Japan has taken a crucial step forward in developing low-cost offshore wind technology.

Recently, an experimental vertical-axis floating wind turbine has been fully installed in the bay off Iki City, Nagasaki Prefecture, kicking off a one-year field demonstration test.

The project is jointly developed by a consortium consisting of Electric Power Development, Tokyo Electric Power, Chubu Electric Power, Kawasaki Kisen Kaisha, Sumitomo Heavy Industries and Albatross Technology. Its goals are to boost the domestic industrial supply chain through technological innovation and slash overall offshore wind construction costs.

The prototype under test boasts a streamlined layout with a three-blade vertical-axis turbine and a cylindrical floating foundation. Its rotor measures merely 9.3 metres across, while the buoy base has a diameter of 1.7 metres with a maximum output capacity of 20 kW. The unit is secured in place by three mooring lines anchored to the seabed.

This minimalist design delivers substantial cost savings. Unlike horizontal-axis turbines, vertical-axis setups require no complex yaw systems to follow wind directions, and their floating foundations feature simpler manufacturing processes, which promise major reductions in construction and operation & maintenance expenses.

Throughout the trial, the team will focus on verifying the system’s operational stability and power generation performance. Once the one-year test concludes, the entire unit will be dismantled, and every component will undergo comprehensive inspections to collect critical ageing performance data.

“Simplified structure holds the key to cost reduction,” said a project lead, adding that vertical-axis floating turbines outperform conventional horizontal-axis models by a wide margin in this regard. To speed up technology commercialisation, the team will integrate data gathered from small-scale trials into the development of larger units to accelerate the rollout of megawatt-class demonstrators. As follow-up megawatt-scale testing advances, this low-cost technical solution is expected to launch commercial 2 MW turbines by around 2030, opening a new cost-effective pathway for Japan’s offshore wind sector.