All 23 caissons that form the protective outer shell of the Princess Elisabeth Energy Island have been installed, completing the foundation works for Belgium's first energy island in the North Sea. Each caisson weighs roughly 22,000 tonnes and measures 58 metres long, 28 metres wide and between 23 and 32 metres high; they were built in Vlissingen with about 300 people working daily, taking around three months each.
Over the coming months the island will be reclaimed with sand inside the caisson structure, followed by cable connections to the mainland in 2027–2028, electrical infrastructure from 2029, and final completion planned for 2031. Jan De Nul completed the foundations within the planned timeframe, enabling grid operator Elia to qualify for the €99 million European subsidy allocated to this phase. At the end of July, rocks holding settled young oysters were installed around the island under the Reefcovery project as a nature-inclusive erosion-protection measure.