| Marine renewable energy features substantial development potential, long-term sustainability, and low environmental impact, making it a vital component of a clean, low-carbon, safe, and efficient energy system. This paper provides a systematic review of the generation mechanisms and resource characteristics of major marine renewable energies—including offshore wind, wave, tidal, tidal-current, ocean thermal, and salinity-gradient energy—considering their energy sources, conversion processes, and current technological maturity. A comparative analysis highlights differences among these resources in terms of technological readiness and economic feasibility. Building on this, the study examines the complementary mechanisms among various marine energy types, exploring their potential for mutual compensation across temporal scales, spatial patterns, and meteorological conditions. The coupling principles and coordination mechanisms of multi-energy complementary systems are also summarized. Drawing on recent research progress and engineering practice domestically and internationally, the paper discusses the advantages of integrated marine renewable energy systems in improving system integration, enhancing output stability, and increasing utilization efficiency. Finally, key challenges in integrated marine energy utilization—such as system-design complexity, coupled-modeling difficulty, and limited experimental validation—are outlined, and future prospects for deep-sea development and industry integration are presented. |
