FN will support lowering French prices for French customers before offering support for the rest of Europe inc UK. So the exports to UK will only be available when the French decide at a price that reflects UK distress value. No longer something that can relied on in emergencies.
I don't think the issues are confined to France. The general interconnector system across Europe is creaking, and creating widespread unhappiness. The Norwegians and Swedes don't like the consequence of importing high prices from Germany and Denmark and the UK and the Netherlands and Poland. There have been a number of occasions when the EUPHEMIA system that decides how the system is balanced and priced has produced some distinctly counter-intuitive flows against price gradients. Abuse of the system to dump renewables surpluses creates problems for local grids that have to back out inertia providing generation or adopt more radical measures such as the phase shift transformers that block flows on AC lines, preventing "free" use of transmission in neighbouring countries between North and South Germany (we also see this abuse of transmission capacity in the UK, with exports from France being re-exported to Netherlands and Belgium at times, or from Norway back to Denmark via the UK). When Dunkelflaute arises (including as the sun goes down in summer) everyone expects everyone else to help out with rapid ramping of dispatchable generation.
Indeed, part of the NESO story is that they have been absorbing some solar surpluses from Europe during the day, and then having to ramp up generation very rapidly as the sun sets in Europe, demanding to import in the evening from the UK. This puts enormous stresses on the system as transmission lines have to flip direction of operation and the power flow has to be re-configured across the grid. I do not envy the Control Room having to devise ways to do this safely, but it has clearly resulted in frequency blips - particularly on May 2nd and June 13th - incidents I highlighted along with Kathryn Porter which were picked up by Claire Coutinho who started asking awkward questions on the back of them - as well as the incidents later in June and early July.
The events of 23rd June were felt particularly acutely in the Netherlands, where the sudden cutting off of UK export saw local balancing prices reach €4,000/MWh - a level associated with paying for demand reduction.
We exported the power cut to save the NESO/Miliband bacon. We can only expect that interconnectors will prove less reliable in future too. Of course, we should remember that Ireland imposed bans on power exports during the energy crisis in 2022, and some of the "technical faults" on the North Sea Link to Norway seemed more political than engineering motivated.
How NESO manages the domestic system and the interface with interconnectors appears to be under-appreciated. The EUPHEMIA system and NESO role needs to go under the microscope. No amount of local synthetic inertia supply domestically can provide the assurance for the large intra-day load swings across interconnectors.
How NESO protocol for the gas network to provide the gas fired capacity ramp up required at dusk hours is a mystery too.
A fact finding - as opposed to a fault finding- comprehensive review might become necessary; better to undertake in the late summer/early autumn 2026 than to risk grid failure in winter.
NESO’s enthusiasm for Net Zero is, naturally, commendable, it does appear that their recent initiatives — including the imaginative decision to avoid permanent records, the adventurous lowering of inertia limits, and the spirited attempt to rely on synthetic inertia that unfortunately failed to materialise when required — may collectively constitute what one might delicately describe as a system‑wide flirtation with catastrophe.
Given that the grid operators themselves have felt compelled to seek external assistance, and that the SQSS committee has expressed reservations of a magnitude rarely seen outside discussions of experimental aircraft, it may be prudent to consider whether NESO’s current strategy is less a plan for energy security and more a blueprint for a countrywide blackout.
I merely ask, whether Ed Miliband is entirely confident that NESO’s present course — guided as it is by ideological enthusiasm rather than the tedious constraints of physics — will keep the lights on, rather than provide the nation with an unplanned demonstration of what life was like before electricity.
As it currently stands, the Government had better issue each and every household a guidance note of what to do as and when the National Grid shuts down- Prepare to Survive, with handy tips to have candles, tinned food, batteries, a windup radio, a windup phone recharger, with the helpful reminder that the Nation could be back to full power within 4 to 16weeks………….meanwhile Local Government will offer guidance but no assistance (a re run of the Nuclear attack and survive).
I entirely disagree that "NESO’s enthusiasm for Net Zero is, naturally, commendable". Net Zero is a foolish and unattainable objective set up by deluded people who do not understand the nature of climate variation.
Yes. We are confronted with a fundamental contrast between two attitudes to reality.
As Philip K. Dick so clearly put it, "Reality is that which, when you stop believing in it, doesn't go away".
Reality must be exactly as we choose to describe it; and we choose to describe it as exactly fitting our desires and beliefs.
The first is the scientist’s attitude, and should be that of the philosopher in the broadest sense - any human who wishes, above all, to understand reality either to interact with it advantageously or merely for the satisfaction of understanding.
The second, unfortunately, is that of the lawyer, the politician, the economist, and everyone who flatters power rather than speaking truth to it. Powerful humans being what they mostly are, flattery is much more effective in obtaining the necessities and luxuries of life.
