The potential for tapping electricity from the streams and rivulets of Sri Lanka has been on the test-bed for quite some time. I saw one operational a few miles outside Avisswella a few years back. A small concrete wall was constructed across a village stream high up in its course from the hills. The water was led via a 3inch polythene pipe to a vertically mounted turbine-alternator. The switching system delivered current to about 10 households in this remote village strictly for purposes of lighting at night. Very little maintainence was needed for this set up.
Recently on a visit to Castlereigh in the highlands I saw this mini-hydro project set up by 'Vidya-shilpi' the organization supplying schools with laboratory equipment. They had built a concrete water channel from a nearby stream and this water powered a turbine down below. The pictures show the water channel and the point where it was being led to the valley below to power the turbines.
