With apologies to Jules Verne – high voltage direct current (HVDC) cables convey rather more than 20,000 volts. According to Wikipediai most typically use voltages between 100 kV and 800 kV (although they are not limited to this range). Generally HVDC cables are used for wind farms some distance off shore (or to circumvent issues associated with overland transmission), but increasingly the UK’s wind generation is planned to come from islands, with a plan to “export” surplus electricity long distances. HVDC cables are seen as the means by which the electricity is to be transferred from the islands to the mainland.

As we saw in For Peat’s Sakeii and Utilities Futility,iii the Viking Energy wind farm on Shetland is one such development. The plan by SSE is to connect to the National Grid on the mainland via a new HVDC cable. More accurately, the power from Shetland has to reach the mainland via two long subsea cables and a switching station. All elements have to work or the whole system fails. There will obviously be some loss of energy because of the length of transmission required. Not surprisingly, in the face of considerable local opposition, SSE is expressing great confidence in the reliability of such a cable, as reported by Shetland Newsiv:

THE PROJECT director in charge of building the Kergord converter station and 600MW interconnector infrastructure linking Shetland to the national grid expects the subsea link to be available for 99.8 per cent of the time.

Curiously, however, the report in the Shetland News also goes on to say:

Lerwick Power Station will remain on standby, should the cable fail, until at least 2035.

A sensible precaution, or perhaps a sign of less confidence than the official line suggests? Also, given that the plan is that electricity is to be exported from Shetland to the mainland (which implies electricity surplus to Shetland’s needs), why the need for Lerwick Power Station to remain on standby? Oh I see – because wind power is unreliable, and if Shetlanders were forced to rely simply on the electricity generated by the wind farm, even in such a windy place, they would be left without power for significant periods of time.

SSE/Viking Energy may also have run into a new problem. According to the Energy Voice websitev:

Suspected unexploded ordnance has been found along the route of the planned subsea cable that will link Shetland to the mainland.

However, significant though that development might (or might not) prove to be, that’s a side issue. My purpose here is to take a look at the performance of HVDC cables to date, and to ask questions regarding the reliability of offshore and island wind farms as a source of steady power for the UK mainland National Grid.

Caithness – Moray HVDC Cable

SSE have been keen to cite the Caithness – Moray HVDC cable as an example of an earlier cable that hasn’t caused any problems.

In our experience with the Caithness to Moray cable – the most directly relevant one, which we installed in 2018 – we had no issues at all with the cable being damaged or being out of service.”

But is this so? Laid (in fact) in 2017, it appears that by 2018 problems had already become apparent. Because of the nature of the necessary remedial works, and the sensitive nature of the site, it was necessary for an Environmental Appraisal Report to be commissioned. Although elements of it have been redacted, it is available onlinevi.

From this we learn:

Scottish Hydro Electric Transmission Plc (SHET) have developed a High Voltage Direct Current (HVDC) electricity transmission link between Caithness (Noss Head) and Moray (Portgordon)… In early 2018, information became available that suggested there was a fault in the (offshore) installed cable. The location was identified as being at KP 13.158 (approximately 13km from Port Gordon landfall). A cable repair and associated activities were undertaken by NKT in early 2018.

The report was required in connection with additional works, identified as including the following:

Cable remediation and backfill at KP1.6‐3.6, including rock placement if required; Installation of 2 x new lengths of DC cables & 1 x FO of cable between KP11‐16 and potentially KP83‐86 (dependent on cable inspection results);

Cable de‐burial and inspection at KP 83‐86;

Burial of newly installed cable, use of rock placement if required; and

Removal of old cables at KP11‐16 and KP83‐86 (dependent on cable inspection results).

Maybe the claim that they had had no problems with the cable laid in 2018 involved a careful choice of words, if the problems all related to the cable laid in 2017, and not to a replacement cable laid in the following year?

Western Link HVDC cable

This cable has experienced numerous problems, as the Energyst websitevii makes clear:

The failure of the high voltage undersea cable between west Scotland and north Wales last month resulted in National Grid ESO paying almost £31m for wind farm operators to curtail output.

