Slashdot Mirror

← Back to Stories (view on slashdot.org)

Latest "Green" Power Generation — Your Feet

Posted by timothy on from the my-feet-could-power-gas-generators dept.

gbjbaanb writes "Remember those ideas that suggested hooking gym machines to the power grid? Well, the Times is reporting that something like this to harness free energy is about to become a reality — the footfall of trudging shoppers is to become the latest source of emission-free energy. 'Engineers who have modelled the effects of the technology at Victoria Underground station in central London have calculated that the 34,000 travellers passing through every hour could power 6,500 lightbulbs. ... The plans for heel-strike generation follow successful trials last year at a bridge in the Midlands where generators converted energy from trains passing above into electricity powering a flood detector.' Possibly the most important thing for the readership is at the end: 'There could also be a range of domestic uses, for example powering iPods by plugging them into batteries placed in the owners' heels, using technology which is already available.' Obviously you'd have to get up and walk around, but, as they say, it's the thought that counts."

33 of 189 comments (clear)

  1. There is no free lunch by Omniscious · · Score: 5, Insightful

    As well as no free energy.

    1. Re:There is no free lunch by dougmc · · Score: 4, Insightful
      Energy from the sun is approximately free, especially when you put your solar panels on top of building and such rather than in fields ... but I digress. (I said approximately -- the solar panels are not free, and neither are any other components or their maintenance.)


      But as for free energy -- this is not it. By putting generators in the ground that are moved by people walking on them, it will make it harder to walk. I don't know the specifics, but I'm guessing that parts of the floor will move up and down a little as people walk on it, probably a few milimeters. It might be somewhat akin to walking on sand -- and I have to wonder what it would do to a wheelchair.

      This might be practical if you're in a remote location where electrical power is unavailable and you only need a little -- but beyond that, the solution seems worse than the problem. (And really, solar power is more practical for remote areas where you need only a little power.)

    2. Re:There is no free lunch by evanbd · · Score: 3, Interesting

      Exactly. This article completely ignores the most interesting question -- is it cheaper or more expensive than other zero-emissions sources of energy, like solar? In some specialized applications, human power is nice. But in a supermarket or train station, power is readily available, and this should be compared on even footing in terms of $ per watt of generation capability against other options. Somehow I doubt it beats out solar power. Sure, it may be (*) cleaner than fossil fuels, but what's the point if it costs more than solar?

      * Depends whether you count the marginal fossil fuel cost of food calories, which are a very expensive form of energy by the time they reach your plate. There are reasonable arguments both ways.

    3. Re:There is no free lunch by FinchWorld · · Score: 4, Insightful
      As well as no free energy.

      There is however an amass of energy out there going to waste.

      --
      "I may be full of crap about this game, and I may be wrong, and that's fine." -Jack Thompson
    4. Re:There is no free lunch by Escogido · · Score: 4, Funny

      this should be compared on even footing in terms of $ per watt of generation capability I think that if this energy source is compared on even footing with other ones, it wins hands, err, feet down.
    5. Re:There is no free lunch by gbjbaanb · · Score: 5, Informative

      by people walking on them, it will make it harder to walk

      I remember some adverts for training shoes that had fluid capsules inside them to reduce stresses on your joints (or something, probably just marketing). People bought them but didn't complain they were difficult to walk in. If the generation systems are of the same order, then I can't see a problem.

      I imagine it would cost a fair bit to install, but there's paths everywhere, whereas solar panels have a limited amount of area they can be installed on. Also, these wouldn't require the noxious chemicals solar panels are made of, and wouldn't require as much maintenance (I think).

      For other areas, I thought bridges etc had to have soem 'squidginess' to them, or the traffic riding on them would quickly shake it to bits. As the article said, this principle also applies to antennas that wave in the wind, so its not just going to be used in every pavement in the world.

    6. Re:There is no free lunch by BPPG · · Score: 4, Funny

      As well as no free energy. Apparently somebody was paying attention in Grade 10 chemistry.
      --
      What's the value of information that you don't know?
    7. Re:There is no free lunch by sentientbeing · · Score: 5, Informative

      Youre right.

