研究紹介 / Research introduction
研究紹介 / Research introduction
English follows Japanese.
私は現在,大阪大学大学院 工学研究科 地球総合工学専攻 船舶海洋工学コースの海洋空間開発工学領域で「ポイントアブソーバー型波力発電装置の発電効率向上」および「ジャイロ式波力発電装置の最適制御による常時最大発電効率の実現」に関する研究を行っています.
近年,地球温暖化対策やエネルギー安全保障の観点から再生可能エネルギーの活用が急務であり,日本では洋上風力発電を将来の主力電源と定めて積極的に開発しています.海には洋上風力以外にも豊富なエネルギーが存在し,洋上風力発電の開発によって送電網などの設備コストが低減されるため,将来的には様々な海洋エネルギーの活用が見見込まれています.海洋エネルギーの中でも,エネルギー密度が高い波力を用いた波力発電は将来有望であり,洋上風力発電との併用による相乗効果も期待できます[1].
波力発電には様々なコンセプトが存在します.特に私は,ポイントアブソーバー型(図1)とジャイロ型(図2)の波力発電に注目しています.前者では,海底などに係留されたスパー部と海に浮かぶフロート部の相対変位を利用し,後者では波による装置の動揺から生じるジャイロモーメントを用いて発電します.しかしながら,どちらの手法においても,装置(浮体)一つ当たりの発電量が少ないため,発電効率向上が求められています.
私たちの研究グループでは,図3のように浮体Aで計測した入射波から浮体Bの入射波予測を行い、浮体Bまわりの波動場を予測する手法を確立しました[2].この研究を発展させることで浮体の運動を予測し,各浮体のリアルタイム最適制御を行うことで発電効率向上を目指しています.欧州では既にポイントアブソーバー型波力発電装置の開発が進んでおり,CorPower Oceanというスウェーデンの企業が実証実験まで完了しています.(詳細は下部の動画をご覧ください)
また,博士後期課程から新たにジャイロ式波力発電装置に注目しており,ジャイロを用いたアンチローリング機構に関する研究にも取り組み予定です.
以上のように,私は波力発電に関する研究を主軸としつつ,多様な海洋開発や再生可能エネルギーだけでなく,自然災害対策にもかかわっていきたいと考えています.
I am currently conducting research in the Subarea of Ocean Space Development, Department of Naval Architecture and Ocean Engineering, Division of Global Architecture, Graduate School of Engineering, The University of Osaka. My research focuses on improving the power generation efficiency of Point Absorber Wave Energy Converters and developing optimal control of Gyroscopic Wave Energy Converters to achieve maximum power generation efficiency at all times.
In recent years, addressing climate change and ensuring energy security have made adopting renewable energy an urgent priority. In Japan, offshore wind power has been designated as a key future energy source and is undergoing active development. Beyond offshore wind, the ocean contains a wealth of untapped energy resources. The development of offshore wind power is expected to reduce infrastructure costs, such as for grid connections, paving the way for broader utilization of various marine energy sources in the future. Among these, wave energy stands out due to its high energy density. Wave energy conversion is a promising technology with potential synergies when combined with offshore wind power systems[1].
There are various concepts for wave energy conversion. Promising approaches are the Point Absorber and Gyroscopic. The former generates electricity using the relative motion between a floating buoy and a moored spar structure, as illustrated in Fig. 1. Conversely, the latter generates electricity using the gyro-moment resulting from the device's motion due to waves, as illustrated in Fig. 2. However, the power output per device (buoy) remains relatively low in both methods, necessitating improvements in efficiency.
Our research group has developed a method[2] to predict the wave field around one buoy (Buoy B) using incoming wave measurements taken at another buoy (Buoy A), as shown in Fig. 3. Building upon this method, we aim to improve power generation efficiency by predicting the motion of the buoys and implementing real-time optimal control for each device. In Europe, point absorber wave power converters are already being developed, and a Swedish company called CorPower Ocean has even completed a demonstration test. (For details, please see the video at the bottom.)
Now, I'm focusing on a new gyroscopic wave power generator as my Ph.D. research, and I plan to consider gyro-based anti-rolling mechanisms.
While my primary focus is on research related to wave energy conversion, I aim to contribute not only to various aspects of marine development and renewable energy but also to disaster prevention and mitigation efforts.
[1] Zhou, Y., et al. (2020). Coastal Engineering, 162, 103731.
[2] Yoshimura, R., et al. (2025). Applied Ocean Research, 158, 104539.