Abstract
Local atmospheric conditions surrounding an off-shore Oscillating Water Column device — OWC hereinafter —, in particular wind action, may affect OWC performance and efficiency, specially over long harvesting intervals, i.e. yearly energy production. This work proposes an experimental study of a simple off-shore OWC where different ambient conditions are compared. More specifically, it proposes a set of experimental tests in laboratory wave flume, under both calm and external wind conditions, which represent a more realistic situation in full-scale prototypes. The results show that the external wind modifies the ambient conditions by changing the temperature, humidity and pressure values of the air surrounding the OWC device, affecting the density and the thermodynamic balance. This affects negatively the OWC performance, reducing the maximum pneumatic power by up to 15%, which can be extrapolated to a reduction of 3% in the total amount of annual energy produced.