Harvesting ocean wave energy

Annular concentrator for focussing water waves.

Systems that harvest energy from ocean waves can be important renewable energy sources, especially if methods for energy extraction can be improved. Some existing ocean energy systems work by concentrating the waves into a smaller area, making energy harvesting easier. But the extraction efficiency gets limited when too much wave energy gets reflected.

Chinese researchers from Xiamen University and Zhejiang University have now developed a new structure that concentrates water waves without reflecting them back from the shore to improve the efficiency of ocean wave energy.

They have exploited ideas from modern optical engineering and have devised a ring-shaped structure that achieves wave concentration without reflection. They have also tested the device performance using 3D-printed and small-scale prototypes and numerical simulation. With further development, the technique may find practical deployment in offshore wave energy projects. Another aspect of this development is the possibility of using this device to lessen the impact of tsunami waves, the researchers said.