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Nippon Steel Engineering uses Sesam in developing Japan's offshore wind projects

Offshore wind is seen as a key part of Japan’s strategy to transition to cleaner energy sources.

The opportunity and challenge

In 2018, the Japanese government announced plans to generate 30-45 GW of wind power by 2040, with 10 GW of that coming from offshore wind. This was followed by the launch of the country’s first offshore wind auction in 2019, which resulted in several large-scale projects being awarded to developers. No doubt, Japan’s offshore wind market is relatively new but rapidly growing, primarily driven by Japan’s commitment to reduce its dependence on nuclear power and fossil fuels in the wake of the Fukushima disaster in 2011. 

However, there are also real challenges facing the market, including a lack of experience and infrastructure for offshore wind development as well as the harsh marine environment with earthquakes and typhoons. 

Engineers in Nippon Steel Engineering take the challenges 

Nippon Steel Engineering is the engineering company representing the NIPPON STEEL GROUP. The company is developing the plant equipment technologies and steel utilization technologies that have been amassed in the steel manufacturing industry to promote social and industrial infrastructure projects across the globe.

In recent years, Nippon Steel Engineering has been a key player in the offshore wind industry, focusing on developing new technologies and products leveraging its expertise in steel structural manufacture and its commitment to innovation to help accelerate the global transition to renewable energy.

The company has developed a range of high-performance steel products specifically designed for offshore wind turbines. These products include large-diameter steel pipes for foundations, as well as steel towers and other components that can withstand the harsh marine environment.

In addition to producing steel products for offshore wind turbines, Nippon Steel Engineering is also involved in wind farm development. The company has formed partnerships with several offshore wind developers in Japan and elsewhere, providing technical expertise and other support to help bring new wind projects online.

Rise to the challenge

"As a wind turbine foundation designer at Nippon Steel Engineering, my job is to ensure that the structures we design can withstand the harsh environmental conditions of offshore wind farms in the 20 plus service years. To do this, I use DNV’s Sesam software," Yuta Nakano, Marine Engineering & Construction Division, said. 

Sesam’s analysis tools help engineers simulate how the structure will behave under different environmental conditions. The analysis provides design support and can show if the structure will experience excessive stresses or vibrations, which could lead to fatigue and failure over time. If any potential issues are identified, users can quickly adjust the design and run the simulation again until they are confident that the structure will perform as intended. 

Sesam’s Offshore Wind package is one of the most commonly used solutions by Nippon Steel Engineering, and it has become an essential part of their design work. "I use Sesam, which has a strong and rich modeler module. It helps me with wind-wave analysis and conducting design surveys based on globally authorized ISO standards, which has made designing seamless and easier. The good thing about Sesam is that it can automatically process results, which is especially important when designing for fatigue. I specifically like the software feature as it allows me to assign colors to sections and visually check the model," Nakano san said. "As the Ishikari Offshore Wind Farm’s design party, we need to conduct an analysis of tens of thousands of cases, which can take a few months if we process the data on our own local PCs. However, using the Sesam Cloud service, we can run several thousand cases simultaneously and complete the analysis overnight or within a day, shortening the design period by a few months. This has helped us in submitting deliverables to clients confidently, as Sesam was developed in accordance with international standards, such as ISO and DNV standards, and allows us to conduct analysis in accordance with such standards," Nakano san said.

Nagisa Fukuda, Marine Engineering & Construction Division, said: "I have been using Sesam for my offshore wind turbine foundation design work for the past few years. My primary goal is to complete the design work quicker and more efficient, and Sesam helps me achieve this through its cloud computing functions and user-friendly interface." It allows engineers to design offshore wind structures that are safer, more reliable, and more cost-effective, which is crucial in the highly competitive offshore wind industry. "Sesam has already become an essential part of our design work." Fukuda san said.

Are the standards "good enough" for a good design?

"Standards are based on a lot of trials and research, but it is important that we have further verification," Fukuda san said. The challenges of designing a jacket structure for offshore wind turbines include fatigue design and analyzing and evaluating wind turbines to ensure they do not collapse during earthquakes, which is a difficult issue unique to Japan. 

For smaller structures engineers can conduct trials to verify the validity of the design analysis. However, actual offshore wind structures are very large, and trial methods are quite limited. "It is very important to know whether the results are valid or not, so I think it is important to use a program that has been thoroughly verified for validity, such as Sesam." 

Sesam is a proven solution for designing offshore wind turbine foundations and is compatible with wind turbine manufacturers' design programs.

The onboarding process, the webinars, trainings, and technical support

Nippon Steel Engineering has been using DNV's training programs for new employees and members assigned to departments that use Sesam. In addition to that, DNV’s technical webinars and well-documented tutorials and manuals have been very helpful in learning how to use Sesam effectively.

"We have also developed in-house training and tutorials within the department in Japanese. In this way, experienced users can transfer knowledge to each other. We plan to continue using Sesam for offshore wind projects and approach new projects to win more orders," Nakano san said. "The well documented tutorials and manuals make it easy to understand Sesam’s functions. Also, the customer support system is well organized, so if you have a specific question, the customer support staff will answer it immediately. Especially when we onboarded Sesam for our first wind project, we had a lot of questions. We were able to get answers in a very timely manner, and I think that was very good," Fukuda san said. Sesam software empowers wind engineers to deliver reliable work when it matters.

Leaning towards future

"Leaning towards the future, we are thinking of developing more efficient design and exploring floating type of offshore wind structures for economic reasons. Sesam has piloted in the design flow for floating offshore wind turbine foundations, and we are in the process of developing a design flow for floating offshore wind structures," Fukuda san said.

"We are aiming for sales of 100 billion yen in 2030 in the offshore wind turbine-related business. To achieve this goal, it will be important for us to carry out the design work quickly and efficiently. I believe that using Sesam software is indispensable for the company."


Began as the engineering division of Nippon Steel Corporation in 1974. Over a period spanning 40 years since the foundation, the company have expanded the operating bases to countries and regions outside of Japan such as China, Southeast Asia and India. Nippon Steel Engineering work globally, responding to the needs of various steel industry, energy industry, government, local authority, and private sector clients from each of the territories.


  • Customer name: Nippon Steel Engineering
  • Website:
  • Market: automotive, construction and energy industries
  • Product: Sesam


Why we chose DNV:

  • Industry-standard for offshore wind turbine foundations
  • Widely used in Europe, matured and proven solution
  • Compatibility with wind turbine manufacturers’ design programs

This is what we gained:

  • Rapid analysis with cloud computing capabilities
  • Ability to process large model
  • Streamlined design processes

My primary goal is to complete the design work quicker and more efficient, and Sesam helps me achieve this through its cloud computing functions and user-friendly interface.

  • Nagisa Fukuda ,
  • Offshore Wind Design & Engineering Section ,
  • Nippon Steel Engineering

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Nippon Steel Engineering uses Sesam in developing Japan's offshore wind projects

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