Hydropower harvesting from a small scale reciprocating system

Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (C) 2010 Elsevier Ltd. All rights reserved.