Two HVAC transformer platforms for Greater Changhua Offshore Wind Farms

3D model of one of the substations at Changhua Wind Farm

3D model of one of the substations at Changhua Wind Farm


Daniel Noermark, Ramboll Oil & Gas

Daniel Noermark Jensen

M.Sc., Project Manager
T: +45 5161 7212

The Greater Changhua 1 & 2a offshore wind farm project is a significant step towards Taiwan’s transition to renewable energy. Ramboll designed the two large 600MW offshore substations for the wind farm.

Taiwan on the road to sustainability

The Greater Changhua 1 & 2a Offshore Wind Farms mark Taiwan’s active pursuit of replacing coal with sustainable energy sources. Danish energy company Ørsted - a global leader in the development and operation of offshore wind farms - is currently developing the Greater Changhua projects in Taiwan consisting of four offshore sites with an expected total capacity of 2.4 GW. 

Supporting Ørsted from conceptual design to installation

Ørsted contracted Ramboll to carry out the conceptual and detailed design of the two 600MW high voltage (HVAC) offshore substations needed to distribute the electrical power from the offshore turbines to shore. Ramboll’s services also included technical support during the approval process in Taiwan as well as engineering support during fabrication and installation phases. 

The extreme environment of Greater Changhua

Greater Changhua is located 35 to 60 kilometers off the Changhua coast in the strait of Taiwan providing numerous challenging design conditions, including:

  • Frequent and severe earthquakes
  • Seasonal typhoons and windspeeds in excess of 200 kilometers per hour
  • Weak soil conditions prone to liquefaction

Durable design for a challenging environment

Due to the extreme weather conditions at the site, the focus of the design team is to devise a resilient and durable solution able to withstand the extreme environment in Taiwan. The challenging soil conditions on site also call for innovative thinking in terms of jacket foundation techniques and installation.

Ramboll’s scope of work

The unmanned substation platform was designed to carry equipment for high voltage transmission and distribution and other facilities such as diesel generator, batteries and panels for wind turbine control. 

The scope for Ramboll included the complete detailed design of the topside and jacket structural components to an “Issued for construction” completion state. For the remaining disciplines such as technical safety, low voltage design, utility and ventilation, a technically robust basic design was provided allowing the client to approach the market and receive the most cost and time effective bids. 

Ramboll assisted Ørsted throughout the phases:

  1. Conceptual design of the jacket aiming to produce a technically feasible jacket and topside concept without “showstoppers”
  2. Detailed design of the jacket and topside, in close cooperation with Ørsted’s discipline Lead Engineers.
  3. Support during fabrication and installation and clarification of questions raised by the fabrication contractor
  4. Assistance during the approval process by the local Taiwan Professional Engineers. 

Time schedule

The main design phase for the two substations ran until 2019. The final phases, which concern technical assistance during tendering, fabrication and installation, are expected to proceed until 2021.


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