Yes, on a more human level I have seen the interaction of plant operators & the engineers/management when operating chemical plant. The operators like to run the plant at below nameplate capacity: it gives them an easy life, & they know from long experience just how hard you can push a plant before getting an unscheduled shutdown. Management want to wring every last ounce out of the plant, not realising how close to shutdown/disaster they are edging towards. I suspect the same thing is happening here, but with far greater consequences to the general public.
We seem to be living in an age where significant groups of people (sadly including many with access to the levers of power) think that they can ignore reality - whether that's in the form of Net Zero or the belief that people can be surgically mutilated into becoming a different sex.
The problem is that if the government starts to provide guidance to households as to what to do when the inevitable power cuts happen then the public might start to wonder WHY the power cuts are happening and blame government.
"It is outrageous that NESO management should claim the whistleblowers have somehow let the company down when they are clearly trying to save us all from potential catastrophe".
Outrageous, certainly: but utterly predictable. To NESO (in the form of its executives) the company has interests entirely separate from those of the nation and the people - and, as this fine article shows, sometimes opposite to them.
The moral must be that it is wrong in principle to entrust vital national interests to commercially-motivated corporations.
and (perhaps) effectively government-controlled - but there's the rub. Whatever the degree of government control in reality, the Energy Act has provided a convenient firewall to shield the government from responsibility or blame.
Just as with all the thousands of other quangos, NGOs, and other arm's length bodies that have been created over the years, NESO can be portrayed as fully independent of government and operated by experts in the public interest.
If and when anything goes wrong - no matter how badly - it will not be the government's fault. That is, I believe, the only consideration in choosing this type of relationship. The government retains, no doubt, complete control in practice while retaining the freedom to cry "Not me, guv!"
And even if the worst comes to the worst, it will usually turn out - years after the event - that no individual was to blame. “Systemic failure”, don’t you know…
I find it a deep irony that after I made voluble complaint to OFGEM and the BEIS Select Committee about NGESO being part of National Grid having a massive conflict of interest in being asked to plan the system, resulting in all solutions leading to a massive expansion of the grid, the entire planning department under Claire Dykta was transplanted lock, stock and barrel into NESO to continue in exactly the same vein.
I have suggested that an independent plan could be produced by Great British Nuclear showing how a nuclear based grid could achieve enormous economies in grid spending, and that the industry could assemble its own planning team that might negotiate between alternative visions of the future.
Surely this calls for a real independent "full on", fully traceable audit of the entire NESO operation from start to finish with nothing left out otherwise by 2 completely different fully independent audit companies who then share their findings with an other independent authority to produce a clean picture of what is going on before we go any further down the rabbit hole. Otherwise this whole thing is just a sham. There's far too much at stake here for it to be done any other way.
Other data feeds (skip rates), generation by type have has some outages in recent weeks as well as the inertia one you mention - imho there needs to be a real effort to fix/improve data and transparency
I would be interested to know why the frequency dropped? Was it loss of supply, and if so what capacity was that loss.
This is a problem with saying all was under control as faults are beyond anticipation so sufficient reserve on line power is required to guard against that. Inertia helps, but there needs to be generators or storage able to react instantly.
NESO claim our grid is reliable and has an exemplary record, that is history, but continuing to run closer and closer to the cliff edge, in my view, is totally unacceptable and policy should be reversed.
Im not sure why frequency was dropping but NESO procure on a daily basis split by six periods/day a host of frequency support services. The ones that are used for close frequency control are Dynamic Moderation(DM) & Dynamic Regulation(DR). These are used to fine tune frequency (this used to come for free with steam turbines as the machines would automatically adjust steam supply). These two are pre fault services. They also have post fault services of Dynamic Containment along with Quick Reserve and Slow Reserve and a new service called Balancing Reserve. Then they have units that are contracted to provide mandatory frequency response generally gas or pumped storage.
On the 23rd in block 6 (1800-2400) they had procured 200MW of DM and 400MW of DR. These are provided by batteries and they are required to provide the services for 60m. So at best they had 600MWhs of injection but straight away frequency was falling so its highly probable that the batteries were exhausted quickly. I dont believe the control room has visibility of this currently although that is another update thats coming. There were also fossil fuel units online that may have been contracted to provide mandatory frequency response so be interesting to see how much they injected above their self dispatched levels.
All in all its getting highly complex to manage the grid and I feel NESO would have been much wiser about using this as an opportunity to expose that challenge and declare they would do a deep dive and look on what they need to do differently. Miliband doesn't want to hear this and Shanks has foolishly played on. Anyhow both will be gone in 24hrs.
'NESO claim our grid is reliable'. Tell that to the operators of Heathrow Airport who lost a fortune when a faulty transformer (that the operator knew about) failed.
