Would it be nice to have these kinetic doors or revolving entrances build in at the gates of our holy Mecca ! there are more than 5 Million people entering and leaving 5 gates each year. I would guess that each gate can let in 20 people to enter and exit same time. That is a produce huge kinetic and blessed energy !
any suggestion how to introduce this idea to the authorities ?

regards
Waleed Yousuf

*IF* even a miniscule amount of garnered energy ends up being cost-efficient to recover the intial investment, within a reasonable time-frame, this seems like a reasonable idea to me, especially at places such gargantuan airports with heavy in-out pedestrian traffic through out much of the day, evening, and wee morning hours.

Even if the answer is no, I wonder if linking this system with another green technology might make it far more useful. Specifically, if solar panels (the kind that can work even in coudy weather, ideally) could provide the right amount of electricity to keep the door rotating constantly at the average speed travel through it anyway, then I assume there are few costs (small ones, at that) beyond the initial investment in the solar panels, meaning ROI might be achieved in a reasonable time-frame as well.

And even if the net power generated remains small for any given building, there’s the multiplier effect, as others have noted. Maybe, on average, a building might generate only an average sufficient to power a single light bulb say, six hours per day. Multiply that times a million buildings, and perhaps the economics begin to make sense. And take out a light bulb as well, as some have suggested — more than doubling energy costs saved.

The idea *sounds* good, anyway.

Mekhong Kurt
Bangkok, Thailand

In my head, you don’t have to say “Americans/Westeners” since, well, Americans are a part of the western world as well as Europe, South America, Canada et.c. I, myself, is from Sweden and is also considered a “westerner” is constantly told by my trainers that i should take each and every possibility to use my own muscles. Pull/Push the door open instead of puching the button. Take the stairs, if feasible, instead of the elevator. Walk to the store instead of driving the car. Each action in itself is pretty ignorable, but it all adds up in the long run.
I am also one of those who don’t pay for health clubs since i can keep my condition running, doing push-ups, sit-ups, back-ups, chin-ups and all kinds of ‘ups in my home. 15 minutes a day is all it takes.

My post was half jokingly a push in the “you really do have to stop thinking about what one product does, think bigger people” direction. This door will not produce enourmous amounts of energy. Neither will piezo thingys in pavements or floors. But together the end result is bigger. It all adds up.

Perhaps writing about westerners (like me) was a bad thing. Perhaps I should have written “Swedes” since we starts to see the problems here too, now that more and more american (there you have it) companies area spreading wild with products filled with obscene amounts of sugar, fat and other healthyness. The life-style is also getting less active. This is not a good combination. But seriously. What other part of the world suffers from serious weight problems and over-consumerism? Not Africa for sure. Finding ‘big’ people in Indonesia or Asia isn’t that easy either. Sure, they exists. But all-in-all they’re pretty rare. Why? The food of course matters big time, but i’d be really surprised if these problems would not start popping up when they get to the same “great standard” as us westerners and starts driving the car to the near-by mall.
But maybe i’m just being ignorant.

Maybe this is the start of a new Revolution. ;)

Lets say the motors cost $1000 each. That’s six thousand dollars, which could be used to buy energy efficient LED or CFL bulbs. An LED bulb will last 15 years and cost $20, and save about 20 W/bulb over even fluorescent tubes. So the same amount of investment could generate 50 watts of power, or save 6000 watts. Again, the numbers just don’t add up.

Most revolving door assemblies on the market today already employ some sort of braking mechanism so that the doors can resist exterior wind loads and interior ’stack’ loads. Without these brakes, the doors would likely revolve non-stop, with or without human interaction. It would seem to make sense that an electrical generator would impose no greater resistance if the braking mechanism were omitted and replaced entirely with the generator alone. The generator would then serve as the ‘brake’ when the doors were not in use. The net result yields ‘free’ energy, door control, and no net increase in per-capita hamburger (i.e. food energy) consumption.