Offshore Wind Growth and HVDC Developments in the North Sea: Key Trends and Future Outlook

Europe is pursuing an ambitious energy transition to become the world’s first climate-neutral continent by 2050. To reach this goal, the region has set stringent targets to decrease reliance on Russian fossil fuels and increase the adoption of renewable energy across the power and transportation sectors. Significant strides are being made in developing solar and offshore wind projects, in line with the European Council and Parliament’s directive to achieve a 32% share of renewable energy by 2030.

The North Sea region is witnessing a significant surge in offshore wind energy development (Figure 1), driven by ambitious targets set by key countries bordering its shores. The North Sea Energy Cooperation (NSEC) countries have ambitious goals. By 2030, they target a combined 120 GW of offshore wind capacity. The UK, a leader in offshore wind technology and deployment, has set a remarkable target of achieving 40 GW of offshore wind capacity by 2030. Germany, aiming to bolster its renewable energy capacity, has outlined plans to install up to 20 GW of offshore wind power by 2030. Similarly, the Netherlands has committed to reaching 11.5 GW of offshore wind capacity by 2030, underscoring its role in the region’s renewable energy transformation. Denmark, known for its pioneering efforts in wind energy, aims to have at least 10 GW of offshore wind capacity operational by 2030, contributing substantially to its ambitious climate goals. These targets exemplify a collective regional effort to capitalize on the North Sea’s wind resources, positioning offshore wind as a cornerstone of European sustainable energy strategies.

Advancing Renewable Energy Integration: Key Transmission Plans and Initiatives

According to the European Commission Ten-Year Network Development Plan (TYNDP), there are ambitious plans to significantly increase cross-border transmission infrastructure across Europe. The objective is to achieve a high-voltage direct-current (HVDC) cross-border interconnection target of 23 GW by 2025. This expansion aims to enhance connectivity and facilitate greater energy exchange between countries. Looking further ahead, the plan outlines a more substantial increase, to expand the cross-border transmission capacity to 64 GW by 2030. This strategic development is intended to support the integration of renewable energy sources, improve grid resilience, and strengthen the overall efficiency of the European energy network.

TenneT’s 2 GW Program. TenneT, the transmission system operator (TSO) for the Dutch-German region, finalized a major agreement for its 2-GW program, which entails deploying 14 HVDC transmission systems, each with a capacity of 2 GW. This initiative is set to be executed in the Dutch and German sectors of the North Sea, with completion targeted for 2031. The primary objective of this ambitious project is to bolster offshore wind energy supply and enhance the renewable energy framework across the region.

The deployment will introduce a substantial offshore wind energy capacity of 28 GW, aligning with about 30% of the European Union’s (EU’s) renewable energy expansion targets. TenneT is focused on optimizing transmission capacities to achieve up to a 50% reduction in the environmental impacts related to offshore wind energy transmission. This project is expected to facilitate the delivery of clean wind energy from the North Sea to approximately 35 million households, supporting regional sustainability objectives. This initiative underscores TenneT’s commitment to advancing offshore wind infrastructure, facilitating large-scale renewable energy integration, and driving sustainable energy solutions for the future.

North Sea Wind Power Hub (NSWPH) Programme. The NSWPH programme, established in March 2017, is a collaborative initiative involving leading TSOs from North Sea countries: Energinet, Gasunie, and TenneT. The programme envisions creating a high-capacity grid connecting Dutch, German, and Danish offshore wind sites, with a capacity ranging from 2 GW to 6 GW. This grid will follow a hub-and-spoke model, where electricity corridors extend in North-South or East-West directions, linking offshore wind farms and potentially branching out to neighboring countries.

UK’s HVDC Centre Leading Innovations. The National HVDC Centre in the UK is a pioneering facility dedicated to advancing this technology, which is crucial for efficiently transmitting electricity over long distances. Located in Cumbernauld, Scotland, the Centre is a research and development hub, providing a testing environment for HVDC systems and components. Its mission is to support the transition to a low-carbon energy system by enhancing the reliability and integration of HVDC technology into the UK’s power grid. By collaborating with industry, government, and academia, the Centre aims to drive innovation, improve grid connectivity, and contribute to the overall efficiency and sustainability of the national energy infrastructure.

Policies Supporting Transmission Development

Several policies and plans are in place to encourage renewable energy deployment and infrastructure development in the North Sea region. They include:

• REPower EU Action Plan

• • Objective. Increase the EU’s renewable energy target to 45% by 2030, up from the previous 40%.
  • Strategies. Promote the deployment of solar PV, rooftop solar, heat pumps, and other technologies to rapidly decarbonize the continent.
  • Key Actions. Accelerate and simplify permitting processes for renewable projects and enhance grid infrastructure.

• North Seas Energy Cooperation (NSEC)

• • Members. Belgium, Denmark, France, Germany, Ireland, Luxembourg, the Netherlands, Norway, Sweden, and the European Commission.
  • Purpose. Coordinate the development of offshore energy and related grid infrastructure.
  • Recent Developments.
    • April 2023 – Signing of the Ostend Declaration, which updated offshore wind development targets.
    • October 2023 – Creation of the European Wind Power Action Plan to align the clean energy transition with industrial competitiveness and continue the success of wind power in Europe.
    • November 2023 – Agreement on a shared action agenda to strengthen European supply chains, integrate the energy system by 2050, and balance energy needs with environmental stewardship in the North Sea.

• North Sea Summit (Denmark 2022)

• • Participants. Denmark, Belgium, Germany, and the Netherlands.
  • Goals. Quadruple combined offshore power generation capacity.
  • Esbjerg Declaration.
    • 2023 Targets – Achieve 65 GW of offshore wind capacity by 2030 and 150 GW by 2050.
    • Purpose – Transform the North Sea into a major green power source and enhance climate neutrality and energy security.

