Two MIT students have won a cash prize and international kudos after developing a plan to generate energy using "Crowd Farms."
James Graham and Thaddeus Jusczyk's scheme was judged the winner at the Holcim Forum 2007, focused on the theme of urban transformation and funded by the Holcim Foundation for Sustainable Construction. According to MIT, the students' proposal "was based on the notion that sustainable energy production will increasingly reject monolithic power plants in favor of varied and dispersed micro-generation – from the sun, the wind, from water and geothermic activity, and even from ourselves."
The idea is to harvest energy generated by people, though there's no plan for a sinister virtual reality policed by sentient programs. Rather, crowds would be harvested by walking across special floors made up of blocks which could move up and down as people stepped on and off them. MIT says that "the slippage of the blocks against one another as people walked would generate power through the principle of the dynamo, a device that converts the energy of motion into that of an electric current."
Wow - so that's what a dynamo does.
The idea is that such Crowd Farm floors would be built into train stations or other places where large numbers of people walk about, generating lots of power. It seems that the two young geniuses have calculated that "one step, for instance, can power two 60W light bulbs for one second."
Or to put it another way, the MIT postgrads reckon that a person walking across their special floor will generate 120 watts walking at a normal 60-steps-per-minute pace.
That's interesting in itself. One of the most efficient ways for human beings to generate power by muscular effort is on stationary pedal cycles - that's why you can normally go faster on a bike than you can run, and why pedal-powered boats usually beat ones with oars. Healthy people can deliver 150 watts total via pedals for up to three hours before total exhaustion*. It's more normal to assume that a human can sustainably put out 75 watts of mechanical power - and a good deal of that is necessary for moving him or her self along.
Walking across a "Crowd Farm," floor, then, will be tough enough to totally exhaust a healthy human being in 3 hours - or probably a lot tougher, as up-and-down floor blocks won't be as efficient as pedalling. It'll be like going on a StairMaster set to maximum, or running up an escalator the wrong way.
Whatever. Let's assume the MIT chaps are right, and one person can put out 120W at a reasonable level of effort and still have enough puff left to move him or herself along.
"Multiply that step by 28,527 and you have enough energy to power a moving train," they say.
How true: that's 3423 kilowatts, enough to power four or five twin car Metro trains, if you believe the Amsterdam transport authority. If you crammed those trains full, you could get as many as 1500 people in them, according to the Dutch metro people. Of course, for every person in the trains, you'd need another twenty unfortunates - in reality, probably fifty or more - sweating furiously away in the station "Crowd Farms."
Say it takes twenty minutes for your train to get to your stop. You'll only have to spend six hours minimum working like a galley slave in the queue at the station.
Maybe there's a reason we don't use pedal-powered trains, come to think of it. And maybe there's a bloody good reason we don't use human-driven generators to drive electric railways, which would be even less efficient.
We don't do it because it would be incredibly expensive and inefficient - or, to put it more bluntly, it would be stupid. It makes more sense to walk to work than power a train by bouncy floors. People use trains because they need to cover ground more quickly than their unaided bodies can do it.
To win their prestigious cash prize, Graham and Jusczyk have not had to actually build any of their ambitious demo project, which includes "a regional train station ... two subway stations, an athletic field with a spectator area, music halls, theatres, nightclubs and a large gathering space for rallies, demonstrations and celebrations. As crowds increase for large events, they have the potential to reform and merge adjacent spaces, creating temporary deformations of the surfaces that would increase the amount of energy produced ..."
However, the MIT brainboxes did make a stool with a flywheel in it, which would harvest energy from people sitting down. This was apparently exhibited as an example of cutting-edge American thinking at the Venice Biennale. The "power-stool," as MIT aptly calls it, can apparently produce enough juice to briefly run, not one, but four - count them, four - LEDs.
By this point, it may not be a surprise to most readers that Graham and Jusczyk are not students of engineeering or science. They are, of course, working towards Masters degrees in the Architecture school.
We suspect their research may have mainly consisted of watching The Matrix, in which the evil machine civilisation somehow manages to wring enormous amounts of power out of farmed humans in tanks.
"Combined with a new form of fusion, the machines had found all the power they would ever need ..." says Morpheus.
Substitute the terms "bullshit," "architecture student" and "a way to win a prize" at the appropriate places.®
*According to the International Human Powered Vehicle Association, for instance.