TEPCO Begins EIA for 420 MW Choshi Offshore Wind Project in Japan

Tokyo Electric Power Company Renewable Power (TEPCO RP) has started the environmental impact assessment (EIA) for a proposed up to 420MW Choshi offshore wind project off Choshi City in Chiba Prefecture, Japan. The proposed fixed-bottom offshore wind farm would cover approximately 4,000 hectares and is planned to comprise 21–27 turbines, with each turbine rated between 15MW and 20MW. 

TEPCO RP submitted the planning-stage environmental consideration document on 20 August 2026, with public inspection and consultation running from 21 August to 25 September 2026. The assessment area is located offshore of Choshi, with part of the wider environmental assessment area extending toward Asahi City. 

The project is significant because the Choshi area was previously awarded to a Mitsubishi Corporation-led consortium during Japan's first offshore wind auction. Mitsubishi withdrew from the project in August 2025 amid a substantial increase in construction costs. TEPCO RP's initiation of the EIA indicates that it is positioning itself to participate in the re-tender of the Choshi development area.

Under the preliminary schedule, construction could start in 2031 or later, with commercial operation targeted for 2032 or later, subject to the EIA, permitting and subsequent development decisions. 

TEPCO has existing offshore wind experience in Choshi. Its 2.4MW Choshi Offshore Wind Power Facility, Japan's first fixed-bottom offshore wind facility, began demonstration operations in 2013 and entered commercial operation in January 2019.