Consultancy Cornwall Insight calculated the figure based on Balancing Mechanism data and prices during what was an exceptionally windy month.

The Western Link HVDC cable went down on 10 January and remained offline until 8 February. It was the cable’s third complete trip in as many years.

So problematic has this cable proved to be, that:

Following the latest outage,Ofgem has opened a probe into the £1.3 billion Western HVDC connector, which links Highland wind farms via Hunterston to North Wales.

So far as I am aware, we still await the outcome of the Ofgem probe. Since the above article appeared (on 25th February 2020), there have been additional problems, with a further outage lasting from 15th February to 13th March 2021. Whenever a problem of this nature occurs, there are inevitably costs. As an online article from S&P Globalviii tells us:

Since the link went offline on Feb. 15, GB metered wind output has been sharply constrained, with output up to 2.1 GW lower than National Grid’s final forecasts, failing to outturn above 12 GW,” S&P Global Platts Analytics said March 3.

Within the Balancing Mechanism, the volume of accepted bids in Scotland reached 430 GWh in February, up from 46 GWh in January when the link was fully available, it said.

Between Jan. 1 and Feb. 15 National Grid reported daily average constraint costs of GBP0.5 million/day. This rose to GBP6.1 million/day from Feb. 16 to Feb. 25, before wind generation dropped.

“Balancing Services Use of System (BSUoS) charges – the cost of balancing the transmission system of which both generators and suppliers are liable – reached an intra-day high of GBP15.3/MWh on Feb. 25, the highest level since Dec. 27, 2020,” Platts Analytics said.

BritNed HVDC cable

As the UK increasingly phases out fossil fuels from its electricity generation programme, the need to import electricity from elsewhere becomes increasingly important. At the very moment I type this, a late summer’s evening in 2021, 17.4% of the UK’s electricity is being supplied via interconnectors, and (by chance – the number fluctuates) 3.5% of the whole of the UK’s electricity is at this moment being supplied via the BritNed HVDC cable, that is the interconnector between Britain and the Netherlands. It can readily be appreciated that this is an important cable. And yet it has an unhappy history. I can do no better than tell its story by quoting from an article which appeared on Watt-Logic’s websiteix on 17th March 2021:

The 1 GW BritNed interconnector linking GB with the Netherlands has suffered another fault and is expected to be out of service until late April, meaning it has spent much of this winter out of action. In addition to contributing to a tight GB market, these outages illustrate some of the challenges facing offshore electricity infrastructure, particularly in sub-sea environments.

BritNed tripped on 8 December and did not return to service until 9 February due to a cable fault. The damaged cable section was found approximately 100 km off the Dutch coast at a water depth of 40-50 meters. Repairs were successfully carried out within 29 days despite severe weather. But now the interconnector has developed another fault, probably with the cable again, and is expected to remain out of service until 22 April.

These outages mean that BritNed will have been offline for a significant portion of Winter 2020, a risky position given it holds a capacity market contract for the current delivery year. There have been two Capacity Market Notices (“CMNs”) issued this year, the second of which came just days before BritNed’s first outage. While a failure to deliver following a CWN [sic] does not attract penalties unless a Capacity Market Stress Event occurs, the issuance of both CWNs [sic] and Electricity Margin Notices this winter, combined with high price volatility, indicate the markets have been much tighter than usual.

By the way, please see “Counting the Cost”x for an explanation of Capacity Markets.

Orkney – Pentland East cable

This cable was replaced in late 2020 and the announcement of the completion of the work was welcomed with much publicity from SSE and others. However about 2 months later it was very quietly announced that the new £30 million cable had unexpectedly failed.

There is as yet no word on whether or not it is to be repaired, as the old one was reconnected, at considerable expense. We can only assume that the cable failure was catastrophic.

As I understand it, Ofgem have conditionally approved a larger capacity cable to Orkney, with final approval depending on enough wind farm capacity being approved to justify the cable. Perhaps if the larger cable is fully approved, SSE will simply write off the failed cable. Presumably they are hoping that the old, reinstated cable lasts until the larger cable is approved.

