The Borssele III and IV is a 731.5MW offshore wind power project located in the Dutch North Sea, off the coast of Zeeland province, Netherlands.

The project is owned by the Blauwwind consortium that comprises Partners Group (45%), Shell (20%), Mitsubishi Corporation’s subsidiary Diamond Generating Europe (15%),  Eneco Group (10%), and Van Oord (10%).

While the main construction works were started with the installation of the first monopile foundation in October 2019, the initial power was produced in the month of August 2020. The last of the 77 wind turbines was installed in November 2020 and the full-fledged commissioning of the 731.5MW wind farm is expected in early 2021.

The Borssele III and IV offshore wind farm is expected to generate It is estimated to generate 3,000 GWh of green electricity a year which will be enough to power approximately 825,000 Dutch households while meeting approximately 2.3% of the country’s total electricity demand.

Location and site details

The Borssele III and IV offshore wind power project is located adjacent to the Borssele I and II wind farm, at the southern border of Dutch Exclusive Economic Zone in the North Sea, approximately 22km (14miles) off the coast of Zeeland province, Netherland.

The project area occupies approximately 122km2 and the water depth at the wind farm site ranges from 16m to 38m.

Borssele III and IV offshore wind farm make-up

The Borssele III and IV offshore wind farm comprises 77 V164 9.5MW wind turbines from MHI Vestas. Each turbine is mounted on an 85m-long monopole foundation.

With a rotor diameter of 164m, each turbine has a swept area of 21,124m2. The nacelle of the turbine measures 9.3m-high, 20.7m-long, and 8.8m-wide.

Power evacuation

The electricity generated by each turbine is gathered and transmitted through approximately 175km of 66kV inter array cables connected to TenneT’s Borssele Beta offshore substation.

The gathered electricity will be stepped up to 220kV at the offshore substation and transmitted through 220kV export cables connecting an onshore substation where it will be further stepped up to 380kV for transmission into the national electricity grid.

Power purchase agreement

Shell and Eneco Group signed a power purchase agreement (PPA) with the Blauwwind consortium in June 2018.

Shell and Eneco Group will each purchase 50% of the electricity produced by the Borssele III and IV offshore wind farm for a period of 15 years.

Contractors involved

MHI Vestas was awarded the turbine supply contract while Sif Holding was contracted to supply 77 monopile foundations for the Borssele III and IV offshore wind farm project in April 2018.

Van Oord was responsible for the design, engineering, procurement, construction and installation of the foundations and inter-array cables.

Prysmian Group was subcontracted by Van Oord for the supply of 66kV submarine inter-array cables for the project in June 2018.

TennetT was responsible for the design and construction of the Borssele Beta offshore substation as well as for the grid connection.

Borssele III and IV Offshore wind power project background

The Dutch Government awarded the Blauwwind consortium the rights to develop, construct, and operate the Borssele III and IV Offshore wind power project in December 2016.

The project is backed with a 30-year lease agreement with an estimated operational life of 25 years. The financial closure on the project was accomplished in June 2018.