Hitachi Energy powers China’s 66 kV offshore wind farm with dry-type transformers

Hitachi Energy, a global leader in electrification, announced that it has provided the 69 kV HiDry dry-type transformers to an offshore wind power project built by China Huaneng Group at the L Site in the north of the Shandong Peninsula in eastern China. The new product offers environmental benefits to support stable grid integration and the reliable power supply of the offshore wind farm, serving customers in accelerating the growth of offshore wind power.

The offshore wind power project, in the waters off the north coast of the Shandong Peninsula, has a site center 70 kilometers from shore in water deeper than 50 meters. It is currently China’s deepest offshore wind farm and the largest in Shandong Province in terms of single-unit capacity. The total installed capacity is 504 megawatts (MW), with plans to install 42 units of 12-MW wind turbines.

Hitachi Energy will provide HiDry offshore wind dry-type transformers for Envision Energy Co., Ltd., the wind turbine supplier of the project. This product features a completely oil-free design to minimize the risks of potential oil leakage and fire, enhancing its environmental and safety performance. Moreover, its compact design, combined with superior performance under vibrations and corrosion resistance, makes it well-suited for turbine spaces. It is engineered for harsh offshore operating conditions. Additionally, the dry-type design doesn’t need oil-related maintenance, which helps lower maintenance costs.

The 69 kV HiDry offshore dry-type transformer is an innovative product developed by Hitachi Energy to offer an alternative with dry technology to the traditional liquid-immersed transformers, helping to meet the growing demand of 66 kV offshore wind farms in China. The offshore wind farms that operate at the 66 kV voltage level allow the use of larger turbines, more efficient power collection, and greater cost savings.

During the “14th Five-Year Plan (2021-2025)” period, China has planned five major offshore wind power bases, each with 10 million kilowatts (kW) of capacity, in the Shandong Peninsula, the Yangtze River Delta, southern Fujian, eastern Guangdong, and Beibu Gulf in Guangxi to achieve the scaled development of offshore wind power. Currently, more than half of the world's operational offshore wind capacity is in China, with 42 gigawatts (GW) connected to its grid1. The North L site wind farm, a key project of Shandong Peninsula's 10-million-kW offshore wind power base, will generate 1.7 billion kWh annually, sufficient to meet the residential electricity consumption needs of 1.59 million people in China.

Note:

1.       National Energy Admission first quarter press conference (2025)