50Hertz, the transmission system operator (TSO) for eastern Germany, has awarded its Ostwind 4 project to GE Vernova, in consortium with Drydocks World, a DP World company that provides marine and offshore services to the renewable energy sector, among others. The project involves the design, construction, and commissioning of a 2-GW high-voltage direct-current (HVDC) electric transmission system—the first of its kind in the German Baltic Sea—connecting offshore wind farms to the German grid. Ostwind 4 is the fourth offshore project designed to connect wind farm areas northeast of Rügen island to the German power grid (Figure 1). Both an offshore converter platform and an onshore converter station will be built as part of the project. This is the first time an offshore wind farm in the German Baltic Sea will include 525-kV HVDC technology, which can transport more power than alternating current (AC) connections with lower losses across longer distances.
1. Ostwind 4 is the fourth project to connect offshore wind farms (OWFs) from the northeast of Rügen island to the German power grid. Courtesy: 50Hertz The wind farm concession area in which the project will be located was purchased during an auction by Total Energies. The area is located on the edge of the German Exclusive Economic Zone (EEZ). A subsea cable that will be approximately 110 kilometers (km) long is due to run from the offshore converter, through the Greifswald Bodden, to Lubmin near Vierow. An underground cable that will be approximately 4 km long will run from Lubmin to the planned substation with the counter-converter in the municipality of Brünzow in the district of Vorpommern-Greifswald. The DC will be converted back to AC at that point and fed into the 50Hertz extra-high-voltage transmission grid. The contract for the production and installation of the subsea and underground cables was awarded to the Danish company NKT in 2023.
Collaboration Key to State-of-the-Art Transmission Project
The GE Vernova–Drydocks World consortium is responsible for delivering both the offshore converter platform and the onshore converter station, enabling seamless transmission of electricity from offshore wind farms in the Baltic Sea to the German transmission grid. As the consortium leader, GE Vernova will supply advanced HVDC technology, including voltage-sourced converters (VSC), high-voltage transformers, air-core reactors, and g3 gas-insulated switchgear (GIS). GE Vernova’s g3 (pronounced “g cubed”) insulating gas is an alternative to sulfur hexafluoride (SF6) insulating gas, with a drastically lower environmental impact—global warming potential (GWP) reduced by more than 99%, comparatively. Meanwhile, g3 products feature the same ratings and same dimensional footprint as SF6 options, and operate with no restriction under the same temperature range as SF6 products (down to –30C). As part of the Ostwind 4 project, GE Vernova will handle civil works for the onshore converter station and grid automation telecommunications equipment. The company said the project will also benefit from GE Vernova’s new HVDC Competence Center in Berlin, which is focused on developing leading-edge technology to improve grid stability and integrate more renewable energy. Drydocks World will manage the engineering, procurement, construction, and installation of the wind energy converter stations’ topsides and jacket structures. The topside, which will be fabricated at Drydocks World’s Dubai facility, will integrate advanced equipment designed and manufactured in Europe. Once completed, the platform will be transported and installed in German waters. “The Ostwind 4 project exemplifies the power of international collaboration in advancing renewable energy solutions,” said Captain Rado Antolovic, CEO of Drydocks World. “Drydocks World is honored to support Germany’s transition to sustainable energy by delivering cutting-edge offshore infrastructure that embodies engineering excellence and environmental stewardship. This achievement reaffirms our unwavering commitment to innovation and sustainability, setting new benchmarks for offshore wind projects and supporting global efforts to build a greener future.”
‘Pioneering Work’
“The awarding of the contract to GE Vernova and Drydocks World marks the beginning of a new chapter in the use of wind energy in the Baltic Sea. 50Hertz is the first transmission system operator to deploy 2-GW/525-kV technology in this sea area. This is pioneering work,” said Stefan Kapferer, CEO of 50Hertz (Figure 2). “We want to ensure that the entirety of the technically and economically viable offshore wind energy potential in the Baltic Sea is exploited, primarily with the help of direct current technology. To do this, we need to think and act in an even more networked way across national borders. One prerequisite for this is the creation of legal and regulatory conditions that enable wind farms in the waters of other EU [European Union] states to be connected to the German transmission grid.”
2. Leaders are shown here after the symbolic signing of the contract. Standing are Stefan Hartge (GE Vernova), Marco Nix (50Hertz), Capt. Rado Antolovic (Drydocks World). Sitting are Johann Bindele (GE Vernova), Stefan Kapferer (50Hertz), HE Sultan Admed Bin Sulayem (Dubai Port World). Courtesy: 50Hertz/Kathrin Heller GE Vernova noted that Germany has an ambitious energy transition (Energiewende) framework, which aims to phase out coal entirely by 2030 and achieve net-zero emissions by 2045. It said Germany’s Climate Law requires 80% of the country’s electricity supply to come from renewable sources by 2030, with a target of 100% by 2035. “Projects like Ostwind 4 are crucial in meeting these goals, enabling the efficient transmission of renewable energy from offshore wind farms to the national grid and reducing dependence on fossil fuels,” GE Vernova said. “Ostwind 4 represents a crucial milestone in our mission to electrify and decarbonize with the energy to change the world. By leveraging our advanced HVDC technology, this key infrastructure project underscores the essential role of offshore wind to ensure European energy security and to accelerate the global energy transition. This order also highlights the rapid growth in GE Vernova’s Electrification segment, our fastest growing business, as our customers invest in the grid. We are very proud to collaborate with 50Hertz and Drydocks World to advance Germany’s renewable energy goals and set a new standard for a resilient and sustainable grid infrastructure,” said Philippe Piron, CEO of GE Vernova’s Electrification business. “Drydocks World’s pivotal role in the Ostwind 4 project underscores its technical excellence and commitment to advancing sustainable infrastructure. This award reflects DP World’s broader mission to drive clean energy transitions and economic growth. As the global energy landscape evolves, we remain dedicated to leveraging our expertise and innovative capabilities to support initiatives that drive clean energy transitions and economic development,” said Sultan Ahmed bin Sulayem, group chairman and CEO of DP World. “Ostwind 4 demonstrates the advancements in HVDC technology that GE Vernova delivers to support the integration of renewable energy sources at transformative scales. The use of our voltage-sourced converters, g3 gas-insulated switchgear, and robust system design ensures not only efficient power transmission but also operational reliability over long distances. We are honored to lead this project in collaboration with our consortium partner Drydocks World and support 50Hertz in pushing the boundaries of energy innovation,” added Johan Bindele, leader of Grid Systems Integration at GE Vernova’s Grid Solutions business. —Aaron Larson is POWER’s executive editor (@POWERmagazine).
