Scottish and Southern Electricity Networks (SSEN) serves 59 of these western islands, ensuring these communities are connected to vital power supplies.
Some 280 miles (450km) of SSEN cables link the islands to the mainland electricity system. The network of cables stretches from Lewis and Harris in the northern Outer Hebrides, to Jura and Islay in the Inner Hebrides further south, powering homes, businesses, schools - every aspect of daily life.
With such an integral role to play in these island communities, SSEN aims to do more than provide energy safely and reliably. Working in partnership with WSP, SSEN wants to help celebrate, and protect, the heritage and biodiversity of these beautiful islands, ensuring their unique character is preserved for generations to come.
Here are just a few examples of projects where WSP is supporting SSEN to fulfil this ambition.
The Isle of Coll
Like many of the west coast isles, there are no gas mains on the Isle of Coll. Just 13 miles long and 4 miles wide, Coll is served by a single 11KV subsea electricity cable. Everyone on the island is dependent on electricity for power, including heating and lighting their homes.
“This places a huge moral and social responsibility on SSEN,” says Katy Urquart, subsea projects environmental manager at SSEN. “Especially when you look at the island’s demographics - about a third of that population are over the age of 65, and there are only about 150 properties. We’re very aware of the vulnerability of our customers to any disruption in supply, which is why we keep a very close eye on the condition of the cables which deliver power to these remote communities.”
Coll’s first cable was installed in 1987 running from the neighbouring Island of Mull under the sea to the Bay of Sorisdale on Coll. After just 14 years (in 2001) SSEN’s inspection regime revealed damage to the cable - a result of strong currents moving the cable over the rocky seabed as well as from trawler fishing boats dragging nets.
A new cable was installed and monitored using remotely operated subsea inspection tools. But by November 2018, this connection was also in need of repair. A project is now underway to lay a new, double-armoured cable in a nearby new location, away from intense fishing activity.
SSEN is consulting with local communities, local businesses, elected members and other key stakeholders to help minimise disruption. But the company wants to achieve more than a consensus on how to approach the project, SSEN is taking the opportunity to talk to people on Coll about what life is like on the island and form an audio library of local experience. The project has been delayed by the impact of the COVID19 pandemic, and the community’s experience of the pandemic will now also form part of the stories the project seeks to tell.
Katy says, "A lot of utilities, civil engineering and construction companies, parachute into a community, build the project and leave again. We wanted to create a programme that will not only benefit the community for generations to come in terms of a reliable power source, but one that will also build our relationship with the community, bringing people together to celebrate their historic and proud island traditions.”
Revealing Coll’s rich heritage
This oral history project sits alongside SSEN’s efforts, working in partnership with WSP, to uncover, and share with the public, new archaeological insights about Coll, as well as other island communities.
Kevin Mooney, Principal Heritage Consultant at WSP, explains: “Much of the archaeological remains that the team discovered as part of the cable replacement project speak to the sustainable and unique way of life in this part of the world centering on crofting.
“The northern portion of Coll is an emotive landscape with very few inhabitants in it and dispersed isolated communities. Crofting as a way of life is dying out, but there is still a small crofting community on Coll which is situated around the Bay - where the cable comes up from the sea. It’s important that any project recognises this and minimises its impact on this traditional way of life.”
Crofting - a long tradition
Crofting is a traditional social system in Scotland, which is defined by small scale food production characterised by its common working in community townships. The crofting lifestyle survives around arable vegetable production with poorer quality hill ground used as common grazing for cattle and sheep.
“Evidence of a rich crofting tradition on Coll was very clear,” says Kevin. “We know that in prehistory - six or seven thousand years ago - the inhabitants of Coll were harvesting and processing grains and vegetables. Our investigations also show there has been very little development in the area, which means the land has not been disturbed much over the centuries.”
Interesting findings to date include ‘byers’ (small kelp kilns), and two small ‘nausts’ (boathouses). WSP also uncovered a small number of previously unrecorded cairns located on hills across the assessment area. These are wayfaring piles of stones (now grassed over), which potentially allowed the crofting community to navigate their way around the area. They may have also helped the crew of fishing boats along the bay to work out and triangulate where exactly they were.
