Project Records

Sumitomo Electric has secured a contract from National Grid Electricity Transmission to supply and install the 140km HVDC subsea cable for Sea Link project linking Kent and Suffolk in the UK, with construction starting in 2027. The cable will be manufactured at Sumitomo Electric’s new factory at Port of Nigg in Scotland, supporting the UK’s Great Grid Upgrade program and clean energy goals.

The project will strengthen the local supply chain, contribute to the UK's Clean Power 2030 and Net Zero 2050 initiatives, and create over 200 direct jobs plus additional employment in related sectors. With more than a century of subsea cable expertise, Sumitomo Electric will deliver the project in a timely manner.

Sumitomo Electric has been awarded 525kV DC XLPE underground cable systems for the Korridor A-Nord project by Amprion GmbH, one of Germany’s transmission system operators. Under the contract, we are responsible for the design, manufacturing, logistics, installation, jointing, commissioning and maintenance of the approximately 300km long cable route. The route connects the converter stations in Petkum, located at Emden, and Osterath, near Düsseldorf. Through the 2GW transmission system, clean energy generated by offshore wind farms in northwestern Germany flows south—powering the nation’s future. This milestone marks a significant advancement in one of the country’s most vital energy infrastructure developments. The project will be implemented as part of a long-term strategic collaboration between the two companies.

Sumitomo Electric has successfully handed over the cable system to Greenlink Interconnector Ltd. The project covered the manufacture and installation of onshore HVDC cables in Ireland (24 km) and Wales (6 km), as well as 160 km of submarine cables. The Greenlink Interconnector links the electricity grids of Ireland and the United Kingdom, creating a new connection between Great Island in County Wexford and Pembrokeshire in Wales. Power can flow in either direction depending on supply and demand in each country.

This is part of the Project Lightning for the Abu Dhabi National Oil Company (ADNOC) which is the first submarine HVDC network in the Middle East (route length of approx. 140km) using Sumitomo Electric’s state-of-the art 400kV DC XLPE cable technology. The system operation is expected to be started in 2026.

The joint venture of Sumitomo Electric and Siemens Energy has completed connecting India’s first HVDC link featuring voltage-sourced converter (VSC) and DC-XLPE cable technology. The 2GW electricity transmission system consisting of two links which consists of DC-XLPE cable and overhead transmission line between Pugalur in the southern state of Tamil Nadu to Trichur in Kerala State. Siemens Energy supplied the two converter stations for the ±320kV HVDC system while Sumitomo Electric was responsible for the XLPE HVDC cable system comprising four cables (a route of 27km each). It started its operation since March 2021.

Nemo Link is a HVDC power transmission system between UK and Belgium. We delivered and completed a 400kV DC XLPE insulated cable, which was the world's first and highest-voltage DC XLPE insulated cable in January 2019.
Over the first 7-year period, NEMO Link has continuously transmitted maximum of 1GW between UK and Belgium since the commencement of power transmission in January 2019. It was also reported that an availability of the cable system was remarkable more than 99.5%, and during 2025, only 47 minutes of unplanned outage (just 0.009%).

These HVDC XLPE submarine cables connect Hokkaido to Honshu and have a route length of 43 km. This is the world’s first projects consisting of HVDC cables with LCC converters and overhead lines operating under polarity reversal. The system has been in operation since 2012.

This project involves laying a 230kV AC submarine cable (1.2GW, two circuits) along a 27km route between Cebu and Bohol islands, aiming to resolve the growing power supply-demand imbalance on Bohol Island. Sumitomo Electric was responsible for the design, manufacturing, and installation of the system, including the 230kV AC XLPE cable, and successfully completed the work on schedule, despite the highly challenging nature of the deep-sea installation. The operation was started since 2024.

Sumitomo Electric has completed the design, manufacturing, and construction of transmission and substation facilities for the Sumita Tono Wind Farm, one of Japan’s largest wind farms. These facilities have been handed over to the contractee, Shimizu Corporation which had a BOP contract with Green Power Sumita Tono LLC. The Sumita Tono Wind Farm started commercial operation on May 11, 2023.
The underground transmission line with a voltage of 154kV spanned a long distance of approximately 35 km, requiring extreme precaution in handling. Sumitomo Electric, however, successfully completed the installation within the scheduled timeframe by leveraging its technical expertise and construction capabilities accumulated through domestic transmission line projects.

The project required the removal and discarding of one spare phase of an existing 138kV oil filled submarine power cable and the installation of a new circuit of three-core, double armoured, 69kV XLPE submarine cable in its place with ancillary equipment, accessories, and integrated communication fiber for a fully functional cable system in the Stikine crossing. This crossing is approximately 17,400 feet (5,300m) long and a maximum water depth of about 700 feet (215m) between Vank Island and Woronkofski Island, southeast Alaska, USA. Sumitomo Electric sucessfully completed the installation in 2021.

Sumitomo Electric successfully completed the pipe type cable to XLPE cable system retrofit replacement project in San Francisco, California in May 2020. The project consisted in installing a new 115kV AC XLPE Triplex underground power cables into an existing 8” steel pipe, to feed into the existing substations between San Bruno and South San Francisco, CA, connecting the San Mateo to overhead lines. The circuit route that connects the two substations between the interchange section is approximately 1,200 feet (365 meters) in length. There was a requirement for the power cables to be replaced while keeping the existing 8-inch-diameter (about 20.3cm) steel pipes intact. It had started the operation since 2018.

The project was jointly awarded to Sumitomo Electric and Siem Offshore Contractors (SOC) of Germany by TenneT TSO GmbH in 2012. The scope covers the supply of materials and the installation works for a 155kV three-core HVAC submarine cable system (total length: 15km, route length: approximately 6.5km) connecting the offshore substation of Innogy Nordsee 1 Offshore Wind Farm and the offshore converter platform of the offshore wind farm in Germany.