SP Transmission Plc

SP Transmission plc (SPT) is the electricity transmission licensee for central and southern Scotland within the SP Energy Networks group of ScottishPower, part of the Iberdrola group. It owns, develops and maintains the onshore high‑voltage transmission network in this region, operating as one of three onshore transmission owners in Great Britain alongside National Grid Electricity Transmission in England and Wales and Scottish Hydro Electric Transmission in the north of Scotland. SPT’s system forms the transmission corridor between Scotland and England and is physically interconnected to the Northern Ireland transmission system via a high‑voltage direct current interconnector. The SP Transmission system comprises around 4,000 circuit kilometres of overhead line and cable and 154 substations operating at 400 kV, 275 kV and 132 kV, covering an area of about 22,951 km². It supplies nine major demand customers directly and underpins demand for roughly two million end‑users connected via the SP Distribution network through 14.5 GVA of transformer capacity. Around 6.5 GW of directly connected and large embedded generation, including 36 power stations, is connected within the SPT area, and the network is responsible for connecting and transferring large volumes of offshore wind and other renewable generation, contributing to national offshore wind targets towards 2030 and the wider net zero objective. Operating under the RIIO‑T2 price control and the Network Innovation Allowance framework, SP Transmission undertakes innovation projects to improve system performance, asset management and integration of low‑carbon generation. Initiatives include development of a “System Health Map” that consolidates transmission asset data into a centralised analytics platform to support condition‑based interventions. The company reports increasing capital expenditure to deliver transmission reinforcements and upgrades required to facilitate government renewable energy and net zero targets, and it engages closely with Ofgem, the Electricity System Operator and offshore wind developers on coordinated onshore solutions for Pathway to 2030 and related offshore network coordination workstreams.