Ocean Thermal Energy Conversion in Kumejima, Japan: A Comprehensive Technical and Socioeconomic Analysis of the Kumejima Model and Its Global Implications

Ocean Thermal Energy Conversion (OTEC) represents a promising renewable energy technology that harnesses the thermal gradient between warm surface seawater and cold deep seawater to generate continuous baseload electricity. This paper presents a comprehensive analysis of the Kumejima OTEC Demonstration Facility in Okinawa Prefecture, Japan, which has been operational since 2013 and stands as the world's only continuously operating OTEC system. The study examines the technical specifications, operational performance, economic viability through integrated deep seawater utilization, and the international expansion of the "Kumejima Model" to countries including Malaysia, Palau, Mauritius, and Nauru. Key findings indicate that while the 100 kW demonstration facility successfully validates OTEC technology for over a decade, commercialization requires scaling to 1 MW by 2026-2027, with future targets of 100 MW by 2030. The Kumejima Model's integration of aquaculture, agriculture, cosmetics production, and desalination generates approximately 2.5 billion yen ($17 million USD) annually and creates over 140 jobs in a community of 7,600 residents, demonstrating a viable pathway for sustainable island development. This research synthesizes technical data, economic indicators, and policy frameworks to assess OTEC's potential as a renewable energy solution for tropical and subtropical regions globally.