Borssele Alpha Offshore High Voltage Substation

The Offshore High Voltage Substation (OHVS) Borssele Alpha (jacket and topside) is required to link up the wind farms to be built offshore in the South-West section Borssele 1 & 2 areas of the Dutch North Sea. HSM Offshore is also partner for TenneT’s next offshore wind energy project, Borssele Beta (700 MW).

Client TenneT TSO B.V.
Location Dutch North Sea
Contract EPCIC
Contract award September 2017
Completion August 2020
Consultant/Engineer Iv-Offshore & Energy / Joulz

Project information

The Borssele Alpha project, together with the Borssele Beta project, are the first large-scale grid connections to be constructed under the National Energy Agreement for offshore wind farms in The Netherlands. The scope covers engineering, procurement, construction, transport, installation, connection and testing of the OHVS. The Borssele Alpha and Beta OHVS will be the largest AC substations in the world.

Dimensions
  • Topside 58x32x26 metres
  • Jacket 37x35x55 metres
  • Piles 61 metres each
Weight
  • Topside 3700 tonnes
  • Jacket 2900 tonnes including cable deck and J-tubes
  • Piles 1400 tonnes
Capacity
  • Total Power 700 MW (2×350 MW)
  • Intake Voltage 66 kV
  • Export Voltage 220 kV

Process Seen in action

Next project

See all projects
Scroll to discover