The Ishikari Bay New Port Offshore Wind Farm is a 112 MW offshore wind facility located in Hokkaido, Japan, that reached commercial operation in January 2024, a notably smaller build than the 520 MW project JERA originally floated for the same bay back in 2020. The completed facility pairs 14 Siemens Gamesa turbines with a 180 MWh battery system, feeding Hokkaido Electric Power Network under a 20 year agreement.

Ishikari Bay Offshore Wind Farm Ownership Widens as Hokkaido Chip Demand Grows

In September 2025, JERA sold part of its stake to Hokkaido Electric Power and Tohoku Electric Power, expanding ownership to four companies as regional utilities work to secure long term power for Hokkaido’s expanding chip sector. That dynamic mirrors Japan’s broader semiconductor buildout, including Tower Semiconductor’s $3 billion Toyama and Niigata expansion, which likewise leans on government support to secure the industrial base behind AI hardware.

Project Overview

• Project Name: Ishikari Bay New Port Offshore Wind Farm
• Location: Ishikari Bay New Port, Hokkaido, Japan, off the coast of Ishikari City and Otaru City
• Project Value: Not publicly disclosed
• Client or Owner: JERA and Green Power Investment Corporation, joined since September 2025 by Hokkaido Electric Power and Tohoku Electric Power
• Main Contractor: Kajima Corporation for onshore works, with a Shimizu Corporation and Nippon Steel Engineering joint venture for offshore works
• Key Components: 14 Siemens Gamesa 8 MW turbines totaling 112 MW, plus a 180 MWh battery storage system
• Procurement Model: Developer led project held through the special purpose company Green Power Ishikari LLC
• Construction Start: October 2022
• Expected Completion: Commercial operation achieved January 1, 2024
• Strategic Impact: Ranked as Japan’s largest operational offshore wind farm at commissioning, supplying power under a 20 year feed in tariff agreement while regional authorities weigh further Hokkaido offshore capacity to serve chip manufacturing and data center growth

Project Team

• Original Developer: Green Power Investment Corporation
• Co-Owner: JERA, via its renewable energy arm JERA Nex
• Co-Owners since 2025: Hokkaido Electric Power Co., Inc. and Tohoku Electric Power Co., Inc.
• Onshore Contractor: Kajima Corporation
• Offshore Contractor: Shimizu Corporation and Nippon Steel Engineering joint venture
• Turbine Supplier: Siemens Gamesa Renewable Energy
• Power Offtaker: Hokkaido Electric Power Network, Inc.

Reported 26th August 2020: JERA Co Inc., a joint venture between TEPCO Fuel & Power based in Japan has announced their plans to construct a 520 MW offshore wind farm in Hokkaido, Japan’s northmost island off Ishikari Bay on the west coast. JERA stated that the facility would consist of up to 65 wind turbines in total located at least 2.5 kilometers offshore from the cities of Ishikari and Otaru. The number of turbines will be lower if the JERA chooses a more powerful windmill that can generate up to 14 MW per unit.

Also Read: Egypt awards contract for construction of 250Mw wind farm in the Gulf of Suez.

The planners for this project also predict that there may be a deployment of an energy storage system in order to mitigate the impact of wind generation output fluctuations on the power grid. It is estimated that JERA will take around 3 years to complete the construction of the 520 MW Hokkaido offshore wind farm.

The company JERA has also submitted environmental impact documents to the Minister of Economy, Trade, and Industry on Monday said it believed Ishikari Bay to be suitable for the development of bottom-fixed offshore wind power generation due to its favorable wind conditions, shallow seabed, and the spare capacity of the nearby power grid.

Recently, Japan announced that though offshore wind power currently provides only a tiny fraction of their electricity supply, it is set to grow after the law, the Offshore Wind Promotion Act, came into force last year to spur development. If the government’s wind power efforts are successful, Japan’s offshore power generation cost could fall to as low as US$0.076 per kilowatt-hour (kWh) in the early 2030s, close to the current cost of 5-6 yen/kWh in Europe. Orsted, the world’s largest offshore wind farm developer, together with Tokyo Electric Power Company, also announced plans to make a bid for a planned auction for an offshore wind project off Choshi, in Chiba, near Tokyo.