In the northern provinces of Laos bordering on China and Vietnam can be found an interesting example of an appropriate technology for generating electricity--rudimentary, low-cost, robust, and not reliant on overseas experts to install. The turbine/generator which is used is shown below. A propeller turbine is located at the lower end of the shaft and rests on a bamboo draft tube. The generator mounted at the upper end of the shaft is covered to protect it from the elements.

Numerous examples of this technology can be found in Muang Samphanh. Along the Nam Likna, just before it enters the Nam Ou, individual villagers have constructed canals in the streambed to direct a portion of the flow a short distance. This water then flows into one or more short channels each constructed of three wooden planks. The photograph below shows three such channels in the foreground and more in the background.

Each channel has a hole at the end of the bottom board while the two side planks are joined by a bucket with its bottom removed and split along it side. This hole leads to a bamboo draft tube into which is inserted the end of the turbine/generator unit. Water drops about 1 meter and generates an estimated output on the order of 50 W (with greater output for larger drops).

The permanent magnet generator which is located at the top of the shaft from the propeller turbine generates 220 V of alternating current. Two small gauge wires draped over thin bamboo poles and trees and hanging from homes and other structures along the way transmit the electricity for each turbine/generator to the home of the owner of that unit. There, electricity is used for lighting, to power radios and fans, and in a few cases, to power satellite dishes and televisions.

Costs for these entire units, which can be bought a local hardware stores, are below $100.

(Revised June 21, 1997)