Sumitomo Corporation traces its history back to The Osaka North Harbour Co., Ltd. established by Sumitomo Head Office in 1919. With six business units and regional organizations, Sumitomo Corporation operates globally and has been in the offshore wind farm business since 2014.
Sumitomo Corporation is involved in the development and operation of three offshore wind farms in Belgium, two in the UK and two in France. Northwester 2 Offshore Wind Farm is the company’s fourth joint project with Parkwind N.V.
There is an upswing of interest in having offshore wind farms play a growing role in Japan’s energy sector. They efficiently transform wind power into electricity without spoiling the landscape or seascape and with less noise pollution. Since wind power generation is such an excellent fit with the needs of our planet, the technology has a bright future. Eager to know more about wind power generation, I went on my first “online visit.” The more I heard about this offshore wind farm, the more fascinated I became. Once I had connected Belgium and Japan over the Internet, I was able to take a virtual trip to Belgium to see the wind farm. It was great fun!
Northwester 2 Offshore Wind Farm developed and constructed by Sumitomo Corporation came on stream in May 2020. Located in the North Sea, 52 kilometers off the Belgian coast where the sea is about 40 meters deep, the wind farm comprises 23 units of V164-9.5MW, the world’s largest mass-produced wind turbine*, manufactured by MHI Vestas in Denmark. With 9.5MW power generation capacity, this wind turbine is a giant towering 180 meters above the ocean. And with total power generation capacity of 219MW, the wind farm can fulfill the electric power needs of 210,000 households. What a magnificent view of white wind turbines soaring above the blue ocean.
Sumitomo’s partner, Parkwind, develops and operates offshore wind farms and is a member of the Colruyt Group, Belgium’s largest operator of supermarkets. Parkwind originally entered the offshore wind farm business to meet the electricity needs of Colruyt Group’s stores, numbering roughly 1,000, with renewable energy. What a great idea! I was moved. Mr. Motoo Shimada of Sumitomo Benelux, who works in Belgium, explains, “Since the EU aims to achieve zero emissions of greenhouse gases by 2050, the take-up of renewable energy has considerable momentum among EU member countries.” And among the various types of renewable energy, interest in offshore wind power generation is particularly strong, leading to more and more wind farms.
as of August 2020
Great stretches of the seas off Europe are shallow. Even 90 to 100 kilometers offshore, the depth may be only 30 to 40 meters. Since the turbines are on piles driven into the seabed, shallow seas are ideal for offshore wind farms. So the seas lapping the coast of much of Europe are blessed with geographical conditions suitable for offshore wind power generation. Moreover, thanks to technological innovation, larger wind turbines are becoming available, making it possible to harness the wind so as to produce amounts of electricity comparable to those derived from thermal or nuclear power generation.
But the task of erecting huge wind turbines in the hazardous offshore environment must be dangerous and difficult. How is it done?
“Although we have excellent equipment that makes full use of state-of-the-art technology, we always respect and are attentive to the forces of nature. Before using a crane, the crew gathers to reconfirm the procedure. We check the strength of the wind before starting work. If, in the course of work, the wind velocity exceeds a certain threshold, work is immediately halted. Our operational procedures, including safety, are verified by a third-party certification body. Before we start construction, our operational procedures and safety criteria have to be certified,” says Mr. Shimada.
The four pillars are used to jack up the vessel during pile driving to form the foundation for a wind turbine in the seabed.
And these four support legs resting on the seabed are jacked down to elevate the vessel above the sea surface. The yellow unit is the foundation of the wind turbine. Even though the tower is 100 meters tall, adjustment is carried out in centimeters when tightening bolts. During installation, the vessel is jacked up to prevent the impact of waves, thus ensuring the stability necessary for the work.
