BY MAGDALENA OSUMI
Japan sits at the intersection of four major tectonic plates, making it one of the world’s most seismically active countries. Frequent earthquakes, including megathrust events, together with widespread liquefaction risks, present engineering challenges unlike those faced by most European offshore wind markets.
For two decades, offshore wind engineering was shaped by the North Sea’s benign seismic conditions. But as investment shifts toward Japan and other Pacific markets, engineers must confront a question that European standards were never designed to answer: How to build a wind farm that can withstand both a Category 4 typhoon and a massive earthquake?
Environmental assessments in seismically active regions show that designing for wind, waves and currents alone is no longer sufficient from either an engineering or regulatory perspective. Earthquake loading and related hazards, such as soil liquefaction, must be incorporated into project design. European practices simply cannot be adopted in Japan.
The shift has prompted Norway-based DNV, a globally recognized registrar and classification society, to update its recommendations for the design of wind power plants, elevating earthquake loading from what had largely been a secondary consideration to a primary engineering and regulatory concern.
With Japan’s government targeting up to 45 GW of offshore wind capacity by 2040, the issue is urgent. Japan needs dedicated, risk-based design frameworks to address seismic hazards and ensure that projects awarded in the current auction cycle can deliver most of the planned 20–30 GW by 2040. Failure to account for seismic risks in project development could lead to significant cost increases and delays extending well beyond 2030.