MHI's MWT167H/7.0 turbine, formerly known as the SeaAngel, is expected to come online before the end of the year.
A consortium led by Marubeni, in partnership with the University of Tokyo, MHI, and other engineering firms, is developing the project.
The rotor's hub stands 105 meters above sea level, and the topmost height of the turbine is 188.5 metres.
It was towed to the site from Onohama port by a total of five tugboats in a one kilometre long convoy, said Professor Takeshi Ishihara of Tokyo University, technical adviser to the project. The turbine was delivered to Onohama port in June, where it was assembled onto a three-column semi-submersible floating platform.
Mooring will be completed by mid-August, and a cable will be connected between the 7MW turbine and a substation during the first phase of the project.
"The installation of the world’s largest floating windpower turbine at the offshore site can be termed a new milestone in offshore wind," Ishihara said.
A taskforce, referred to as the Fukushima Prefecture Offshore Windpower Study Council, is considering expanding total output at the offshore windfarm to 80MW by 2020, Ishihara said. However, he denied reports of constructing potential for 1GW.
The council will meet a further two times this year.
MHI dropped the SeaAngel name from the turbine earlier this year, so it did not confuse the market, and to avoid competition with MHI Vestas' V164-8MW turbine, according to a spokesperson.