Radar · Projects to watch · 29 / 29
Oga–Katagami–Akita offshore wind farm (315 MW, Round 2)
First deployment of 15 MW-class turbines in Japan, installed by a DEME-affiliated jack-up in 2027; foundation, turbine installation and marine coordination work runs 2026–2028.
Offshore wind · Japan (Asia-Pacific) · every fact below is as reported by the linked sources, checked by hand on 2026-10-08.
- Size
- 315 MW; 21 x Vestas V236-15.0 MW; commissioning June 2028
- Operator / developer
- Oga Katagami Akita Offshore Green Energy LLC — consortium of JERA, J-POWER, Tohoku Electric Power and Itochu
- Phase, as reported
- construction / pre-installation (turbine deliveries from 2026; offshore installation second half of 2027; full commissioning June 2028)
- Checked on
- 2026-10-08
Phase track steps named in the reported phase are marked
- FID
- Engineering
- Fabrication
- Construction
- Installation
- Commissioning
Who builds it as stated by the sources
- DEME (via Japan Offshore Marine JV) — Engineering works and vessel charter for offshore installation of the 21 wind turbines using the jack-up vessel Sea Challenger under Japanese flag; offshore works scheduled second half of 2027; DEME share up to ~EUR 50 million
- Penta-Ocean Construction — Named alongside the project company as the contracting party for the turbine-installation package
- Vestas — Turbine supplier: 21 x V236-15.0 MW (selected 2024; deliveries from 2026)
- Kajima Corporation — manufacturing, procurement, transport and installation of the turbine foundations (contract October 2025)
- JFE Engineering — manufactures and transports the 21 monopiles and transition pieces at its Kasaoka plant, January 2026 to March 2027; first monopile completed August 2026
Key dates as stated by the sources
- FID or award
- Development rights awarded end of 2023 (Round 2); DEME/JOM turbine-installation contract announced 29 May 2026
- Milestone
- First domestically made monopile completed August 2026; monopile/TP supply runs to March 2027; offshore turbine installation scheduled second half of 2027
- Startup target
- Full commercial operation June 2028 per trade press (reconfirmed July 2026, when the design received Bureau Veritas Japan certification)
Disciplines likely needed our inference
- marine operations / installation engineering
- WTG installation and commissioning technicians
- client representatives / marine warranty
- HV cable and substation engineering
- HSE
- package management
Our inference from project kind and phase — not stated by the sources below.
Sources checked on 2026-10-08
- DEME wins contract for offshore wind project in JapanDEME (company newsroom) · published 2026-05-29 · retrieved 2026-09-22
- DEME to Install 15 MW Vestas Turbines at Japanese Offshore Wind FarmoffshoreWIND.biz · published 2026-05-29 · retrieved 2026-09-22
- JFE Engineering Rolls Out First 'Made in Japan' Monopile for Oga–Katagami–Akita Offshore Wind FarmoffshoreWIND.biz · published 2026-08-27 · retrieved 2026-10-08
- Japan's Oga–Katagami–Akita Offshore Wind Project Receives CertificationoffshoreWIND.biz · published 2026-07-22 · retrieved 2026-10-08
- Japan's first order received for domestic monopile production for large-scale offshore wind power project in general watersJFE Engineering (company newsroom) · published 2025-12-26 · retrieved 2026-10-08
- Kajima Inks Foundation Contract for 315 MW Japanese Offshore Wind FarmoffshoreWIND.biz · published 2025-10-23 · retrieved 2026-10-08
Position on our globe: 39.85°N 139.90°E. Location approximate: Off the coast of Oga, Katagami and Akita cities, Akita Prefecture, Sea of Japan side of Honshu. Exact turbine layout not published in sources checked.