The archeological team also uncovered a ‘fish trap’ - a small wall of stones on the coast used to trap seawater (and fish) when the tide came in. While it has not been possible to date the structure, it is possibly prehistoric and was in use all the way up to the mediaeval period and beyond.
The Isle of Lewis and Harris
Another island community that has experienced major change, most recently during the Covid19 pandemic, and over the centuries, is the Isle of Lewis in the Outer Hebrides. It is the most northern of all of the Western Isles with a population of around 18,500.
From the 1950s until 1991, Lewis was supplied by a diesel power station at battery point. When this was decommissioned, a mainland electricity link was established which ran from the town of Fort Augustus, which sits at the south end of Scotland’s famous Loch Ness, over to Broadford, a village on the Isle of Skye, and then from Broadford to Ardmore, then on to Harris, a neighbouring island north of Skye. Power then travels via a 132 kilovolt overhead line up to Stornoway where it is transformed down to a distribution network level and sent out across the islands to power people's homes and businesses.
It’s vital all these ‘assets’ are maintained and updated as they come to their end of life. Stornoway’s substation operated for 30 years but needed to be replaced in 2018 as part of the project to improve the power connection between Stornoway and the other islands.
Simon Hall, consents and environment manager at SSEN, explains: “Replacement isn’t as simple as removing the old substation and installing the new one. This would leave the island without power, so SSEN had to be creative with its plans for replacement. In simple terms it had to build a new one next door to the existing substation and, only when it was completely finished, switch all of the cable connections over to the new unit.”
Protecting and preserving peatland
Creating the new substation involved another challenge for the team. A challenge that had been gathering for hundreds, if not thousands of years - the presence of peat deposits.
Peatlands are the largest natural terrestrial carbon store and the restoration and protection of peatland is a priority for the Scottish government as it seeks to reduce its carbon footprint. It follows that SSEN with support from WSP needed to minimise disturbance to Harris and Lewis’ rich and ancient peatlands, and also consider peat restoration projects.
Although the site of the existing substation was already fixed the team were able to orientate the new substation location in a way that minimised the amount of peat that was disturbed from about 10,000 cubic metres to 4,000 cubic metres. Furthermore, the team made sure that the deepest layers were not affected. This was achieved primarily by looking at the size and orientation of the compound.
Given the island’s long history and rich cultural heritage assets, WSP was also asked to carry out an archeological survey of the site. WSP’s Kevin Mooney soon uncovered, to the south of the site, a prehistoric funerary monument. He explains:
“This took the form of a stone circle. It was completely obscured by around two metres of peat so the potential existed for further archaeological remains across the site. So we introduced a phased approach of archaeological monitoring during the construction of a substation.”
The team also needed to make the best use of the peat that had to be moved to make way for the new substation. Working in partnership with the Scottish Environmental Protection Agency (SEPA), the team identified a peatland restoration scheme just to the south of the site, enabling the project to contribute to the regeneration of local peatland.
It also became apparent that very little radiocarbon dating had been done of peat deposits across Lewis so SSEN agreed to carry out a paleo environmental survey which involved drilling out a core sample of the peat to ascertain its age at various depths.
“We found peat dating to the Mesolithic Bronze Age and mediaeval times,” says Kevin. “So from these early dates, right to the current period, we had a fully preserved stratigraphic sequence, or what we call an environmental baseline on Lewis. Ultimately, the results of this work will be put on record allowing for further research at the University of the Highlands and Islands.”
Achieving a net biodiversity gain
Protecting and enhancing the local peatland ties in with SSEN’s broader commitment to sustainability and, more specifically, to biodiversity. In 2020, SSEN pledged that there would be no net loss of biodiversity value as a result of any of its projects, and it is trying to achieve a biodiversity net gain on all projects consented from 2025.
Biodiversity net gain is expected to enter English law in the near future with requirements contained in the Environment Bill legislation that is sitting in The House of Commons. Other parts of the UK are expected to follow.
SSEN’s Simon says, “By acting now, SSEN is ahead of the game, going beyond future potential legal requirements and setting a sustainable example for our own projects and those of other developers.
“In the case of the Lewis, by reusing all the peatland that needed to be cut to make way for the new substation, we have had a minimal impact on the biodiversity of the site. Working in partnership with WSP, this project has become an exemplar, demonstrating that we can, and are, working to protect our environment, as well as contribute to the communities we serve.”