Whether or not this speculation is correct, this is all on the back of pre-existing problems that were reported by the Orcadianxi in 2019.

Western Isles

This is a particularly dismal story. On 16th October 2020 the cable linking the Outer Hebrides to Skye was cut, causing a blackout affecting 18,000 Hebridean homes. The Guardian reported on it at the timexii:

The 20-mile (32km) cable, which runs on the sea bed from Skye to Harris, failed without warning six days ago.

That forced Scottish and Southern Energy Networks to call on a diesel-fuelled power station in Stornoway to provide back-up electricity, and airlift extra diesel generators from the mainland in case Stornoway’s turbines fail.

SSEN announced on Thursday that the 33,000V cable was unrepairable, adding that it could take between six months and a year before a new cable could be commissioned and laid.

It believes the breach happened at a depth of over 100 metres about 15km offshore from Skye, and is now investigating whether it was cut by a trawler or another vessel. SSEN has asked for local shipping records so that it can pinpoint which vessels were in the area at the time the cable failed.

When the cable failed, a larger replacement cable was requested by many interested in the issue. However SSE do not have much wind farm interest in the Western Isles, and whether or not that influenced them, the larger cable request was rejected. It is worth noting that, when the cable failed, there was an adverse impact on some smaller community based wind farm projects: they could not market the electricity that they were producing, without the cable, and they lost income as a result. These smaller projects were not eligible for constraint payments.

I haven’t yet been able to find confirmation that the replacement cable is operational, though I believe it arrived in May, and the plans were that it should be in place by the end of August 2021.

Gwynt y Môr wind farm

This story confirms the problems, but from a slightly different point of view. As reported on the New Power websitexiii the company that owns the link to Gwynt y Môr wind farm argues that a series of repair outages required following a cable failure in October 2020 should be underwritten by consumers because insurers are leaving the market.

The company notes that the cost of insurance has risen 40 per cent in the past two years and many insurers have declined to provide cover. Offshore wind farm cables have been under the spotlight for outages to repair cable problems, due to manufacturing faults, accidents and other issues.

In April this year, Danish wind farm operator Orsted said it had put aside £350 million to repair or replace cables within its wind farms that had been damaged due to interaction with the sea floor.


Subsea cables fail for many different reasons, including the activities of fishing trawlers, damage from anchors, manufacturing errors, and environmental factors (e.g. seabed roughness and tidal flows) leading to corrosion and abrasion of the cables.xiv Only a few days ago it was reportedxv that the Australian authorities have arrested the Ukrainian master of a Maersk container ship for allegedly damaging a telecommunications cable connecting Singapore and Western Australia, with the ship’s anchor. In that case the cable affected related to telecommunications, and was not an HVDC cable, but the principle remains the same. These cables are vulnerable, and not just in theory – the brief case history above illustrates that the problems are real in practice too.

It’s bad enough blighting beautiful island landscapes with industrial scale wind turbine developments. It compounds the issue when the benefits claimed for them hang by such a fragile thread.

i https://en.wikipedia.org/wiki/High-voltage_direct_current

ii https://cliscep.com/2021/06/29/for-peats-sake/

iii https://cliscep.com/2021/07/06/utilities-futility/

iv https://www.shetnews.co.uk/2021/08/19/subsea-cable-very-reliable-says-project-director/

v https://www.energyvoice.com/renewables-energy-transition/344908/suspected-unexploded-ordnance-found-along-route-of-planned-shetland-hvdc-link/

vi http://marine.gov.scot/sites/default/files/environmental_appraisal_-_redacted_0.pdf

vii https://theenergyst.com/western-link-failure-sees-national-grid-pay-31m-to-turn-off-wind-farms/

viii https://www.spglobal.com/platts/en/market-insights/latest-news/electric-power/030521-uks-western-hvdc-link-due-back-in-service-week-starting-march-15-nat-grid

ix http://watt-logic.com/2021/03/17/another-britned-outage-illustrates-the-risks-of-the-current-offshore-infrastructure-regime/

