22nd February 2018
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Electricity firm lays out latest cable plan

, by , in News

By JOHN ROBERTSON

Scottish and Southern Energy could connect Shetland to the National Grid for at least £100 million less if it is allowed to lay a single cable circuit instead of having to provide an emergency back-up. The company is trying to persuade the UK electricity regulator Ofgem of its case but is being kept waiting for its verdict.

SSE, which is Shetland’s partner in the Viking windfarm project, this week displayed its latest plans for the seabed cables and the large converter station at Upper Kergord which it would build at a cost of £200m-£300m to send power from the 150 turbines to customers in Scotland. Power from the grid could also be sent northwards to keep Shetland’s lights on when the windfarm was not producing.

An environmental statement has been completed and the planning application is expected to be submitted to Shetland Islands Council at the end of next month. Without a cable and converter station the windfarm plan would be killed off because there is no other way of exporting its potential 540MW of power. Equally, if the windfarm fails to get approval there will be no need for the cable.

Scottish and Southern’s power lines subsidiary Scottish Hydro Electric Transmission Limited (SHETL) hosted a public roadshow in the Whiteness and Weisdale Hall on Wednesday. There was not a lot to see apart from a selection of wall charts and maps but experts from the power company were on hand to answer questions from the stream of people who popped along.

The converter station caused some controversy when announced last year due to the large size of the industrial buildings planned for hill land belonging to Hunters of Scatsta in the picturesque Kergord valley. This week no finalised designs were yet available for the station and several options are said to still be under consideration and due to be completed over the coming months. For illustration purposes the buildings included in images of how the valley would look are based on the design of a converter station which SSE has applied to build in the Western Isles.

The converter station will house noisy, giant transformers to change the electricity from AC to DC so the minimum amount of power is lost from the line during its five-mile underground trip to the sea in Weisdale Voe and the 200-mile journey onwards to Portgordon, near Buckie.

No up-to-date cost was available for the project this week. Last year’s price tag was £200m-£300m over the course of 40 years, depending on whether one or two cable circuits is required, but it is only what they call an indicative figure and has not changed since the last roadshow in April last year. Project manager Greg Taylor said a more accurate costing would be known in the next couple of months.

All the plans for the project have been worked out on the basis that two cable circuits will be required by Ofgem, each consisting of two strands. He said the watchdog would not commit itself regarding SSE’s preferred option of one 550MW cable circuit until after the company’s formal planning appli­cation is lodged. Last year there was talk of three sets of cables being required because, according to Mr Taylor, no converter station existed which could handle more than 350MW. Now they can handle up to 1,000MW from a single cable circuit.

One significant change to the plans revealed last year is the route of the proposed cable once it makes landfall in Weisdale Voe and goes nearly three feet underground to snake up the valley. It had been planned to come ashore at the east side of the voe, south of the Swedish houses, but following consultation it has been switched to Cott on the west shore, opposite Kalliness.

The prospect of high-voltage cables near houses and places where children play is causing con­sternation among residents despite assurances that there are no health risks and the only visual sign after construction will be a warning signpost.

One mother, Anita Mayes, who visited the roadshow, was worried about the potential effects of living near high-voltage cables.

She said she would no longer allow her children to play near the area where the cable might come ashore, close to a beach and local beauty spot where the King of the Cocos Islands, John Clunies Ross, was born.

“It’s a lovely spot that will be ruined,” she said. “We’ll just have to keep our fingers crossed it doesn’t come.”

There have been claims in the press that electrical currents from cables could be hazardous to human health and could destroy fish stocks on the seabed but according to SSE representatives at the roadshow the twin sections of the cable are of equal and opposite polarity and cancel each other out, causing a negligible electrical field. One SSE expert said the Baltic Sea was criss-crossed by such cables with no effect on fish stocks.

Mrs Mayes said there were other general concerns in the community about the effects on people living near high-voltage power lines, including those carrying power from the turbines to the converter station in Kergord. “It’s not something you are wanting to take a risk on,” she said. Even though the windfarm is a long way off, if it comes at all, it may already be having an effect on house prices for properties near turbines. She said one family she knows who are looking to return to live in Weisdale would not consider potential houses in Kergord because of their proximity to the windfarm.

The proposed undersea cable would cross six telecoms cables and one oil pipeline during its journey. Mr Taylor said it would be buried in the seabed for all but two or three per cent of its journey and engineers are considering the best option for covering those remaining sections which travel over rock, which could include rock armouring and concrete “mattresses”.

SHETL believes the main risks to the cable are from trawling, anchors dragging from boats or fixed fishing gear, boat groundings and from fish farm anchors in inshore grounds, such as in the approaches to Weisdale Voe. However, burying the cable and informing fishermen of areas where it remains prominent on the seabed should minimise concerns.

About John Robertson

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