Flagship energy island slimmed down to cope with soaring costs

The Belgian government has scaled down a flagship energy island project due to soaring costs for high-voltage direct current (HVDC) infrastructure, meaning plans for one of three offshore wind farms in the area have been put on hold.

Going forward with just the alternating current (HVAC) infrastructure elements of the Princess Elisabeth Energy Island project will result in savings of up to €3bn ($3.42bn), according to Belgian energy minister Mathieu Bihet.

Plans for an artificial island located 45km west of the Belgian port of Ostend were first approved by the federal government in 2023.

This island is intended to enable wind farms in the Princess Elisabeth Zone to be connected to Belgium’s grid more efficiently, reducing requirements for transmission lines and cutting operation and maintenance costs.

The project was also aimed at enabling a new HVDC interconnector with the UK, via the Nautilus link.

Construction started last year, but costs estimates have tripled since 2021 to €7bn-€8bn currently, according to the Belga News Agency.

Supply chain constraints for the supply of HVDC infrastructure, including cables and two converters, was identified as the key pressure point for prices.

Bihet described the decision to proceed with the alternating-current part of the project for the time being as “sound management for a secure energy future, without run-away costs for consumers”.

Belgian transmission system operator Elia said implementation of the alternating current (HVAC) contracts remain on track, thus underpinning two of the three future offshore wind farms — with capacities of 700MW and 1400MW respectively.

This means 60% of the new Princess Elisabeth wind zone is still being implemented, the company said.

A third wind farm, also with a capacity of 1.4GW, was dependent on the two HVDC converters being installed.

In addition to connecting this wind farm, the converters would also enable the development of a hybrid interconnector to the UK.

“We continue to study the installation of a second direct-current interconnection with the UK with our partners,” Bihet stated.

'Alternative concept'

Elia was upbeat, describing the government's decision as an "alternative concept for the next phase of the Princess Elisabeth offshore energy hub".

"The ambition remains the same: to further develop and optimise wind production capacity in Belgium’s second offshore wind zone, while also realising a second interconnector with the United Kingdom," the company stated.

Elia also agreed with the government's stance on soaring costs, describing "unprecedented global increases in the price of high-voltage direct current (HVDC) technology and related services required for offshore development".

The TSO described the government decision as a mandate to move forward and "identify the best possible solution for the realisation of the energy hub at the lowest possible cost".

"Elia is delivering this project within a legal framework. Thanks to the government’s decision, its implementation can now continue," said Frédéric Dunon, CEO of Elia Transmission Belgium.

Dunon said the objectives of further offshore development and a second interconnector with the UK had been reaffirmed as "key elements in Belgium’s long-term energy policy".

Jan de Nul, the main contractor on the energy island project, is building 23 concrete caissons that will form the outer ring of the island, each weighing 20,000 tonnes. Construction is expected to finish in 2026.

In 2021, the Belgian federal government decided to more than double the capacity for offshore wind.

In addition to the already operational 2.3GW, up to 3.5GW of offshore wind capacity was to be added by 2032, chiefly in the new Princess Elisabeth wind zone.