Offshore wind foundations | Sif X Kajima Corporation

In 2020, Kajima Corporation, one of Japan’s largest construction firms, selected Dutch manufacturer Sif to provide the monopile foundations for the Akita Noshiro offshore wind farms, the first commercial-scale offshore wind project in Japan. This is both the first contract in Japan for Sif, and the first major offshore wind construction project for Kajima. The wind farms, that will provide the energy equivalent to 130000 households, are set to begin operation in 2022.

The partners

Sif, a Dutch leader in offshore foundations

Sif was founded in the Netherlands in 1948 and is now among the largest steel tubular manufacturers worldwide for foundations for offshore wind farms and oil & gas platforms. Over its 70 years of history, the company has produced more than 1700 foundations. Sif employs 600 people and operates a 42 hectares assembly and storage facility in the Port of Rotterdam.

In the offshore wind sector, Sif’s products - monopiles up to 11 meters, used to support the offshore wind turbines - are being used for the foundations of nearly 60 projects located in the UK, France, Denmark, the Netherlands, Belgium and Germany. Sif provides its components to leading European energy firms and developers such as Orsted, Vestas, Eon and Vattenfall. Besides monopiles, Sif also manufactures transition pieces, which carry elements such as boat landings, ladders and platforms, attached to the monopile foundation.

At the moment, Sif is mainly active in north-western Europe, but the company plans to expand its business internationally. It opened its sales office in Japan in 2019.

Kajima Corporation, 180 years of experience in construction

Founded in 1840, Kajima Corporation is one of the oldest and largest construction companies in Japan, with nearly 8000 employees. Its services include design, engineering, construction and real estate development. Over the last 20 years, Kajima also expanded its operations to the environmental sector.

Early in its history, the company developed links with the West. Its founder, carpenter Iwakichi Kajima, built the first western-style building in Yokohama in 1860 and the first offices in Japan of several Western trading firms. Today, Kajima Corporation has subsidiaries in Asia, Oceania, Europe and North America. In Europe, Kajima operates its construction business in Poland and the Czech Republic, and its property investment and development business in the U.K. and France.

In the offshore wind, Kajima was the general contractor for the first fixed-foundation turbine in Japan, in 2013. It is currently in charge of the engineering, procurement, construction and installation contract for the Akita Noshiro project, the first commercial-scale offshore wind farm in Japan. It was also awarded in 2020 the construction contract for Akita Yurihonjo, a project set to become operational in 2024.

The partnership: Building the foundation for the first commercial offshore wind project in Japan

Concept view of Akita Port wind farm, set to open in 2022 (photo: AOW)

Located in the northern part of Japan’s main island Honshu, Akita Noshiro is the first commercial-scale offshore project in Japan, with a planned capacity of 140 MW provided by 33 turbines supplying the energy equivalent to 130000 households. Comprising two wind farms (Akita Port and Noshiro Port) and valued at around 100 billion yen (830 million euros), it is planned to be operational in 2022. The construction, operation and maintenance are supervised by Akita Offshore Wind, a consortium of Japanese companies established in 2016 by trading house Marubeni.

Kajima Corporation was awarded by Akita Offshore Wind the contract for the engineering, procurement, construction and installation of the project. It is the first significant offshore wind contract for the 180 years old construction firm.

In March 2020, Dutch manufacturer Sif signed a contract with Kajima Corporation to manufacture the monopiles and transition pieces for the Akita Noshiro project. On the occasion of this first contract for a project in Japan, Sif CEO Fred van Beers declared: “This is an important milestone and a confirmation that 5 years of investment in building up strong business relations in the developing Japanese offshore wind market has paid off”.

The Dutch company is in charge of manufacturing 33 monopiles and transition pieces - representing a total of 25000 tons of steel. The first 9 monopiles arrived from Rotterdam to Akita in January 2021, allowing the start of the construction of the offshore foundation that will support the turbines. 

The company CEO’s commented: “Sif is evaluating the development of the Japanese offshore wind market for some years now. Sif recognizes the ongoing development of offshore wind in Japan and therefore has decided to open a sales office in Tokyo in 2019 to study further expansion of Sif’s business activities in Japan. This first delivery of Sif monopiles to Japan is an important milestone for us.”

Besides its Dutch monopiles, the Akita Noshiro wind farms will have other European dimensions: the Danish-Japanese joint venture MHI Vestas will supply and maintain the 33 turbines, while the installation vessel will be provided by a British company.

Delivery of the first monopiles in Akita, January 2021 (photo: AOW)

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