Development and Assessment of a Hybrid Breakwater-Integrated Wave Energy Converter

Abstract

Harnessing and using marine renewable energy at seaports is a promising solution to put these energy-intensive infrastructures on the right track to energy self-sufficiency and environmental sustainability, reducing their carbon footprint. This paper presents a summary of the main conclusions and achievements of a recently concluded R&D project that encompassed the experimental study of an innovative hybrid wave energy converter integrated into a case-study rubble-mound breakwater in the Port of Leixões, Portugal. It also describes the prospective studies planned in two ongoing projects, PORTOS – Ports Towards Energy Self-Sufficiency and WEC4Ports – A hybrid Wave Energy Converter for Ports, intended to further develop and assess this promising technology. It has been demonstrated that its wave-to-wire efficiency and annual energy production are 27.3% and 35.0 MWh/m per year, respectively, for the case-study location. Hence, a 240 m long device could provide more than half of the port’s electricity consumption, which vows for the device’s potential. Moreover, the impact of its integration into the case-study breakwater showed that it leads to a 50% reduction of overtopping discharges over the structure, and no significant effects on the structure’s wave reflection, although the stability of the toe berm blocks was negatively impacted. Overall, the conclusions obtained are favourable to the integration of this technology into rubble-mound breakwaters. Notwithstanding, further research is still needed, namely in terms of wave forces acting upon the structure, important for the assessment of the functional performance and lifecycle readiness of the technology, and the use of PTO control strategies. This is being addressed in PORTOS and WEC4Ports projects.

Keywords

• Blue Ports
• Oscillating Water Column
• breakwater stability
• Overtopping WEC
• Energy self-sufficiency