Overview
On March 26, 2026, METI (Ministry of Economy, Trade and Industry), MLIT (Ministry of Land, Infrastructure, Transport and Tourism), and MOE (Ministry of the Environment) published proposed revisions to the Promotion Zone Designation Guideline and the Central Method operational policy for offshore wind development in Japan.
The revisions are driven by the amended Renewable Energy Sea Area Utilization Act, which was enacted in June 2025 and is scheduled to take effect on April 1, 2026. The guideline changes serve as the institutional preparation for that implementation.
Three key changes are introduced:
- Introduction of viability screening indicators for zone selection
- Shift to government-led environmental assessment (centralized EIA)
- Formalization of turbine setback rules from shipping lanes in open-sea areas
This article explains each change and its practical implications based on the original source material.
Note: The proposed revisions will undergo a public comment period, after which a finalized version will be issued.
While this article focuses on a specific topic, those looking to understand Japan’s overall offshore wind policy and regulatory framework should also read our comprehensive summary here:
👉 Japan’s Offshore Wind Policy & Regulatory Framework Explained
1. Viability Screening Indicators
1-1. Background
Until now, the evaluation of commercial viability at the “promising area” screening stage was conducted through a “comprehensive assessment” under the Promotion Zone Designation Guideline, but without explicit quantitative benchmarks.
The revised guideline introduces reference indicators across three dimensions — wind speed, water depth, and onshore transmission line distance — to support a more structured and transparent assessment of project viability at an early stage. The stated objective is to balance the expansion of offshore wind deployment with the containment of public cost burden.
1-2. Reference Indicators
Wind Speed (NeoWins annual average at 140m hub height)
| Threshold | Rating |
|---|---|
| ≥ 8.5 m/s | 1 (Highest) |
| 8.0 – 8.5 m/s | 2 |
| 7.5 – 8.0 m/s | 3 |
| 7.0 – 7.5 m/s | 4 |
| < 7.0 m/s | Requires further scrutiny |
The 7.0 m/s threshold corresponds to a theoretical capacity factor of 35% or above for a 15 MW-class turbine assuming a Rayleigh wind speed distribution. However, areas below 7.0 m/s are not automatically excluded.
Water Depth
| Threshold | Rating |
|---|---|
| 15 – 30m | 1 (Highest) |
| 30 – 40m | 2 |
| 40 – 50m | 3 |
| < 15m | Requires further scrutiny |
| > 50m | Requires further scrutiny |
Bottom-fixed offshore wind is assumed to target water depths of approximately 50–60m or less. Deeper sites are expected to adopt floating wind technology.
Onshore Transmission Line Distance (to grid connection point)
| Threshold | Rating |
|---|---|
| < 10 km | 1 (Highest) |
| 10 – 25 km | 2 |
| 25 – 40 km | 3 |
| 40 – 60 km | 4 |
| > 60 km | Requires further scrutiny |
1-3. Practical Implications
These indicators are not hard cutoffs. They serve as reference values for a comprehensive evaluation of viability — meaning that a “requires further scrutiny” rating on one dimension does not automatically disqualify a zone if other conditions are favorable.
However, the guideline states that areas where viability cannot be sufficiently demonstrated will be subject to continued review of improvement measures. In practice, this means that zones with weaker fundamentals will face higher justification thresholds in future screening rounds.
Additionally, the guideline now explicitly states that even where provisional grid capacity or connection reservations exist, if the grid connection cost is prohibitively high and project viability cannot reasonably be expected, the area will be judged as lacking “appropriately secured” grid access.
2. Government-Led Environmental Assessment (Centralized EIA)
2-1. Problem Under the Previous System
Under the previous framework, environmental impact assessments (EIAs) were conducted individually by each developer. This meant that before promotion zone designation, multiple developers would run parallel scoping and methodology studies for the same area, creating confusion among local communities.
2-2. Revised Process
Under the amended Renewable Energy Sea Area Utilization Act (effective April 1, 2026), the Ministry of the Environment will now conduct marine environmental surveys before promotion zones are designated, rather than leaving this to individual developers post-auction.
The revised process is as follows:
- METI and MLIT notify MOE of the target area’s location and boundaries
- MOE prepares a draft survey methodology document, which is publicly disclosed with explanatory meetings
- Opinions from relevant local governments are collected from the perspective of environmental conservation
- The survey methodology document is finalized, and field surveys are conducted
- Survey results are notified to METI and MLIT and publicly disclosed
- Promotion zone designation decisions are made considering the survey results
As a result, developers are exempted from the scoping and methodology stages of the EIA process. Selected developers will only need to conduct the preparation and evaluation stages of the environmental assessment.
