Swing Along Green Power

Giraffe Street Lamp is a very cute self-sustaining swing design that provides illumination at night. It harnesses kinetic energy each time you swing and as a double back up, utilizes the solar panel hood to soak some more energy goodness. It’s a very clever design that interweaves play and eco sense into the urban environment. Something that our future generation may as well get used to!

Designers: Chen Wei & Lu Yanxin


  • brian t says:

    Oh, here we go again. Those “power calculations” are nonsense, particularly the first line. What is going on there? If you’re expecting to get a continuous 42W from the swing while it’s in operation, you are asking the users to put in more than 42W continuous power. Really? Where else would the energy come from?

    Think about how a swing works when you’re not trying to extract energy from it. The swinger (?) puts in a little work (energy) on each cycle, and most of that energy is preserved, so that the swing’s energy gradually increases over time. The energy is in the form of potential energy at the top of the swing, and kinetic energy at its lowest point.

    Those calculations (if correct) assume that all that energy, which normally takes time to build up, is extracted on every downward swing, so that the swing stops dead at the lowest point. None of it would be carried through to the upward swing – so that thing is not a swing, it’s an exercise machine. It has a duty cycle – the user has to “charge it up” with potential energy before it can be extracted – so the power delivery would not be continuous, anyway, even if people would do that work for you.

    The likely scenario: a little girl or an old lady would get on the seat and try to swing – but it’s too hard, because you’re making her work to charge your batteries. The swing doesn’t SWING, because you’re extracting all the swing energy from it. So it just sits there, rusting, covered in graffiti, until it’s demolished to make way for a playground.

    I don’t know how many times I have to say this: There Is No Such Thing As A Free Lunch (TANSTAAFL). Designers should talk to an engineer, or at least an engineering student, before trying anything that requires engineering knowledge – and energy is not magic, it’s a well-established engineering field.

    This keeps happening here – remember the “energy-harvesting shopping carts” that would feel like they were being pushed uphill all the time? People are not your battery chargers: you have no business tring to make them work for free. The energy in a swing is not “wasted” and ready to be “harvested”: the energy is what makes a swing SWING, and if you take it away, you no longer have a swing!

  • Erik Moen says:

    Hear hear. Actually, an engineer is quite unnecessary, at least in this case, as anyone with a passing grade from high school science could have explained this.

  • Jimmy C says:

    @brian t: Thanks for the advice. Next time, use some tact.

  • brian t says:

    That WAS tactful. Be thankful I’m not a client being asked to spend money on this.

  • Jimmy C says:

    No, it really wasn’t. PROTIP: It’s never smart to call a simple concept “nonsense”. You’ve pointed out the problem, but you have not done so in a kind and chivalrous fashion. And don’t be arrogant, either, Mr. “I don’t know how many times I have to say this.” I’m betting you’ve never had to say it at all. And what do I have to be thankful for? If you don’t want to spend money on this, that’s your problem.


    design toys. I guess designer satisfaction.

  • robert says:

    The first photograph made me think this was 3 stories tall. Then I saw the photo with the people using it. Very interesting and beautiful design.

  • Zeev says:

    I’m working in the playground field for the last 25 years.
    I can say – clearly – without going into the technical issue, that there is an interesting concept in this fantastic design.
    I would like to contact with the designers.
    Can someone pass me contact info’ with the designers..?

  • Hunter says:

    It’s never smart to call a concept nonsense, unless of course it is.

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