Weathering the storm Power bosses reveal action plan to tame wild winds
IT was a once-in-a-decade event that left more than 80,000 people without power and battered communities throughout Scotland.
Last year, Storm Arwen brought disruption and devastation to the power grid, felling trees and trapping isolated communities for days while engineers struggled to get them back online.
But the ferocious storm which blew in at the end of November 2021 was just one of five “exceptional” weather events to hit north of the Border last winter, and energy companies have been preparing for more to come as this year’s season arrives.
Lessons have been learned and millions of pounds spent on the network, but the expectation is that storms such as Arwen will be more frequent in future as the climate changes.
Guy Jefferson, chief operating officer at Scottish Power Energy Networks, is in charge of making sure a network of power lines and substations stretching through central Scotland to St Andrews and Perth remains robust in spite of what the weather can throw at it.
Hundreds of miles of overhead lines, all vulnerable to the vagaries of the wind, support communities dependent on Scottish Power’s vital services.
“The previous two years [to last year], we had maybe one exceptional event in each,” he said. “Then we had five in one year.
“We’re preparing for the worst and hoping for the best, as I always put it.
“We’ve got to prepare and make sure that we learned any lessons we had to learn, and got things in place both in terms of what we always do, and in terms of building on top of that.”
Storm Arwen, which followed hot on the heels of Storm Barra, made landfall in the British Isles on November 26 last year and made its way through Ireland, Scotland and England before finally dying out across the Channel in France.
Two people lost their lives and more than £40 million was paid in compensation by the power companies to customers left without power, some in the north-east of Scotland – served by Scottish and Southern Energy (SSE) – for up to a week.
Amid criticism of the length of time it took to reconnect households, SSE will this year adopt a “reasonable worst case” approach to keeping customers informed about how long they will be without power, to prevent expectations being dashed if an emergency drags on.
A spokesman for the company said: “Following the impact of last year’s exceptional storm season, SSEN Distribution has engaged constructively with the
Department for Business, Energy and Industrial Strategy (BEIS), the Scottish Government and the regulator, Ofgem, as part of external reviews into Storm Arwen.
“We set up a dedicated project team to manage and prioritise the delivery of actions identified in external and internal reviews.
“Alongside improvements to internal plans, processes and procedures, a particular area of focus has been on customer communication and embedding an estimated time of restoration (ETR) communications process.”
The company has also committed an additional £3.5m of funding to support customers and communities in the areas worst impacted by Storm Arwen.
This money has paid for enhanced protection of key circuits and other contingency measures such as tree cutting, undergrounding of power lines, and installing generation hook-up points at key locations on the 33 kilovolt “backbone” of the network.
Chopping down trees is an unheralded part of guarding against storms, but falling foliage and wind-blown branches are often the biggest threat to the electricity network, not the wind.
Scottish Power has spent millions from its annual £75m maintenance budget on felling trees which could pose a danger to power lines.
Guy Jefferson said: “We spend £5m actually cutting trees, believe it or not because that was the main issue. It wasn’t that our network wasn’t robust – it was the trees falling over and going through our network [of power lines].
“We also have a special regime to do winter checks over the course of September and October, where we do basic checks on the overhead lines that we know have caused issues in the past, and also our substations – making sure that everything is as it should be.”
Predicting the weather is an inexact science, but power companies look to the future on a daily basis. Scottish Power receives daily forecast as well as three- and five-day predictions, so it “knows what’s coming down the track”, Mr Jefferson said.
This information is shared across the power companies, as are staff when the situation calls for it.
Arrangements are in place for engineers and call-handlers from across the UK to be deployed to other companies if one area suffers an extreme weather event.
New technologies are being brought to the fore, too,with Scottish Power investing in its LV (low voltage) support room, which helps pinpoint locations where faults might occur before they even happen.
Pop-up pylons, which fit together like a giant Meccano set, can be rolled out while the increasing use of drones is allowing energy companies to survey damage to more remote areas.
Mr Jefferson said: “We use drones on the network to assess damage in a storm situation where sometimes you can’t get to places because roads are closed, but you can get to places with drones. That’s been a real improvement.”
But on the ground it is local communities which have been drafted in to help make a concerted effort to prepare for the worst of the weather.
Local resilience forums, comprising councils, police, emergency services, roads departments and the NHS, have been meeting regularly with the power companies to prepare for the storms to come this winter, wargaming scenarios such as those encountered when Arwen arrived.
Mr Jefferson said: “That’s some of the things we’ve been exercising – what are the trigger points – in order to bring those groups together so we’ve got them ready to go when the likes of Arwen happens again.
“We can work together to make sure that our customers and members of the public and vulnerable people have got the support they need when events like that hit.”
We spend £5m cutting trees. That was the main issue. It wasn’t that our network wasn’t robust – it was the trees falling over and going through our power lines