Sainsbury's nicking petrol off customers?

Rolandtheroadie

I'd complain and get them to put in 6 inch high speed bumps instead. I'll be ok though, I've got a diesel (going by all the posts it only affects petrol cars).

All joking aside, !!!!!! off and go to Tescos.

bonzer

Bongedone wrote: »

How is gravity and weight a "magical free energy" ?

You seemed to be implying you thought there was no energy input coming from your car petrol tank by your previous "taking energy from the earth" comment. If something comes down due to gravity, something must have put it up in the first place - in this case petrol.

Bongedone wrote: »

Anyhow, if it is taking the power from the cars momentum you should really be slowing down at the point in the picture anyway.

So your car is being accelerated by petrol and is being decelerated by the system at a point where you would need to stop anyway and dissipate heat into the brakes? So in effect you're saying it's doing something like regenerative braking except the power is going into the store instead of your car?

If you've got a Toyota Prius or an electric vehicle, it's definitely nicking your vehicles energy because you cannot then use the vehicles inbuilt regenerative braking system as Sainsbury's have had the energy first.

You only need the brakes if you cannot judge the distance over which your car will naturally come to a halt (or something unpexpected happens). When you're coming up to a junction, to save petrol you should come off the accelerator early rather than use the brakes. So doesn't this system assume you're going to need to use the brakes so therefore takes away your opportunity to save petrol.

Still don't think it's a good idea.

DaisyClaire

For petes sake you don't get kinetic energy from petrol! [slaps forehead]

Kinetic energy is down to the motion; ie: the extra energy generated from movement.

We possess kinetic energy simply by walking, running etc. Gravity is the force which keeps us 'stuck to the ground' kinetic energy is the energy created as we move, friction.

If sainsburys want your petrol that badly I would personally find a syphon more effective!

DCFC79

Bonzer surely the plates would either return to be flush with the tarmac or be slightly high than the tarmac,

but seriously theres more serious issues out there, in anycase bonzer would you be using the petrol station,

Bowdyjan18

bonzer wrote: »

Sainsbury's are apparently installing a series of plates in the car park in their new Gloucester store that you drive over which powers a generator. This then supplies power to the store.

http://www.guardian.co.uk/environment/2009/jun/15/sainsburys-kinetic-plates-speed-bumps

The claim is this doesn't affect car efficiency. So where's the energy ultimately come from that powers this? So you drive over a raised plate which must very slightly slow your car down, then your engine has to work slightly harder to pick up speed again as a result (i.e. you must use slightly more petrol because it's putting a slight hill in your way).

So isn't this effectively nicking petrol out of your tank to power their store? Isn't this also a really inefficient method of generating electricity?

Shop somewhere else ?

vikingaero

Bowdyjan18 wrote: »

Shop somewhere else ?

Yep. I would make a stand OP and drive to Tesco 3-4 miles down the road. :rolleyes::D

Bowdyjan18

Lmao ^^^^^^^^^^

savemoney

Perhaps the OP should be entitled to compo like some free nectar points just for him

To many of us have other things to worry about like living and paying bills

daveyjp

"the extra energy generated from movement"

Extra energy? Where's that come from then? I still think the laws of physics state that energy can neither be created or destroyed.


No kinetic energy from petrol? How much kinetic energy does a car have? Half mv squared rings a bell. Where does the car gets it's kinetic energy?

globalds

Looks like they just use the slowing energy that would just turn to heat in the brakes.
So if there was a speed bump before a car park ..you would brake anyway .
This link has a video

http://www.unsoughtinput.com/index.php/2007/05/15/the-electro-kinetic-road-ramp-environmentally-friendly-engineering/

Looks like it is equivalent to a speed ramp

The narrator could do with a bit of kinetic energy ..