      I remember this being debunked using basic energy estimates and calculations last year by The Register.

      http://www.theregister.co.uk/2007/07/30/all_the_power_they_would_ever_need/

      --

      ------
      beware he who would deny you access to information, for in his mind he dreams himself your master
    8. Re:There is no free lunch by smaddox · · Score: 4, Informative

      Also, these wouldn't require the noxious chemicals solar panels are made of, and wouldn't require as much maintenance (I think). Noxious chemicals?

      Silicon, and trace amounts of boron and phosphorous are noxious? You need to go back to chemistry class. Not only is silicon one of the most abundant elements on earth, it is one of the least harmful to humans.

      Also, solar cells don't really require maintenance. You would want to clean them occasionally to get optimal power, but that involves spraying them off with a hose. That is the beauty of photovoltaics - there are no moving parts to break.
    9. Re:There is no free lunch by TubeSteak · · Score: 3, Informative

      I remember some adverts for training shoes that had fluid capsules inside them to reduce stresses on your joints (or something, probably just marketing). People bought them but didn't complain they were difficult to walk in. If the generation systems are of the same order, then I can't see a problem. I read an article (I can't find it, but I'm sure someone will pull it up) where they discussed the issues around cushioning in shoes.

      What they found is that your body is used to a certain 'feel' from the ground when you walk. It turns out that more cushioning = more stress on your joints, because your body notices the lack of pressure & compensates with harder heel strikes.

      The article tied all this into walking barefoot and some shoes that were about as close to walking barefoot as you can get.

      Anyways, the moral of the story is that you do work harder with cushioned shoes and they're not good for the health of your feet & lower joints.
      --
      [Fuck Beta]
      o0t!
    10. Re:There is no free lunch by flyingsquid · · Score: 3, Insightful
      6,500 lightbulbs may sound like a lot but if it costs millions...

      6500 light bulbs isn't all that much. Let's be generous and say that each bulb is a high-powered, inefficient 100-watt incandescent bulbs. 6500 bulbs x 100 watts = 650,000 watts, or .65 megawatts. To put things in perspective, a coal or nuclear plant might put out 500-1500 megawatts of power (according to various Wikipedia pages). Obviously, the power output is going to be a lot lower if they're talking about 15 watt compact fluorescent bulbs, however; that'd be about 100 kilowatts of power. That's a respectable amount of power, but you've got to ask (1) how expensive is it going to be, (2) how widely applicable is this model going to be, and (3) how reliable is this power source? Presumably foot traffic is going to decline substantially at night, and perhaps on weekends and major holidays, so the average power generation will be much lower than peak power generation.

      I thought this article http://www.npr.org/templates/story/story.php?storyId=90714692 provided a much more practical take on the problem. Apparently, factories, mills and refineries which generate high temperature exhaust can use that exhaust to generate power. A major difficulty here is legislative, not technological; if you install the machinery to generate power from the heat produced by a steel furnace, laws designed to protect utilities mean that it's often difficult to sell it.

      That being said, I don't think that recycling waste heat, or any other single technology will solve our energy problems. We need a whole suite of technologies- the ability to drill for deeper oil deposits, more cost-effective mining of tar sands and oil shales, more efficient cars, solar, wind, and more efficient houses, cars, and light bulbs- to increase our supply and reduce our demand.

    11. Re:There is no free lunch by maxume · · Score: 4, Informative

      Probably:

      http://nymag.com/health/features/46213/

      --
      Nerd rage is the funniest rage.
    12. Re:There is no free lunch by gbjbaanb · · Score: 3, Informative

      Me? You're the one that needs to go back to eco-warrior class.

      IIRC it was cadmium used in the manufacture that made solar cells not as green as they could be.


      A quick google says
      However there are many environmentalists and some scientists that are worried about the potential negative impact of solar cells (photovoltaic technology). This is because manufacturing process of photovoltaic cells needs toxic metals such as mercury, lead and cadmium

      Still, I think its better than coal-fired power, but don't think any green energy generation is the perfect answer to all problems.