"Back in 2019, when still just ESO, CEO Fintan Slye announced they would “be able to fully operate Great Britain’s electricity system with zero carbon by 2025."
That announcement was made on April Fool's Day, which I'm sure is totally coincidental. I'm also sure that it's totally coincidental that one of Extinction Rebellion's core demands when it was set up in 2018 was the impossible complete decarbonisation of the UK by 2025 (i.e. Net Zero). Starting on April 15th 2019, they took over London for 11 days, glueing themselves to roads and what not, costing the Metropolitan Police £7.5 million. Immediately afterwards, Michael Gove, Environment Secretary at the time, met with their leaders to discuss their demands.
I'm sure it's entirely coincidental that the government did implement Citizen's Assemblies, which was another core demand of Extinction Rebellion and Net Zero 2050 was introduced by PM Theresa May by statutory instrument with virtually no debate in Parliament in June 2019. That was to be her poisonous, vainglorious departing legacy to the UK after having spent three years trying to nobble Brexit. In that context, the announcement by ESO on April 1st 2019 to operate "a zero-carbon electricity system in 2025, whenever there is sufficient renewable generation" looks like an attempt to head off the XR protests, which obviously didn't work, hence Gove met up with them at the end of April. The rabid, climate crisis obsessed Green Blob has been driving this insanity for years and Labour and Conservative governments have willingly bent over backwards, even actively colluded and participated, in driving the Net Zero fantasy forward - including when Coutinho was in office.
Supply voltage, frequency and capacity remained well within operational limits and the grid continued to function impeccably, thanks to Comrade Stalin.
As modelled retrospectively by Neso, thereby relegating the importance and primacy of real world data at the actual time of the incident which demonstrated conclusively that Grid security WAS at risk. This is now beyond absurd.
They used to talk about the Net Zero trilemma, the balancing of sustainability (so called low-carbon), affordability and security. This was always just flannel as it was obvious from the start that these were mutually irreconcilable objectives when putting so much emphasis on such unsuitable technologies as intermittent wind and solar.
As for Slye’s unbelievable 2019 claim that the grid could be 100% decarbonised by 2025, the latest Energy Institute report shows that “renewables” (defined as mainly wind and solar) contributed 51% of UK electricity in 2024, corresponding to just 14% of UK total energy supply. In other words, Net Zero is going nowhere other than to deindustrialise the economy, slowly and very expensively.
Back in 2019 few had any inkling of the particular security constraints entailed in trying to put heavy reliance on “renewables” which are not only weather-dependent but are also intrinsically unstable as they are incompatible with how the grid was designed to operate, the painful lesson from the Spain national blackout of April 2025.
What is stopping the authorities from admitting that the entire Net Zero endeavour has been a huge mistake which needs to be abandoned, especially as most of the rest of the world doesn’t give two hoots about it? I can only conclude that malign deep state influence is being brought to bear for some inscrutable unfathomable ulterior motive.
To be a honest a grid failure would be the icing on the cake, a black start scenario would kill Net Zero stone dead. The available steam turbine units to absorb the cold load overload are Drax and Nuclear, They blew all the coal ones up, just to claim bragging rights. Dinorwig features in plans I have seen for the start up, but it would probably be empty, flat out trying to prevent the inevitable.
Fintan Slye must be thick skinned, he is in the firing line when it all goes dark. The deliberate failure to issue the data is also a sign of a cover up. I watched the debate as it was after PMQs (my favourite comedy) the government guy was "slippery". PS I now have 3 small portable generators, 5kW in total, I must get round to trying to synch them up. The day that they will be needed is coming up.
What’s more, your February 2024 post was mostly about shortage of supply during midwinter Dunkelflautes. It didn’t even mention the grid instability risks of over-reliance on inertia-less renewables, the cause of the later April 2025 national blackout in Spain.
It's worth explaining why the transmission constraint issue is important, particularly given that the grid didn't actually fall over or exceed its statutory frequency limits (although it did exceed the levels that are reportable under GC0105 provisions that were amended following the August 2019 blackout, so we should expect NESO to provide those reports).
Part of the SQSS System Quality and Security Standard is that the system should be operated to be resilient to the loss of any particular key element: a major generator, interconnector or transmission line - the so-called N-1 criterion. Operating configurations are always tested against how the system would try to re-optimise for any of these hundreds of potential failures. We usually think of the vulnerability being major supply over interconnectors or the larger power stations and wind farms when operating near capacity. However, when transmission lines are fully loaded - or worse, overloaded by up to 700MW as report in The Times - they can become a key risk. If one transmission line trips out or fails, then Kirchoff's Laws ensure that the power tries to re-route via the remaining network, adding load to the nearest alternative routes (in electrical terms), which can in turn result in those lines becoming overloaded in turn and tripping out, creating a very rapid cascade that descends into extensive blackout. Prime examples include
Such blackouts overwhelm traditional last ditch efforts to prevent further spread via Low Frequency Demand Disconnection programmes, and can affect very wide areas very rapidly. Heavily overloaded lines pose enormous risk, because N-1 calculations assume that only the safe maximum load has to be redistributed, not some large excess on top.
