Portable Ocean Wave Energy Harvesters: Recent Advances, Challenges, and Future Perspectives

Portable Ocean Wave Energy Harvesters (POWEH) offer a potential approach for supplying autonomous low-power marine sensing systems; however, their long-term reliability, durability, and economic viability remain insufficiently demonstrated. But conventional wave energy converters are often big, expensive, and fixed to seabed structures, which makes it hard to use them in different places and makes it hard to sell them. People have been paying more attention to portable ocean wave energy harvesters in recent years. These are small, light systems that can be set up anywhere and do not need to be moored or anchored. These devices are meant to power autonomous ocean sensors, emergency buoys, and maritime applications that do not need to be connected to the grid. This review looks closely at the development trends, structural designs, and power take-off mechanisms of portable wave energy systems. We compare different types of harvesters, such as mechanical, electromagnetic, piezoelectric, and hybrid ones, based on their design principles, conversion efficiency, and scalability. Focus is directed towards the importance of symmetry in structural design, dynamic response, and energy conversion. The structure, whether symmetric or asymmetric, has a crucial role in determining mass distribution, stiffness traits, vibrational dynamics, hydrodynamic loading, and the capture of multi-directional wave energy, thereby influencing the overall performance, resilience, and stability of portable harvesters. The review goes on to talk about the main problems with dynamic stability, frequency tuning, environmental adaptability, and energy management when things are portable. Finally, new strategies like nonlinear dynamic designs, self-tuning mooring systems, and hybrid energy integration are suggested as ways to improve performance and reliability. The insights from this review are meant to help future innovations that will make it possible to use portable ocean wave energy technologies in a practical and long-lasting way.