Van Oord-led group wins Borssele innovation site

NETHERLANDS: Oyster beds will be planted around two 9.5MW turbines at the Borssele V demonstration site, following a tender for the innovation site won by a consortium led by offshore services specialist Van Oord.

The Borssele V test site will be situated north of the Borssele III project

The Two Towers consortium — consisting of offshore contractor Van Oord, project development services provider Investri Offshore and financial advisors Green Giraffe — won the tender for the test site situated in the Borselle zone, off the Dutch coast.

A technology demonstration site was added to the zone in June 2015, to support the Netherlands' offshore wind sector. 

Two Towers will plant oyster beds around two MHI Vestas V164-9.5MW turbines and deploy a ‘slip-joint’ clamp between the monopile and transition piece, the group stated.

A ‘slip-joint’ typically consists of a pile with a slight outer coning top section, with a tower section with an internal matching coning surface above.

The clamp connection will be coated with an aluminium-based protective layer to increase the life expectancy of the tower and reduce the need for maintenance.

This could make it "easier and cheaper to build wind turbines", the Netherlands Enterprise Agency (NEA) suggested.

Meanwhile, rocks will be placed around the turbines to limit the flow of water over the seabed and avoid disturbing the sediment. This will create "an ideal habitat" for oysters, the NEA claimed.

The oyster beds will prevent erosion of the sea floor around the turbines’ foundations and help to create reef systems, enabling the "diversification of the North Sea", the consortium stated.

Van Oord will be responsible for the project's design and construction, Green Giraffe will act as project managers and finance the project, while Investri Offshore will serve as project director, the consortium stated.

Two Towers' submission was the only bid received in the tender for the test site, which is to be situated alongside the 1,482MW Borssele projects.

The group will receive a subsidy of up to €15 million for "the purpose of testing the innovations", the NEA stated, with a further €35 million for the electricity supplied.

Borssele V will be operational in 2021, the consortium said. The 700MW first and second phases of the Borssele cluster are due online in 2020, with the 700MW third and fourth stages following a year later.