For electric cars, why don't we have an electric motor, powered by batteries, each battery recharged by alternators in each wheel. As the wheel turns, the alternator generates power to charge the batteries, going down hills, the wheels turn without or at least with reduced assistance. Also, regenerative braking. Everytime the brakes are applied, a generator that is embeded in the pad will turn. Obviously the brake generator pad will have to be replaced from time to time. Anyway, I just thought of it earlier and it seems so simple that I must be overlooking some glaring reason it won't work or someone would probably already be doing it. I'm not saying it would be perpetual motion, it would just be ultra energy efficient. So please, if there are any oversights I made that render this idea impractical, please let me know.
2007-11-01 11:25:53 · 17 answers · asked by Jim 2 in Science & Mathematics ➔ Engineering
What I mean is that the generators in the wheel would recover some of the energy as the wheel turned. The wheels would be turning constantly as the car was in motion. That means they would be charging the batteries even as they went uphill, but that while the car was going downhill, the wheels would still be turning. The batteries would still be charging even though the car doesn't need to use as much energy to go downhill. The car would still need to be plugged into the wall socket when you got to your final destination of the day. I was wondering if the alternators would help recover some of the energy used in motion. I was just wondering if the energy used to turn the alternators would help extend the range of an electric car, or if they would take away from the range.
2007-11-01 12:03:28 · update #1
Physics. You are correct in saying that it would NOT be perpetual motion. The reason this idea would not work is becase in order to generate energy through all of your "generators" additional energy is required to preform jobs that your car was built to do. For example the generators in the wheels increase friction between the axel and the wheel causing more energy to be needed to turn the wheel. So in the end your would only be loseing energy. I hope this answer helped.
2007-11-01 11:33:23 · answer #1 · answered by Anonymous · 3⤊ 1⤋
You need to get a better grasp of the Law of Conservation of Energy. If you put an additional load (i.e., turning resistance) on a turning wheel, then it will take up some of the energy of the wheel and it will spin slower.
Also, some ideas put forth for electric cars involve having four independent motors for each wheel. These motors also act as generators (or alternators as you say) for the regenerative braking -- a motor and a generator are one and the same!
2007-11-01 12:43:40 · answer #2 · answered by Michael S 2 · 0⤊ 1⤋
The first part of your question is why cars do not have alternators in each wheel. The best answer to that is that your second suggestion, regenerative braking, is a better solution.
If you have regenerative braking, then you get to choose when you apply your alternator (i.e., your brakes are attached to an alternator or a flywheel), and it's not just when you're going downhill.
2007-11-01 11:31:55 · answer #3 · answered by sub7ime 3 · 0⤊ 1⤋
Becuase if it takes 100 watts (example) to turn the altertnators, then it will take 100W additional power from the motor while driving, plus any inefficencies. So, you will just lose more energy in that case.
The regenerative braking is nothing new, they just do it in the transmission to save on components. An alternator at each wheel is a little redundant.
2007-11-01 11:32:34 · answer #4 · answered by Eric 2 · 2⤊ 1⤋
Without getting into why or why not practical solutions like yours have not been developed, I want to say there is still the basic design problem with the weight and size of batteries and generators needed to run a vehicle more than 50+ miles without a lengthy recharging time.
2007-11-01 11:48:56 · answer #5 · answered by navymom 5 · 0⤊ 1⤋
Try this: start a regular car and let it idle slowly. Then take off the neg. batt. cable. See how it speeds up just to lose that little drag. If you put the drag of four alternators plus push 3,000 lbs; on an electric motor, it's going to use up an awful lot of HP just to keep going. Much more than alts. can supply. Bob H.
2007-11-01 12:33:55 · answer #6 · answered by Bob H 7 · 0⤊ 1⤋
also think of it from a marketing perspecive..
how are other electric cars powered? Are they dependable? Are they fast? what kind of energy do they use? Which cost more to operate? Which cost more to produce? which cost more to buy? Which is the most environmentally safe? That is what consumers want to know. When you come up with the better electric car then your idea will work..If you already have it, run with it. We need cars like that! Build your car and put her to the test. Very few people are ambitious enough to chase their dreams.
2007-11-01 11:41:23 · answer #7 · answered by ✿❃❀❁✾ Stef ♐ ✿❃❀❁✾ 7 · 0⤊ 1⤋
The only reason electric cars have not been used more and researched more is the thought that electric means the car will not move very fast! You are going to help with the future!
2007-11-01 11:33:17 · answer #8 · answered by olivemai 3 · 0⤊ 1⤋
Well thats how it works. Did you read this off a toyota brocure?
Just remember if you go down a hill you will have to go up a hill at some stage and the energy produced going down will not be enough to get you back up again.
2007-11-01 11:30:52 · answer #9 · answered by goatslunch 6 · 0⤊ 1⤋
If you take power from the turning wheel, it's
regenerative braking and you're slowing the car.
There is no free lunch.
2007-11-01 14:06:23 · answer #10 · answered by Irv S 7 · 0⤊ 1⤋