Some of the best ideas are those that seemingly make something out of nothing but that in fact create something new from simply noticing what's been in front of you all along. These are the kind of profound ideas that eventually appear obvious in hindsight. A fantastic example of this is "Crowd Farms," the harvesting of the energy of human movement in urban settings - like commuters in a train station or fans at a concert. The idea was envisioned by two graduate students at MIT's School of Architecture and Planning, James Graham and Thaddeus Jusczyk, in a proposal they made for a Sustainable Construction competition earlier this year.
A Crowd Farm in Boston's South Station railway terminal would work like this: A responsive sub-flooring system made up of blocks that depress slightly under the force of human steps would be installed beneath the station's main lobby. 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.
Brilliant, simple, and much-needed innovation in finding new and better sources of energy.