x https://cliscep.com/2021/08/15/counting-the-cost/

xi https://www.orcadian.co.uk/power-cable-fault-results-in-rackwick-work/

xii https://www.theguardian.com/business/2020/oct/22/scottish-energy-company-ssen-investigates-blackout-caused-by-subsea-cable-failure

xiii https://www.newpower.info/2021/08/gwynt-y-mor-reveals-battle-to-insure-offshore-wind-cables-40-premium-hike-and-scores-or-providers-decline/

xiv https://www.prosperoevents.com/why-subsea-power-cables-fail/

xv https://www.poandpo.com/news/maersk-ship-captain-charged-over-underwater-cable-damage-off-perth/


  1. 25 Aug : SSEN Transmission responds to subsea cable concerns
    “The Caithness-Moray HVDC link, which has been operational since January 2019,
    currently has a 99.8 per cent availability rate, having been unavailable only during pre-planned outages.

    “The Shetland HVDC link, which is scheduled to be fully operational by 2024,
    has been designed to be protected against potential damages
    and will be buried in the sea bed via a remotely operated submersible units
    which cut the trench in which the cable is laid at a specified depth, which is then covered by protective materials.”


    That is contradicted by a reader’s letter on Aug 23, which lists breakages and outages


  2. “Lerwick Power Station will remain on standby” which means that someone has to pay for this perfectly good source of power to sit idle but be available while money is flushed away elsewhere. Thank you for a great summary of the problem with cables.


  3. ‘Subsea cables fail for many different reasons…’

    Including Brexit, natch:



  4. Vinny, interesting link – thanks. I vaguely remember the story at the time. A quick search of the internet does indeed suggest that the project has been dead since at least 2019. I very much doubt it was Brexit that killed it – more likely the expense and sheer unfeasibility of the scheme would be my guess.


  5. Moyle interconnector:


    “In August 2011, the interconnector went out of service. Repairs were made and the cable became operational again with 450 MW in February 2012. However, further faults meant that a major part of the interconnector had to be taken out of service until it could be augmented with the additional return cables, completed in 2016. This restored capacity to the full 500 MW.

    In February 2017, the cable suffered another fault, halving capacity to 250 MW. However full capacity was restored in September 2017, following repairs by Nexans.”


  6. “Tasmanian Government Wants Compo Over 2015-16 Basslink Failure”


    “The Tasmanian government has threatened to take legal action against the operators of a Bass Strait electricity cable, Basslink, that failed and contributed to an energy crisis in the state.

    Energy Minister Guy Barnett said on Thursday the government believes it is entitled to damages over the Basslink outage in December 2015.

    “The state proposes to initiate the dispute next week unless Basslink agrees to compensate it for its losses,” he said in a statement.

    At the end of last year, Basslink rejected an analysis of its subsea cable outage of 2015-16 released by Hydro Tasmania that said the subsea cable was pushed beyond its design limits.

    “The DNV GL analysis indicates that the cable had been operated by BPL in a manner that allowed it to exceed its temperature design limits during a number of periods in its service life. This overheating and subsequent cooling of the cable has resulted in degradation of the cable,” Hydro Tasmania said at the time.

    “DNV GL concluded that the cable failure was the probable result of electrical energy discharge within the cable as a result of polarity reversal and cooling shortly before the 20 December 2015 cable failure.”

    Basslink retorted that the report merely put forward one idea and did not provide any “conclusive and definitive proof”.

    “Hydro Tasmania’s experts did no actual testing on the Basslink cable or any similar HVDC [high-voltage direct current] cables. They used a theoretical model based on certain assumptions to come to a set of conclusions,” Basslink CEO Malcolm Eccles said. “These assumptions make the experts’ conclusions speculative and not based on actual facts.”

    The Basslink Interconnector was down between December 2015 and June 2016, with the fault discovered 90.5km from the Tasmanian coastline, and removed and capped three months after going down.

    Basslink completed its cable joint repairs in June 2016 following months-long delays due to excess water damage.”


  7. Skagerrak:


    “The 240-kilometre (150 mi) Skagerrak 1–3 scheme consists of a 113-kilometre (70 mi) overhead line and a 127-kilometre (79 mi) underwater cable.”