• Port of Ostend Summit (Belgium 2023)

• • Focus. Expand offshore wind farms in the North Sea to reduce dependence on Russian gas and fossil fuels.
  • Development Area. Includes the Atlantic Ocean, and the Irish and Celtic Seas.
  • Key Discussions. Diversify sources of critical raw materials for wind turbines and enhance the security of offshore and underwater infrastructure.
  • Ostend Declaration Commitments.
    • 2030 Targets – Develop 120 GW of offshore wind capacity.
    • 2050 Targets – Achieve 300 GW of offshore wind capacity.
    • Signatories – Belgium, Denmark, France, Germany, Ireland, Luxembourg, the Netherlands, Norway, and the United Kingdom.

Overview of HVDC Market Developments in the North Sea

The total HVDC pipeline capacity in the North Sea for the UK, Germany, and the Netherlands is set to exceed 70 GW. The market will be predominantly driven by voltage source converter (VSC) technology. HVDC-VSC technology has made significant strides in terms of cost reduction and increased transmission capacity. This progress has led to the clear dominance of HVDC VSC in Europe, meeting the bidirectional transmission needs of cross-border applications. Among the HVDC projects, 25 GW will be dedicated to cross-border connections, while 45 GW will focus on nationwide projects (Figure 2). This distribution underscores the significant role of VSC technology and the emphasis on regional and national energy integration in the North Sea region.

Cross-Border Energy Transmission Initiatives. The North Sea region is witnessing a surge in HVDC interconnection projects, with several key initiatives enhancing cross-border electricity exchanges. Notable projects include Greenwire North and Greenwire South, which connect the UK and Ireland, and Eurolink, linking the UK with the Netherlands. Major cross-border projects such as the Continental Link with Norway and the Second Interconnector between Germany and Belgium further highlight the growing emphasis on regional connectivity.

Potential Cross-Border Energy Transmission Projects. The NeuConnect Interconnector will establish the first direct power link between Germany and Great Britain, connecting two of Europe’s largest energy markets for the first time. Currently under construction, the project involves laying approximately 725 kilometers of land and subsea cables, creating an ‘invisible highway’ between the two countries. This new link will enable the transfer of up to 1.4 GW of electricity in either direction, facilitating greater energy exchange and enhancing the integration of renewable energy sources across these major markets.

LionLink is a pioneering multi-purpose interconnector project being developed by TenneT and National Grid Ventures (NGV), creating a new electricity link between the Netherlands and the UK. This innovative project not only facilitates cross-border electricity transmission and trade but also integrates a 2-GW Dutch offshore wind farm, enhancing decarbonization, energy independence, and security of supply for both countries. LionLink represents a significant step toward an integrated North Sea grid, with the potential to supply up to 2 GW of electricity.

Nationwide Transmission Projects Expanding and Upgrading Domestic Networks. From 2024 to 2030, the potential pipeline for HVDC nationwide projects is substantial across North Sea. The UK plans to develop 17.6 GW of HVDC capacity, while Germany aims to add 22.5 GW. The Netherlands is also contributing with a projected 6 GW. These developments highlight the significant investment in HVDC technology by the three major markets to support the region’s energy transition and enhance grid integration (Figure 3).

Recent Advancements in HVDC Technology in the North Sea Region

Other projects are also expanding grid capabilities while enhancing energy integration, safety, and reliability.

Multi-Terminal HVDC Hub: Enhancing Regional Energy Integration. In Germany, the four grid operators—TenneT, Amprion, 50Hertz, and TransnetBW—are jointly developing three multi-terminal HVDC hubs. These hubs will directly connect HVDC offshore wind export links with onshore HVDC networks, facilitating the transfer of wind power to southern regions while eliminating the need for additional converters and reducing associated energy losses.

DC Circuit Breaker for Ultra-High-Voltage 800-kV Transmission Lines: Enhancing Safety and Reliability. Recently, the four German transmission system operators—50Hertz, Amprion, TenneT, and TransnetBW—also teamed up with industrial partners Siemens Energy, GE Vernova, and Hitachi Energy to launch an innovative project involving DC circuit breaker technology for 800-kV ultra-high-voltage lines. This initiative, heralded as an energy future “made in Europe,” introduces a unique technical concept that could play a crucial role in achieving a climate-neutral grid in the future.

In the German North Sea alone, there are plans to install 70 GW of offshore wind energy. The challenge lies in efficiently bringing this energy ashore and distributing it across the country in the most cost-effective and spatially efficient manner possible. DC circuit breakers are expected to gain prominence, particularly in Europe, as the number of HVDC cross-border interconnections continues to grow. This trend is in line with Europe’s objective of reaching 15% interconnectivity by 2030.

DC circuit breakers designed for extra-high-voltage applications have progressed from Technology Readiness Level 3 (TRL 3), where they were primarily in the conceptual and proof-of-concept phase, undergoing initial laboratory testing and analysis. They have advanced to TRL 5, indicating significant development progress where extensive testing has confirmed their capability to reliably interrupt DC in laboratory or demonstration systems. However, further refinement is still required to achieve full commercial viability.

Offshore wind production in the North Sea is increasingly recognized as a cornerstone of Europe’s energy transition, with capacity expected to reach more than 200 GW by 2050, in line with net-zero energy targets. As this capacity expands, the infrastructure must keep pace, including significant advancements in HVDC technology.

—Kainat Yousaf is an analyst, and Asad Tariq is a senior analyst at PTR Inc.