The graph on TopGear was interesting, it's partly why there are projects all over the world looking at green solutions for public transport.

i can remember the dynamo on my push bike when i was a kid to power the lights, im sure there doing it but if they are using two wheels on a electric car to give motion, then why arnt the other two wheels harnessing power from the motion to charge a second bank of batteries which are idle, so when the first bank are getting near to depletion the second bank takes over then the first bank goes into charge mode a super dooper alternator thingy

michaelphillips wrote:good old boris is fighting hard to meet the euro emissions for london watching topgear other night and they showed a graph of daily massive emissions etc yet on the bus strike day it halved the norm..

That was a bit disingenuous. The only traffic allowed in Oxford St are buses and taxis. So obviously if there aren't any buses on a particular day, there is no other traffic to replace them. The graph just showed less emissions because there was less traffic.

But I hate diesel anyway. Always have, always will.

gn2 wrote:The graph on TopGear was interesting

Sorry GN, which graph ?

Mr Philips - the energy either gives you motion or it gives you a charge, it can't give you both - remember how your old dynamo made it harder to pedal?

So you can only do it with unwanted motion (when you are braking)
That is what regenerative braking is
It reverses the circuit to the motor and absorbs the energy from the motion and sticks it in the battery

so the rear wheels have the motors for power... and the front wheels are just rotating, so a belt driven alternator attachment to the front wheel shaft so when the front wheel was in motion could not work the alternator of a car is driven by the engine by belt, so i thought a forward motion/movement with a belt disengagement freewheel for the stop cycle of the front wheel, would not work then in supplying power to a second battery bank (which is on standby to take over when the first battery bank is at a certain percent of remaining power) the battery banks could alternate between themselves in supplying power, worked out at to which point in relation to distance of miles/time to repower.

these are just thoughts in my head

Bluebottle wrote:Sorry GN, which graph ?

It was a measurement of pollution in London which showed a fair reduction during the bus strike.
As is normal with TopGear environmental stories they didn't go into much detail.

This link gives a more detailed and less biased review of the story: http://i100.independent.co.uk/article/p ... eJvO9YBp5x

michaelphillips wrote:so the rear wheels have the motors for power... and the front wheels are just rotating, so a belt driven alternator attachment to the front wheel shaft so when the front wheel was in motion could not work

The rear wheels would have to provide additional power to drive the alternator attached to the front wheels.
You can't get something for nothing.
The alternator attached to an engine requires energy to drive it round, remove the alternator and the fuel economy will improve.

Regenerative braking works well down hills, as the vehicle goes downhill the batery charges.
You might think that is something for nothing, but you had to use energy to get to the top of the hill and it is some of that energy which you get back with regenerative braking.

Conventional brakes throw energy away.
Energy you've paid for at the pumps.
In a conventional petrol/diesel vehicle you spend money with the throttle but can save money by not using the brakes.

ok no alternator then but at the front of the vehicle will be suspension / steering rack and roll bar etc, yet the front wheels are rotating, could be probably be on cv interlinked joint or something to the left and right front wheel (as no engine there) so something could be a rotational factor, the central part of this assembly could be a generator, if you look at the big wind farm turbines its just a propeller blade that spins inside an armature which generates electricity (generator loosely described)

so there is no need for additional power at the rear as the front wheels spinning freely through the generator

If there is a generator on the front it will have to be driven, the energy to drive it needs to be added to the rear wheels.
Wind turbines don't turn in still air.....

gn2 wrote:If there is a generator on the front it will have to be driven, the energy to drive it needs to be added to the rear wheels.
Wind turbines don't turn in still air.....

it would be driven from the rotation of the front wheels in motion, the central shaft from the internals of the connection to the wheel (with the magnets on it) is attached to the front wheels, either side can have a generator or central mount one, the cv joints will compensate for suspension movement like your car does, just thinking aloud but as a wind turbine can then why not a rotational shaft to the front wheels

Hooking up a generator to the front wheels has the same effect as applying a brake.
Extra energy needs to be added to overcome the braking resistance.

Did you do any Physics at school...?