    “Skagerrak 2 repair, Norway – Denmark
    The national power grids between Denmark and Norway are connected through four DC-links crossing the Skagerrak strait, capable to carrying 1700 MW of renewable energy to the two countries’ energy mix. One of the cables, the Skagerrak 2, was damaged due to external impact. The damaged part was located about 36.5 km north of Bulbjerg in Denmark.”


    Keep looking, and more and more examples of failure are there to be found.


  8. Mark – thanks for the digging on this “Fishy” topic.

    my only question is – as they are buried in the seabed & rocks laid to protect them, how do they get “damaged due to external impact” ?

    or am I missing something (dragnets etc) !!!


  9. or – “conspiracy theory alert” – Russian Subs with big snipper like things attached !!!


  10. Thanks also from me Mark. I have failed to respond so far because I wanted to look up in Future Energy Scenarios what the future holds for us re: interconnectors. The first interesting thing to note is:

    GB becomes a net exporter of electricity by 2040 in all scenarios

    Net export in 2050 seems to range (reading from the graphs) from 0-150 TWh, depending on scenario. (Dudgeon, remember, generated 1.7 TWh last year).

    There is a large net export of electricity over the interconnectors across the year; this helps manage renewable generation output and meet peak demand.

    –System Transformation scenario

    The question arises: are other countries also generating Net Zero scenarios where the excess juice they make from renewables are exported? I can’t help thinking that when we need the juice, so will they, and when we won’t, they won’t. (Allowing a 1-hour shift in peak demand, etc.) Will our friends say “Non!”

    And all a nefarious state or organisation, SPECTRE, etc, would have to do to discombobulate us would be to “accidentally” drag an anchor for a significant distance.


  11. dfhunter – the short answer is that I don’t know. However, manufacturing errors and corrosion (from salt water) are both possible even in buried cables. I suspect that long cables aren’t entirely covered in boulders for protection (imagine the size of that task!), so significant lengths of cable are probably vulnerable to damage from drag-nets, anchors etc.

    I tend to prefer cock-up over conspiracy theory, but given that the authorities make the position of cables known (so that anchors and drag-nets can – in theory, at least – avoid them), there must be a large risk of hostile actors, to whom the information is readily available, being able to damage them if they want to.

    I don’t want to over-state the problems, but given the track record of cable failures, problems there undoubtedly are.


  12. Why are we having to rely on a bunch of amateur journalists to do all of the heavy lifting here? Why couldn’t someone who is getting paid have done Mark’s job for him?


  13. Update:

    “Faulty 19 mile-long Harris to Skye subsea cable replaced”


    “A subsea electricity cable between the islands of Harris and Skye affected by a fault last October has been replaced.

    The new 33 kilovolt (kV) cable has gone live following a £28m project by energy company SSEN Distribution.

    Since October, customers on Harris have been supplied with electricity by back-up power stations at Battery Point and Arnish on Lewis.

    The fault also stopped power being exported from Lewis and Harris renewable schemes to the mainland grid.

    The new cable runs from Beacravik on Harris to Ardmore on Skye. Beaches dug up at both locations during the work have been reinstated to their “natural state”.

    SSEN Distribution said repairing the broken cable was ruled out because the fault had occurred on part of the powerline 100m (382ft) underwater.

    The company said laying the new cable had required “significant offshore work” using specialist marine vessels.”

    What the BBC article omitted to mention (must have slipped the journalist’s mind) is that the replacement cable came from China.


  14. Latest on the planned interconnector for the Viking Energy wind farm on Shetland:


    “This consultation sets out our views on our assessment of SSEN Transmission’s proposed costs for delivery of the Shetland HVDC Link project.”

    The consultation end date is 4th October 2021.

    The executive summary within the consultation document includes this:

    “In November 2020, we received a ‘Project Assessment’ submission from SSEN Transmission, for its proposed Shetland HVDC Link project (the Shetland Link). The project will provide an electricity transmission connection between the Scottish mainland and the Shetland Isles.

