As we aim to realize a decarbonized society, Japan, surrounded by the sea, is said to be a country with high potential for the introduction of offshore wind power generation. On the other hand, Japan has not had much of an "offshore industry" to date, and is still in the process of accumulating its know-how. Against this backdrop, why did you launch Horizon Ocean Management (HOM), which focuses on the maintenance of offshore wind power generation facilities? We also asked them about the current status of offshore wind power generation and the challenges it faces.

Imatomi: The introduction of renewable energy is essential to realize a de-carbonized society. Among these, offshore wind power is said to be the trump card for renewable energy because it can be introduced on a large scale offshore and its generating cost has been decreasing compared to other power sources, making it a competitive power source. Given the recent geopolitical risks, the ability to produce energy in resource-poor Japan is also a major attraction.

Imatomi: Yes. From the standpoint of wind conditions and other factors, Japan's offshore wind power potential is among the highest in Asia. According to some estimates, Japan has the potential to generate about twice as much electricity as its electricity demand.

Imatomi: The reason Europe is ahead of other countries is that it has long been involved in the offshore industry, including oil and gas drilling, and has accumulated knowledge in this area. This knowledge, including not only equipment but also human resources and engineering, has been transferred to offshore wind power. Japan, on the other hand, has almost no offshore industry and needs to acquire new knowledge. We have sufficient technological capabilities, manufacturing know-how, and meticulous services, so I think it is important for us to develop our business on a larger scale in the future.

Imatomi: It can take as long as 10 years from the planning stage to the start of operation. As for costs, 1 GW of power generation capacity, which is equivalent to one nuclear power unit, is estimated to cost 200 billion yen. In actual projects, I believe that most projects have a generating capacity of 0.3 to 0.5 GW and a cost of 100 billion yen. It is said that about 30% of the cost is the initial cost such as design and materials and equipment, and about 70% is the service cost such as maintenance and management.

Nishida: Offshore wind turbines are precision machines consisting of nearly 20,000 parts. Therefore, it is important to maintain and manage these components to ensure stable power generation. Although some parts can be manufactured domestically, there are currently few parts made in Japan, and the government aims to cover 60% of the total cost, including parts, domestically by 2040. We established Horizon Ocean Management in part because we believe that providing a stable long-term energy supply through the maintenance and management of offshore wind power generation is also in Japan's national interest.

Imatomi: We have been supplying steel products to oil and gas companies for some time. In the course of our work, we have witnessed a shift by oil drilling companies to offshore wind power generation. In 2012, we invested in the Global Energy Group of Scotland, which was looking at wind power generation as a new industry at a time when oil energy was still the main source of energy.

Nishida: Looking at Japan in light of the trends in Europe, I felt that many companies are not aware of the maintenance of offshore wind turbines, which will be a problem for power generators in the future. In addition, in order to undertake maintenance, they have to deal with all kinds of malfunctions of offshore wind turbines. Long-term maintenance is required to develop a project for 10 years at most, and to operate it for 20 years or more after completion. Conversely, we hoped that through maintenance we would be able to acquire a great deal of knowledge about offshore wind power, from which we could expand our business.

Nishida: There are many difficulties, such as traveling to the site by ship, maintenance in unstable locations, handling precision equipment that is prone to failure, locating failure points among 20,000 parts, and maintenance of wind turbines by climbing higher than a skyscraper. In addition, submarine power lines are prone to accidents such as ship anchors getting caught in them, and maintenance is sometimes performed underwater. Although drones are used on the surface, much of the work is done manually, and offshore wind turbine maintenance requires skills and experience that are not without risk.

Nishida: In "business structuring," an O&M (Operation & Maintenance) strategy is a long-term operational plan for 20 to 30 years. Maintenance of offshore wind power is risky, so the O&M strategy is one of the most important parts of the plan. In procurement and manufacturing, we inspect the manufacturing process of components to ensure that there are no errors (material and equipment inspection). Transportation" includes inspections of structures at ports of loading and unloading, acceptance inspections in Japan, and tracking of raw materials. Installation" includes inspection and repair services of foundation structures in base ports and at sea. We are able to provide such consistent services because of the knowledge we have gained through our maintenance experience.

Nishida: Wind power generation has grown from 1-2 MW/unit in the past to 14 MW/unit recently. HOM is currently working with about 20 companies in Japan and overseas to provide maintenance services, but it may be necessary to accumulate more knowledge from the perspectives of "preventing accidents and breakdowns," "ensuring stable operation by taking appropriate measures when they occur," and "addressing issues that are yet to be seen. It may be necessary to accumulate more knowledge from the perspectives of "preventing accidents and failures," "properly responding to incidents and ensuring stable operation," and "addressing issues that have not yet been identified.

Imatomi: What is often referred to are the 3 S's (Scale, Speed, and Sustainability). Sustainability here means "sustainability" and "predictability". Since project development takes a long time and the investment is huge, the perspective of Sustainability is important, and maintenance can be seen as critical.

Nishida: Offshore wind power is in its infancy not only in Japan but also worldwide, and the United States and other Asian countries such as Taiwan, Vietnam, and South Korea are also making efforts. Japan has top-class wind power generation potential, so we would like to take the lead in accumulating knowledge in the three Ss and expand from Japan to the rest of the world.

Imatomi: First of all, I would like to contribute to the development of offshore wind power generation, which is called the trump card of renewable energy. In addition, as I mentioned at the beginning of this presentation, I would like to realize self-sufficiency in electric power in Japan, a country with few natural resources.