09 May 2024

Sumitomo Electric Receives Order for Hokuto-Imabetsu HVDC Link Enhancement Project

Sumitomo Electric Industries, Ltd. announces that it has received the contract for the 250-kV DC XLPE (cross-linked polyethylene) cable construction, a pivotal part of the Hokuto-Imabetsu HVDC (high-voltage direct current) Link Enhancement Project being implemented by Hokkaido Electric Power Network, Inc.

The Hokuto-Imabetsu HVDC Link, also known as the New Hokkaido-Honshu HVDC Link, connects the power grids of Hokkaido and Honshu (mainland of Japan) in order to expand the renewable energy, ensure the stable supply and adjustment of electric capacity, and strengthen the resilience of the transmission network in Hokkaido area. This link has started its operation since March 28, 2019.

Sumitomo Electric, which constructed the underground section of the New Hokkaido-Honshu HVDC Link, has recently been awarded the construction project for the additional New Hokkaido-Honshu HVDC Link, which is projected to increase the transmission capacity of the existing New Hokkaido-Honshu HVDC Link. In this project an additional 250-kV DC XLPE cable approximately 24 km will be installed inside the Seikan Tunnel so that the total transmission capacity of interconnection lines between Hokkaido and Honshu will be increased from 0.9GW to 1.2 GW.


Including this project, Sumitomo Electric will execute all three DC XLPE cable interconnection projects in Japan:  Hokkaido-Honshu HVDC Link by Electric Power Development Co., Ltd., existing and additional New Hokkaido-Honshu HVDC Link by Hokuden Network.

The Organization for Cross-regional Coordination of Transmission Operators formulated the "Long-Term Policy for Nation-Wide Grids - the Master Plan for Nation-Wide Interconnected Grids" in March 2023 to achieve the government's goal of carbon neutrality by 2050. This plan includes additional new wide-area interconnected grid development projects aimed at not only achieving "S+3E"*1 simultaneously, realizing carbon neutrality by 2050, and maintaining stable power supply, but also strengthening the resilience of power grids and transitioning primary power sources from carbon-based to renewable energy. Consequently, the importance of DC XLPE cables has increased significantly to achieve above goals. Sumitomo Electric will strive to contribute to realize the Master Plan for Nation-Wide Interconnected Grids with the international and Japanese supply record and reliability of DC XLPE cables which we have developed and manufactured for a long time.

Project overview

Transmission capacity 0.3GW
Total cable route length Approximately 24 km
Installation location Inside the Seikan Tunnel
Cable specifications 250-kV DC XLPE cable
Start of construction April 2024
Scheduled completion December 2027

*1  "S+3E" is a concept that prioritizes “Safety” while ensuring "Energy Security," "Economic Efficiency," and "Environmental Compliance."

■ Reference
・Press release on May 16, 2019
 Sumitomo Electric Completes HVDC Cable Projects in Europe & Japan
・Sumitomo Electric Group e-magazine “id” (Published in June 2022)
 At the Forefront of Direct Current Power Transmission Cables


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