Power output estimation for oscillating water columns: An assessment of experimental methods

Abstract

The present study concerns the quantification of the power output of an Oscillating Water Column (OWC) in a laboratory environment. It presents the development of a novel, more accurate methodology to quantify OWC power output in a laboratory setting and evaluates existing estimation methods to highlight their accuracy and limitations. The proposed approach employs camera recordings and relevant image processing techniques to accurately capture the water surface elevation inside the OWC. By incorporating the spatial variation of the free-surface elevation, the resulting spatio-temporal dataset provides power-output estimates of higher accuracy, underscoring the benefits of the proposed methodology. However, as this approach may not always be practically feasible for all experimental setups, it is also used to assess alternative approaches that are commonly adopted. This assessment reveals that larger wave heights lead to more significant errors in the estimation of device efficiency; the latter ranging from 16 % to 33 %. As a whole, the present study enhances our understanding of power output estimation approaches and their respective errors and limitations. Thus, it provides clear and practical guidance regarding the selection of a suitable approach.