@weatherman: the american way: convenience. oh, i'm so proud to be from this great nation of 300 million couch potatos.

i live not too far from the city, so i can tell you: given how many revolving doors are in the city, a little technology could go a long way.

rimplestultskin

Yes elevators have a counterweight that's sixty percent of the max load of the elevator rating. There's really not much energy to be had even if it was full and going down, they are really efficient using the weight system.

Hello_Newman

@SportBilly: Welcome to the joke.

ideaman2020

This was featured in the "Power Surge" episode of Invention Nation ([science.discovery.com]).

Left out of this article: the fact that the two inventors are hot chicks. One is particularly hot.

InterMurph

It's a good idea. Goes right up there with self powered watches. The momentum from swinging your wrist powers the watch. So to solve the problem with elderly people having a problem pushing the door, why not either make it a hybrid, or save some of the energy made, to give a powered button option...
Kind of like the handy cap button.

Acid_Burn

@DCGaymer: Actually, there is a non-profit group named Roundabout in South Africa that builds and is installing merry-go-round water pumps all over the region. The pump is integrated into the merry-go-round which local village children play on (no coercion required). The water pump fills a large storage tank that villagers can draw from. It has been hugely successful, with over 500 pumps already installed in South Africa alone.

Baudrillard's Ghost

Reply to OUTLANDERSSC (above)

They already use gearing or highly viscous fluid on the revolving doors which damps their spin. The kinetic energy is dissipated in these systems so the door spins within a relatively predictable range of speeds. (Read: Nobody gets hit from behind by the door when lil' Ricky runs in and gives it a big push.)

The difference in this concept is that it would replace the existing mechanisms (fluid or gears) with the internal resistance of a generator. So the energy transferred by people into the door isn't dissipated (old idea) but captured (new idea).

gregalee

Meh. This idea is as clever as replacing the Manhattan sidewalks with piezoelectric generators.

ripfire4

Elevators operate on a counterweight system, tho. Meaning going up or down, they expend the same amount of energy. There's really no 'free-fall' in an elevator that can capture energy back. Maybe regenerative breaking would work with elevators, but it seems unlikely.

trendspotter

@The Turtle: People would probably be pissed off that the resistance of the little generator in the spool causes them to snag little squares off of the sheet prematurely, thus forcing them to wipe daintily.

Kaiser-Machead

They should also do this for elevators; people have to walk up, but can ride the elevator down with resistance provided by the generator depending on weight...

weatherman

No, the real mother lode of untapped kinetic energy in America is those gigantic toilet paper dispensers in public bathrooms, like at the mall. Just put a generator on the hub of that bad boy, and you'd generate enough power to bake an entire day's worth of Cinnabons.

The Turtle

@Gann: @jabber:

been done before. Who gyms are powered like this. Equipment is expensive though.

Rob C

@outlanderssc I read somewhere the doors are heavy on purpose to keep the wind from blowing through them...that or they could just use lighter panels for people to push through...

Nissan288

@jabber:

I thought some gyms did that now, or at least used the pedal power to fuel the electronics of the stationary bike.

RoyalKennebecasisAdventurersSociety

@ideaman2020:
Um they do. That's how your car battery retains its charge.

SportBilly

We should attach this technology to cars! Then we could generate electricity wherever we go...

ideaman2020

Why stop at just doors. Why not apply this to exercise machines in gyms. There's a whole lot wasted kinetic energy being wasted there everyday.

jabber

@outlanderssc: You should try opening new revolving doors that have a new carpet laid underneath. Before the constant revolving finally flattens the fabric, it's a bitch to push through. I've seen older residents give up and use the side door lol.

Kaiser-Machead

Just get Will Farrell to power the city. Problem solved.

Kaiser-Machead

@DCGaymer: I like it.

Sqube

Dog on leash + revolving door. Could be messy!

nincompoop

ONE 5th grade field trip goes through revolving doors and you could power Manhattan for like 30 years.

n/a

I doubt it would generate that much electricity, but better some than none I suppose. I don't understand motorized revolving doors - what's the point of that? Is it really that hard to push a revolving door?

weatherman

I like doors to do the work for me, not the other way round.

hanswurst0815

I have a similar idea for gym equipment.

Gann

Think of all the electricity a Merry-go-round would make. Kids just NEVER stop.

DCGaymer

Neat idea, but the first time it breaks the building super will just disconnect the generator.

Plus, as it is those doors are hard to open for kids and old people, imagine if you add the resistance of a generator as well.

outlanderssc

stupid hypocritical electric doors.

Geisrud