RIIO-T3 Load Re-openers

VSRE - XH and XJ Routes Overhead Line Uprating Works

This Project Assessment (PA) submission sets out SP Transmission’s (SPT) case for delivery of the VSRE project, which forms part of NESO’s Holistic Network Design (HND) and has been identified as a Clean Power 2030 project to support delivery of a 95% clean power system by 2030. The HND is expected to deliver material consumer value, while Clean Power policy places strong emphasis on security of supply and enabling economic growth.

This document is SPT’s first PA submission under the RIIO T3 Load Re Opener Framework. The submission has been prepared in accordance with the requirements of Special Licence Condition (SpC) 3.18 (Load Re opener and Price Control Deliverable) and the associated guidance documents, including the Load Re opener Guidance and Submission Requirements and the Re opener Guidance and Application Requirements. SPT is requesting £142.077m.

Ahead of submission, SPT welcomed Ofgem’s constructive engagement through a programme of structured deep dive sessions and discussion with Ofgem’s leadership team via the new Load Boards. The PA submission has also progressed through SPT’s internal data assurance arrangements in line with Ofgem’s Data Assurance Guidance (DAG).

Redactions may be applied to the published version of this submission where content is commercially confidential or otherwise sensitive.

Click here to view the full VSRE project assessment (redacted)

Glenlee to Newton Stewart Reconductoring Works

This Eligibility Letter submission made to Ofgem sets out SP Transmission’s (SPT) plans to increase the capacity of the existing transmission network in southwest Scotland, enabling the connection of contracted renewable generation, largely made up of onshore wind.

These works comprise: (i) reconductoring of the existing 132kV overhead line between Glenlee and Newton Stewart using High Temperature Low Sag (HTLS) conductors; (ii) replacement of the existing earthwire and associated fittings; (iii) targeted tower strengthening, refurbishment and painting works; and (iv) replacement of the cable section connecting the route into Newton Stewart Substation.

The works are currently programmed to commence and complete in the RIIO-T3 period.

Full justification for the preferred investment option is presented within this Eligibility Letter submission, together with a detailed description of the proposed solution.  This is consistent with the requirements of Special Licence Condition (SpC) 3.18 (Load Re-opener and Price Control Deliverable) and the associated guidance documents, including the Load Re-opener Guidance and Submission Requirements and the Re-opener Guidance and Application Requirements. 

Redactions have been made for this published document due to the sensitivity of the content as it includes confidential information with commercial sensitivity.

Click here to view the full Glenlee to Newton Stewart Reconductoring Eligibility Letter (redacted)

Click here to view the Glenlee to Newton Stewart Reconductoring Eligibility Letter Redaction Justification table

Branxton to Braxbess 400/132kV Collector Substation Works

This Eligibility Letter submission made to Ofgem sets out SP Transmission’s (SPT) plans to provide additional transmission infrastructure in the Branxton area to facilitate the connection of contracted Battery Energy Storage System (BESS) developments.

These works comprise: (i) the installation of a new 400kV SF₆-free Gas Insulated Switchgear (GIS) bay at Branxton 400kV Substation; (ii) an approximate 2.15km 400kV cable circuit from Branxton Substation to the new  “Braxbess” 400/132kV Collector substation located at the User’s site; and (iii) the establishment of Braxbess 400/132kV Collector substation, equipped with two 400/132kV 360MVA transformers.

The works are currently programmed to commence and be completed in the RIIO-T3 period.

The investment will build upon the wider Branxton network development, enabling the efficient and coordinated connection of energy storage projects while maximising the use of shared transmission infrastructure and supporting wider network capacity requirements.

Full justification for the preferred investment option is presented within this Eligibility Letter submission, together with a detailed description of the proposed solution.  This is consistent with the requirements of Special Licence Condition (SpC) 3.18 (Load Re-opener and Price Control Deliverable) and the associated guidance documents, including the Load Re-opener Guidance and Submission Requirements and the Re-opener Guidance and Application Requirements. 

Redactions have been made for this published document due to the sensitivity of the content as it includes confidential information with commercial sensitivity.

Click here to view the full Branxton to Braxbess 400/132kV Collector Substation Eligibility Letter (redacted) 

Click here to view the Branxton to Braxbess 400/132kV Collector Substation Eligibility Letter Redaction Justification table