An accurate methodology for determining the efficiency of energy harvesting PZ elements

Abstract

This paper describes a new experimental methodology for accurate measurements of the efficiency of energy conversion in PZ (piezoelectric) elements. These elements are often used to monitor on-line the progressive structural damage of engineering structures, such as bridges, aircrafts and pipelines. Harvesting energy from small amplitude mechanical vibrations of such structures can revolutionize these monitoring techniques by increasing their reliability, reducing the maintenance cost and making them fully autonomous. As the quantity of electrical energy that can be harvested from vibrations is rather low, it is important to ensure that the piezoelectric elements are operating at the best possible efficiency.