In the heat, line capacity was much reduced: a key limitation is how hot the line gets from the combination of heating by the weather and sun, and I^2R Ohmic heating (strictly Z^2R, which includes the reactive power load as well as the forward power load). Since the Ohmic element scales with the square of currents the impact of reduced headroom from other heating can bite quite hard on power rating, with power only scaling with the current at constant voltage. Overheated lines can sag, potentially failing physically or shorting out when contacting things below them. That's what started the Northeast Blackout in 2003 in the US NE and Ontario, and it's why the blackout risk was much higher (and likely much more extensive) than NESO/Shanks have pretended publicly.
Inertia is important as a source of energy to arrest frequency declines that can head into blackouts: it is wholly automatic, relying only on the laws of physics rather than clever switching that relies on detecting a problem to be solved very rapidly or manual intervention. The amount of inertia available relative to demand scales with the time available for wider intervention to restore normal operations, and the time scales inversely with the size of the problem to be solved.
I repeat here a comment I made at Watt-logic.com on the topic of inertia
OFGEM did agree to lowering the minimum inertia on May 28th from 120GVAs to an initial 110GVAs for at least 10 weeks, with a review before a further step down to 102GVAs if the review sees no obstacles after NESO made further submissions in response to being refused permission in December.
It is notable that in mid May NESO outturn inertia data started to go missing almost every other day, and continued every other day throughout June: data updates have now been suspended with no reason given other than “review”.
Following the investigation into inertia we did last year which showed that NESO were apparently frequently breaching the inertia minimum mandate, NESO suddenly decided that “Outturn” doesn’t mean that (as records at Wayback confirm), because supposedly it excludes inertia provided under Pathfinder project contracts for synchronous condensers that report directly to the Control Room. As some inertia measurement is done by observing grid response to tiny injections of power they would need to actually subtract the Pathfinder inertia covered by such measurements to exclude it from their outturn number
I have subsequently checked back on the year from April 2025 and found 18 days where 120GVAs was breached with Pathfinders added (back) in to NESOs Outturn numbers. In the period starting this April they were initially scrupulous after they submitted their updated their submission, but since permission was granted for lower inertia the available data suggest they have driven a coach and four through what is meant to be a key element of the Security and Quality of Supply Standard (SQSS). Moreover, the Pathfinder data show frequent experiments with cutting provision during June.
This is an aspect that was skirted around during the Urgent Question in Parliament. Donald Lumsden, the new MP for Aberdeen South, asked whether inertia provision had been sufficient and was given a handwaving answer by Michael Shanks, the Miliband deputy. Although it appears inertia was sufficient on 23rd June itself (there was heavy dependence on CCGT) there are already 4 days with clear breaches of the interim 110GVAs standard with half the data missing, with levels as low as 91GVAs recorded including Pathfinders.
As I understand it, grid frequency can dip below statutory limits when demand exceeds supply and it can rise above the upper limit when supply exceeds demand, e.g. very windy, sunny, warm days. Either way, the safety of the grid is threatened if the frequency excursions continue and become more severe, and you need inertia on the grid to damp down these frequency oscillations. So, if you have a combination of low inertia and a significant mismatch of supply and demand due to weather dependent renewables generating too much or too little 'clean' electricity, you're in big trouble.
Crunch will come when FN wins the French election next year.
Interesting re FN, please elucidate. Would le Pen deliberately make a political move against Britain?
NESO needs putting under a microscope, perhaps Mr Musk can raise a big enough fuss?
FN will support lowering French prices for French customers before offering support for the rest of Europe inc UK. So the exports to UK will only be available when the French decide at a price that reflects UK distress value. No longer something that can relied on in emergencies.
I don't think the issues are confined to France. The general interconnector system across Europe is creaking, and creating widespread unhappiness. The Norwegians and Swedes don't like the consequence of importing high prices from Germany and Denmark and the UK and the Netherlands and Poland. There have been a number of occasions when the EUPHEMIA system that decides how the system is balanced and priced has produced some distinctly counter-intuitive flows against price gradients. Abuse of the system to dump renewables surpluses creates problems for local grids that have to back out inertia providing generation or adopt more radical measures such as the phase shift transformers that block flows on AC lines, preventing "free" use of transmission in neighbouring countries between North and South Germany (we also see this abuse of transmission capacity in the UK, with exports from France being re-exported to Netherlands and Belgium at times, or from Norway back to Denmark via the UK). When Dunkelflaute arises (including as the sun goes down in summer) everyone expects everyone else to help out with rapid ramping of dispatchable generation.
