The responsibilities and obligations for the safe installation, operation and maintenance of our transmission network are split across two parties – the Transmission Owners (TO) and National Grid Electricity System Operator (NGESO).

Our licenced company, SSEN Transmission is the TO of the electricity network which operates at voltages of 132kV and above in the north of Scotland. We own the existing system and are responsible for the planning, design, construction and maintenance of a network which currently comprises 148 Grid Substations, 5,070km of circuits, 161km of High Voltage Direct Current (HVDC) circuit, 11,656 transmission towers (pylons) and structures.

NGESO ensures that minute by minute electricity demand is matched by an equal volume of electricity generated by power stations.

In addition to its obligations to operate the network, NGESO is also responsible for the coordination, issue and management of contracts for the connection of new, large power stations using all technologies – wind, hydro, marine, gas, nuclear or coal.