PRINCESS ELISABETH ISLAND: Building Europe’s First Offshore Energy Hub
European energy powerhouse, Elia Group, is pushing ahead quickly with the Princess Elisabeth offshore energy hub project, developing what will be the world’s first artificial energy island. Charting the path for the industry in the future, this unique and complex project continues to take shape in the Belgian North Sea.
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45 kilometres off the Belgian coast, in the cold waters of the North Sea, something entirely without precedent is rising from the seabed. Princess Elisabeth Island is not a wind farm, nor a substation, nor an interconnector — it is all three simultaneously, and more. It is the world’s first artificial energy island: a concrete and sand structure that will serve as a power hub gathering electricity from multiple offshore wind zones, acting as a landing point for hybrid interconnectors with the UK and Denmark, and connecting Belgium’s offshore generation capacity to the wider European grid. When operational, it will channel 3.5 gigawatts of offshore wind energy from the Belgian North Sea — enough to power the equivalent of millions of homes — and will do so through infrastructure that Europe has never built before.
The project is the work of Elia, the Belgian transmission system operator, and it sits at the heart of Belgium’s ambition to position the North Sea as the engine of its energy independence. For years, that ambition was articulated in policy documents and European frameworks but now it is being built. The 2025 construction season brought the completion of the 2025 caisson installation campaign, with Jan De Nul deploying the last of the prefabricated concrete caissons that form the island’s foundation — 23 in total, constructed from 7,000 tonnes of Holcim’s ECOPlanet low-carbon cement. In June 2025, the first steel was cut for the island’s HVAC infrastructure, marking the transition from seabed preparation to active energy system construction.
The caissons themselves represent a feat of marine engineering. Each one is a hollow concrete box, manufactured onshore, floated out to the North Sea, positioned with precision at the island site, and sunk into place to form the outer shell of the structure.
Filled with sand and sealed, they create the stable platform on which Elia will build the island’s operational infrastructure — a port, a helipad, high voltage switching equipment, transformer stations, and the cable connections that will link the island to wind farms, to the Belgian shore, and to the UK and Denmark via hybrid interconnectors. Engineering firm, Tractebel, has been involved across the full technical scope, from concept through design and construction supervision. Smulders, as part of the Modular Offshore Grid programme, is delivering key offshore grid components. Jan De Nul has handled the marine installation campaign. The contractor roster reads as a who’s who of European offshore energy expertise.
Former Belgian Prime Minister Alexander De Croo set the political frame for what the island represents: “The North Sea is set to become the powerhouse of our energy independence, and Princess Elisabeth Island will be a crucial part of this process. Belgium has long been a pioneer in offshore wind, and by continuing to innovate, we are further consolidating our position for the future. This gives our Belgian companies more opportunity to do groundbreaking work, both here and abroad, as well as guaranteeing sustainable, competitively priced energy for our citizens and businesses.”
HVAC AND ADAPTATION
The first steel cut in June 2025 marked a moment as significant in its own way as the caisson installations. HVAC — high voltage alternating current — infrastructure is the electrical backbone through which the island will gather power from the offshore wind farms in the Belgian North Sea zone and transmit it toward shore. The cutting of the first steel plate signalled that the project had moved from civil engineering to energy systems engineering, and that the schedule was holding.
It has not been a project without complexity. The Belgian government’s decision to pursue an optimised configuration for the HVDC components — the high voltage direct current systems that would have carried power through the hybrid interconnectors to the UK and Denmark — introduced a period of adaptation.
The revised approach separates the immediate delivery of the island’s core HVAC infrastructure from the longer-term realisation of the HVDC interconnector ambitions, allowing the project to maintain momentum while the financing and regulatory framework for the DC components is resolved.
Frédéric Dunon, CEO of Elia Transmission Belgium, said: “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. Along with our partners and the authorities, Elia remains fully committed to delivering Belgium’s offshore energy hub that will strengthen our country’s future electricity supply and support Europe’s energy transition.”
The strategic ambition has been explicitly reaffirmed. Dunon was also clear that the interconnector objective — a second link with the United Kingdom in particular — remains central to the project’s long-term purpose: “We support the government’s ambition to realise the project’s core objectives through an optimised configuration which is adapted to current market conditions. We are pleased that the strategic importance of further offshore development and a second interconnector with the United Kingdom has been reaffirmed. These are key elements in Belgium’s long-term energy policy.”
Ongoing environmental management is also part of the construction picture. The Easter 2026 continuation of the DOVO old sea mine clean-up operation — clearing unexploded ordnance from the seabed around the island site — illustrates the extraordinary preparatory complexity involved in building permanent infrastructure in a North Sea that carries the legacy of two World Wars. It is the kind of detail that rarely features in the headline announcements, but without it, no construction campaign proceeds.
COLLABORATION AND CONSEQUENCE
Princess Elisabeth Island does not exist in isolation. It is the Belgian expression of a broader European strategic logic: that the North Sea, with its vast and reliable wind resource, should become the primary source of clean electricity for north-west Europe, and that the infrastructure to make that possible must be built collaboratively across borders. The UK, through its own offshore wind ambitions and its participation in the interconnector negotiations, is part of the same picture. So are Denmark, the Netherlands, Germany, and the other states surrounding the North Sea whose governments committed at the North Sea Summit to a coordinated expansion of offshore capacity.
The numbers that frame this context are significant. Europe has targeted 300 gigawatts of offshore wind capacity by 2050. The North Sea alone, according to RenewableUK, is expected to provide a substantial proportion of that figure, with multiple countries developing both national capacity and the interconnected grid infrastructure needed to share it efficiently across the continent. Princess Elisabeth Island is not the only energy hub being proposed in European waters, but it is the first to be built — and what is learned here will shape every subsequent project.
Elia Group’s recognition as BEL20 Company of the Year in January 2026 underlines the standing the organisation carries as it delivers this work. Bernard Gustin, CEO of Elia Group, said: “Nothing we are achieving today, nor what we aspire to build for tomorrow, would be possible without our teams. This award only strengthens our commitment to push further, deliver better, and keep earning the trust placed in us. Our mission remains unchanged: to deliver sustainable value for our shareholders, reliable service for our customers, and critical infrastructure that will support the communities we serve for generations to come.”
That mission is visible in the North Sea right now: in the caissons placed on the seabed, in the first steel cut for HVAC systems, in the mines being cleared, and in the engineering teams from across Europe working on a structure that has never been built before. Princess Elisabeth Island is a proof of concept for what European energy collaboration can achieve when ambition is matched with engineering and sustained by political will. The island is rising. The next question is how quickly the rest of Europe follows.
Images © Elia Group