Indeed, part of the NESO story is that they have been absorbing some solar surpluses from Europe during the day, and then having to ramp up generation very rapidly as the sun sets in Europe, demanding to import in the evening from the UK. This puts enormous stresses on the system as transmission lines have to flip direction of operation and the power flow has to be re-configured across the grid. I do not envy the Control Room having to devise ways to do this safely, but it has clearly resulted in frequency blips - particularly on May 2nd and June 13th - incidents I highlighted along with Kathryn Porter which were picked up by Claire Coutinho who started asking awkward questions on the back of them - as well as the incidents later in June and early July.
The events of 23rd June were felt particularly acutely in the Netherlands, where the sudden cutting off of UK export saw local balancing prices reach €4,000/MWh - a level associated with paying for demand reduction.
We exported the power cut to save the NESO/Miliband bacon. We can only expect that interconnectors will prove less reliable in future too. Of course, we should remember that Ireland imposed bans on power exports during the energy crisis in 2022, and some of the "technical faults" on the North Sea Link to Norway seemed more political than engineering motivated.
How NESO manages the domestic system and the interface with interconnectors appears to be under-appreciated. The EUPHEMIA system and NESO role needs to go under the microscope. No amount of local synthetic inertia supply domestically can provide the assurance for the large intra-day load swings across interconnectors.
How NESO protocol for the gas network to provide the gas fired capacity ramp up required at dusk hours is a mystery too.
A fact finding - as opposed to a fault finding- comprehensive review might become necessary; better to undertake in the late summer/early autumn 2026 than to risk grid failure in winter.
NESO’s enthusiasm for Net Zero is, naturally, commendable, it does appear that their recent initiatives — including the imaginative decision to avoid permanent records, the adventurous lowering of inertia limits, and the spirited attempt to rely on synthetic inertia that unfortunately failed to materialise when required — may collectively constitute what one might delicately describe as a system‑wide flirtation with catastrophe.
Given that the grid operators themselves have felt compelled to seek external assistance, and that the SQSS committee has expressed reservations of a magnitude rarely seen outside discussions of experimental aircraft, it may be prudent to consider whether NESO’s current strategy is less a plan for energy security and more a blueprint for a countrywide blackout.
I merely ask, whether Ed Miliband is entirely confident that NESO’s present course — guided as it is by ideological enthusiasm rather than the tedious constraints of physics — will keep the lights on, rather than provide the nation with an unplanned demonstration of what life was like before electricity.
As it currently stands, the Government had better issue each and every household a guidance note of what to do as and when the National Grid shuts down- Prepare to Survive, with handy tips to have candles, tinned food, batteries, a windup radio, a windup phone recharger, with the helpful reminder that the Nation could be back to full power within 4 to 16weeks………….meanwhile Local Government will offer guidance but no assistance (a re run of the Nuclear attack and survive).
I entirely disagree that "NESO’s enthusiasm for Net Zero is, naturally, commendable". Net Zero is a foolish and unattainable objective set up by deluded people who do not understand the nature of climate variation.
I think Mr Davison is being ironic throughout- "tedious constraints of physics" lol.
Yes. We are confronted with a fundamental contrast between two attitudes to reality.
As Philip K. Dick so clearly put it, "Reality is that which, when you stop believing in it, doesn't go away".
Reality must be exactly as we choose to describe it; and we choose to describe it as exactly fitting our desires and beliefs.
The first is the scientist’s attitude, and should be that of the philosopher in the broadest sense - any human who wishes, above all, to understand reality either to interact with it advantageously or merely for the satisfaction of understanding.
The second, unfortunately, is that of the lawyer, the politician, the economist, and everyone who flatters power rather than speaking truth to it. Powerful humans being what they mostly are, flattery is much more effective in obtaining the necessities and luxuries of life.
Yes, on a more human level I have seen the interaction of plant operators & the engineers/management when operating chemical plant. The operators like to run the plant at below nameplate capacity: it gives them an easy life, & they know from long experience just how hard you can push a plant before getting an unscheduled shutdown. Management want to wring every last ounce out of the plant, not realising how close to shutdown/disaster they are edging towards. I suspect the same thing is happening here, but with far greater consequences to the general public.
We seem to be living in an age where significant groups of people (sadly including many with access to the levers of power) think that they can ignore reality - whether that's in the form of Net Zero or the belief that people can be surgically mutilated into becoming a different sex.
"NESO’s enthusiasm for Net Zero is, naturally, commendable,"
On what basis do you make this claim?
Quite. When we do have the inevitable power cuts I'd like it if we can disconnect the Net Zero zealots first.
The problem is that if the government starts to provide guidance to households as to what to do when the inevitable power cuts happen then the public might start to wonder WHY the power cuts are happening and blame government.
