Small remote communities often lack basic utilities such as electricity supply for lighting, refrigeration, communications etc. It is usually uneconomic to provide mains power, even when high voltage lines pass by a village. Diesel-powered generators require fuel which is expensive and difficult to bring into remote areas. They are noisy and they require maintenance which is often not done in non-technologically literate societies, either because of lack of knowledge or lack of awareness of the importance of maintenance. Neither wind nor sun provide reliable power in humid tropical regions where there is a lot of still, overcast weather, even when wind turbines or solar panels can be located above the trees. Towers attract lightning strikes which can destroy electronic controls, fungus grows on solar panels, and the multiple electrical connections on photovoltaic arrays corrode away in hot, humid climates. Micro-hydro is an attractive option in mountainous areas, and author 1 has built a 30 kW high head and a 3 kW low head plant, using village, surplus and discarded materials. Both are operating satisfactorily. However conventional micro-hydro is not possible in flat country where there is little elevation, and work is now in progress to evaluate suitable hydrokinetic turbines or water wheels on rivers in the humid tropics. Numerous companies around the world are now developing hydrokinetic turbines to harvest tidal and river flows, but a major problem with most designs is clogging by floating debris, which could be worst when used in tropical rivers.