Technological and commercial comparison of OWC and SSG wave energy converters built into breakwaters

The paper presents a comparison between two different wave energy technologies built into breakwaters: the Oscillating Water Column (OWC) and the Sea wave Slot cone Generator (SSG). The applications resulted to be equivalent and economically feasible with a cost of <0.33 €/kWh considering 10 years payback time. The comparison is based on two installations, one for each solution: OWC breakwater in Mutriku, Basque Country, Spain and SSG breakwater in Swakopmund, Namibia. The concepts differ from working principles: the first is based on wave to pneumatic energy conversion where air trapped in a chamber is compressed by the incoming waves to an air turbine, while the second is based on the overtopping principle, where potential energy of incoming waves is stored in a number of reservoirs at higher level than sea water level and converted into electricity by mean of low head hydro-turbines.