Uist’s grid connection at risk as Ofgem push back on sub sea cable replacement
Local renewable energy producers have raised concerns that the undersea cable connecting Uist to the national grid is at risk if urgent replacement works do not go ahead.
Under current arrangements, the energy regulator ofgem must approve all network operator business plans before any major projects can proceed through a system known as RIIO2 (Revenue=Incentives+
Innovation+Outputs).
Scottish & Southern Electricity Networks’ (SSEN’s) business case for this next five year period prioritised replacing the current 46.1km Uist-Skye subsea cable with two shorter cables, running from Skye to Loch Carnan in the south and to Lochmaddy in the north, improving capacity and resilience for the islands.
Ofgem has pushed back to SSEN, rejecting plans to replace the cables and demanding further information is provided to justify the spend.
The undersea cable is the only means by which Uist connects to the national grid; without it we cannot import power to, or export power from, the islands. If the cable were to fail, the islands would be reliant on the limited capability of Carnan power station and costly, environmentally damaging back up diesel generators.
The situation is of concern to community renewables companies Uist Wind and Storas Uibhist, who are fearful of a repeat of the situation two years ago, when the cable connecting Harris to Skye failed, restricting power export and leaving Lewis and Harris reliant on back-up generation for a full year.
As a result of the Harris failure, insurance companies are no longer prepared to cover business losses associated with undersea cable failures, which leaves local community companies unable to recover lost income should the Uist cable fail. This in turn requires substantial reserves to be maintained and putting millions of pounds of community investment at risk at a time when the communities of Uist are facing extreme financial hardship.
The current health of the 31 year-old Uist cable is deemed to be worse than the Harris cable was at the point if its failure in 2020, and by 2028, is expected to present more than four times the risk of failure. In its business case submissions, SSEN said: “The probability of failure is 1.8858 in 2023/24 rising to 6.1268 by the end of ED2, 2028. The Skye – Harris 33 kV subsea cable had a Probability of Failure of 1.3126 and failed in October 2020.”
An Ofgem spokesperson told Am Pàipear: “Ofgem has not rejected the needs case for replacing the Uist supply cable. However, proposals by developers need to fully demonstrate how they meet that needs case. Ofgem is focussed on ensuring the resilience of infrastructure connecting the Scottish Islands.
SSEN confirmed that they were working with Ofgem to justify the need for funding, adding: “We are hopeful of a positive outcome when its Final Determinations are announced at the end of November.”
Community renewable projects across the Western Isles have issued a joint letter to Ofgem Chief Executive, Jonathan Brearley, saying: “We believe that this decision questions the Government’s and OFGEM’s commitment to Net Zero and decarbonisation targets, as well as the importance they place on remote communities within the network. The overall drastic impact this decision could have on the quality of life of the communities these networks serve should not be underestimated. We ask that OFGEM work with SSEN to find a solution to this issue as soon as possible, and we would welcome a response to detail how this can be done.”
Comhairle nan Eilean Siar has issued a statement blasting Ofgem’s decision: The Comhairle is engaging with OFGEM over its shortsighted approach to asset replacement, which could have catastrophic consequences for the Uist and Barra community in the near future. In light of OFGEM’s failure to regulate electricity prices or to enable grid connection to the islands, the Comhairle will now consider whether OFGEM is fit-for-purpose as an energy sector regulator for the 21st Century when the planet is plunging into climate crisis and island households are having to choose whether to heat or eat due to rapidly escalating electricity prices.”
The fragility of our grid connections and the soaring cost of energy has raised the question of whether Uist could be self sufficient in terms of power, supporting its own electricity needs on-island. Figures given to Am Pàipear by SSEN show from Barra to Berneray, we typically import and consume 8.43 MW of power from the grid, and produce and export around 11.4MW.
Sector stakeholders including Community Energy Scotland, Comhairle nan Eilean Siar, elected members and our community owned renewables companies have signed up to support Power for People, a campaigning group seeking to introduce a local electricity bill that would make it easier for people to buy the electricity produced within their own communities.
