# UK National Grid and SSEN Transmission Advance Groundwork on 2 GW Eastern Green Link 2 HVDC Link

> Civil engineering works have commenced at the converter station sites in Peterhead, Scotland and Drax, North Yorkshire for Eastern Green Link 2 (EGL2), the UK’s longest subsea HVDC link. The £4.3 billion project will unlock 2 GW of renewable power transmission with heavy-duty 525 kV converter transformers.

- **Publish Date:** 2026-09-27
- **Category:** transmission-substations
- **Reading Time:** 5 min
- **Original Source Citation:** [National Grid Electricity Transmission & SSEN Transmission](https://www.nationalgrid.com/news/2026/09/eastern-green-link-2-converter-station-civil-milestones-peterhead-drax)
- **Tags:** Eastern Green Link 2, EGL2, National Grid, SSEN Transmission, HVDC Converter Station, Peterhead, Drax, Subsea Cable, UK Grid
- **Canonical URL:** https://voltformer.com/news/uk-national-grid-ssen-accelerate-egl2-peterhead-drax-2gw-hvdc-superhighway
- **Markdown Source:** https://voltformer.com/news/uk-national-grid-ssen-accelerate-egl2-peterhead-drax-2gw-hvdc-superhighway.md

## The UK’s Largest Subsea Electricity Superhighway

Developed as a joint venture between SSEN Transmission and National Grid Electricity Transmission under Ofgem’s Accelerated Strategic Transmission Investment (ASTI) framework, EGL2 spans 505 km—including 436 km of subsea HVDC cable across the North Sea. The link will transmit enough green electricity to power two million British homes.

At Peterhead and Drax, deep piling and heavy foundation works are underway to support the massive converter hall superstructures, which will house state-of-the-art Voltage Source Converter (VSC) valves and associated harmonic filter banks.

## Heavy-Duty 525 kV Converter Transformers and High-Capacity Bushings

The electrical core of both terminal substations relies on bespoke 525 kV HVDC converter transformers engineered to withstand combined AC and DC dielectric stresses. Because the units must operate reliably under continuous offshore wind volatility, the transformers incorporate advanced on-load tap changers (OLTC) with vacuum switching technology and continuous dissolved gas analysis (DGA) monitoring.

Logistical planning for transporting the 320-tonne transformer main tanks from specialized coastal ports to the Drax site in Yorkshire involves custom multi-axle girder bridge transport vehicles and coordinated highway reinforcements.

## Critical Milestone for Clean Power 2030 Targets

EGL2 serves as a cornerstone of the Great Grid Upgrade, designed to relieve severe thermal constraints along the Anglo-Scottish transmission boundary that currently cost British consumers hundreds of millions of pounds annually in renewable curtailment constraint payments.

With subsea cable fabrication progressing at Prysmian facilities and converter technology being manufactured by Hitachi Energy, offshore cable laying is scheduled to begin in 2027 towards commercial operation in 2029.

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