The crew lives on the vessel. All crewmembers have their own rooms with an en-suite shower and toilet. Communal facilities include a gym and a sauna. It looks comfortable. Crewmembers spend two weeks aboard, followed by a spell ashore for rest and recuperation. There is a chef on board who prepares delicious, nutritious meals. Mr. Soichiro Nakano of the Power Infrastructure Dept. No. 2, a department responsible for Sumitomo Corporation’s overseas renewable energy business, has worked on this vessel. “You may imagine that offshore construction is largely done by rough and ready men with a seafaring background. In reality, crews are a diversified group of people. Each crewmember has a role and everyone cooperates to ensure the work proceeds safely and smoothly. Nevertheless, the weights in the gym are heavy. They must be designed for big strong person, they were not for me,” says Mr. Nakano with a smile.
The well-equipped gym includes running machines and exercise bikes so that crewmembers can stay in trim while refreshed by the sea breeze.
There are always about 80 crewmembers on board. Work is done in two shifts around the clock. The environment is challenging and the work demanding. Mr. Nakano says, “To work on an offshore wind farm project, you need to have a license certified by the Global Wind Organisation (GWO). You have to be trained and know what to do if an accident occurs offshore, including survival and rescue techniques at sea and actions to be taken in the event of fire. Although everything about an offshore wind farm is on a gargantuan scale, attention is paid to the smallest details. This meticulous approach is also evident in all matters relating to the environment.
“In order to minimize the impact on marine life, a bubble curtain is created around the foundation when pile driving into the sea bed as a noise mitigation measure. A large ring is laid around the construction site underwater on the seabed to generate air bubbles, which form a curtain that reduces noise. We also take steps to protect seabirds. Based on observation of migratory birds, when selecting sites for wind turbines, we avoid their customary routes,” explains Mr. Shimada. With sustainability as their watchword, offshore wind farms like this are clean energy systems with impeccable environmental credentials. Marine life, birds, and wind turbines can all flourish. It is a vision that I find deeply appealing.
Offshore wind power generation is expected to grow and flourish in the EU, where it is not only attuned to rising environmental awareness but also promises to deliver substantial economic benefits. As the technology advances, I am sure that the Japanese archipelago will be dotted with a growing number of offshore wind farms. I cherish the hope that in the coming years Sumitomo Corporation will find many opportunities to utilize in Japan the experience in the offshore wind power generation business that it has gained in Europe. That is my key takeaway from this first online visit.
Construction work continues around the clock as long as the wind is low and the sea calm. Since such offshore conditions are typical in European coastal waters during the summer, that is when most of the installation and maintenance work is done.
Technological innovation of offshore wind power generation never stops!
The number 164 in the wind turbine model name “V164-9.5MW” is a reference to the 164-meter rotor diameter, which is about half the height of Tokyo Tower (333 meters). The scale is on a par with that of a high-rise building. This propeller-type wind power generation system is the most suitable for such a big wind turbine. The wind rotates the blades, the gearbox increases the number of rotations to the number necessary for power generation, and the generator converts rotational energy into electric energy. The development of larger wind turbines and new technologies has been accelerating in recent years. Whereas the current mainstream offshore wind turbines are those with a foundation fixed to the seabed, wind turbines mounted on floating platforms have also emerged. Technological innovation continues at a brisk pace.
Wish we could control the weather!
Editor’s note
In February 2020, when installation of wind turbines for Northwester 2 Offshore Wind Farm took place, the strongest winds those working on the project had ever experienced whipped up the waters of the North Sea for days. For other wind farms in operational phase and already generating electricity, the windy conditions were of course good news. But for Northwester 2 Offshore Wind Farm, the weather slowed the progress of construction. On top of that, Belgium went into lockdown in response to the COVID-19 pandemic. On learning of the successful completion of the wind farm in these challenging circumstances, the editorial team broke into spontaneous applause. From the scudding clouds and breaking waves in the photos taken during the installation work, one can get a sense of how blustery the weather was. Meanwhile back in Brussels even the famous Manneken Pis, the capital’s much-loved signature statue, wore a mask!
Number(Manga Reportage "Visits to Sumitomo Group")
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