"It is outrageous that NESO management should claim the whistleblowers have somehow let the company down when they are clearly trying to save us all from potential catastrophe".
Outrageous, certainly: but utterly predictable. To NESO (in the form of its executives) the company has interests entirely separate from those of the nation and the people - and, as this fine article shows, sometimes opposite to them.
The moral must be that it is wrong in principle to entrust vital national interests to commercially-motivated corporations.
I thought NESO was government owned- and effectively government controlled.
Perhaps you are being ironic?
You are correct, but I was not being ironic - at all. NESO was set up by the Energy Act 2023 - very recent. It is government-owned:
"NESO is a private company limited by shares that is wholly owned by the Secretary of State".
https://en.wikipedia.org/wiki/National_Energy_System_Operator#Governance_and_organisation
and (perhaps) effectively government-controlled - but there's the rub. Whatever the degree of government control in reality, the Energy Act has provided a convenient firewall to shield the government from responsibility or blame.
Just as with all the thousands of other quangos, NGOs, and other arm's length bodies that have been created over the years, NESO can be portrayed as fully independent of government and operated by experts in the public interest.
If and when anything goes wrong - no matter how badly - it will not be the government's fault. That is, I believe, the only consideration in choosing this type of relationship. The government retains, no doubt, complete control in practice while retaining the freedom to cry "Not me, guv!"
Completely agree. Authority without accountability. Always a fatal combination.
Still you get well paid for being the fall guy. 3/4 of a million I gather.
And even if the worst comes to the worst, it will usually turn out - years after the event - that no individual was to blame. “Systemic failure”, don’t you know…
I could do that. Chair a meeting once a month…
I find it a deep irony that after I made voluble complaint to OFGEM and the BEIS Select Committee about NGESO being part of National Grid having a massive conflict of interest in being asked to plan the system, resulting in all solutions leading to a massive expansion of the grid, the entire planning department under Claire Dykta was transplanted lock, stock and barrel into NESO to continue in exactly the same vein.
I have suggested that an independent plan could be produced by Great British Nuclear showing how a nuclear based grid could achieve enormous economies in grid spending, and that the industry could assemble its own planning team that might negotiate between alternative visions of the future.
Surely this calls for a real independent "full on", fully traceable audit of the entire NESO operation from start to finish with nothing left out otherwise by 2 completely different fully independent audit companies who then share their findings with an other independent authority to produce a clean picture of what is going on before we go any further down the rabbit hole. Otherwise this whole thing is just a sham. There's far too much at stake here for it to be done any other way.
Other data feeds (skip rates), generation by type have has some outages in recent weeks as well as the inertia one you mention - imho there needs to be a real effort to fix/improve data and transparency
I would be interested to know why the frequency dropped? Was it loss of supply, and if so what capacity was that loss.
This is a problem with saying all was under control as faults are beyond anticipation so sufficient reserve on line power is required to guard against that. Inertia helps, but there needs to be generators or storage able to react instantly.
NESO claim our grid is reliable and has an exemplary record, that is history, but continuing to run closer and closer to the cliff edge, in my view, is totally unacceptable and policy should be reversed.
Im not sure why frequency was dropping but NESO procure on a daily basis split by six periods/day a host of frequency support services. The ones that are used for close frequency control are Dynamic Moderation(DM) & Dynamic Regulation(DR). These are used to fine tune frequency (this used to come for free with steam turbines as the machines would automatically adjust steam supply). These two are pre fault services. They also have post fault services of Dynamic Containment along with Quick Reserve and Slow Reserve and a new service called Balancing Reserve. Then they have units that are contracted to provide mandatory frequency response generally gas or pumped storage.
On the 23rd in block 6 (1800-2400) they had procured 200MW of DM and 400MW of DR. These are provided by batteries and they are required to provide the services for 60m. So at best they had 600MWhs of injection but straight away frequency was falling so its highly probable that the batteries were exhausted quickly. I dont believe the control room has visibility of this currently although that is another update thats coming. There were also fossil fuel units online that may have been contracted to provide mandatory frequency response so be interesting to see how much they injected above their self dispatched levels.
All in all its getting highly complex to manage the grid and I feel NESO would have been much wiser about using this as an opportunity to expose that challenge and declare they would do a deep dive and look on what they need to do differently. Miliband doesn't want to hear this and Shanks has foolishly played on. Anyhow both will be gone in 24hrs.
'NESO claim our grid is reliable'. Tell that to the operators of Heathrow Airport who lost a fortune when a faulty transformer (that the operator knew about) failed.
"Back in 2019, when still just ESO, CEO Fintan Slye announced they would “be able to fully operate Great Britain’s electricity system with zero carbon by 2025."
