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English Market Produces Energy With Kinetic Plates

Posted by samzenpus on from the parking-power dept.

Johnathan Martinez writes "Sainsbury's market in England has installed 'kinetic energy' plates in the parking lot of its store in Gloucester. The plates are an experiment with a newer energy producing technology. The plates create as much as 30 kWh of energy as cars drive over them. The weight of the cars puts pressure on the plates creating kinetic energy to run a generator. The current is used to power the store and will lower the energy consumption of the market."

29 of 404 comments (clear)

  1. useful energy is not free by seanadams.com · · Score: 4, Insightful

    This is just an gas powered electric generator, the likes of which rube goldberg would be proud of. You'd be better off siphoning a thimble of fuel from each car, selling it, and using the proceeds to buy electricity from the utility.

    1. Re:useful energy is not free by MichaelSmith · · Score: 4, Insightful

      This is just an gas powered electric generator, the likes of which rube goldberg would be proud of. You'd be better off siphoning a thimble of fuel from each car, selling it, and using the proceeds to buy electricity from the utility.

      True but if you are going to build speed humps and waste energy that way, this may make sense.

      --
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    2. Re:useful energy is not free by Kickboy12 · · Score: 4, Insightful

      Another Point: You ever driven in a parking lot? Count the number of speed bumps you go over. I wonder how "fuel" the stores are "stealing" from you by making you drive slow over these bumps. Replace those with plates. Might actually get some energy while making people drive slower at the same time. What a concept!

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      google.slashdot
    3. Re:useful energy is not free by Unipuma · · Score: 2, Insightful

      Since this method converts potential energy into kinetic energy (the car pushing down), this means your car will be moving from a higher position to a lower position, losing it's potential energy.

      Since your car has to drive out of the 'pit' it was lowered into, when the plate came down, your car has to expend the energy necessary to climb back out of that 'pit'.

      So your car is directly providing the energy to power this plate system.

    4. Re:useful energy is not free by Shadow+of+Eternity · · Score: 2, Insightful

      The numbers are bullshit, but so are all these suggestions that the plates are magically causing MORE gas/battery power to be wasted than would happen otherwise.

      --
      A bullet may have your name on it but splash damage is addressed "To whom it may concern."
    5. Re:useful energy is not free by Rakishi · · Score: 3, Insightful

      So it'd be the same as dropping a giant stone on the plate? Free perpetual energy? No? Then where is the energy coming from? Remember those pesky laws that keep perpetual motion machine from working?

      The energy doesn't come from gravity but rather from the potential energy of the car via gravity. The car has to gain that energy from the kinetic energy of it's engine somehow since nothing is free.

      Let's say the plate is 1cm above the ground with no car on it. The car's engine exert extra energy to raise the car onto that 1cm plate. The plate then falls and takes that energy from the car by dropping it back to it's previous height. Had the plate not been there the car would not have used the gas needed to generate the energy to raise it 1cm against gravity.

      Sort of sad how little physics is taught in school nowadays that people actually believe energy can come from essentially nowhere.

    6. Re:useful energy is not free by fractoid · · Score: 3, Insightful

      OK, let's put the cars bumper to bumper at 15km/h (which is about usual for a car park) and assume they're 5m long and have a gap of 3m between them. Any given plate would then have a car moving over it every two seconds, or 1800 times an hour. They're going to have to have 132 plates to generate that amount of power per hour, and realistically they'll need at least twice that many.

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    7. Re:useful energy is not free by Rakishi · · Score: 2, Insightful

      I agree, it all comes down to how people brake and how much of the energy would have been wasted for braking anyway.

      On the other hand hybrid and electric cars have regenerative braking so they even reclaim that energy. Given that they're becoming rather popular there may soon be very few places such a system has any real overall advantage.

    8. Re:useful energy is not free by fractoid · · Score: 2, Insightful

      The difference there is that the speed bumps don't sink under your car. The only lost energy from driving over a speed bump is the energy absorbed by your shockies as they damp the motion of your suspension. It's still a good point, though - the amount of energy they 'steal' per car is so trivial that no-one will notice. If you were driving on a road made of the things, it'd probably have a measurable effect on fuel usage, though.

      --
      Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
    9. Re:useful energy is not free by MichaelSmith · · Score: 3, Insightful

      Well maybe they can integrate it into the bazillion speed humps then. The energy may not be "free" but I certainly think all the arguments I've read on this article are ridiculous. The energy "Stolen" from drivers would be negligible, most of the energy would be coming from that wonderful thing called gravity!

      How can energy come from gravity, other than building a one way system when things up high (say asteroids) and moved to somewhere low (say Sydney) and the potential energy recovered in the process.

      --
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    10. Re:useful energy is not free by Sulix · · Score: 2, Insightful

      e=m*v^2

      Scale that down to ~half: e = 0.5*m*v^2

      (Assuming relativistic effects are ignored, of course).

      Either way, 30 kWh is ridiculous. You'd need the plates to move quite a bit.

    11. Re:useful energy is not free by Viol8 · · Score: 4, Insightful

      You're wasting your time trying to explain this I'm afraid. Some people are so utterly clueless when it comes to basic physics that it would be funny if it wasn't such a sad reminder of the state of schooling these days.

    12. Re:useful energy is not free by Peet42 · · Score: 4, Insightful

      The numbers are bullshit, but so are all these suggestions that the plates are magically causing MORE gas/battery power to be wasted than would happen otherwise.

      Add together the energy required to lift the weight of the car up onto each plate, then back up from the level of the plate to street level after the plate has sunk down - you'll find it's more than the car would have used traveling the same distance on the level. They're effectively making each customer pay a levy to use their checkouts, yet making themselves look "greener" by shrouding it in misdirection.

