Jan De Nul Group has completed the installation of four medium-voltage export cables connecting the Changhua County offshore wind farm to the shore, as well as the upgrade of the onshore substation.

This substation upgrade was essential for the connection of the first state-owned wind farm ‘Taiwan Power Company Offshore Windfarm Phase 1 Project – Demonstration’ to the Taiwanese power grid.

Jan De Nul’s cable-laying vessel Willem de Vlamingh installed the four subsea export cables from the offshore wind farm site, 10 km off the coast, to the shore where they were connected at the landfall area near Fangyuan.

For the complex beach pull-in operations including passing over a shallow water sandbank, Jan De Nul Group teamed up with its Taiwanese partner Hung Hua Construction who provided essential marine equipment, including a jack-up barge.

Due to the presence of a nearshore oyster farm and an important shipping lane for fishermen on the subsea export cables route, the cables had to be pulled through 1km-long underground ducts, which had previously been installed by horizontal directional drilling (HDD) up to 21 metres below the seabed.

“Originally, the HDD’s were stipulated in the contract to be 300 meters long, but Jan De Nul decided to extend them in order to prevent any damage to the sensitive coastal zone and fish farms. As such, we demonstrate once more Jan De Nul’s global care for the environment. Our offshore cable team did an amazing job, as did our onshore civil construction team who worked on the HDD together with Taiwanese companies Hung Hua and Magitech.”

 Jan Kop, project director at Jan De Nul Group.

After the cable installation, trenching works started. For the nearshore trenching works, Jan De Nul’s Starfish excavators used an in-house developed plough-skid and jet-skid. For the offshore trenching operations, the cable-laying vessel Willem de Vlamingh also acted as a trenching support vessel.

Together with its Taiwanese subcontractor Chung-Hsien Chen, Jan De Nul Group completed the installation and commissioning of new electrical equipment, including high voltage transformers, high-voltage and medium-voltage switchgear, a new SCADA control room and emergency power supply, inside the onshore substation in Da Cheng. This custom designed upgrade was essential for the substation to be able to receive power generated by the new offshore wind farm.

After passing a 24-hour energization test, the upgraded substation was connected to the national grid for the first time in this new configuration.

Offshore works progress

In the meantime, the offshore foundation installation of 84 pin piles and 21 jackets is making steady progress and Jan De Nul Group’s consortium partner Hitachi continues preparing the wind turbines in the Taichung marshalling port.

The turbine installation campaign, due to start in August, will feature Jan De Nul’s Offshore jack-up installation vessel Taillevent.

The ‘Taiwan Power Company Offshore Windfarm Phase 1 Project – Demonstration’ has been awarded to the consortium Jan De Nul–Hitachi in February 2018.

Jan De Nul Group is responsible for the full balance of plant, including design, fabrication and installation of the foundations, and the provision of the offshore vessel for the installation of the wind turbines. Also included is electrical scope, including the supply and installation of the cables both onshore and offshore, as well as upgrading an electrical substation.

Hitachi is in charge of manufacturing, assembly, installation and other works related to the 21 Typhoon certified offshore wind turbines using a downwind rotor, each with a capacity of 5.2MW.

The Jan De Nul–Hitachi consortium is responsible for the first five years operation and maintenance (O&M) of the TPC Changhua offshore wind farm Phase 1.