50Hertz, the transmission system operator (TSO) for East Germany, has awarded its Ostwind 4 project to GE Vernova, in consortium with Drydocks World, a DP World company that provides, among other things, maritime and offshore services to the renewable energy sector. The project involves the design, construction and commissioning of a 2 GW high-voltage direct current (HVDC) electrical transmission system – the first of its kind in the German Baltic Sea – connecting offshore wind farms to the German electricity grid. Ostwind 4 is the fourth offshore project designed to connect wind farm areas northeast of the island of Rügen to the German electricity grid (Figure 1). As part of the project, both an offshore converter platform and an onshore converter station will be built. This is the first time that an offshore wind farm in the German Baltic Sea will use 525 kV HVDC technology, which can transport more power than AC connections with lower losses over longer distances.
1. Ostwind 4 is the fourth project to connect offshore wind farms (OWFs) from the northeast of the island of Rügen to the German electricity grid. Thanks to: 50Hertz The wind farm concession area in which the project will be located was purchased by Total Energies during an auction. The area is located on the edge of the German Exclusive Economic Zone (EEZ). A submarine cable with a length of approximately 110 kilometers (km) will run from the offshore converter, via the Greifswald Bodden, to Lubmin near Vierow. An underground cable of about 4 km long will run from Lubmin to the planned substation with the counter-inverter in the municipality of Brünzow in the Vorpommern-Greifswald district. The direct current is then converted back into alternating current and fed into the 50Hertz extra-high-voltage transmission network. The contract for the production and installation of the submarine 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 supplying 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 consortium leader, GE Vernova will supply advanced HVDC technology including voltage source converters (VSC), high-voltage transformers, air nuclear reactors and g3 gas insulated switchgear (GIS). GE Vernova’s g3 (pronounced “g cubed”) insulating gas is an alternative to sulfur hexafluoride (SF6) insulation gas, with a drastically lower impact on the environment; the global warming potential (GWP) has been reduced by more than 99% in comparison. Meanwhile, g3 products have the same classifications and the same dimensional footprint as SF6 options, and operate without limitations under the same temperature range as SF6 products (up to –30C). As part of the Ostwind 4 project, GE Vernova will carry out the civil works for the onshore converter station and telecommunications equipment for network automation. The company said the project will also benefit from GE Vernova’s new HVDC Competence Center in Berlin, which focuses on developing leading technology to improve grid stability and integrate more renewable energy. Drydocks World will manage the engineering, procurement, construction and installation of the topsides and jacket structures of the wind energy converter stations. The topside, which will be manufactured at Drydocks World’s Dubai facility, will feature state-of-the-art equipment designed and manufactured in Europe. Once completed, the platform will be transported and installed in German waters. “The Ostwind 4 project is an example of the power of international cooperation in advancing sustainable 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 management. This achievement reaffirms our continued commitment to innovation and sustainability, setting new benchmarks for offshore wind projects and supporting global efforts to build a greener future.”
‘Pioneer work’
“The award 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 groundbreaking work,” says Stefan Kapferer, CEO of 50Hertz (Figure 2). “We want to ensure that the entire technically and economically viable potential for offshore wind energy in the Baltic Sea is exploited, mainly using direct current technology. To achieve this, we need to think and act across national borders in an even more networked way. One condition for this is the creation of legal and regulatory conditions that allow wind farms in the waters of other EU [European Union] states to be connected to the German transport network.”
2. Leaders are shown here after the symbolic signing of the contract. Standing are Stefan Hartge (GE Vernova), Marco Nix (50Hertz), Captain Rado Antolovic (Drydocks World). Seated are Johann Bindele (GE Vernova), Stefan Kapferer (50Hertz), HE Sultan Admed Bin Sulayem (Dubai Port World). With thanks to: 50Hertz/Kathrin Heller GE Vernova noted that Germany has an ambitious energy transition framework (Energiewende), which aims to phase out coal completely by 2030 and achieve net-zero emissions by 2045. Germany’s climate law requires that 80% of the country’s electricity supply must come from renewable energy sources. energy sources by 2030, with a target of 100% by 2035. “Projects like Ostwind 4 are crucial to achieving these goals, as they enable the efficient transmission of renewable energy from offshore wind farms to the national electricity grid and reduce dependence on fossil fuels,” said GE Vernova. “Ostwind 4 represents a critical milestone in our mission to electrify and decarbonize with the energy to change the world. Using our advanced HVDC technology, this important infrastructure project underlines the essential role of offshore wind energy to ensure European energy security and 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 electric grid. We are very proud to work with 50Hertz and Drydocks World to advance Germany’s renewable energy goals and set a new standard for resilient and sustainable grid infrastructure,” said Philippe Piron, CEO of the Electrification division of GE Vernova. “Drydocks World’s central role in the Ostwind 4 project underlines the company’s 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 committed 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 is delivering to support the integration of renewable energy sources on a transformative scale. The use of our voltage converters, g3 gas-insulated switchgear and robust system design ensure not only efficient power transmission, but also long-distance operational reliability. 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,” said Johan Bindele, leader of Grid Systems Integration at GE Vernova’s Grid Solutions business. —Aaron Larson is the editor-in-chief of POWER (@POWERmagazine).
