This MSIP application presents the needs case for the creation of a new Grid Supply Point (GSP) Substation at Gremista on Shetland and associated 132kV network infrastructure connecting Gremista GSP to Kergord substation.  This will connect Shetland to the GB energy system for the first time, via the Shetland High-Voltage Direct Current (HVDC) transmission link which is currently being progressed, supporting Shetland’s future security of supply.

When connected, the GSP will remove Shetland’s dependence on diesel generation as the primary source of generation from Lerwick Power Station, which will then transition to a standby mode of operation to provide a backup supply in the event of an outage on the Shetland HVDC link.

This development will deliver the following key benefits:

  • Meet the need for a transmission demand connection to connect the Shetland Islands to the mainland GB transmission system, supporting our RIIO-T2 goal to transport renewable electricity to power up to 10 million homes;
  • Ensures SSEN Distribution demand customers will be provided with a connection to the transmission system by 2024, supporting our RIIO-T2 goal of delivering every connection on time;
  • Enable’s the timely transition of Lerwick Power Station into standby mode in 2025;
  • Avoids the significant additional investment that would be needed to maintain the existing Lerwick Power Station by procuring a new enduring solution; and
  • It will Introduce energy diversification to Shetland supporting the decarbonisation of the local electricity demand network. This will help contribute towards Net Zero targets by changing the need for Lerwick Power Station to operate as the primary source of supply, resulting in a significant reduction in carbon emissions from the burning of diesel fuel.

The project will consist of a new 132/33kV GSP at Gremista with a 22km double circuit 132kV connection, which will be a combination of both Underground Cable (UGC) and Overhead Line (OHL), between Gremista GSP and Kergord substation.

As part of the optioneering process we have carried out a route and asset technology assessment driven by the unique geographical and environmental challenges on Shetland. Our approach was supported by extensive stakeholder engagement carried out virtually in 2020 and in person in 2021.

Any confidential or commercially sensitive information has been redacted from the document.