    This consultation is seeking stakeholder views on our proposed efficient cost allowances for the Shetland Link, as well as our proposed modifications to SSEN Transmission’s licence to support delivery of the project.

    The link will be a 600MW single circuit connection that serves the dual purpose of exporting renewable generation from windfarms on and around the Shetland Isles to the mainland and providing a new secure supply connection to Shetland as the Lerwick Power Station reaches its end of life.

    SSEN Transmission submitted its initial costs for delivering the Shetland Link to Ofgem in November 2020, amounting to £657.8m. As discussed and agreed with us, it provided further updates to those costs in May and August 2021, bringing the costs to £675.4m. We are minded to provide an ex-ante allowance of costs of £628.6m for delivery of the project, which constitutes a reduction of £46.8m (6.9%) to SSEN Transmission’s submitted costs. This proposed reduction is the result of our careful review of SSEN Transmission’s submitted costs over the past eight months, including benchmarking those costs against similar projects and our detailed assessment of SSEN Transmission’s contracting and risk management strategy.”

    Interesting planned costs reduction. Watch this space.


  15. “Interesting planned costs reduction”

    are you sure that’s what the Ofgem statement means ?

    as ever I had to look up the meaning for “ex-ante” & got lost in the long grass of definitions !!!


  16. dfhunter, I’m not sure of anything where ofgem is concerned. The document is lengthy and, as you say, is peppered with definitions, none of which makes it easy. However, subject to watching this space for possible alternative developments, I’m content for now to take “a reduction of £46.8m (6.9%) to SSEN Transmission’s submitted costs” at face value.


  17. What’s interesting in this context is the Anglia One winfarm was originally going to have a +/- 300kV DC system because of the long run (down to Bawdsey & then overland to Bramford 400kV station). What they seem to have ended up with is 220kV 3 phase AC. Dunno what that does to the power factor loss in the capacitance but I guess they must have thought the TCO was better with AC.


  18. “Fire shuts one of UK’s most important power cables in midst of supply crunch
    Coal plants being warmed up as market prices surge to £2,500 per MWh from a norm of £40”


    “A major fire has forced the shutdown of one of Britain’s most important power cables importing electricity from France as the UK faces a supply crunch and record high market prices.

    National Grid was forced to evacuate staff from the site of the IFA high-voltage power cable, which brings electricity from France to a converter station in Kent, where 12 fire engines attended the blaze in the early hours of Wednesday morning.

    The fire has halted electricity imports via the 2,000 megawatt power cable until March next year and could not have come at a worse time for the UK’s squeezed markets, according to experts. The UK faces record energy prices after a global gas market surge raised the cost of running gas power plants, which has been compounded by a string of power plant outages and low wind speeds.

    The all-time energy price highs are expected to send bills soaring for the next year and cause a string of small energy companies to go bust. It has already forced some steelmakers to shut their factories during hours of peak electricity demand.

    The market price at one of the UK’s main electricity auctions cleared at a record price of £2,500 per megawatt-hour for the hours of peak demand on Wednesday, compared with a typical baseload price of about £40/MWh throughout 2019 and 2020.

    Phil Hewitt, a director of the market consultancy EnAppSys, said the fire was “a major event” because it could lead to an extended outage at the IFA cable.

    “It puts the GB market in a risky position for the winter and especially if we suffer from periods of low wind and cold temperatures,” he added.

    The electricity system operator, which is owned by National Grid, said there would be enough electricity to meet the UK’s peak demand on Wednesday evening. However, market experts fear the latest blow to the UK’s power system could cause prices to rise further and will increase the UK’s reliance on running its last remaining coal plants.”

    Of course, all this stuff is linked up. I could just as relevantly have posted this as a comment on “Counting the Cost”. We can join the dots. Why can’t the Guardian, BBC, and most importantly, the politicians?


  19. The BBC has caught up now, too:

    “UK power prices soar after key cable hit by blaze”


    “A key electricity cable between Britain and France has been shut down, sending wholesale energy prices soaring.

