There’s anger over SSEN’s decision to replace the damaged subsea cable with a like-for-like 33kV line

However, not everyone on the island is jumping for joy at the decision, with some commentators having expected an upgrade to the cable.

Following analysis of procurement, cable manufacture and licensing considerations, it is expected that the replacement cable will be energised and operational by end of August 2021.  

The replacement 33kV cable, which SSEN claim will provide increased capacity of between 8 and 10MW compared to the existing link, is expected to arrive in the UK in late May of next year.

In reaching this decision, SSEN Distribution worked with SSEN Transmission to undertake a whole system analysis of a range of technical options for the cable replacement. 

The company say that following extensive consideration, including engagement with local stakeholders and affected parties, the decision in favour of a 33kV replacement has been made to protect against further security of supply risk to customers on Lewis and Harris and to limit environmental and community impacts.

Detailed analysis of alternative solutions, including a new 132kV link, presented replacement timescales of February 2023 at the earliest, leaving customers and communities exposed to undue risk over three winters as well as being unable to resume renewable electricity export.  

The decision to proceed with the replacement 33kV also avoids up to 200,000 tonnes of CO2 emissions from the diesel-powered back-up stations during the timescale projected for a larger cable option.

Mark Rough, Director of Customer Operations, SSEN Distribution, said: “Faced with considering replacement options in an emergency scenario, we’ve had to balance the opportunity to progress whole system solutions with the need to restore Lewis and Harris to normal supply and generation conditions in reasonable timescales, limiting impacts where possible.

“We recognise from our engagement with the community there are a range of views about the optimum solution, each with its own trade-offs.  In exploring options, it became clear that the conditions and timescales related to a larger solution posed a number of challenges which could not be reconciled without leaving customers and network users exposed to significant risk.

“Our priority as distribution network operator remains to ensure a safe and secure supply of electricity to homes and businesses on the islands whilst limiting any risk to supply wherever possible.  Today’s decision supports that outcome.”

Whilst SSEN acknowledges recent calls from some stakeholders for a larger capacity cable to be installed and ringfenced for community renewable schemes, it is important to note that this is not permitted under industry rules and regulations.  Any additional capacity must be allocated in line with the contracted position of developers on a first-come, first-served basis and network operators cannot discriminate between ownership models or technologies.

Separately, SSEN Transmission has confirmed that it remains committed to take forward a transmission link to the Western Isles with its progression remaining subject to regulatory approval. This, in turn, requires sufficient levels of renewable electricity generation on the Western Isles to demonstrate commitment to take projects forward, in line with Ofgem’s expectations.

Community developers with a significant interest in connecting are therefore encouraged to make a formal application to secure their place in the queue to connect, which will support the investment case to take forward the link.

Na h-Eileanan an Iar SNP MSP Alasdair Allan has “cautiously” welcomed the announcement by Scottish & Southern Energy Networks (SSEN) that a replacement subsea cable between Skye and Harris will be in place before next winter. He highlighted the need for SSEN not to let that timetable slip, and stressed the great difficulties for community renewables that there will be until the link is renewed.

Alasdair commented: “This is encouraging news, as Lewis and Harris have not been connected to the national grid since the cable broke.

“I have had discussions with SSEN and other stakeholders, who have made clear that the current power generation capabilities in the island are capable of meeting the demands of island consumers over this winter. However, it was also made clear that this comes with an impact in terms of fuel costs and significantly higher emissions.

“Many will be disappointed, as am I, that the opportunity is not being taken by SSEN to install a larger capacity cable, though the waiting time involved for that would, I would recognise, have been completely unacceptable. The earliest date that a larger cable would be able to be operational by would be February 2023. Also, the extra capacity would not be usable until at least 2025 due to other network constraints on the mainland. It is to be hoped therefore that the firm date next year for a replacement cable will now be met.

“I am very conscious, however, that the current situation is causing real problems for many community renewables projects and the organisations which they support locally. I hope that SSEN will now open up some more capacity for these projects by lessening some of the constraints currently in place.”

Stornoway Trust Factor Iain M. Maciver hailed the good news stating: “It is comforting to learn that the Trust’s well aired concerns over the adverse effects a prolonged shut down would have on our existing wind farms are now being sensibly addressed.

The prospect of these turbines being enabled to get reconnected to the grid within the coming year will no doubt be regarded as a huge Christmas present by those who own them.

Community beneficiaries can now look forward to receiving their much needed funding support sooner than was initially feared.

The Trust’s stance for the 33kV solution is not just to protect what is already here but also to protect the best interest of aspiring developers from what both the Trust and the Comhairle saw as an untenable alternative.

Fundamental to our efforts to justify the merits of the 600MW Arnish subsea link is our projected need for upwards of 100MW of community owned generation to accommodate what we believe that sector can viably offer.

Not only can that be achieved in a more cost effective way without the same degree of risk but it will also accommodate the power the community’s own stake in the Stornoway and Eishken projects will require.”

Islands MP, Angus MacNeil was asked for comment but did not respond.