Danish transmission system operator (TSO) Energinet and its German counterpart 50Hertz have opened the tender for key equipment for their joint project, Bornholm Energy Island, in the Baltic Sea.

The project will transmit 3GW of offshore wind power from a hub on Bornholm Island to customers in Germany and Denmark.

The partners planned to expedite the tendering process after talks with potential vendors during the summer of 2023, to reserve production capacity at the earliest opportunity.

They intend to begin awarding contracts in the second half of 2024, with plans to split the tender into multiple contracts.

HVDC equipment for stations in Germany and Denmark will be tendered as one joint contract to be sent to prequalified vendors.

50Hertz and Energinet aim to procure HVDC-breakers, a major technology for the energy island, as an option. These can be produced as part of the initial construction or as a separate tender during a later phase.

Energinet Energy Islands vice-president Hanne Storm Edlefsen stated: “We cannot ignore the current market situation. HVDC circuit breakers will play an important part in the operation of our energy island but are not crucial in the initial phase.

“Therefore, we have decided that it is more important to ensure a competitive bidding process and to keep up the pace of the green transition to secure the supply of clean electricity to consumers in Germany and Denmark.”

Energinet noted that construction on the Danish part of the project can commence when it secures an environmental permit and archaeological excavations are complete in 2025. 

Installation and construction can begin in Germany upon receipt of permits from the authorities.

Bornholm Energy Island is a new project connecting multiple offshore wind farms.

The electricity from the wind farms will be centralised at the hub and converted into HVDC to be transported via sea and land cables to onshore substations in Zeeland, Denmark and Mecklenburg-Western Pomerania, Germany.

In August 2022, the German and Danish governments agreed to increase the capacity of Bornholm Energy Island from 2GW to 3GW.

The island can supply clean power to 4.5 million homes.