The Borssele series: Making of

Over the next few months, Offshore Energy will be taking a closer look into the now operational Borssele offshore wind projects: Borssele 1 & 2, Borssele 3 & 4, and the Borssele innovation site.

The three projects – one developed by Ørsted, one by the Blauwwind consortium, and one by the Two Towers consortium – have each marked an industry-first in one way or another. Through a series of articles, Offshore Energy will dive deeper into the tendering, planning, financing, and building the offshore wind farms.

The facilitator of the projects’ contribution to the offshore wind sector was the Dutch government, which allocated one Borssele site for offshore wind innovation and set up the tendering processes for the projects in a way that they resulted in the most competitive prices at the time.

Ørsted (then known as DONG Energy) won the tender for Borssele 1 & 2 in July 2016 by submitting a bid of 7.27 Eurocents per KWh and crossing the levelized cost of electricity (LCoE) mark of EUR 100 per MWh in the offshore wind sector. With this price secured, the 752 MW project was set to be the world’s cheapest offshore wind farm.

Borssele 1 & 2 marked a ‘first-ever’ for Ørsted as well, as it was the first offshore wind farm the developer built in the Netherlands.

The wind farm was fully commissioned in November 2020, only seven months after the first of its 94 Siemens Gamesa 8 MW turbines was installed.

Five months after Ørsted was awarded development rights at the first tender in 2016, the Blauwwind consortium won the Borssele 3 & 4 tender, pushing the prices further down with its winning bid of 5.45 Eurocents per KWh and allowing for even bigger subsidy savings than the first Borssele project. The government said that, with the energy price outlook at the time, Borssele 3 & 4 could be operated without subsidy after seven and a half years.

The tender win also marked a strong entrance for the oil & gas major Shell into the offshore wind market through the Blauwwind consortium, which also comprises Partners Group, Diamond Generating Europe (subsidiary of Mitsubishi Corporation), Eneco, and Van Oord.

The first of the project’s 77 Vestas 9.5 MW turbines was installed at the end of May 2020 and all units were in place by the end of November 2020. The 731.5 MW Borssele 3 & 4 went into full operation in February 2021 and received its project certificate this month.

Situated within the site III of the Borssele Wind Farm Zone, the Borssele innovation site (Borssele V) was tendered at the beginning of 2018, when the Two Towers consortium – comprising Van Oord Renewable Finance, Investri Offshore and Green Giraffe Holding – was awarded the rights to install the wind turbines and offshore wind innovations for demonstration purposes.

For the testing of its innovations, the consortium will receive an innovation subsidy of up to €15 million and a maximum subsidy of €35 million for the electricity supplied.

One of the demonstration projects aims to investigate methods for the development of oyster reefs at offshore locations as part of a research programme relating to the restoration of European flat oyster beds. For this purpose, the consortium is placing reef structures with oysters on the scour protection around the project’s two wind turbines, where an eco-friendly scour protection called Ecoscour is being used.

Van Oord has also installed a Slip Joint foundation at the site, the first time anywhere that a submerged Slip Joint was used on a full-sized offshore wind turbine on a fully commercial basis. The Slip Joint is an alternative connection between a monopile and a transition piece, consisting of two conical sections placed on top of each other.

The innovation site, whose two Vestas 9.5 MW wind turbines were fully commissioned this February, features several other innovations, all of which have been developed by Van Oord in cooperation with other research partners.

The aim of testing and demonstrating innovations at the Borssele V site is to contribute to lowering both the Levelised Cost of Energy (LCoE) and the environmental impact of offshore wind farms.