    13. Re:There is no free lunch by zippthorne · · Score: 3, Interesting

      W=f*d

      In the case of the shoes, work done compressing the cushion approximately come back on the up-stroke. It's fairly conservative (in the physics sense). You'll find that if the shoes had tiny holes in the cushions, it'd be quite a bit harder to walk in them, especially if they had a lot of vertical play. The difference between a spring and a shock absorber.

      --
      Can you be Even More Awesome?!
    14. Re:There is no free lunch by tehdaemon · · Score: 3, Insightful

      Yes, Wikipedia is your friend, but you have to know how to use it. Most solar cells are not cadmium telluride.

      From this wikipedia link,

      First-generation photovoltaic cells (also known as silicon wafer-based solar cells) are the dominant technology in the commercial production of solar cells, accounting for more than 86% of the terrestrial solar cell market.

      T

      --
      Laws are horrible moral guides, moral guides make even worse laws.
    15. Re:There is no free lunch by vimm · · Score: 3, Funny

      That would be smaddox's edit on Sunday June 8, at 5:14 pm

    16. Re:There is no free lunch by Deadstick · · Score: 3, Insightful
      Probably something akin to walking up a slight incline.

      And that would be bad for the typical obese American or Brit how?

      rj

  2. Waste of resources by jafiwam · · Score: 4, Insightful

    Humans can't power much continuously. At full tilt on an efficient machine a PRO biker can light a 100 watt bulb. The average luser working out, not worth the bother.

    All the equipment, moving parts, maintained, used to capture human power won't reach the point of break even on any of this stuff. (If you pay your maintenance guy at least.)

    They'd be better off CLOSING the stinking gyms and making people work out outside and not DRIVE there than capturing that power.

    Green is not complicated, often, it is SIMPLE.

    1. Re:Waste of resources by dougmc · · Score: 4, Informative
      I may agree that extracting energy from humans like this isn't practical, but your figures are wrong.


      A world-class bike sprinter can put out 1500-2000 watts for a short period of time, perhaps a minute or so. Lance Armstrong can put out about 500 watts for 30 minutes or so, and a somewhat lesser amount for many hours.

      I'm a pretty weak pedaler, but I can put out about 100 watts for an hour or so without too much trouble.

  3. Not green energy by BradMajors · · Score: 5, Funny

    Using humans to generate electricity is not a green source. Humans generate methane, a green house gas, from their fuel (food).

    1. Re:Not green energy by gbjbaanb · · Score: 5, Funny

      Using humans to generate electricity is not a green source

      yeah, we should ban humans and all the world's energy problems would be over.

  4. Re:success to-date sounds limited by mikael · · Score: 3, Interesting

    I would think that piezo-electric mats that absorb sound would create more energy while at the same time reducing the amount of noise would be more practical than collecting potential energy from passing trains.

    --
    Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
  5. who writes these articles? by brunokummel · · Score: 5, Funny

    ...Obviously you'd have to get up and walk around, but, as they say, it's the thought that counts."
    GREAT ! If it's the thought that counts why do I have to get up and walk around??..I could only imagine that I'm walking around and watch those batteries juice up....
    --
    What is best in life? To crush your enemies, to see them driven before you and to hear the lamentations of their women.
  6. Emission free? by BobNET · · Score: 5, Funny

    I'm pretty sure my feet are producing harmful emissions right now...

  7. Cool toy, but... by RyanFenton · · Score: 4, Interesting

    This sounds as practical as trying to harness the 'incredible power' of our stomach acid for energy generation. I'm sure we could power a lot of lightbulbs in a lot of ways - but I think there are better options than relying on extracted energy from human movement. It's like relying on whale and pig fat as a major power source - it just doesn't scale past a small market segment.

    What we want is to use something more scalable, like algae-based oils, using arid and other unfarmable land, and not using fresh water sources for production. That, plus increases in solar power efficiency are much more direct ways of gathering usable energy, which could scale far beyond our current needs in a sustainable way. That way, we raise the standard of living of people by increasing energy production, rather than make them stick battery chargers on their feet.

