SSEN Transmission, the 75%-owned subsidiary of Perth-based SSE plc, said it will submit to the UK energy regulator Ofgem its plans to deliver at least £22 billion in “mission-critical grid infrastructure” through its business plan for the RIIO-T3 price control, which covers the period from April 1, 2026, to March 31, 2031.
SSEN Transmission said its business plan will drive economic growth, supporting up to 37,000 UK jobs — 17,500 of them in Scotland — adding up to £15 billion of value to the UK economy and £7 billion in Scotland.
Rob McDonald, Managing Director of SSEN Transmission, said: “Our RIIO-T3 Business Plan sets out an ambitious, deliverable blueprint, to unlock the unprecedented levels of investment required to deliver UK and Scottish net zero and energy security targets, including the Clean Power by 2030 mission.
“In what is one of the largest investment programmes of all time in Scotland, this plan will also support tens thousands of jobs across the country, turbo-charging the economy and delivering a transformational and lasting legacy for communities, the economy and nature.
“We now look forward to working constructively with Ofgem, Government and wider stakeholders to ensure the future regulatory framework secures the investment required to support the nation’s ambitious goals and delivers the vast economic opportunities the clean transition presents.”
SSEN Transmission said its plan sets out a clear and evidence-based need for an expected known total expenditure of around £22.3 billion over the RIIO-T3 period.
This compromises a baseline total expenditure of around £6 billion and around £16 billion of committed strategic investments that have already received approval of need from Ofgem through its ASTI framework and LOTI Uncertainty Mechanisms.
SSEN Transmission said it has also set out the potential for an additional £9.4 billion of future “Uncertainty Mechanism” expenditure, which could bring the total expenditure over the RIIO-T3 period to around £31.7 billion.
Economic analysis, which has been independently peer reviewed by consultancy BiGGAR Economics forecast that, if delivered in full, the potential £31.7 billion total investment could support up to 37,000 jobs across the UK, 17,500 of which in Scotland, including 8,400 in the north of Scotland.
It would also add £15 billion in value to the UK economy, £7 billion of which in Scotland, including £3 billion in the north of Scotland.
“These investments will also provide significant local benefits, including community benefit funding, which, based on draft UK Government guidance, is expected to deliver well in excess of £100m in community benefit funding for projects being taken forward across the RIIO-T3 period,” said SSEN Transmission.
“It will also support the development of at least 1,000 new homes across the north of Scotland, creating a legacy in the communities that will host construction workers by delivering housing that will support local need once projects are completed …
“Delivery of this plan, the associated Government targets it will enable and the significant economic benefits it will unlock will require unprecedented and accelerated levels of strategic investment in the north of Scotland’s electricity network infrastructure.
“It is crucial that Ofgem’s regulatory framework reflects this urgency and the wider economic context against which this investment must be secured.
“The successful delivery of this plan therefore requires a financial framework commensurate with the scale of the task and capable of attracting the unprecedented levels of investment needed to deliver the clean energy transition and protect future energy consumers.”
Ofgem is expected to launch a Call for Evidence from December 18, 2024, to February 10, 2025, followed by the publication of its Draft Determinations in June 2025 and Final Determinations in December 2025.
Alistair Phillips Davies, Chief Executive of SSE plc, said: “The RIIO-3 price control comes at a critical juncture in the effort to deliver a cleaner, more secure and affordable electricity system for current and future generations.
“With a new national mission to deliver clean power by 2030 in order to boost energy security and protect future consumers, unlocking the right level of investment during the next price control will be key.
“We’re setting out today the extent of our ambition and commitment; it is now crucial that Ofgem backs that ambition with an investable and financeable framework, setting an appropriate cost of equity that recognises the unprecedented levels of investment required to decarbonise the economy and deliver a clean power system.”