Decision on our project assessment for the Hinkley-Seabank electricity transmission project


Hinkley-Seabank (HSB) is a Strategic Wider Works (SWW) project, being developed by the Transmission Owner (TO) for England and Wales, National Grid Electricity Transmission (NGET). HSB is a NGET's technical solution for connecting EDF's Hinkley Point C (HPC) nuclear power station to the GB transmission network. It will be one of the largest extensions of the transmission network in recent decades. As proposed by NGET, it comprises:

  • 49 km of 400 kV overhead lines – mostly using ‘T-Pylons’ rather than traditional lattice towers;
  • 8.5 km of underground cabling through the Mendip Hills Area of Outstanding Natural Beauty (AONB);
  • construction of a new substation and a reconfiguration of two existing substations; and
  • a reconfiguration of the local 132 kV network.

In our October 2019 Project Assessment consultation, we presented our minded-to position on the economic and efficient costs for the HSB project. This document confirms our final decision to provide NGET with a total allowance of £655.7m for the delivery of the project. This is a £60.0m deduction from NGET’s requested cost for the project.