That announcement was made on April Fool's Day, which I'm sure is totally coincidental. I'm also sure that it's totally coincidental that one of Extinction Rebellion's core demands when it was set up in 2018 was the impossible complete decarbonisation of the UK by 2025 (i.e. Net Zero). Starting on April 15th 2019, they took over London for 11 days, glueing themselves to roads and what not, costing the Metropolitan Police £7.5 million. Immediately afterwards, Michael Gove, Environment Secretary at the time, met with their leaders to discuss their demands.
I'm sure it's entirely coincidental that the government did implement Citizen's Assemblies, which was another core demand of Extinction Rebellion and Net Zero 2050 was introduced by PM Theresa May by statutory instrument with virtually no debate in Parliament in June 2019. That was to be her poisonous, vainglorious departing legacy to the UK after having spent three years trying to nobble Brexit. In that context, the announcement by ESO on April 1st 2019 to operate "a zero-carbon electricity system in 2025, whenever there is sufficient renewable generation" looks like an attempt to head off the XR protests, which obviously didn't work, hence Gove met up with them at the end of April. The rabid, climate crisis obsessed Green Blob has been driving this insanity for years and Labour and Conservative governments have willingly bent over backwards, even actively colluded and participated, in driving the Net Zero fantasy forward - including when Coutinho was in office.
Supply voltage, frequency and capacity remained well within operational limits and the grid continued to function impeccably, thanks to Comrade Stalin.
As reported in Pravda
As modelled retrospectively by Neso, thereby relegating the importance and primacy of real world data at the actual time of the incident which demonstrated conclusively that Grid security WAS at risk. This is now beyond absurd.
https://x.com/KathrynPorter26/status/2078750097031262325
On your Alice in Wonderland theme. The quest for Net Zero appears to be part of the Red Queen effect.
Now, here, you see, it takes all the running you can do, to keep in the same place.
They used to talk about the Net Zero trilemma, the balancing of sustainability (so called low-carbon), affordability and security. This was always just flannel as it was obvious from the start that these were mutually irreconcilable objectives when putting so much emphasis on such unsuitable technologies as intermittent wind and solar.
As for Slye’s unbelievable 2019 claim that the grid could be 100% decarbonised by 2025, the latest Energy Institute report shows that “renewables” (defined as mainly wind and solar) contributed 51% of UK electricity in 2024, corresponding to just 14% of UK total energy supply. In other words, Net Zero is going nowhere other than to deindustrialise the economy, slowly and very expensively.
Back in 2019 few had any inkling of the particular security constraints entailed in trying to put heavy reliance on “renewables” which are not only weather-dependent but are also intrinsically unstable as they are incompatible with how the grid was designed to operate, the painful lesson from the Spain national blackout of April 2025.
What is stopping the authorities from admitting that the entire Net Zero endeavour has been a huge mistake which needs to be abandoned, especially as most of the rest of the world doesn’t give two hoots about it? I can only conclude that malign deep state influence is being brought to bear for some inscrutable unfathomable ulterior motive.
Here’s a 12-minute Daily Sceptic podcast of Richard Lyon explaining his new renewables Subsidy Clock, currently ticking towards £228 billion: https://www.climateskeptic.org/p/the-climate-skeptic-podcast-episode-8b7?utm_campaign=email-half-post&r=8t7a0&utm_source=substack&utm_medium=email.
I’d be interested to know if this is accessible by anyone who doesn’t subscribe to The Daily Sceptic.
Subsidy clock is here: https://subsidyclock.co.uk
To be a honest a grid failure would be the icing on the cake, a black start scenario would kill Net Zero stone dead. The available steam turbine units to absorb the cold load overload are Drax and Nuclear, They blew all the coal ones up, just to claim bragging rights. Dinorwig features in plans I have seen for the start up, but it would probably be empty, flat out trying to prevent the inevitable.
Fintan Slye must be thick skinned, he is in the firing line when it all goes dark. The deliberate failure to issue the data is also a sign of a cover up. I watched the debate as it was after PMQs (my favourite comedy) the government guy was "slippery". PS I now have 3 small portable generators, 5kW in total, I must get round to trying to synch them up. The day that they will be needed is coming up.
Sadly my article from October February 2024, is turning out to be somewhat prescient.
https://davidturver.substack.com/p/wait-for-the-blackout?r=nhgn1&utm_campaign=post-expanded-share&utm_medium=web
What’s more, your February 2024 post was mostly about shortage of supply during midwinter Dunkelflautes. It didn’t even mention the grid instability risks of over-reliance on inertia-less renewables, the cause of the later April 2025 national blackout in Spain.
It's worth explaining why the transmission constraint issue is important, particularly given that the grid didn't actually fall over or exceed its statutory frequency limits (although it did exceed the levels that are reportable under GC0105 provisions that were amended following the August 2019 blackout, so we should expect NESO to provide those reports).
