The SSG Wave Energy Converter: Performance, Status and Recent Developments

The Sea-wave Slot-cone Generator concept (SSG) is a Wave Energy Converter based on the wave overtopping principle utilizing several reservoirs placed on top of each other, in which the energy of the incoming wave will be stored as potential energy. The water captured in the reservoirs will then run through turbines for electricity production. The system utilizes a wide spectrum of different wave conditions by means of multiple reservoirs, located at different levels above the still water level. Thereby, it obtains a high overall efficiency and it can be suitable for shoreline and breakwater applications, presenting particular advantages such as: sharing structure costs, availability of grid connection and infrastructures, recirculation of water inside the harbor, as the outlet of the turbines is on the rear part of the system. Recently, plans for the SSG pilot installation were in progress at the Svaaheia site (Norway), Port of Hanstholm (Denmark) and Port of Garibaldi (Oregon, USA). In the last-mentioned two projects, the Sea-wave Slot-cone Generator technology is integrated into outer harbor breakwater and jetty reconstruction projects. Comprehensive studies have been performed in the last years on wave loadings and on hydraulic performances (overtopping and reflection) in order to optimize the structure design. This paper addresses the influence of various parameters (geometry, wave characteristics) on overtopping, reflection and wave loading and it draws conclusions on performances of the system. The results are derived both from multiple laboratory tests as well as numerical simulation. Feasibility studies have been done to investigate the full-scale SSG breakwater concept.