    National Grid said a fire and planned maintenance at a site near Ashford in Kent means the cable will be totally offline until 25 September.

    Half of its capacity, or one gigawatt (GW) of power, is expected to remain unavailable until late March 2022.

    On Wednesday, British electricity prices for the following day jumped by 19% to £475 per megawatt hour (MWh).

    The fire at the Interconnexion France-Angleterre (IFA) site broke out in the early hours of Wednesday. The site was evacuated and there were no reports of casualties.

    After the fire an electricity interconnector running under the English Channel was “not operating”, the National Grid said in a statement.”

    Although the failure is significant, the headline does a disservice to the truth by trying to suggest that that prices soared after, i.e. because of, the blaze that prevented the cable from importing electricity from France. As is made clear further in to the report, prices were already soaring, because of the ridiculous electricity generation system we have in place, it’s just that the energy crisis (funny they never use the words “crisis” or “chaos” in this context) was exacerbated by the cable failure:

    “The link can carry up to 2GW of power, and had been importing electricity from France in recent days, after UK prices hit a record high of £540 per MWh on the wholesale energy market.”

    Not a mention anywhere of the shambolic electricity generation system we have in this country, thanks to over-reliance on unreliable sources of energy generation, and a pointlessly complex system of regulation, plus reliance on imports.


  20. I’ve commented on the BBC story, by way of Cliscep community outreach. (Politely, in reply to comments on proposed solutions.)

    We seem to have a good system going here, so long as the goal is to increase prices, decrease stability, and ultimately trigger failures. It seems we have cut out more and more of the grid’s reliable bits, and fixed the resulting gaps with brown paper and bits of string.

    Is this concentrating any minds among those whose opinions might actually have the possibility of making change? Or are we locked onto a path that takes us to inevitable crisis?

    I find it interesting that I disparage the use of the word “crisis” as it pertains to climate change, but reach for it now in connection with our electricity grid. The question is, are my fears of the consequence of climate change policies any more valid than others’ fears of climate change itself?

    Liked by 1 person

  21. Update:



    “SSEN, part of SSE PLC, has completed a project to replace the subsea electricity cable between Skye and Harris, following a cable fault in October last year.

    Teams from Scottish and Southern Electricity Networks (SSEN) Distribution connected and energised the new cable this week before gradually returning the network to normal operation – reconnecting Lewis and Harris to the mainland electricity network.

    The £28 million cable replacement project involved significant offshore works using specialist marine vessels – the Maersk Connector and Grand Canyon 3 – working with principal contractor, Global Offshore, to successfully install and protect the 33 kilovolt (kV) cable between Ardmore, Skye and Beacravik in Harris.

    The project included land-based works at each shore end to connect the new cable to the existing electricity network and restore local beaches at Ardmore and Beacravik to their natural state.

    Since October, Battery Point and Arnish Power Stations on Lewis have been running at full-duty operation, alongside on-island renewable generation, to ensure a safe, secure and reliable supply of electricity to local homes and businesses. These stations will now return to back-up operation.

    “While reliability of power supplies has been maintained, we recognise the impact to the community as a result of this fault and would like to thank stakeholders, including local generators and wider community partners for their continued patience and engagement during the fault period.

    “I’d also like to thank our teams in our operational centres, power stations and contract partners for their ongoing commitment during a highly complex operation to help keep the power flowing and restore the network.”

    As part of its draft business plan for the next price control period, RIIO-ED2, running from 2023 to 2028, SSEN Distribution is proposing a number of strategic subsea investment projects in the Western Isles, including an upgrade to the circuit between Skye and Uist.

    SSEN Distribution continues to assess the future resilience and electricity demand needs for customers and communities on Lewis and Harris. This includes close liaison with SSEN Transmission on its proposed 600MW HVDC transmission link to the Western Isles, which remains subject to developer commitment and regulatory approval.

    A third-party study will be carried out prior to SSEN Distribution’s final business plan submission in December to assess options, including the installation of a second 33kV cable between Skye and Harris, if the current transmission needs case is not taken forward. All plans will be subject to regulatory approval.”

    Liked by 1 person

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