Japan is accelerating the deployment of offshore wind power, and one of the most symbolic projects in this effort is the Yamagata Yuza Offshore Wind Power Project. This initiative is part of the Japanese government’s third round of offshore wind power auctions—commonly known as “Round 3”—and represents a critical step toward achieving the national targets of 10 GW of offshore wind capacity by 2030 and 30–45 GW by 2040.
With a total planned capacity of 450 MW, the project will significantly contribute to the decarbonization of Japan’s energy mix through fixed-bottom offshore wind power. It is also expected to drive regional industrial development and economic revitalization. This article provides a detailed overview of the project, including installation locations, site conditions, and schedules.
➡ For an overview of all ten Promotion Areas as of 2025, see:
Promotion Areas for Offshore Wind in Japan – 2025 Overview
1. Project Overview
| Project name | Yamagata Yuza Offshore Wind |
| Developer | Yamagata Yusa Offshore Wind LLC |
| stakeholders | Marubeni Kansai Electric Power BP Iota Holdings Limited TOKYO GAS Marutaka CORPORATION |
| Location | Offshore Yuza town, Yamagata Prefecture |
| Type | Fixed-bottom Offshore Wind Power |
| WTG | SGRE |
| Price | 3 JPY/kWh |
| Capacity | 450 MW (15 MW × 30 turbines) |
| Start of Construction | November 2027 |
| Operation Period | June 2030 –2055 |
2. Location and Site conditions
2-1. Wind Conditions
The wind speed within the zone is approximately 7.0–8.0 m/s (at 100 m altitude).
2-2. Water Depth
Within the zone, approximately 15% of the area has a water depth of less than 15 m, approximately 65% is less than 30 m, and approximately 80% is less than 35 m.
The deepest point within the zone reaches approximately 41 m.
2-3. Seabed Conditions
No exposed bedrock has been confirmed within the zone.
Regarding the soil properties at cone penetration test investigation points, the layer down to approximately 6 m from the seabed surface consists of loose sandy soil. Below that, sandy soil layers continue as the dominant formation, transitioning to densely compacted sandy soil as the primary stratum from approximately 20 m depth.
2-4. Port Infrastructure
Sakata Port is planned to be utilized as the construction base port.
3. Project Overview
3-1. Consortium Members
Marubeni Corporation
A leading general trading company with the most extensive track record in offshore wind power in Japan.
Kansai Electric Power Co., Inc.
One of the largest electric power companies in Japan.
BP Iota Holdings Limited
A global top-tier international energy company.
Tokyo Gas Co., Ltd.
Japan’s largest gas utility and a leading new power supplier.
Marutaka Co., Ltd.
One of the largest general construction companies based in the Shonai region.
3-2. Project Implementation Structure
Construction Phase
Source: Public document by the Agency for Natural Resources and Energy, METI
Operation Phase
Source: Public document by the Agency for Natural Resources and Energy, METI
4. Project Schedule
4-1. Overall schedule
- January 24, 2022: 1st Statutory Council Meeting
- September 2, 2022: 2nd Statutory Council Meeting
- December 19, 2022: 3rd Statutory Council Meeting
- March 29, 2023: 4th Statutory Council Meeting
- November 17, 2025: 5th Statutory Council Meeting
Development & Design Phase (2024–2027)
- December 2024: Award of Public Auction
- Environmental Impact Assessment, Wind Conditions, Wave and Seabed Geological Surveys
- Local Stakeholder Consultations and Coordination
- Wind Farm Certification and Construction Plan Submission
Construction Phase (2027–2030)
- November 2027: Construction of Onshore Substation and Transmission Infrastructure
- March 2029: Installation of Offshore Foundations and Cables
- July 2029: Turbine Assembly and Installation
Operation & Maintenance Phase (2030–2055)
- Turbine Maintenance: SGRE
- Operation Management (BOP): SPC
Decommissioning & Repowering Phase (Post-2055)
Source: Public document by the Agency for Natural Resources and Energy, METI
4-2. EIA status
| 事業名称 Project name | 事業者名 Developer | 手続段階 EIA Stage | 容量 Capacity | 基数 Turbines | 出力 Rating | 更新日 Last Updated |
|---|---|---|---|---|---|---|
| （仮称）山形県遊佐沖洋上風力発電事業 Yuza Offshore Wind Project | 遊佐沖洋上風力発電に係る環境アセスメント共同実施コンソーシアム Consortium for Joint Implementation of Environmental Assessment for Yuza Offshore Wind Power Project | 方法書 Method Statement | Up to 450MW | Up to 52 | 9.5 – 15MW | 2025/3/25 |
| （仮称）山形県飽海郡遊佐町沖着床式洋上風力発電事業 Fixed-Bottom Offshore Wind Power Project off Yuza Town, Akumi District | 伊藤忠商事株式会社 ITOCHU Corporation | 配慮書 Scoping Document | Up to 494MW | Up to 52 | 9.5 – 15MW | 2022/04/05 |
| （仮称）遊佐洋上風力発電事業 Yuza Offshore Wind Power Project | 日本風力開発株式会社 Japan Wind Development | 方法書 Method Statement | Up to 500MW | 36 – 46 | 9.5 – 15MW | 2022/03/22 |
Source: Environmental Impact Assessment Case Information (Ministry of the Environment, Japan)
5. LCOE and IRR Estimation
Evaluating the bankability of offshore wind projects requires close attention to key cost indicators such as LCOE (Levelized Cost of Energy) and IRR (Internal Rate of Return). However, in Japan’s Promotion Zones, detailed project-level cost information remains limited in publicly available materials. As a result, investors and developers often lack sufficient data to form a fully informed assessment.
To address this gap, DeepWind applies a proprietary cost model using representative site conditions for each project, including wind resource (capacity factor), water depth, distance to port, and distance to grid connection point. Based on these input parameters, we estimate CAPEX, OPEX, LCOE, and IRR in a consistent framework.
This approach allows us to provide a cross-project comparison of the relative economic positioning of Japan’s Promotion Zone projects.
▶ For the latest model assumptions and updated relative positioning, please refer to the cost analysis Pillar article below.
👉 Cost Realities of Japan’s Offshore Wind: Analyzing LCOE and IRR Across 12 Promotion Zones (Latest Edition)
Conclusion
Yamagata Yuza Offshore Wind Power Project represents a significant milestone in Japan’s push for renewable energy. With a strong focus on sustainability, economic development, and technological innovation, it lays the foundation for the expansion of offshore wind power in Japan.
To explore how this area compares nationally and understand Japan’s offshore wind roadmap, visit:
Promotion Areas for Offshore Wind in Japan – 2025 Overview —
your guide to Japan’s offshore wind Promotion Areas.
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- 🌊Projects – Get an overview of offshore wind projects across Japan’s coastal regions.
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- 💡Cost Analysis – Dive into Japan-specific LCOE insights and offshore wind cost structures.