This is to highlight the recent developments of the "Palang Thai" (Energy Independence) Organization. Chris Greacen married a Thai woman and has worked to bring environmentally sound improvements to remote Thai villages near the Burmese border.
http://palangthai.blogspot.com/
The region is rich with many small water flows having moderate head (elevation drop). This mountainous area is cash-poor, and as a result much research and hands-on development has gone into finding the most effective and low-cost micro-hydro solutions using primitive and simple nearby manufacturing capabilities.
The government is encouraging villages to become tied to a coal-powered grid, but lack of rural cash has limited them to seeking the most affordable alternatives.
A fish pond was dug alongside the village stream with a weir (dam) and flume, which is an elevated trough that feeds the turbine.
The stream was diverted to flow into the new loop, then it is returned to its old path. The end of the flume feeds a vertical 6-inch diameter PVC pipe that is 7 feet tall. The generator head is a radial PMA that's wound for 220 VAC at a flow rate of 500 Gallons Per Minute (GPM). It is adjusted for the local 50 cycle, but can be adjusted for 60 Hz components found elsewhere.
A Francis turbine resembles a 3-bladed boat propellor, and just above the prop is a fixed radial vane flow director. The prop is located about one foot below the top of the feed pipe, and runs more off the fall suction below it, than the conventional method of locating the turbine at the bottom of the pipe and using the pressure above it.
There is no battery bank. A simple controller directs power to seven 20-Watt Compact Fluorescent Lights (CFL's) at night, and when lights are not being used the controller diverts some power to an elevated hot water storage heater, and a variety of battery chargers for flashlights, radios, and other devices.
This organization has found they prefer this configuration unless the head is 15 feet or more, at which point they have found a Pelton/Turgo becomes a viable option, though more head than 15 feet dramatically improves Pelton/Turgo performance.
I paraphrased this from "Home Power Magazine" Apr/May-08 issue