    Ultimately, food and fresh water will be bigger concerns going forward - and I don't think we'll be able to grow sustainable crops in our shoes with any toys either.

    Ryan Fenton

    1. Re:Cool toy, but... by rocketPack · · Score: 4, Interesting

      Exactly. Why would we want to rely on an unpredictable, complicated solution to generate a small amount of electricity when we could be harnessing lots of other sources which are much more reliable, scalable, simple, and cheap!

      What about using EM induction to slow down trains? How much electricity could a freight train generate if it stopped using a "third rail" and some magnets beginning a few miles out of town (when it'll already begin slowing down). The savings in mech braking wear and tear, the usefulness of the quantity of electricity generated, the predictability, reliability, simplicity, and cost of such a system make this idea seem so much better than trying to harness the power of "walking."

      But we're not into "useful tech", we want something "clever" sounding and "outside of the box" - even if it's really useless and a waste of resources that could equivocally produce a superior, albeit "boring" and "obvious" solution.

      This green revolution made so much more sense when it didn't have the all the hype. Bring back the old timers!

  8. freeking obesity epidemic by Anonymous Coward · · Score: 4, Insightful

    Most western and industrialized nations people need all the extra exercise they can get. (I said most, not all, some people actually stay in shape, most do not, go ahead, look around you) I think the artificial urban power sucking islands could use around a few million of these generators, help to walk off some of that lard and get some practical benefit from it. I already see those ridiculous belching buses that they praise as mass transit stopping every couple hundred of feet. Egads people can't even walk beyond that? Then they go sit on their asses all day long at some office. Jeebus, how wuss can you get? "OMG it feels like walking on sand! I might get the swooning vapors!"

  9. The idea is not as bad as it seems by ZarathustraDK · · Score: 4, Insightful

    Getting all nerded up and talking about "there is no free energy" only covers it partly, specificly the bad part.

    In 'reality' though there are certain bonusses to a soft walking surface.

    1. You get more traction and reduce slipping of feet (which is a problem on hard surfaces with grains of sand on it).

    2. Damage from falling is reduced.

    3. A soft surface is easier on the joints, which is important for everyone, though especially elderly and disabled people.

    Try finding one of those new fancy playgrounds with a semi-soft rubbery-like surface and walk on it. Much more comfortable to walk on compared to concrete.

    --
    If you quote this signature there'll be 72 copies of Windows ME waiting for you in Heaven.
  10. How about harness doors? by British · · Score: 4, Interesting

    Take a door in a public place. There's a hydraulic mechanism to make sure it doesn't slam shut. There's a bit of a resistance when you open a door. Think of how many times doors in public places open & close on a given day. Sure, it may not be much per 1 door open/shut, but imagine a shopping mall or office with hundreds of doors.

    Take the hydraulic damper and turn it into a generator. Chain together all the doors and have it provide power peak power hours(when the public will be using them). Make them compatible(ie mount-wise) with existing dampers & retrofit them everywhere.

    Slap a generator on those revolving doors too. Imagine the power it could make in a busy downtown area.

    Dang, I should patent this before.........

    1. Re:How about harness doors? by isj · · Score: 3, Informative

      Already done in the comic Gaston, where he invented such a device which could press the juice from 4 oranges, grind 30g coffee and stamp 5 letters. His coworkers were not pleased.

  11. What we really need by Orig_Club_Soda · · Score: 3, Funny

    is all these exercise machines America uses is to plug in to the wall and transfer the energy we expend at the gym and home to be put to use rather than wasted in heat and friction.

  12. Old news by vrjim · · Score: 3, Interesting

    This was brought up in the media last year from the folks at MIT: http://archive.uwire.com/2007/09/11/mit-students-take-step-toward-cleaner-greener-urban-energy/ In fact, I could have sworn I saw the story run here on Slashdot. Can't we just reference the arguments from then so we don't have to rehash them?

  13. Additional Benefits by dave87656 · · Score: 3, Interesting

    It seems that stepping on a tile with pads which push fluid through turbines would have kind of a gel effect or feeling to the people walking on them. This could reduce the impact on the joints and perhaps the fatigue of walking around.