Analysis of wave reflection from wave energy converters installed as breakwaters in harbour

Amplification and renovation of harbours, none the last for the need of straitening existing structures because of the increased storminess due to climate change, is a practice that is repeating itself all around the world. To this purpose, integration of breakwaters and Wave Energy Converters (WECs) based on two different technologies, one based on the overtopping principle and the other of Oscillating Water Column (OWC) type, revealed to be suitable with different advantages compared to offshore installations, among the others: sharing of costs, cheaper accessibility and maintenance, lower loads on the structure, i.e. better survivability. Nevertheless these devices must comply with the requirements of harbour protection structures and thus cope with problems due to reflection of incoming waves, i.e. dangerous sea states close to harbors entrances and intensified sediment scour, which can lead to structure destabilization. The present paper aims to analyse wave reflection from OWC and Sea Slot-cone Generator (SSG) converters, based on experimental results obtained in 2D and 3D facilities. The applicability of formulae available in the literature and derived from costal structures experience are checked. Consideration on induced scour and structure stability are also carried out, and solution for design improvements are finally drawn.