Tokyo Electric Power Company Renewable Power (TEPCO RP) initiated the environmental assessment process to develop a offshore wind farm of up to 420 MW off Choshi, in Japan’s Chiba prefecture. The project envisions fixed-foundation turbines and could begin operating as early as 2032.
The move brings renewed attention to one of the areas included in Japan’s first round of offshore wind energy auctions. The area had been awarded in 2021 to a consortium led by Mitsubishi Corporation, a company that subsequently abandoned its projects from that round.
TEPCO proposes up to 27 turbines off Choshi
Specifically, TEPCO RP submitted the environmental considerations document for the planning stage on August 20. The following day, the Chiba Prefecture opened a public consultation on the project, which will remain open until September 25.
He offshore wind farm the Choshi site would occupy approximately 4,000 hectares; the company is considering installing wind turbines with an individual power output of between 15 MW and 20 MW.
According to the current plan, the project would have a maximum of 27 turbines and reach up to 420 MW of installed capacity. Although the core of the development will be located off Choshi, part of the area included in the environmental assessment extends into Asahi County.
Construction planned from 2031
Furthermore, the preliminary schedule indicates that construction could begin in 2031 or later, operation is planned for 2032 or a later date.
These dates still depend on the progress of the project, the next stages of the environmental assessment, and the necessary permits before starting construction.
The environmental process takes on special importance because it allows TEPCO to make technical progress in an area where it had already shown interest years ago.
Mitsubishi had won the area in the 2021 auction
Previously, TEPCO participated alongside Ørsted in the competition for the Choshi area, however, the auction held in 2021 ended with the selection of a consortium led by Mitsubishi Corporation.
The project awarded at that time included a capacity of 390.6 MW off Choshi, Mitsubishi also obtained two other offshore wind energy developments in Akita Prefecture.
The situation changed in August 2025, when Mitsubishi decided to abandon the three parks after revising its business plans. The company attributed the decision to substantial changes in the macroeconomic environment.
Japan will re-tender three offshore wind energy zones
Following Mitsubishi’s withdrawal, the Japanese government moved towards a new tender for the three areas corresponding to that first round.
The areas that will return to the market are Choshi, Noshiro-Mitane-Oga and Yurihonjo, thus, Japan it seeks to revive developments that had been left without a promoter and maintain the progress of its offshore wind energy industry.
Furthermore, the initiation of the environmental assessment by TEPCO RP once again places the company at the center of the Choshi development. The project now under review increases the potential capacity to 420 MW, compared to the 390.6 MW contemplated in the previous award.
Source: OffshoreWind
Photo: Shutterstock
