Design of small potable water power plants, with regard to grid connection and efficiency

The utilization of very small hydro power plants has been gaining more and more interest lately. In this context the activation and utilization of the potential energy that is inherent in the drinking water stored in highlevel tanks of waterworks is of growing interest. In the paper at hand, considerations about the modification of a small potable water pipeline for electric power generation are presented. Subsequently the complexity of different generator concepts concerning grid connection is compared. Measurements concerning the efficiency of small three-phase induction machines during generator operation are presented. The system described is installed in a box in the basement of the house. A pelton turbine is used because of it´s high efficiency. An induction machine is installed as a generator, without inverter. For high efficiency, an intermittent mode of operation is proposed.