This article introduces a project overview of the Chiba Isumi Wind, which has been designated as a “Promising Zone” under Japan’s Act on Promoting the Utilization of Sea Areas for the Development of Marine Renewable Energy as of October 2025.
The information will be updated as new details become available based on publicly accessible sources.
Other “Promising Zones” can be found in Japan’s Offshore Wind “Promising Zone” Projects — Candidate Areas for Auctions.
1. Project Overview
| Project name | TBD |
| Developer | TBD |
| Consortium Members | TBD |
| Location | Offshore Isumi City, (Chiba) |
| Type | Fixed-bottom offshore wind power |
| WTG | TBD |
| Supply price | TBD |
| Capacity | Approx. 400 MW |
| Start of Construction | TBD |
| Operation Period | TBD |
2. Location
2-1. Sea & Geographical Features
2-2. Port Infrastructure & Grid Connection
3. Consortium Members
4. Project Implementation Structure
5. Project Schedule
5-1. Overall schedule
5-2. EIA status
| Prefecture | Project name | Developer | EIA Stage | Project Scale | Last updated |
|---|---|---|---|---|---|
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Mitsubishi Corporation Offshore Wind Ltd. | Scoping Document | Total output: approx. 520 MW Turbine capacity: 12–15 MW per unit Number of turbines: up to 40 units | July 7, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Renova, Inc. | Scoping Document | Total output: up to 450 MW Turbine configuration: 9.5 MW × 47 units to 15 MW × 30 units | June 3, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Chiba Offshore Wind Power Co., Ltd. | Scoping Document | Total output: up to 500 MW Turbine capacity: 12–16 MW per unit Number of turbines: up to 40 units | June 3, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Isumi Offshore Wind Power G.K. | Scoping Document | Total output: approx. 564 MW Turbine capacity: 12–15 MW per unit Number of turbines: up to 47 units | June 3, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Mitsui & Co., Ltd.; RWE Renewables Japan G.K.; Osaka Gas Co., Ltd.; K&O Energy Group Inc. | Scoping Document | Total output: up to 495 MW Turbine capacity: 12–15 MW per unit Number of turbines: 33–42 units | June 3, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | TEPCO Renewable Power, Inc. | Scoping Document | Total output: up to 660 MW 15 MW × up to 44 units, or 20 MW × up to 33 units | June 3, 2025 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi | Isumi Offshore Wind Power Generation Co., Ltd. | Scoping Document | Total output: up to 696 MW Number of turbines: up to 74 units Turbine capacity: 9.5–20 MW per unit | December 13, 2022 |
| Chiba | (Tentative name) Offshore Wind Power Project off Isumi City | Green Power Investment Corporation | Scoping Document | Total output: up to 630 MW Turbine capacity: 14 MW per unit Number of turbines: up to 45 units | June 21, 2022 |
6. CAPEX/OPEX Estimates
Summary
Other “Promising Zones” can be found in Japan’s Offshore Wind “Promising Zone” Projects — Candidate Areas for Auctions.
Weekly digest with actionable insights for investors, developers, and stakeholders in Japan’s offshore wind. 🎁 Welcome gift: Japan Offshore Wind: 2025 Market Outlook (PDF)📩 DeepWind Weekly
- 🔍Market Insights – Understand the latest trends and key topics in Japan’s offshore wind market
- 🏛️Policy & Regulations – Explore Japan’s legal frameworks, auction systems, and designated promotion zones.
- 🌊Projects – Get an overview of offshore wind projects across Japan’s coastal regions.
- 🛠️Technology & Innovation – Discover the latest technologies and innovations shaping Japan’s offshore wind sector.
- 💡Cost Analysis – Dive into Japan-specific LCOE insights and offshore wind cost structures.
