Influence of the Water Layer on the Performance of A Raindrop Harvester

In a piezoelectric raindrop harvester equipped with spoon the thickness of the water layer modifies the impact dynamics and has an important effect on the performance. To analyze this phenomenon, series of experimental tests carried out in the laboratory with different values of water layer depth are presented and discussed. Results show that the increase in the water depth decreases the resonance frequency. The generated voltage increases with water depth until it reaches an optimum value. Further increases are not beneficial, since large spills take place. Both open circuit voltage and on load voltage are considered.