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Pavegen To Tap Pedestrians For Power In the UK

Posted by samzenpus on from the electric-slide dept.

An anonymous reader writes "Several years ago Laurence Kembell-Cook unveiled Pavegen floor tiles, which capture kinetic energy from footsteps and convert it to electricity. Now after two years of product testing and picking up a slew of awards across the U.K., Pavegen has received its first commercial order — to light up the new Westfield Stratford City Shopping Centre."

23 of 197 comments (clear)

  1. Laws of Thermodynamics... by niftydude · · Score: 4, Interesting

    Energy doesn't appear out of nowhere for free.

    Walking on these floor tiles requires more energy than regular floors.
    So are they going to start paying brits for all the extra food that they need to eat in order to power these things?

    --
    You can never know everything, and part of what you do know will always be wrong. Perhaps even the most important part.
    1. Re:Laws of Thermodynamics... by onion2k · · Score: 4, Interesting

      Perhaps walking on these tiles costs the same amount of energy as regular tiles, but some of the energy that is normally wasted as heat and sound is captured and turned into something useful...

      --
      http://twitter.com/onion2k
    2. Re:Laws of Thermodynamics... by Arancaytar · · Score: 2

      Even if that were true (instead of the tiles just using the energy already dissipated as waste heat and sound), people in developed countries consume far more energy than they expend. The remainder is stored in fat reserves or excreted as waste. That's where this would come from; it'd be an exercise opportunity.

      (Come to think of it, it would be worth a thought to install generators in gyms for the same effect.)

    3. Re:Laws of Thermodynamics... by deek · · Score: 2

      Two thoughts come to mind:
      * This may be a good way to reduce obesity levels in society.
      * Shopping centers with supermarkets and/or food courts will make a killing.

      Rule #1 of supermarket shopping: never shop while you're hungry.

    4. Re:Laws of Thermodynamics... by flimflammer · · Score: 2

      A 5 millimeter flex is not even remotely comparable to walking in sand.

    5. Re:Laws of Thermodynamics... by Arlet · · Score: 2

      The energy is already there- it just currently dissipates as wasted energy, and does nothing

      Uh, no, in order to tap energy from pedestrians, the tile needs to give or flex a bit when you step on it. This takes more energy than walking on a perfectly rigid tile. When walking on rigid tiles, the body stores some of the landing energy in muscles and tendons by stretching them out. When the leg is lifted, the stored energy is released.

    6. Re:Laws of Thermodynamics... by Nursie · · Score: 2

      Think of it as a public service - most tubby city workers could probably do with some more energy expenditure in their day.

    7. Re:Laws of Thermodynamics... by TheRaven64 · · Score: 2

      No it isn't. Every time you step, you lift your foot (more than 5mm!), move it, and then place it down. Your weight is transferred to the new tile. If anything, this is going to be better to walk over than a hard floor, because it reduces the amount of stress on your knees from the impacts on the ground. You're not moving another 5mm, you're just encountering resistance 5mm before your foot hits the real ground.

      --
      I am TheRaven on Soylent News
    8. Re:Laws of Thermodynamics... by delinear · · Score: 2

      Indeed, some amount of flex is actually more comfortable, so long as it's not too deep. This could well be an improvement for some people over a harder alternative (particularly those who have difficulty with high impact surfaces, like the elderly).

    9. Re:Laws of Thermodynamics... by gandhi_2 · · Score: 3, Interesting

      Man this kind of argument pisses me off.

      "5 isn't even remotely comparable to 1000".

      Sure it is. It is 1/200'ths as much. Plenty comparable.

      5 mm flex is not even remotely comparable to world peace, chuck norris, or boreal toads. a flexible floor IS comparable to walking in sand.

      --
      THL phish sticks
    10. Re:Laws of Thermodynamics... by Mindflux0 · · Score: 2

      You have to push through that resistance. That uses more energy. As to other posts about heat/vibration/sound energy, some of that will be gathered I'm sure but that's a minuscule amount of energy.

      The extra energy may not be noticeable and may result in a more comfortable floor though, like you said. Walking on a thick carpet would probably make you use more energy than these plates and people pay extra for them.

    11. Re:Laws of Thermodynamics... by ZeroExistenZ · · Score: 2

      without properly anticipating the different feeling, it may throw a person off-balance.

      Your mother was a woman who worried alot, wasn't she?

      --
      I think we can keep recursing like this until someone returns 1
    12. Re:Laws of Thermodynamics... by blackfrancis75 · · Score: 2

      It's a common turn of phrase by which the writer means the comparison is meaningless due to the extreme difference in magnitude.

      If this was a troll rather than just extreme pedantry, my apologies to the rest of the /. audience for replying.

    13. Re:Laws of Thermodynamics... by AI0867 · · Score: 5, Informative

      Actually, a softer (energy-absorbing) surface is more comfortable to walk on, provided it doesn't absorb excessive amounts.

      The plastic tracks in stadiums are softer than asphalt, which again is softer than concrete. Guess which one people like to run on best?
      Some athletes from poor countries practice on alphalt and find they run slower in a stadium. Concrete would be even faster, but it tends to wreck your knees unless you have good shoes, which, again, absorb energy.

    14. Re:Laws of Thermodynamics... by tibit · · Score: 2

      Since the "body" is nonlinear, taking it through a slightly different path when in contact with the "floor" may in fact transfer some of the energy that would be otherwise wasted -- our body only got so many degrees of freedom, and a moving tile could supply virtual degrees of freedom that potentially make our gait more efficient, and then simply bring the efficiency back down by retrieving the energy that's now not wasted in our musculoskeletal system. This requires a completely active system, though, with the tiles actuated probably in all 6 degrees of freedom (3 translations and 3 rotations). I'm thinking that whatever energy could be retrieved this way is less than inefficiencies in the actuators and their control electronics, though, unless you optimized the heck out of the tile. It'd be one expensive tile.