    13. Re:useful energy is not free by amorsen · · Score: 2, Insightful

      So your point is that it doesn't cost you much energy. My counterpoint is that then it doesn't provide them much energy -- unless energy out > energy in.

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    14. Re:useful energy is not free by Anonymous Coward · · Score: 1, Insightful

      If the plate depresses 3" I'm not shopping there -- 3" is a short curb; something I don't want to drive over once a day, nevermind multiple times a day. And if only one axle is being used only half my car's weight is being used to depress the plate so I guess you could say I exert a force of 0.5 * W twice or just 1.0 * W once -- doesn't really change anything.

      Even just a 1" gap, not even a change in elevation, is a pain in the ass, vibration and bump-wise.

      So this idea would have an anti-green effect with me (even ignoring the wasted vs. useful energy debate) because I'll just drive to a farther market to shop if this gets implemented at my local market.

    15. Re:useful energy is not free by xrobertcmx · · Score: 2, Insightful

      No one said it was per car.

  2. lame? vampiring other people oil? by Tei · · Score: 2, Insightful

    is that energy extracted from the cars? then is not magically created, but just a inefficient way to suck energy from other people use of oil.

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    1. Re:lame? vampiring other people oil? by lxs · · Score: 2, Insightful

      There is no magic involved. They deliberately create a piece of bad road to steal energy.

      Of course this is a very small effect like a 'salami slice' financial scam, but it's still a scam.

  3. No such thing as free lunch... by Mindcontrolled · · Score: 1, Insightful

    And the work for pressing the plates down is done by what? Maybe, that could be, uhmm... the cars driving over them, yes? So basically they are using their customers fuel to power their store and call that "green". Way to go, guys.

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    1. Re:No such thing as free lunch... by DigiShaman · · Score: 2, Insightful

      Well, the customers are using their fuel anyhow to drive in, I don't see what's wrong with making use of a kinetic generator which is also using the pull of gravity to generate the power.

      ***face palm***

      Sigh.

      Ok, that's like saying you increase your fuel mileage by driving down hill. What you are failing to take into account is that all your gains have been lost when it comes time to drive back up it! It's the same idea with these plates, but on a much much smaller scale.

      --
      Life is not for the lazy.
    2. Re:No such thing as free lunch... by lazy_playboy · · Score: 1, Insightful

      You are dumb.

    3. Re:No such thing as free lunch... by Rakishi · · Score: 2, Insightful

      Except they wouldn't have since energy has to come from somewhere and car's don't magically use it for no purpose. The energy they're using comes from raising the car's height (ie: potential energy due to gravity) to the height of the plate. Without the plate that energy would not have been used period as there'd have been no need to raise the car's height.

      Had there been a natural downward slope present (say it was a speed bump, small hill, etc.) then the energy would have been partially reclaimed and converted into kinetic energy for the car. In other words going downhill makes the car go faster and that energy came from when the car had to go up the hill.

    4. Re:No such thing as free lunch... by BeardsmoreA · · Score: 4, Insightful

      No. But afterwards, if you didn't give the engine any gas during the process, it would be moving slower. As lots of people have tried to point out, this might be desirable (see speed bumps). If the driver is just going to accelerate back to speed however, you have gained nothing.

  4. It's not generation by DigiShaman · · Score: 1, Insightful

    It's theft!

    By using these devices, they are stealing energy from the drivers. While one driver may not notice, as a whole, fuel usage is being diverted from all who drive over these things.

    --
    Life is not for the lazy.
  5. This is so stupid it hurts by Timo_UK · · Score: 2, Insightful

    As many other commented, the energy comes off course from the petrol engine of the cars. 1. The efficiency of this system from petrol to electricity must be really low 2. It creates pollution right where you don't want it, in the city: Exhaust fumes plus tire wear

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  6. it's not green by marvinglenn · · Score: 2, Insightful

    TFA calls it a "green energy project". The type of people who think this is green energy are the complete f-ing morons that side track the rest of us from real viable energy advancements.

    Further more, the TFA claims this will "lower the energy consumption of the market". At the inefficiency of this (which is already limited to being no more efficient than a car is itself), it will actually increase the energy consumption of the market.

    --
    The whores get mad when the sluts give it away for free.
  7. Just converting kinetic energy into electrical by theodicey · · Score: 3, Insightful

    Probably 2/3 of the comments so far seem to think this is some kind of perpetual motion machine con. Those people should be embarrassed.

    It's not. It's simple. It's just slowing cars by converting kinetic energy into electrical, instead of dissipating it as heat in the brakes or converting it to potential energy like a speed bump.

    There was a discussion a while back, I think here on Slashdot, about a device that used a revolving door to generate energy. It prompted exactly the same comments. What these people didn't seem to realize is, revolving doors have brakes, and that device replaces the brakes. Same damn thing.

    Do you really think the engineers who designed this device didn't think it through? This reminds me why it's never a good idea to discuss physics on Slashdot. I leave it to psychologists to explain why there are so many kneejerk contrarians.

  8. Re:Cars waste 95% of gasoline energy when cruising by profesor · · Score: 2, Insightful

    I think that for this calculation to be reasonable you need to know the actual fuel usage while maintaining 100kph on a flat highway with no wind. I suspect that it is higher than 18 km/l, that sounds more like a rated highway fuel efficiency number which probably includes a lot more than just maintaining speed on a flat level road.

  9. Re:Cars waste 95% of gasoline energy when cruising by slashbart · · Score: 2, Insightful

    My 0.1 m/s^2 deceleration for a 900kg car shows a drag force (wheels + air + differential + bearings + exit shaft of gearbox) on the car of 90N. I don't need to know where that 90N is coming from.
    So I don't see why I can't do what I did. I think it's completely valid.