A blog by Bless Kuri, Head of Transmission System Planning and Investment

As owner of the electricity transmission network in the north of Scotland, we have a critical role to play in the transition to net zero - by building the transmission infrastructure required to connect renewable electricity generation, and transporting that clean electricity to areas of demand.

Based on feedback from our customers and wider stakeholders, and working with the Electricity System Operator, National Grid (ESO) and the other GB Transmission Owners (TO), we continually review the potential transmission network requirements arising from different scenarios for future demand and generation, looking ten years ahead and beyond. This allows us to identify which parts of the network require strengthening, including the need for new network infrastructure, to deliver the investment required and support the pathway to net zero.  By working in collaboration with the ESO and the other TOs, it allows us to collectively prepare for this investment in the most economical way possible for GB bill payers.

In considering a wide range of credible outcomes and scenarios, we can then develop an evolving long-term plan for what upgrades may be required, and when, to strengthen our network, deliver for our demand and generation customers, and contribute to the wider efficient development and operation of the GB transmission network.

We therefore welcome the publication of the ESO’s annual Network Options Assessment (NOA) report outlining, based on its independent analysis, which major projects will be required to meet the future needs of GB’s electricity transmission system which are measured against NGESO’s Future Energy Scenarios (FES).

For SSEN Transmission, our planned investments outlined in the NOA remain unchanged in this year’s study when assessed under the latest scenarios. This year’s report continues to recommend, under all FES considered by the ESO, that the following proposed East Coast reinforcements in our network area “proceed” to support an expected increase in renewable generation capacity during the continued transition to net zero:

  • East coast onshore 275kV upgrade – upgrading one of the double circuit overhead lines running south from Kintore substation to enhance its capacity at the existing operating voltage of 275kV and establishing a new substation near Alyth by 2023.
  • East coast onshore 400kV incremental reinforcement – a further upgrade of the double circuit overhead line running south of Kintore along with upgrades to the existing 275kV lines running between Blackhillock substation (near Keith), Peterhead substation and Kintore substation to operate at 400kV in 2026.
  • Eastern Scotland to England offshore link (Peterhead to Drax) – the construction of a proposed subsea High Voltage Direct Current (HVDC) link from Peterhead substation to Drax substation in the north east of England by 2029.

Both the East Coast onshore upgrades are included in our Certain View investment plan in our recently published Business Plan for the period 2021-2026: A Network for Net Zero, which also includes pre-construction development to support the delivery of the East Coast HVDC link.

In addition, the NOA report recommends that an additional HVDC link be introduced from North East Scotland to South Humberside by 2031 as a result of further expected renewable generation in the North of Scotland. However, this early stage recommendation is expected to be further refined in next year’s NOA once more detailed investigation and scoping of requirements takes place. We also look forward to the expected inclusion of a net zero scenario in next year’s NOA publication which we believe will help strengthen our contribution to a more sustainable future GB electricity system.

Finally, whilst the NOA identifies a number of projects that meet Ofgem’s eligibility criteria for competition, we note that this does not necessarily mean that these projects will be subject to competition.  We continue to believe that the introduction of competition to onshore transmission must be supported by the necessary primary legislation, which has yet to be introduced.

Further information on SHE Transmission’s progress with the East Coast reinforcements can be found on the following project pages:

 

NOTES

  • The annual NOA process takes information from each of the three GB TOs about their transmission reinforcement options to meet current and future system needs. It combines this with expected generation and demand scenarios and carries out a GB wide cost benefit study to allow the ESO to make independent recommendations for the optimal sequence and timing of transmission investments. For each investment proposed, the NOA report recommends whether to “proceed”, “delay”, “hold”, “stop” or “do not start” based on known and expected system requirements.
  • The NOA process is iterative and we will shortly start work on the January 2021 report. This means continuing to assess the appropriate transmission network developments to take forward against the emerging and updated generation and demand scenarios.  In the event of material changes in the scenarios or other development factors, progression of modified or alternative reinforcement schemes may become justified.

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