A micro-hydro pilot plant for mechanical pumping

This paper deals with a micro-hydro power-plant driven by a pump used as a turbine (PAT), which has been set up and tested in Uganda. The plant, including a gravity water depuration system, supplies clean water to a village by means of a pump directly driven by a PAT working under a waterfall head. As there is no reliable method that allows to calculate the turbine performances from the pump ones, a preliminary laboratory investigation was carried out by testing some commercial pumps as turbines, in order to know the available performances and to make a suitable choice. The overall efficiency of this mechanical system is much higher than it should be with electric conversion systems; moreover, electric systems should increase the power-plant overall cost and complexity and reduce the reliability. The preliminary tests, the technical solutions and the field tests are presented and discussed.