Offshore Construction on Japan’s First Large-Scale Commercial Windfarm

offshoe construction on Japan's first large windfarm
Seajacks Zataran docked in Japan preparing for foundation installations (MOL)

Published Apr 29, 2021 2:21 PM by The Maritime Executive

The offshore portion of the construction work for Japan's first large-scale commercial windfarm project is commencing. Located in the Sea of Japan, the project is expected to be completed by the end of 2022.

The Seajacks Zaratan, owned by a Japanese subsidiary of Seajacks International in which Mitsui O.S.K. Lines (MOL) is also an investor, recently docked in the port of Akita. The vessel, which is a self-elevating platform ship (SEP) specially outfitted to support the construction of offshore windfarms, will be used for the installation work for the foundations for the dual projects off the ports of Akita and Noshiro. The Japanese subsidiary of Seajacks along with the Kajima Corporation is handling the installation of the foundations and later the wind turbines.

Onshore preparation and construction for these projects began a year ago under the management of the Akita Offshore Wind Corporation.  In addition to the construction of the turbines, the project consists of an onshore substation and transmission lines.

Each location will use turbines fixed to the ocean floor with a total annual electrical output of 140MV from the wind farm. At Akita Port, the project will consist of 13 4.2MW wind turbines and at Noshiro Port there will be a total of 20 4.2MW wind turbines.  The electrical power produced from the project will be sold to Tohoku Electric Power Co. under a 20-year power purchase agreement.

The project is seen as a symbolic first step in Japan’s ambitious goals to develop its offshore power industry. In December 2020, the Japanese government announced a goal of generating up to 45 gigawatts of electricity from offshore windfarms by 2040. Based on current projections for the global industry, Japan would be the world’s third-largest generator of offshore wind power.

This phase of the construction is also the next step in MOL’s move into the renewable energy business field through involvement in the installation of offshore wind power generation systems. In 2017, MOL announced its investment with Seajacks for five SEP vessels to be potentially used in the installation of offshore shore energy plants. Since then, MOL has also announced the launch of a business to build and charter a service operation vessel (SOV) to provide maintenance support for the offshore windfarms. The first contract is for the Greater Changhua Wind Farms in Taiwan and MOL anticipates expanding the business to support Japan’s emerging offshore windfarms.