      To do it with a tile that only moves in one direction (vertical) is a pipe dream -- you can only simulate a virtual incline, and add extra effort to walking. You're not recovering any energy that's wasted, you're adding extra effort and recovering that, the losses remain same in absolute sense. Now be careful with cheerful marketing, because if you look at losses in relative sense (say as % of total calories expended), it may well be that the losses decrease as a percentage -- while the total energy needed increases! But it's just that -- happy marketing, as the losses in the absolute sense have not decreased at all, but actually increased!

      To get any sort of real recovery of "wasted" energy, you'd have to replace parts of our musculoskeletal system. Perhaps bypassing instead of replacement would work OK enough, but that still implies an exoskeleton, and those aren't particularly efficient at the moment either.

      --
      A successful API design takes a mixture of software design and pedagogy.
  2. Errors in article by Zouden · · Score: 5, Funny

    I was curious how much energy these things produce:

    The Pavegen floor tiles flex a slight 5 millimeters when stepped on, capturing kinetic energy which is either stored in lithium polymer batteries beneath its surface or converted into 2.1 watts of electricity and distributed throughout surrounding lights.

    It produces 2.1 watts for how long? 1 second? 100ms? I guess it could make some LEDs flash.
    Also:

    Kembell-Cook is now in the running to win the Shell LiveWIRE Young Entrepreneur of 2011 Award which would give him 10,000 lbs to use towards his invention.

    Wow. Will his prize be in the form of a giant cartoon-style weight with "10,000 lbs" written on it? Perhaps they'll drop it on his house.

    --
    "A week in the lab saves an hour in the library"
    1. Re:Errors in article by dutchd00d · · Score: 5, Insightful

      It produces 2.1 watts for how long? 1 second? 100ms?

      For as long as you keep walking, I guess. As long as you produce a Joule each second, you're producing 1 Watt.

      The potential energy in a gravitational field is m * g * h, so if you sink 5 mm with every step, you're producing 9.81 * 0.005 = 0.04905 Joule for every kg of body weight at each step. If you take p(ace) steps per second while walking, you're producing p * m * 0.04905 Joules per second, i.e. Watts, as long as you keep walking. So an 80 kg (~160 lbs) person who walks at 2 steps per second could theoretically (i.e. at 100% efficiency) produce 2 * 80 * 0.04905 = 7.8 Watts. So 2.1 Watts means a 30% efficiency. Doesn't seem unbelievable to me.

    2. Re:Errors in article by galanom · · Score: 2

      As for 2.1W, if you look carefully, it says "2.1 watt-hours" (obviously per step)

  3. entrepreneurialism in the UK dead since '80s by Hazel+Bergeron · · Score: 2, Insightful

    There have been very few interesting inventions in the UK since the '80s, and when they are the authorities / marketroids / everyone are so keen to say "LOOK BRITAIN ISN'T DEAD YET!" that every so often there's a hilarious amount of hubbub surrounding nothing.

    Thatcher taught the current 30-somethings that there is no personal gain in actually producing anything (and it's still communist to do anything other than for personal gain): if you want to get rich, become a middleman. So that's where most of the intelligence has gone.

    Upscaling, this is the real reason why we have the financial crisis[tm] in much of Europe: we have neither the production nor sufficient means of production any more. Germany was careful to maintain its own, thus retaining a now dominant economy - they've taken over Europe in a far more rational and subtle way than earlier last century. The rest of us, taught by the worst, have been spending the last couple of decades moving numbers around, signifying nothing.

  4. Re:Interesting ... by Kuruk · · Score: 2

    Not pointless if installed on down ramps of car parks. Where is save the car owners brakes.

    It would tax a cars fuel on flat ground or ramps uphill. Going downhill your using brakes not fuel.

  5. Waste of energy in manufacture by eastlight_jim · · Score: 5, Insightful

    Some quick back of the envelope calculations: FTFA, each tile generates "2.1 W" per step. If we assume a typical step time of 500ms based a pace of 120 steps per minute this could be interpreted as about 1.05J captured per step.

    The casing is made from stainless steel which required about 53 MJ/kg for production in 2004. If we assume a tile casing mass of 2kg that is 106 MJ required for the steel production alone.

    The shopping centre may be open around 10 hours a day with perhaps 20 seconds between each step averaged over a typical day. This is 1800 steps per day at 1.05J per step giving a total of 1890 J captured per day. Assuming 100% efficiency and a never-closing shopping centre, this gives an energy breakeven for the steel alone of around 56000 days or 153 years.

    I know that other factors are in play such as the potential to raise awareness of environmental issues but this is ridiculous. I noticed that the award that the guy is in the running for is sponsored by Shell and part of me suspects that they know that these things are crap but want to be seen to promote something like this which appeals to the public and appears "green".

    1. Re:Waste of energy in manufacture by bruce_the_loon · · Score: 3, Informative

      You also have to take into account the amount of energy taken to make the ceramic floor tile that this replaces. It probably won't zero out the stainless steel energy, but grinding clay and baking it in a kiln uses some energy.

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      Trying to become famous by taking photos. Visit my homepage please.
  6. Not a bad idea by Sqr(twg) · · Score: 2

    Yes, the average slashdotter can do the calculations in his head and deduce that this will not produce useful quantities of energy, but that does not make it a bad idea.

    This guy will get millions in venture capital while you guys are still slaving away at the bottom of the R&D department of some big corporation.

    And should the "green" venture capital ever run out, I'm sure he can re-brand this as a military application (power for smart landmines perhaps?) and get another billion from the ministry of defence.

    I've seen this done many times before.