Why is HVDC technology used for the EGL2 project instead of traditional AC transmission?

High Voltage Direct Current (HVDC) technology is highly efficient for transmitting large amounts of electricity over long distances, particularly underwater. Unlike Alternating Current (AC), HVDC experiences significantly lower electrical losses over the 436-kilometer subsea route and allows for precise control over the power flow between the Scottish and English grid systems.

How does EGL2 impact the broader European offshore wind integration strategy?

EGL2 serves as a pioneering template for the North Sea Supergrid concept, demonstrating how massive offshore wind clusters can be integrated into national grids. The technical standards, supply chain collaborations, and regulatory frameworks established during EGL2's construction will likely influence future cross-border interconnectors linking the UK with mainland Europe.

What are the main supply chain risks associated with the EGL2 timeline?

The primary risks stem from a global shortage of specialized cable-laying vessels and the high demand for HVDC converter components, which has led to multi-year lead times. Any delays in the manufacturing schedules of Prysmian or Hitachi Energy, or adverse weather conditions in the North Sea during the critical laying phases, could jeopardize the targeted 2029 commissioning date.

Offshore Energy · July 15, 2026 (1d ago) · 1 min read

‘UK’s largest-ever’ electricity transmission project in major construction phase

Analysis

AI-assisted analysis · reviewed by Yuri Kan

The Eastern Green Link 2 (EGL2) project, a landmark 2 GW subsea HVDC transmission link in the UK, has officially entered its major construction phase. This massive infrastructure undertaking represents a critical shift in how offshore wind power is transmitted from northern generation hubs to southern demand centers. For global energy markets, it serves as a technical and regulatory blueprint for executing complex, multi-billion-dollar subsea interconnectors in challenging marine environments.

Key Facts

The Eastern Green Link 2 (EGL2) is a joint venture between National Grid Electricity Transmission and SSEN Transmission.
The project features a 525kV subsea High Voltage Direct Current (HVDC) cable system with a transmission capacity of 2 GW.
The subsea cable route spans approximately 436 kilometers through the North Sea, connecting Peterhead in Scotland to Drax in North Yorkshire.
Major contract awards for the project include Prysmian Group for cable manufacturing and installation, and Hitachi Energy alongside BAM for the converter stations.
The project is estimated to cost approximately £4.3 billion and is scheduled to be fully operational by 2029.
EGL2 is designed to transmit enough renewable electricity to power up to two million UK homes.

Background & Context

The UK's transition to renewable energy has created a geographic mismatch, with the vast majority of offshore wind capacity located in Scottish waters while the primary demand centers remain in the south of England. Historically, the onshore grid has suffered from severe bottlenecks, forcing the system operator to pay wind farms constraint payments to turn off during peak generation. Subsea HVDC links like EGL2 have emerged as the preferred solution to bypass onshore grid congestion without the prolonged planning delays associated with overland pylons.

Market Impact

The progression of EGL2 into active construction bolsters investor confidence in large-scale offshore transmission infrastructure and secures a robust pipeline for the subsea cable supply chain, which is currently facing global capacity constraints. For technology providers like Prysmian and Hitachi Energy, this project solidifies their market dominance in high-voltage direct current systems. Furthermore, the successful execution of this link will significantly reduce curtailment costs for wind developers in the North Sea, ultimately lowering balancing costs for the end consumer.

What to Watch

The immediate milestones to watch include the commencement of marine trenching operations and the civil engineering works for the converter stations at Peterhead and Drax. Industry analysts will also monitor how the supply chain manages potential bottlenecks in raw materials and specialized vessel availability over the 2025-2028 installation window. Additionally, the regulatory treatment of EGL2 by Ofgem will set a precedent for subsequent links, such as EGL1 and EGL4, which are currently in the planning pipeline.

Frequently Asked Questions

Why is HVDC technology used for the EGL2 project instead of traditional AC transmission?: High Voltage Direct Current (HVDC) technology is highly efficient for transmitting large amounts of electricity over long distances, particularly underwater. Unlike Alternating Current (AC), HVDC experiences significantly lower electrical losses over the 436-kilometer subsea route and allows for precise control over the power flow between the Scottish and English grid systems.
How does EGL2 impact the broader European offshore wind integration strategy?: EGL2 serves as a pioneering template for the North Sea Supergrid concept, demonstrating how massive offshore wind clusters can be integrated into national grids. The technical standards, supply chain collaborations, and regulatory frameworks established during EGL2's construction will likely influence future cross-border interconnectors linking the UK with mainland Europe.
What are the main supply chain risks associated with the EGL2 timeline?: The primary risks stem from a global shortage of specialized cable-laying vessels and the high demand for HVDC converter components, which has led to multi-year lead times. Any delays in the manufacturing schedules of Prysmian or Hitachi Energy, or adverse weather conditions in the North Sea during the critical laying phases, could jeopardize the targeted 2029 commissioning date.

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