Kawasaki Kisen Kaisha (K Line) has joined a demonstration project aimed at developing cheaper floating offshore wind turbines that can be manufactured in Japan.
Five partner companies, which also include J-Power, Tokyo Electric Power Company (TEPCO), Chubu Electric and offshore floating wind turbine developer Albatross Technology, will jointly develop a small (20 kW) next-generation experimental floating-axis wind turbine expects costs to fall and domestic production quota to rise.
There is growing interest in floating offshore wind energy in Japan because of its ability to operate in deep water, but cost reductions will be essential to encourage its widespread adoption.
The Floating Axis Wind Turbine (FAWT) is a concept in which a vertical axis wind turbine is supported by a rotating cylindrical floating foundation. According to the developers, the wind turbine can be tilted 20 degrees at maximum power, as it is designed to retain its effectiveness even when tilted. This enables the floating foundation to be downsized and the equipment cost to be significantly reduced.
“The wind turbine section can be inexpensively manufactured by continuous pultrusion, a molding process that involves forming composite materials with carbon fiber reinforced plastics into long shapes. By exploiting the characteristics of installing vertical axis wind turbines close to sea level due to their specific characteristics, operating and maintenance costs for the main turbines are also expected to be significantly lower,” the developers said in a press release.
Wind turbine blades can be manufactured in longitudinal sections with the same cross-sectional shape, eliminating the need for large manufacturing facilities. Japanese companies also hold around 80% of the market share for carbon fibers used in the carbon composite of these wind turbines.
J-Power, the Graduate School of Engineering at Osaka University and Albatross are jointly conducting initial studies on the FAWT concept. In the next phase of the project, small experimental versions of the FAWT will be installed in Japanese waters. After confirming the validity of the analysis and design methods, this could lead to a megawatt-scale offshore demonstration project.
The wind turbine section of the small experimental units is being developed by Fukui Fibertech, and the floating section is being developed by Mirai Ships. Carbon composite molding technology is being developed in collaboration with the Innovative Composite Center (ICC) at Kanazawa Institute of Technology, and motion analysis technology is being developed in collaboration with Osaka University Graduate School of Engineering.