Exergy assessment of hydrogen production by oscillating water column wave energy converter

Abstract

This paper deals with the performance of a Proton Exchange Membrane Electrolyzer powered by an off-shore Oscillating Water Column (OWC), focusing on the sustainability assessment of the electrolyzer through exergy analysis. Exergy efficiency of the electrolyzer is revealed to be related to energy output from the OWC device, which depends on its design scale. The study is supported by both experimental model of a simple off-shore OWC set-up and experimental PEM electrolyzer model, combined with a theoretical approach. Results show that exergy efficiency of the electrolyzer and overall renewability of the process decreases when OWC size scale increases, being the maximum exergy efficiency 60.59, %, and the maximum renewability index 1.54. Higher renewability index and exergy efficiency values are obtained when the OWC diameter chamber is around ≲ 1 𝑚���, although OWC size may affect the value of the Levelized Cost of hydrogen production.