Evaluation of the energy extraction of a small-scale wave energy converter

ABSTRACT This work aims to focus on proposals that could stimulate the development of small scale integrated devices for the global challenge to provide electric energy from renewable alternative resources without major interventions. It presents an evaluation of a small-scale wave energy extraction system that can be installed in marine near shore structures, such as fishing piers. The system is characterized by a small oscillating-water-column (OWC) converter composed by tubes tied to the pillars of the structure. A mathematical model of the OWC device was developed. The model relies on two main components. The first uses linear wave theory to describe the water level variation inside the tube as a result of a wave passing by. The second considers the air flux converted to mechanical torque using Wells turbine equations. The simulations were carried out for different water depths and wave parameters, to evaluate the ratio between the input and output energy throughout the year. For the case study presented in this paper, the performance would be better as long as the device is placed in a position where the waves are less influenced by the bottom friction, but it still has the necessary increment of the wave height.