Japan's Biggest Wind Turbine Unveiled Off Shore
By wchung | 08 Sep, 2025

Japan unveiled its biggest wind turbine about 3 kilometers (1.9 miles) off the coast of Choshi in Chiba Prefecture at a press briefing Monday.

The turbine, located about 50 miles east of Tokyo, rises 80 meters (257 feet) above the water and has a generation capacity of 2,400 kilowatts. Its blades are each 46 meters (147-feet) long. Its foundation extends 12 meters (38 feet) into the seabed. The site was chosen for its high winds and to minimize noise for Choshi residents.

The project cost of 3.5 billion yen ($46.5 million) was two-thirds funded by New Energy and Industrial Technology Development Organization (NEDO) and one third by Tokyo Electric Power Co. (TEPCO), the utility that also runs the Fukushima 1 nuclear power plant.

Off-shore wind farms are “wind power’s trump card” for Japan, said a NEDO spokesman who conducted the press tour. Japan’s mountainous terrain and high population density make land-based wind farms uneconomical.

The turbine will begin producing electricity for the TEPCO grid in January.

Japan already has over 1,870 wind turbines that each produce between 1,000 to 2,000 kilowatts of electricity. Their combined output of 2.5 million kilowatts is about the output of two to three nuclear reactors.

The cost of building offshore wind farms that can match the power output of a pair of modern nuclear reactors would be about $25 billion based on an extrapolation of the cost of the Choshi turbine project and allowing for economies inherent in installing multiple units. By comparison the pair of nuclear reactors would cost about $8 billion. The comparison becomes less uneven after factoring in the cost of insuring against nuclear disasters and disposing of spent fuel. However, the overall cost of wind farms would have to brought down by about 50% to achieve cost parity with nuclear reactors.

In a bid to cut the cost of offshore wind farms, NEDO is currently testing a 1,000-kilowatt floating wind turbine near Kabashima Island in Goto in Nagasaki Prefecture.