Belgium completes massive concrete modules for world’s first offshore energy island

The Belgian electricity system operator Elia is advancing the Princess Isabel artificial energy island, a structure the size of eight football fields built from 23 concrete caissons weighing roughly 22,000 tons each. The caissons were produced in the Dutch port of Vlissingen by the TM Edison consortium—DEME and Jan De Nul—and the last unit was floated in January 2026, beginning the placement phase. After being towed to a prepared seabed foundation, each block will be filled with sand to settle on the bedrock, a process that takes about a day per unit.

Once completed, the island will act as a hub for up to 3.5 GW of wind power from the Princess Elizabeth Zone, using a mix of HVAC and HVDC lines and connecting to future interconnectors with the United Kingdom and Denmark. The design incorporates nature-inclusive features such as kittiwake nesting ledges and habitats for European flat oysters, monitored under the EU-funded NID4BirdLIFE program. Although the European Investment Bank initially funded €650 million, total costs have risen to €7 billion, with civil works expected by mid-2026 and electrical systems installed through 2030, aiming for operation around that year.