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Non-Tech : Alternative energy -- Ignore unavailable to you. Want to Upgrade?

To: Maurice Winn who wrote (4290)	2/19/2008 5:47:13 PM
From: A.J. Mullen	Read Replies (1) \| Respond to of 16955

Ah but (my favorite words!) most trips are short, and most are urban. Don't hybrids, with regenerative braking, make better mileage in urban driving than on the freeway? That's the opposite of most cars. Speeds are higher on freeways, so rolling and wind-resistance are higher, suggesting that braking in urban driving consumes more than the extra resistance of greater speed. What's trivial is subjective of course. To my mind, if it's worth doing, it's not trivial. However, it could be non-trivial (to my mind) and not worth-doing. Best wishes Maurice, Ashley

To: Maurice Winn who wrote (4290)	2/19/2008 8:26:00 PM
From: gg cox	Read Replies (1) \| Respond to of 16955

<<That depends on the journey: <Most of the energy a car uses, is in the acceleration to speed>. On a trip to another city, the acceleration energy is trivial = get up to 100 kph then sit with the engine racing along at 4000 rpm until getting there when wind resistance and rolling resistance is sufficient to stop the car in a few hundred metres. I could do trips like that without having brakes at all. Even around town, brakes aren't really necessary with a manual gearbox.>> Maurice,generally speaking,not talking about extended highway trips, the majority of driving in the world is done in urban areas.Stop and go driving, accelerating to speed onto freeways, then exiting a short while later , then accelerating and merging etc.I know this to be true because everyone i know are constantly doing brake jobs.You know the tremendous draw in a short period of time spooling up a large electrical motor, it will dim the lights (some require soft start)...same is true for a 3000 pound car with regenerative braking going from 60 to 0..yes several seconds but as you say why waste it...ultra cap it.. for the next acceleration. I know what you mean by not using the brakes at all...i do it all the time and drive my wife nuts, but that is not the way that most people drive. SI Bob does it too.That make s3 of us. Message 23142567 <<I was surprised and disappointed when I worked out how little energy would be collected from braking and put back into acceleration.>> Well lets say it is not debatable now, because Toyota and Honda are doing it, and i know they run the numbers. I really believe, that in this area, ultracapacitors will be used more because they can sponge up electrical energy in a hurry and release it just as fast for the life of the car, saving in and outs on the batteries. MXWL Did that Hillman have wig wags for turn signals Mr Bean?<g>