Part of the SQSS System Quality and Security Standard is that the system should be operated to be resilient to the loss of any particular key element: a major generator, interconnector or transmission line - the so-called N-1 criterion. Operating configurations are always tested against how the system would try to re-optimise for any of these hundreds of potential failures. We usually think of the vulnerability being major supply over interconnectors or the larger power stations and wind farms when operating near capacity. However, when transmission lines are fully loaded - or worse, overloaded by up to 700MW as report in The Times - they can become a key risk. If one transmission line trips out or fails, then Kirchoff's Laws ensure that the power tries to re-route via the remaining network, adding load to the nearest alternative routes (in electrical terms), which can in turn result in those lines becoming overloaded in turn and tripping out, creating a very rapid cascade that descends into extensive blackout. Prime examples include
https://en.wikipedia.org/wiki/2006_European_blackout
https://en.wikipedia.org/wiki/Northeast_blackout_of_2003
Such blackouts overwhelm traditional last ditch efforts to prevent further spread via Low Frequency Demand Disconnection programmes, and can affect very wide areas very rapidly. Heavily overloaded lines pose enormous risk, because N-1 calculations assume that only the safe maximum load has to be redistributed, not some large excess on top.
In the heat, line capacity was much reduced: a key limitation is how hot the line gets from the combination of heating by the weather and sun, and I^2R Ohmic heating (strictly Z^2R, which includes the reactive power load as well as the forward power load). Since the Ohmic element scales with the square of currents the impact of reduced headroom from other heating can bite quite hard on power rating, with power only scaling with the current at constant voltage. Overheated lines can sag, potentially failing physically or shorting out when contacting things below them. That's what started the Northeast Blackout in 2003 in the US NE and Ontario, and it's why the blackout risk was much higher (and likely much more extensive) than NESO/Shanks have pretended publicly.
Inertia is important as a source of energy to arrest frequency declines that can head into blackouts: it is wholly automatic, relying only on the laws of physics rather than clever switching that relies on detecting a problem to be solved very rapidly or manual intervention. The amount of inertia available relative to demand scales with the time available for wider intervention to restore normal operations, and the time scales inversely with the size of the problem to be solved.
I repeat here a comment I made at Watt-logic.com on the topic of inertia
OFGEM did agree to lowering the minimum inertia on May 28th from 120GVAs to an initial 110GVAs for at least 10 weeks, with a review before a further step down to 102GVAs if the review sees no obstacles after NESO made further submissions in response to being refused permission in December.
It is notable that in mid May NESO outturn inertia data started to go missing almost every other day, and continued every other day throughout June: data updates have now been suspended with no reason given other than “review”.
Following the investigation into inertia we did last year which showed that NESO were apparently frequently breaching the inertia minimum mandate, NESO suddenly decided that “Outturn” doesn’t mean that (as records at Wayback confirm), because supposedly it excludes inertia provided under Pathfinder project contracts for synchronous condensers that report directly to the Control Room. As some inertia measurement is done by observing grid response to tiny injections of power they would need to actually subtract the Pathfinder inertia covered by such measurements to exclude it from their outturn number
https://watt-logic.com/2025/06/18/should-neso-be-allowed-to-lower-its-minimum-inertia-requirement/
The Reactive Technologies inertia measurement is discussed here
https://watt-logic.com/2021/11/05/measuring-grid-inertia/
I have subsequently checked back on the year from April 2025 and found 18 days where 120GVAs was breached with Pathfinders added (back) in to NESOs Outturn numbers. In the period starting this April they were initially scrupulous after they submitted their updated their submission, but since permission was granted for lower inertia the available data suggest they have driven a coach and four through what is meant to be a key element of the Security and Quality of Supply Standard (SQSS). Moreover, the Pathfinder data show frequent experiments with cutting provision during June.
This is an aspect that was skirted around during the Urgent Question in Parliament. Donald Lumsden, the new MP for Aberdeen South, asked whether inertia provision had been sufficient and was given a handwaving answer by Michael Shanks, the Miliband deputy. Although it appears inertia was sufficient on 23rd June itself (there was heavy dependence on CCGT) there are already 4 days with clear breaches of the interim 110GVAs standard with half the data missing, with levels as low as 91GVAs recorded including Pathfinders.
This needs serious investigation by OFGEM.
As I understand it, grid frequency can dip below statutory limits when demand exceeds supply and it can rise above the upper limit when supply exceeds demand, e.g. very windy, sunny, warm days. Either way, the safety of the grid is threatened if the frequency excursions continue and become more severe, and you need inertia on the grid to damp down these frequency oscillations. So, if you have a combination of low inertia and a significant mismatch of supply and demand due to weather dependent renewables generating too much or too little 'clean' electricity, you're in big trouble.
Well, what do you expect from the religious zealots? Realism?