Construction Starts on HVAC Infrastructure for Belgian Offshore Energy Hub

June 20, 2025, by Adnan Memija

The construction of the high-voltage alternating current (HVAC) infrastructure has begun with a first steel cut ceremony at the HSM Offshore Energy yard in Schiedam, the Netherlands. The HVAC modules will be directly installed on the Princess Elisabeth offshore energy hub (MOG2) in Belgium.

The HVAC substations will house essential components such as power transformers and gas-insulated switchgear (GS). The modules are being built by HSI Pemac, a Belgian-Dutch consortium comprising HSM Offshore Energy, Smulders, and Iv.

The consortium was awarded the engineering, procurement, construction, installation and commissioning (EPCIC) contract by Elia, Belgium’s national transmission system operator (TSO).

Eiffage Details EPCIC Contract for Belgian Energy Island

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Engineering works, including the layout and a detailed 3D model, are being carried out at Iv’s offices in Papendrecht, the Netherlands. The prefabrication is taking place at Smulder’s Belgian facilities and HSM’s Schiedam yard, with the final assembly occurring in Schiedam and Vlissingen.

“This first steel cut is more than the start of fabrication — it is a tangible sign that one of the most strategic energy projects in Europe is moving from plan to reality,” said Hans Leerdam, Commercial Director at HSM Offshore Energy.

The broader HVAC infrastructure for the Princess Elisabeth Island, the world’s first energy island, includes 330 kilometres of 220 kV HVAC subsea cables, divided into two 165 kilometres packages. These cables will connect the island’s AC infrastructure to Belgium’s mainland grid.

“The start of the construction of the island’s HVAC infrastructure shows that the project is progressing steadily— even as we adapt its next phase in line with new market realities. The Belgian government’s recent decision to develop an alternative approach for the HVDC components will ensure that we can maintain the strategic ambition of the project in a more cost-effective way,” said Frédéric Dunon, CEO of Elia Transmission Belgium.

In June, the Belgian federal government announced that an alternative approach for the next phase of the offshore energy hub would be developed.

While aligned with the project’s original goals, the updated approach will be aimed at reducing the costs involved by responding to the sharp global increase in the price of high-voltage direct current (HVDC) technology and related offshore services.

Located 45 kilometres off the Belgian coast, the artificial island will serve as a key connection point for transporting at least 2.1 GW of offshore wind energy generated in the Princess Elisabeth Zone to the mainland.

Construction is already underway with the installation of the first two of 23 caissons at the site. The work is being carried out by TM Edison, a joint venture between DEME and Jan De Nul.