Arcadis Ost 1 Offshore Wind Farm, Baltic Sea

Arcadis Ost 1 is a 257MW offshore wind farm in the Baltic Sea, developed by green energy company Parkwind.

The wind farm, located entirely in German waters, can create enough green energy to power approximately 290,000 households.

The Arcadis Ost 1 wind farm was successful in Germany’s offshore wind auction in 2018 and it obtained permit in March 2021.

The project reached financial close in June 2021, raising €570m of debt from a group of nine lenders. Offshore construction began in June 2022 and the project produced first electricity in January 2023.

Parkwind completed the installation of 24 turbines at the site in April 2023. The remaining three turbines are scheduled to be installed in autumn 2023.

The project is one of Parkwind’s first international projects developed in close collaboration with German authorities.

Location details

The Arcadis Ost 1 Offshore Wind Farm is located within a 12 nautical mile zone, around 19km off the Rügen island in the federal state of Mecklenburg-Western Pomerania, Germany.

The wind turbines of the offshore wind farm will be installed across an area of 29km². Water depth in the region ranges between 41m and 46m.

Arcadis Ost 1 Wind Farm Infrastructure

The 257MW offshore wind farm consists of 27 wind turbine generators, an offshore substation (OSS) with associated connections and internal park cables, an onshore operations and maintenance (O&M) building on Rügen Island and an export cable.

The project uses Vestas V174 wind turbines, each with a production capacity of 9.5MW. The turbines have a swept area of 23,779m².

The turbines and the OSS were mounted on monopile foundations. The 28 XXL monopiles weigh more than 2,000 tonnes each and measure up to 100m in length with a diameter of 9.4m.

The wind turbines were installed using the floating Rotor Nacelle Assembly (RNA) installation method using floating installation vessels.

The 2,380-tonne OSS is 30m high. It was installed by Gulliver, a crane vessel, on its monopile foundation.

Overall, the offshore transformer with its foundation weighs over 5,000 tonnes.

The OSS collects the green power created by the wind turbines and converts it to 220kV level. Subsequently, the electricity is transported onshore to the German Transmission System Operator (TSO) 50Hertz’s grid connection point in Lumbin in Mecklenburg-Western Pomerania.

The electricity is then converted to 380kV and fed into the 50Hertz transmission grid.

Arcadis Ost 1 wind farm financing

In June 2021, Parkwind announced that the Arcadis Ost 1 offshore wind farm reached financial close after raising €570m of debt.

The lenders were KBC Bank, Belfius Bank, Helaba, KfW IPEX-Bank, Coöperatieve Rabobank, Société Générale, ING Bank, EKF Danmarks Eksportkredit and the European Investment Bank.

The financing process was led by Parkwind, with Jones Day and Chatham Partners acting as sponsors’ legal advisors.

The advisors of the lenders were Loyens & Loeff and Watson Farley & Williams. Mott Macdonald acted as the lenders’ technical advisor.

Contractors involved

In September 2019, Parkwind contracted the Hamburg branch office of consulting group COWI for detailed design of wind turbines and OSS foundations of the wind farm.

Vestas supplied the wind turbine generators for the project, while Heerema Marine Contractors performed their installation using floating RNA installation method.

DEME Offshore won the Engineering Procurement Construction and Installation (EPCI) contract for the foundations of the Arcadis Ost 1. Dillinger supplied the heavy steel plates for the monopiles.

Orion, an installation vessel, was used to install the XXL monopiles.

Bladt Industries delivered the substation, with Semco Maritime and ISC Engineering serving as key partners.

In 2020, Parkwind and Steelwind Nordenham signed a contract for the fabrication of monopile foundations for the project. The monopile foundations were fabricated at Steelwind HQ in Nordenham, Germany.

Subsea cable technology and offshore services company JDR delivered the inter-array cables and Global Marine performed the installation work.

Semco Maritime provided design, installation, and commissioning of the high, medium, and low voltage equipment.