Subsea Cable Laying, Protection Innovation Funded in Japan

NYK, as a member of a consortium of four companies (also including: Sumitomo Electric Industries, Ltd.; Furukawa Electric Co., Ltd.; and Mitsui O.S.K. Lines, Ltd.) has been selected by Japan’s New Energy and Industrial Technology Development Organization (NEDO) in an open call for applications related to the "Development of basic technologies for a multi-purpose and multi-terminal high voltage direct current transmission system,” in addition to the “development of construction methods for the installation of cable protecting system, etc.” and the “development of new cable-laying vessels.”

An Offshore Wind Push

As Japan pushes to harness the power of offshore wind for energy there are several challenges to hurdle. First, population densities are generally far from where wind conditions are best, so increasing transmitting power and efficiency is a priority. In particular, constructing long-distance subsea DC transmission, which has less transmission loss than AC and is advantageous for long-distance power transmission in terms of transmission line cost.

In addition to distance, another challenge in areas with high demand is the fact that cables will need to be laid on bedrock where they cannot be buried, according to previous surveys by NEDO. Therefore, installing ducts to protect the cables is required, which will extend the construction period and increase costs. For this reason, it is essential to reduce the cost of construction methods for protecting cables and to develop technologies such as cable-laying vessels and their outfitting equipment that can respond to Japan-specific sea conditions and weather.

NEDO has been working on the technological development of a multi-purpose and multi-terminal high voltage direct current transmission system that can efficiently connect multiple offshore wind-power generation facilities to the power systems and can be used as an interregional interconnection line connecting different supply areas. At this time, NEDO has adopted one technological development theme related to laying subsea DC cables.

In this project, NYK will be responsible for developing DC cable-laying vessels. Through this development, NYK will help realize the introduction and expansion of wind-power generation through an electric power system that can efficiently transmit power from suitable locations for wind-power generation, such as Hokkaido, to areas having great demand for wind-generated power. 

The project has a 2023 budget of approximately $7m, and is planned to run through FY 2025.