Abstract
This chapter per the authors examines the implementation of renewable energy in the marine environment as a critical dimension of the global energy transition. It highlights the consolidation of offshore wind, both fixed-bottom and floating, as a mature technology, while also addressing the potential of emerging resources such as wave and tidal energy, Ocean Thermal Energy Conversion (OTEC), and salinity gradient power. The chapter reviews recent pilot projects in Europe, North America, and Asia, discussing their technical feasibility, cost challenges, and environmental implications. Particular attention is given to hybrid models that combine marine renewables with solar, aquaculture, desalination, and hydrogen production, as well as to policy instruments, marine spatial planning, and community engagement. Through this integrated perspective, the chapter emphasizes the opportunities and limitations of marine renewable energy, presenting it as a driver of the blue economy and a catalyst for sustainable development in coastal and island regions.