2-3. Survey Scope
The items and methods for each marine environmental survey will be determined on a zone-by-zone basis, taking into account regional characteristics and the specifics of the offshore wind project. Examples of survey items cited in the source material include:
- Characteristics of major viewpoints (landscape impact)
- Bird species habitat and distribution
- Sea turtle nesting site conditions
2-4. Preconditions
The Central Method operational policy sets two preconditions for MOE to proceed with the marine environmental survey:
- The relevant prefecture must have initiated coordination with parties whose operations may be affected (fisheries, shipping routes, etc.)
- The prefecture must remain actively involved in coordinating with local stakeholders even during MOE’s survey process
In other words, while the responsibility for conducting the environmental survey shifts to the national government, the responsibility for local stakeholder coordination remains with the prefectural government.
2-5. Practical Implications
For developers, this change removes one of the highest-cost and highest-uncertainty phases from the pre-auction timeline. The early-stage EIA burden — including scoping, methodology design, and initial field surveys — is now absorbed by the government.
For local communities, the previous confusion caused by multiple developers conducting parallel assessments in the same area is eliminated. The process is consolidated under a single, government-led framework, improving transparency and reducing community fatigue.
3. Shipping Lane Setback Rules
3-1. Background
Setback requirements between offshore wind installations and shipping routes have been part of the promotion zone designation criteria and maintenance standards. However, the existing rules were designed primarily for port zones — areas where vessel navigation is already subject to certain restrictions. No formal guidance existed for open-sea areas where free navigation is the default principle.
With project development activity now emerging in areas with significant shipping traffic, the national government issued a formal notification to prefectures on March 24, 2026, establishing the framework for turbine-to-shipping-lane setbacks in open-sea areas.
3-2. Key Principles
The notification establishes the following principles:
- The guidance applies to the early stages of project formation
- Setback distances and the shipping routes to be considered are determined case-by-case based on sea conditions, through coordination with relevant stakeholders (no fixed minimum distance is prescribed)
- Safety measures for surrounding vessel traffic should be considered as needed
- Projects located on existing shipping routes should be aware that detailed analysis of post-construction navigational changes may be required
- At the layout planning stage, discussions should appropriately address the mitigation of impacts on vessel traffic
The notification is structured around five elements: (1) assessment of actual navigation patterns, (2) identification of relevant routes, (3) determination of appropriate collision-avoidance setback distances, (4) stakeholder coordination on setback distances, and (5) considerations for facility layout planning.
3-3. Additions to the Guideline
Based on this notification, two additions were made to the Promotion Zone Designation Guideline:
Addition to “Promising Area” requirements:
If the views of relevant shipping industry associations and operators have not been sufficiently confirmed, and conditions are not in place for substantive discussion on project implementation through the consultation council, the area shall not be classified as a “promising area.”
Addition to “Other Considerations”:
A new section on setback distances between offshore wind installations and areas of frequent vessel traffic in open-sea areas was added, incorporating the key points of the March 24 notification.
3-4. Practical Implications
The most significant change is the explicit inclusion of shipping industry engagement as a requirement for “promising area” classification. If maritime stakeholders are not willing to participate in consultation, the area cannot advance in the pipeline.
This effectively gives the shipping industry a procedural gate over zone progression — a structural shift in who holds influence over Japan’s offshore wind development pipeline. Candidate areas located near major shipping lanes now face an additional hurdle before they can move forward.
What This Revision Means
The March 2026 revisions to the Promotion Zone Designation Guideline and Central Method operational policy introduce three structural changes to the zone selection and project formation process for offshore wind in Japan.
| Revision | Key Change | Primary Impact |
|---|---|---|
| Viability screening indicators | Reference benchmarks introduced for wind speed, water depth, and onshore transmission distance | Developers, financial institutions |
| Centralized EIA | MOE takes over scoping and methodology stages; developer burden reduced | Developers, local communities |
| Shipping lane setbacks | Open-sea rules formalized; shipping industry engagement made a requirement for zone advancement | Developers, maritime industry |
Each of these changes moves in the direction of greater specificity and formalization — replacing previously ambiguous criteria and processes with explicit benchmarks, defined responsibilities, and structured stakeholder requirements. For participants in Japan’s offshore wind market, these revisions increase both the transparency and predictability of the zone selection process.
Note: The proposed revisions will undergo a public comment period, after which a finalized version will be issued. This article will be updated if the confirmed version contains material changes.
Source: MLIT — Joint Committee on Offshore Wind Promotion (Port Subcommittee / Renewable Energy Integration Working Group), March 26, 2026
For a broader understanding of Japan’s offshore wind legal system, policy structure, and support measures, be sure to check out our pillar article:
🌊 Japan’s Offshore Wind Policy & Regulatory Framework Explained