Session: 09-07-01 Tidal & Current Energy II

Submission Number: 180444

Development and Field Evaluation of a Tidal Current-Powered Monitoring Buoy for Sustainable Ocean Observation 

In recent years, as global climate change and ocean pollution have increasingly altered marine environments, the importance of sustainable marine resource management and continuous data acquisition has become more critical. Reliable ocean observation is essential for understanding long-term environmental changes and supporting sustainable coastal development.

Therefore, this study presents the development and field evaluation of an autonomous monitoring buoy powered by tidal current energy for the purpose of acquiring oceanographic data. The system integrates a compact vertical-axis tidal turbine, rechargeable batteries, ocean sensors such as current velocity meter and chlorophyll sensor, and an LTE communication module, enabling real-time transmission of ocean data to remote servers.

The tidal turbine in this device was designed using a Savonius-type configuration, and optimization was achieved through a method combining genetic algorithms with machine learning using artificial neural networks. The objective functions were to improve the power coefficient and reduce torque fluctuations, ensuring sufficient power generation even under low flow conditions.

A prototype buoy incorporating the optimized turbine was constructed and initially validated through water tank experiments. Subsequently, long-term field tests were conducted off Amakusa island, Kumamoto Prefecture, Japan, to evaluate its actual power performance and operational stability.

During the seven-month deployment, data on tidal current velocity, chlorophyll, water temperature, generated voltage, and battery condition were continuously recorded. The buoy maintained a stable power balance under variable tidal conditions, with battery voltage recovering almost completely during spring tides. Moreover, by analyzing the long-term balance between power generation and consumption, and correlating it with tidal current simulations, potential deployment sites for the system were identified.

These results demonstrate the feasibility of utilizing micro-scale tidal energy as a sustainable power source for long-term autonomous observation platforms. The outcomes contribute to the advancement of sustainable ocean monitoring technology, supporting the development of smart marine observation networks and future smart fisheries systems.

Presenting Author: Reiko Yamada Nagasaki University

Presenting Author Biography: Reiko Yamada is a Ph.D. student at Nagasaki University, Japan. Her research focuses on the development of micro-scale tidal current turbines for autonomous ocean monitoring buoys. She has been engaged in both numerical simulations and field experiments to optimize power generation and energy balance for long-term ocean observation systems.

Authors:

Reiko Yamada Nagasaki University
Adam Mwero Nagasaki University
Garcia Patxi Nagasaki University
Yusaku Kyozuka Nagasaki University
Daisaku Sakaguchi Nagasaki University