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  1. #1
    Junior Member
    Join Date
    Jan 2008

    Hybrid technologies comparison??

    Hello All,

    New member here.

    I am trying to establish the feasability of various hybrid technologies in terms of mass and cost per vehicle.
    I am aware that any increase in mass will be incorporated into the increased efficiency value, but think of a matrix with technology/configuration down the side and level of hybridization across the top, with the mass and cost throughout the table and you get the idea.
    Technologies/architectures/configurations to be included: ISG stopstart, Regen, cylinder deactivation, batteries (range of chemicals), caps, fuelcells (ignoring infrastructure issues), flywheels, hydraulic accumulators, etc etc etc

    Any info source would be greatly appreciated.

    Thanks folks


  2. #2
    I saw a great article, I believe it was in and MIT engineering newsletter, that I think covered this well. Unfortunately, I didn't get a copy of it :-(
    It plotted a blend from ICE (Internal Combustion Engine) to BEV (Battery Electric Vehicle) by percent of propulsion from zero (pure ICE) to 100% (pure BEV) and showed how fuel economy, CO2 emission, cost, and other 'good' and 'bad' stuff vary with this mix. The plots clearly showed that anything electric reduces the 'bad' stuff and increases the 'good' stuff, in a monotonic curve with the optimum being 100% BEV.
    My experience is that there are many things one can to to try to capture the inefficiencies of an ICE but none come close to the benefits of just getting rid of the ICE altogether. Once you get rid of it, you must come up with some other means of carrying the necessary energy to operate with. This is where one must look at the alternatives such as batteries, caps, fuel cells, flywheels, springs rubber bands, hydrolic accumulators (actually compressed air), etc.
    All of these alternatives pale in their ability to store energy compared to gasoline with the exception of hydrogen. The problem with hydrogen, of course, is getting the hydrogen - a very inefficient process. The best batteries store about 10% of the energy of gasoline (for a given weight) and the rest store significantly less. The benefit of the other things, of course is that their conversion efficiency (with the exception of compressed air) is much better than ICE.
    I wish I could point you toward a quick, easy comparison source but, other than Sherry Boschert's book "Plug-in Hybrids", I don't know of a clear reliable source.

  3. #3

    Dear cianm Just a couple of

    Dear cianm
    Just a couple of things to think about with a summary at the end.
    Though it is true that weight has a large influence in MPG of a Hybrid or a BEV, there are many other things that influence mileage that are not being used currently. For instance, did you know that Chevron owns the rights to the NIMH battery and will not allow a vehicle to be powered with more than about 30% of the power of the engine?
    The electric RAV 4 cars that I know of are over 125,000 miles old with greater performance than when new. The last EV1's got over 200 mile range on NIMH batteries, but please pay attention: NEVER BUY CHEVRON GAS! The Prius is designed to use the greatest percentage of this rule. Even though the battery used is made in Japan, all auto manufacturers are prevented from designing a CAR sold in America powered by more than that percentage (unless made by individuals). Guess why the EV1 and others have been scrapped?
    The other technology is Lithium Ion. Chevron does not own this technology but Lithium Ion is difficult to charge and can explode if mistreated. A great deterrent, but not impossible to overcome.
    Hence the Phoenix truck (soon) and the Tesla sportster (now being made) that drive up to 250 miles all-electric. They have figured out ways to handle many things such as non explosive batteries and 10 minute charging (truck).
    The point I am trying to make is that all 'charts' you might find are good for estimating performance, but individual results are always different. Even the way YOU might drive. By the way, in warm climates, Propane is less expensive than gas and has more POWER, gets better MPG as well as being clean burning. Nobody is working on that because it freezes below 30 Deg F. Inconvenient!


  4. #4

    Tommmeee, I agree with the

    I agree with the spirit and theory of your post but have Just a few minor corrections for accuracy sake:
    The Tesla Roadster can go about 250 miles on a charge but takes 3.5 hours to fully charge (some estimates are that it could handle 1 hour charging if a large enough industrial charger were available). 3.5 hours is the fastest one would expect to charge at home using a 220V, 70A circuit since that's about all the excess capacity a house might be wired for.
    The Phoenix truck can only go about 120 miles on a charge but its batteries can be fully charged in 10 minutes (with a huge, industrial charger). At home, it would charge in a few hours.
    I don't know of anyone who went 200 miles on an EV1. The most I ever heard of was about 180 miles on the NiMH version. My personal best was about 150 miles but the last 30 miles were creeping below 30 mph. Realistically, the NiMH EV1 could go about 120 miles at normal highway (65 - 70 mph) speeds on a charge.

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