What a great term. Parasitic power generator refers to technology that captures energy from human activity that is otherwise released as waste - think electricity from people on treadmills, the energy from people walking through subway stations, and the power transmitted through dancers to the floor (talk about a Dance Dance Revolution). This post from Paul Kedrosky, referencing an article in the WSJ (subscription required) caught my eye.
I've been on a lot of highways lately. Every time I look out the window I wonder if there is a way to put small wind turbines along the edges of the road that would be powered by the cars speeding by and could return that energy to the cities connected by the highways.
What strikes me about these ideas is how site specific they are. As we think about alternative and renewable energy sources, considering the appropriateness of different technologies to different situations seems critical, instead of just pronouncing one technology to be the universal answer (Such as, say, ethanol. Which would seem to me to recreate the fossil fuel industry only in Iowa instead of Texas).