Project · Offshore wind · Japan

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.

Checked by hand against the sources below (2026-10-20).

  1. Engineering (done)
  2. Fabrication (now)
  3. Transport & installation (next)
  4. Hook-up
  5. Commissioning
  6. Operation

Now Fabrication (reported: construction / pre-installation (turbine deliveries from 2026; offshore installation second half of 2027; full commissioning June 2028))

Next Transport & installation · H2 2027 (offshore turbine installation scheduled second half of 2027, as reported)

Roles Project management & controls · Construction & supervision · QA/QC & HSE · Role groups per phase: our planning assumption from the Crew Forecast model.

Later Operation June 2028 (planned commercial operation 30 June 2028, as reported)

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Who works on it as the sources name them

  • DEMETransport & installationEngineering works and vessel charter for offshore installation of the 21 wind turbines using the jack-up vessel Sea Challenger under Japanese flag; offshore…
  • Penta-Ocean ConstructionTransport & installationNamed alongside the project company as the contracting party for the turbine-installation package
  • VestasEquipment & supplyTurbine supplier: 21 x V236-15.0 MW (selected 2024; deliveries from 2026)
  • Kajima CorporationTransport & installationmanufacturing, procurement, transport and installation of the turbine foundations (contract October 2025)
  • JFE EngineeringTransport & installationmanufactures and transports the 21 monopiles and transition pieces at its Kasaoka plant, January 2026 to March 2027; first monopile completed August 2026
Kind
Offshore wind
Country
Japan
Size
315 MW; 21 x Vestas V236-15.0 MW; commissioning June 2028
Operator
Oga Katagami Akita Offshore Green Energy LLC
Position
39.85°N 139.90°E, approximate

Sources

  1. DEME wins contract for offshore wind project in JapanDEME (company newsroom) · published 2026-05-29 · read 2026-10-20
  2. DEME to Install 15 MW Vestas Turbines at Japanese Offshore Wind FarmoffshoreWIND.biz · published 2026-05-29 · read 2026-09-22
  3. JFE Engineering Rolls Out First 'Made in Japan' Monopile for Oga–Katagami–Akita Offshore Wind FarmoffshoreWIND.biz · published 2026-08-27 · read 2026-10-08
  4. Japan's Oga–Katagami–Akita Offshore Wind Project Receives CertificationoffshoreWIND.biz · published 2026-07-22 · read 2026-10-08
  5. 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 · read 2026-10-08
  6. Kajima Inks Foundation Contract for 315 MW Japanese Offshore Wind FarmoffshoreWIND.biz · published 2025-10-23 · read 2026-10-08
  7. Project OverviewOga Katagami Akita Offshore Green Energy LLC · read 2026-10-20
  8. Presentation at the 10th Offshore Wind Power Seminar (Event Date: October 9, 2026)Oga Katagami Akita Offshore Green Energy LLC · published 2026-10-13 · read 2026-10-20
  9. FY2025 Consolidated Financial ResultsJERA · published 2026-04-27 · read 2026-10-20
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