. That much pressure would cut you in half very easily. kinda
    like riding a bomb, but I guess sitting on 20 gallons of gasoline comes with risks to.
  21. maple1

    maple1 Minister of Fire

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    Seems to me it takes a lot of energy to compress air.
  22. JRP3

    JRP3 Member

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    But it's not just my opinion, the Vice President of Tata Engineering basically said the same thing. If you don't believe me that's fine but you probably should listen to him:
    The company knows it's a huge problem and no one trying to develop these things before has been able to over come it because you can't change the laws of physics. This has all the signs of someone high up in the company falling in love with the idea and the underlings not being able to tell the emperor that he has no clothes. I would think a scientist or engineer should be able to calculate the potential energy of air at a certain pressure in a certain volume, and the energy used and lost to get it there, and see that this cannot work. All the time and money wasted on this could have been put to better use elsewhere. I just wish people would look more critically at these concepts and not fall in love with an idea. This idea is so deeply flawed on such a basic level there is no logical reason that it has gotten this much attention. Hydrogen has similar problems as well but much of that research has been pushed by oil companies trying to hold on to control of transportation energy.
  23. mbcijim

    mbcijim Member

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    Can't believe it took so long for anyone to point that out. Concrete gets destroyed at 3,000 psi. If that thing lets go, lookout. You can put firewalls between 20 gallons of gas and a passenger, but what about pressure? Can you firewall pressure? Interesting enginneering question.
  24. JRP3

    JRP3 Member

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    Actually I did mention that in an earlier post:
    One of the many problems with this concept.
  25. jebatty

    jebatty Minister of Fire

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    20 gallons of gasoline in a flimsy metal can isn't exactly a puff of smoke. If those can be protected from collision explosion, I would expect a tank that can safely store high pressure air can be similarly protected.

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