The objective of this study is to discuss the structure and hydrodynamic performance of a shoreline wave energy converter coupled with breakwater. A scale model was built in the laboratory at Hohai University, and then was employed to investigate the performance of developed wave energy device. In the physical model, friction force was employed as the power take-off damping, and the instantaneous output power could be calculated using the measured tension forces and the recorded motion of float. Experimental results show that the resonance state of float plays an important role for the wave energy extraction, and the average output power and conversion efficiency under the resonance state can be up to 0.13 W and 32.6%, respectively. When subjected to shorter waves, the wave energy conversion rate is more satisfactory though the average output power is small. In addition, the water depth is found to be significant for the posture and the motion characteristics of float.
The energy in ocean waves holds enormous potential for pollution free electricity generation (Clement et al., 2002). To date, many studies (Falcao, A. F. O., 2010) have been devoted to harness the wave energy, and abundant wave energy converters (WECs) have been designed and proposed to increase the wave power conversion efficiency. Generally, the existing WECs can be classified to either shoreline, nearshore, or offshore according to their location (Cruz, 2008). Shoreline devices are usually fixed or embedded in the shoreline, and the operating water depth is relatively shallow compared with that for other two categories. Shoreline devices have several meaningful advantages such as: being close to the utility network, convenience for installation and maintenance, and good survivability as they experience a reduced likelihood of being damaged under extreme weather. Meanwhile, shoreline wave energy devices also have disadvantages: the modification of coastal orography, the damage of possible locations of marine species, less available wave energy in shoreline installations than in offshore locations, etc. Thereby, it is essential for shoreline WECs to choose suitable installation points, optimize structural design and establish an operation strategy.