Tidal resource and interactions between multiple channels in the Goto Islands, Japan

S Waldman,S Yamaguchi,R O’Hara Murray,D Woolf

doi:10.1016/j.ijome.2017.09.002

S Waldman, S Yamaguchi + Show 2 more

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https://doi.org/10.1016/j.ijome.2017.09.002

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Abstract

The Goto Islands in Nagasaki Prefecture, Japan, contain three parallel channels that are suitable for tidal energy development and are the planned location for a tidal energy test centre. Energy extraction is added to a 3D numerical hydrodynamic model of the region, using a sub-grid momentum sink approach, to predict the effects of tidal development.The available resource with first-generation turbines is estimated at 50–107 MW peak output. Spreading turbine thrust across the whole cross-section to prevent bypass flow results in a 64% increase in peak power in one channel, highlighting the importance of 3D over 2D modelling.The energy available for extraction in each strait appears to be independent of the level of extraction in other straits. This contrasts with theoretical and numerical studies of other multi-channel systems. The weak interactions found in this study can be traced to the hydraulic effects of energy extraction not extending to neighbouring channels due to their geometry.

Highlights

IntroductionIn 2010 nuclear power provided 25% of Japan’s electricity [1], making Japan the third-largest producer of nuclear energy in the world [2]
Work is in progress to set up a marine energy test centre, similar to the European Marine Energy Centre in Scotland, in the Goto Islands of Nagasaki Prefecture [5]
Numerical modelling has been used to predict the effects of tidal energy extraction from the Tanoura, Naru and Takigawara Straits in the Goto Islands using tidal energy converters (TECs) of the type planned by OpenHydro for deployment in the region

Summary

Introduction

In 2010 nuclear power provided 25% of Japan’s electricity [1], making Japan the third-largest producer of nuclear energy in the world [2]. Following the tsunami of 2011 and the subsequent events at the Fukushima Daiichi nuclear power plant this figure dropped to less than 2% (in 2012) as the nation’s reactors were taken off-line, and most of the shortfall was replaced by fossil fuels. While there has been some limited resumption of nuclear generation, this is deeply unpopular with sections of the public [3]. As part of a strategy to increase domestic energy supply, the Japanese government plans for 22–24% of electricity to be generated by renewables in 2030 [4]. Work is in progress to set up a marine energy test centre, similar to the European Marine Energy Centre in Scotland, in the Goto Islands of Nagasaki Prefecture [5]

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