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!)
I have this image of a 12th-century-appearing riverside mill that's actually a highly-efficient part of a 21st-century distributed energy system.
I've actually considered, in more fanciful moods, sticking one of these things guerilla-style in the river that runs outside of my house.
And my dream home has for a long time been an old british watermill, the millwheel driving a generator, solar roof, and maybe a few windmills in a small plot. Plenty of options for driving the server farm.
Ah well, maybe one day...
Last winter, in India, I met an engineer who helps rural villages install micro-hydro. Most of the villages he works with are far away from the road or rail head and have never really seen electricity.
What really struck me was that his stories about electrification involved the rapid, over 6-12 months, destruction of the social fabric of these villages. Changes that our societies took many decades to assimilate happen virtually with the flick of a switch.
I was wondering if there was any way to prepare people or somehow phase in the arrival of electricity so that the social fabric isn't so violently destroyed.
The MicroHydro systems linked to are way more involved than I expected. Imagine a small, water tight turbine that you just lower into a stream. No digging of channels, no tubine buildings, just a turbine generator in the water with a cable coming out.