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Transportation Technology

Peugeot Citroen To Introduce Compressed Air Hybrid By 2016 204

cylonlover writes "With a few exceptions, such as Volvo's Air Motion Concept, major automotive manufacturers have generally shied away from compressed air technology. PSA Peugeot Citroen is bucking this trend with its 'Hybrid Air' powertrain that addresses the limited range of compressed air energy storage technology by combining it with a gasoline powered internal combustion engine. The company plans to have Hybrid Air powered vehicles on the road by 2016."
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Peugeot Citroen To Introduce Compressed Air Hybrid By 2016

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  • Compressed air. (Score:5, Informative)

    by serviscope_minor ( 664417 ) on Friday January 25, 2013 @01:42PM (#42692765) Journal

    Not many details about it.

    I guess you can re-use cylinders from the ICE for compression and expansion, which would save on weight.

    Though the main problem with compressed air is that it cools and lowers pressure after it's been compressed, which is a big source of inefficiency. Large amounts of the energy are lost as heat. No mention on how they tackle that. For a lot of hybrid use, I suppose that insulating the tank would work quite well, but they imply that it can run off air for a large amount of the time, suggesting that the air will stay in the tank for a while and therefore cool down substantially.

    Still though, batery charging isn't exactly 100% efficient and the simplicity could outweght the reduced efficiency.

    Also, free A/C in summer.

  • Re:Compressed air. (Score:4, Informative)

    by Charliemopps ( 1157495 ) on Friday January 25, 2013 @02:09PM (#42693089)

    You've got that backward. Air gets hot as its compressed. Very hot. To store the kind of PSI they'll need, that tank will be scortching hot unless they have some system to use that heat. Then, when it's released and the air expands, it cools. It says the drive train is hydrolic. I suspect it's a lot like a hydrostatic garden tractor. They've got a pully that when they spin it produces drive. If you've got compressed air driving that pully, and you have a gasoline engine driving it at the same time, the engine would be extremely efficient to begin with... then, as the compressed air tank loses preasure the load on the gasoline engine would become greater, reducing its efficiency. The result is that it's actually a gasoline powered car that gets a great efficiency boost while it still has air in its tank. Once it runs out, its just a normal car. So you can have a very efficient drive to and from work, but trips to grandmas not so much.

  • Re:great idea (Score:5, Informative)

    by h4rr4r ( 612664 ) on Friday January 25, 2013 @02:14PM (#42693167)

    No one has heard of who?

    These are major car brands in the EU.

  • by ryzvonusef ( 1151717 ) on Friday January 25, 2013 @02:20PM (#42693251) Journal

    Here is some some quick responses.

    1- No, running around in car with gas full of high pressure tank is the not the end of the world, people (including yours truly) do it with CNG enabled cars.

    2- As for compression/decompression energy losses, same as for CNG, you need to cool it it blah blah, and is done so on a commercial scale at every CNG station; therefore can be done.

    3- CNG suffers from power problems on steep climbs, same seems to be the case for air. But for regular commute, it's perfect and economical.

    4- Air car suffer from low power density (much lower than CNG), but AFAIK, a full tank can last you the usual daily commute, which ought to be enough for a small city car. (which is what it will be able to power anyway, can't carry the load of bigger cars as of yet) And you could charge at work too(regular mains-running onboard compressor apparently take 3-4 hrs), so there is that.

    5- MDI realised that air alone won't be enough, so they have been developing hybrid versions themselves.

    TL;DR Air could prove to be good for the usual regular commute, since fuel costs will be minimum (air is free, all it will cost is running the compression and pump, which, looking at local CNG setups, will prove to much less than petrol equivalent, if commercially done)

    Here is some aircar nerd sites:

    - []

    - []

    (I would take their figures with a grain of salt, but well, the video shows running prototypes, so at least there is *something*)

  • Re:Compressed air. (Score:5, Informative)

    by h4rr4r ( 612664 ) on Friday January 25, 2013 @02:22PM (#42693269)

    So instead of air, which is cheap, safe and readily available, you want to use h2o2 which is none of those things. It is also corrosive. The lower the purity of the h2o2 the less energy you are storing.

    I see literally no upside to your suggestion.

  • by jfengel ( 409917 ) on Friday January 25, 2013 @02:22PM (#42693279) Homepage Journal

    Interesting. According to this more recent article: []

    it appears to have worked out well enough to expand the experiment.

  • by g8oz ( 144003 ) on Friday January 25, 2013 @04:07PM (#42694687)

    The compressed air designation is very misleading. This is a hydraulic hybrid, using a hydraulic pump/motor the same way a normal hybrid uses a battery - for acceleration and storing braking energy.

    Hydraulic hybrid vehicle (HHV) technology has been slowly maturing and is very promising. It is already in use for some advanced heavy trucks. Garbage trucks in particular, with their stop and go usage profile benefit from their efficiencies.
    UPS is trying some out. Manufacturers like Navistar and Eaton are on board

    In the U.S the EPA has been at the forefront of the research. See their page about it: Hydraulic Hybrid Research []

    In 2011 the EPA announced a partnership with Chrysler to produce an HHV minivan that would give you a 60% improvement in city driving fuel economy.

    Hybrid Batteries are expensive and can't handle the braking energy a truck generates. Hydraulic technology is cheap, well understood, and gives you more bang for your buck.

  • Re:LOL (Score:5, Informative)

    by spectrokid ( 660550 ) on Friday January 25, 2013 @04:34PM (#42695009) Homepage
    The "sahara" version of the 2CV had 2 engines (front and back) and 4WD. It was so light it would easily pass through loose sand where other jeeps got stuck. The "DS" looked like a modern aerodynamical car in 19-frickin-55. Hydro-pneumatic suspension, power steering, swivelling headlights. They sold 12000 the first day. British Top Gear compared the suspension of the C6 to a BMW 7 series by driving around on a horse track with a video camera strapped to the roof. With the Citroen, you could actually see the horses.
  • Re:LOL (Score:4, Informative)

    by jcdr ( 178250 ) on Friday January 25, 2013 @04:58PM (#42695239)

    You should replace "European" in your text by "UK". But UK is an exception about this.
    All others European countries use SI units: litre and meter. Usually the car consumption is rated in L/100km.

I go on working for the same reason a hen goes on laying eggs. -- H.L. Mencken