Micro-hydropower is solar- and wind- power's neglected step-sister. Maybe it's because of the imagery: solar power evokes sleek mirrored surfaces, shining cleanly in the sun; windpower evokes green and open spaces, blue skies and a nice stiff breeze; micro-hydro makes one think of wet feet, mud and falling water. But whatever the reason, it's looking like distributed hydropower generation is ready for a glass-slipper moment.
Micro-hydro is often overlooked for a few other obvious reasons: you need a stream or other running water nearby (arid regions need not apply); seasonal flows of streams often vary wildly; and initial investment is often more costly than for other forms of alternative energy.
That said, small generators powered by the force of running water can, in the best circumstances, produce much more power, more cheaply than nearly any other alternative - especially if technological improvements now in the pipeline arrive as planned and innovative "revolving funds" to help rural villages finance their construction live up to their billing. Some observers even claim that there's a Moore's-law-like effect beginning to take off in micro-hydro research, with new turbines costing less and delivering more on a routine basis. If that happens, the lights will shine wherever the water falls.
(Then there're the really weird ideas, like ultra-micro-hydro, and distributed hydro systems in cities stormsewers, charging batteries for streetlights. Thanks, Derek!)
