Projects id Formidable Social Challenges Challenge to Spread the Use of Renewable Energy— Underpinning the largest wind farm in Japan —

To Ensure a Stable Supply of Large Amounts of Electricity — Sumitomo Electric’s front-line capabilities to give shape to design —

Construction work to bury power transmission lines

The construction work was performed even in the severe cold of winter

The construction work was performed even in the severe cold of winter

Construction work to bury power transmission lines

Underground power transmission cable

Underground power transmission cable

The maximum number of on-site staff was about 500.

The maximum number of on-site staff was about 500.

To offer the functionality of the group companies
as a package

The Sumitomo Electric Group was preparing for commencement of the construction of Wind Farm Tsugaru, but it had not officially received an order. First, an order was placed for construction of the wind farm. Kajima Corporation, a major general contractor, received the order as an EPC contractor. EPC stands for engineering, procurement and construction, and refers to a project construction contract. It had been cooperating with GPI, as had the Sumitomo Electric Group, from an early stage in terms of the layout of wind turbines and construction design. Thus, the Sumitomo Electric Group had to receive an order from Kajima for the transmission and transformation equipment and construction. Masanori Sugiura of the Energy Solution Sales Div. was at the forefront of this process.

“Wind Farm Tsugaru was the first project for us to design the transmission and transformation equipment as a package. We did not have any in-house precedents or experience, so we faced obstacles when we conducted various studies. I remember searching for solutions blindly with cooperation from the personnel involved. I was in charge of negotiations and consultations with Kajima. This was also the first time for Kajima to handle a 100 MW-class power transmission system. At first, it was difficult to help them understand our highly technical proposal regarding both power transmission and transformation. We patiently continued to give in-depth explanations. I felt that communication gradually became smoother. Eventually, we could win the contract probably because Kajima highly evaluated our overall capability, including our proposal for the transmission and transformation package, product lineup of power transmission and distribution cables for any voltage, and the top manufacturing and construction capability in Japan to achieve a short construction period. It was in December 2017 when we overcame all technical issues. I had a strong sense of satisfaction that we were able to begin the next phase of this new challenge by taking full advantage of our overall capability, which is the strength of the Sumitomo Electric Group,” said Sugiura.

Finally, construction of Wind Farm Tsugaru began.

Masanori Sugiura Energy Solution Sales Div., Social Infrastructure Sales and Marketing Unit
Masanori Sugiura
Energy Solution Sales Div., Social Infrastructure Sales and Marketing Unit

Collaboration among players in different business fields
— Kajima, Sumitomo Electric and Sumitomo Densetsu

In December 2017, a groundbreaking ceremony was held to mark the start of overall construction. In July 2018, construction work to lay the 154 kV cables commenced. Subsequently, construction of connection equipment and electricity receiving and transformation equipment progressed as needed. Morimasa Akemoto, General Manager, Business Development, Civil Engineering Dept. of Tohoku Branch, Kajima Corporation was in charge of the overall wind farm construction project as the manager of the Wind Farm Tsugaru construction office. Akemoto had experience managing many construction sites before, but this was the largest project ever to undertake a package contract, including construction of the foundation of the power plant, design of the construction method, and construction of power collection, transmission and receiving equipment. This was a highly challenging mission.

“The project was promoted through collaboration among players in different business Fields: Kajima, Sumitomo Electric and Sumitomo Densetsu. I focused on coordination because the corporate cultures and policies were different. There were as many as nearly 60 worksites. We had to construct 38 wind turbines and lay underground power transmission lines for a distance of about 34 km. The number of personnel involved in on-site operations was about 500 at the maximum. In promoting such a big project, I attached importance to creating an atmosphere where workers who participated in the project were able to feel that they were working on a common goal. I wanted to ensure that workers were motivated and glad to be involved in the on-site operations,” said Akemoto.

The Sumitomo Electric Group and Kajima had worked together in past projects. However, this was the first time for Akemoto to work with the Sumitomo Electric Group. What was his impression?

“I must admit that I had confidence in the Sumitomo Electric Group in terms of engineering due to its track record and history. We had some disagreements, but we deeply trusted each other. Mutual trust was built based on a sense of commitment. We shared the same pride and passion, which only highly motivated people have, to complete the project within the schedule with determination and achieve a stable electricity supply. Our project was highly evaluated by GPI thanks to the Sumitomo Electric Group’s efforts to solve difficult technical issues. I hope to work with the Sumitomo Electric Group again on a new wind power generation project, whether onshore or offshore, or within Japan or overseas,” said Akemoto.

Morimasa Akemoto General Manager, Business Development, Civil Engineering Dept. Tohoku Branch, Kajima Corporation
Morimasa Akemoto
General Manager, Business Development, Civil Engineering Dept.
Tohoku Branch, Kajima Corporation

A mission to embody the performance of our products

Sumitomo Densetsu, one of the group companies, played a key role in this project for Kajima. To lay the power collection and power transmission cables, it was necessary to dig up the ground for a distance of about 56 km. The company also formulated a plan to build underground conduits under public roads and studied the civil engineering work of conduits by conducting a survey to select an appropriate route and holding consultations to obtain authorization. Sumitomo Densetsu promptly performed the construction work to lay the cables.

Wataru Sakaguchi of the Power Cable Project Engineering Div. of Sumitomo Electric was assigned to the team for the construction of substations and installation of cables concurrently with the civil engineering work by Sumitomo Densetsu. Sakaguchi joined this project from the survey phase and was officially assigned to the project with the commencement of cable installation in July 2018.

“August 1, 2019 was set as the date for ‘power receiving.’ Installation of transmission and transformation equipment and cables had to be fully completed by this date. Power receiving refers to connection to the grid of the electric power company without power generation. It was necessary to check whether the electrical equipment used for grid connection functioned properly by receiving electricity of 154 kV from the electric power company. This was an important milestone in the construction of the power plant. However, the city receives a lot of snowfall each year, and the construction period was virtually ten months. The schedule was very tight. We were responsible for embodying the performance of our products for delivery to customers. I thought that I could not make a mistake, but I was also confident that there would be no problem if I worked in the same way as I did at other sites. I was in charge of progress management while ensuring safety and quality. I had a strong sense of cooperation with Kajima in this process. At the end of the project, I was told by Manager Akemoto, ‘This project could not be completed without Sumitomo Electric.’ This was the highest compliment I could have received, which certainly gave me a feeling of satisfaction,” said Sakaguchi.

The front-line capabilities of the Sumitomo Electric Group to give shape to design were demonstrated at this site. Wind Farm Tsugaru came into operation and started commercial operation in April 2020.

Wataru Sakaguchi Chief, Tokyo Construction Group Underground Cable Dept., Power Cable Project Engineering Div.
Wataru Sakaguchi
Chief, Tokyo Construction Group
Underground Cable Dept., Power Cable Project Engineering Div.

Construction of a grid connection switching station

To Create a Sustainable Future on a Global Scale
— Showcasing a vision of renewable energy in Japan —