The SE@PORTS project involves the development of a hybrid WEC based on the combination of an oscillating water column (OWC) and an overtopping based WEC (OWEC), thus integrating two WEC solutions into a single system with the potential of incorporating the advantages of each WEC, whilst mitigating their intrinsic weaknesses.
The OWEC consists of a number of reservoirs one over each other (above the mean water level), which store, temporarily, the overtopped water of incident waves. When returning the stored water to the sea, low-head multi-stage hydraulic turbines are used to convert the potential energy of the stored water into electric power. As for the OWC, it is composed of a semi-submerged chamber open to the sea below, which keeps a trapped air pocket above a water column. The action of waves forces the column to act like a piston, moving up and down, forcing the air out of the chamber and back into it again. This continuous bi-directional stream of high-velocity air passes through a turbine that converts it into energy.
The resulting hybrid WEC module, based on an OWC-OWEC solution, encompasses considerable challenges, such as the need for the design to accommodate two different concepts, which requires adaptations in terms of geometry, coupling and integration onto the sheltering structure. However, the possibility of creating a structure capable of offering adequate sheltering conditions to ships at port and providing significant clean and renewable energy supply to the local port infrastructures, therefore reducing the environmental impact and improving the self-sustainability of the harbor, justifies the expended time and resources on this innovative research and development effort!