Wave energy converters: a comprehensive review of research progress, key challenges, and future trends

Wave energy converters (WECs) have attracted growing research interest as a promising marine renewable technology due to the high energy density and utilization potential of ocean waves. Over the past two decades, substantial academic and industrial efforts have advanced WEC technologies in hydrodynamic design, control strategies, and performance validation. However, large-scale commercialization remains constrained by persistent technical and engineering challenges. This review systematically synthesizes global research on WECs from 2005 to 2024 to identify key insights, knowledge gaps, and development trends. Over 70 countries and regions have contributed to this field, with China leading in publication output and European countries playing a central role in international collaboration. These global efforts have shaped a broad and evolving knowledge base that underpins four dominant research themes: (1) device geometry optimization, (2) array configurations, (3) structural integration with other offshore infrastructure, and (4) advanced power take-off (PTO) control strategies. Although these topics are technically diverse, they share a consistent objective, which is to improve energy capture efficiency and ensure reliable operation under complex marine conditions. Addressing these challenges requires continued progress in high-fidelity hydrodynamic modeling, adaptive control, and robust PTO design, which have become major focuses in recent high-impact studies. Advancements in these areas, together with large-scale prototype testing and standardized performance assessment, are essential for moving WECs toward pre-commercial and large-scale deployment.