Is the National Grid sufficiently resilient?

[mike57]

Moderator note: split from https://www.railforums.co.uk/threads/ecml-mml-major-power-problems-09-08.188171/page-9#post-4147074

Sounds like a grid failure, it seems that various parts of the country are affected, London, Cardiff and the Liverpool as well as parts of east Anglia seem to be affected. National rail is reporting problems in the first 3 areas.

This could either be caused by a sudden loss of generation, or a failure of one of the trunk high voltage lines which distribute power around the country.

What tends to happen is that first fault causes surges in other transmission lines, which in turn fault, leading eventually to grid separation. The following article explains the cause behind a major blackout in the NE USA in 2003 https://en.m.wikipedia.org/wiki/Northeast_blackout_of_2003.

Fluctuations in frequency are a sign of an unstable grid. The problem with wind and solar power is that they are not always on, you need other technology to provide a base load and to back up when when they are not available.

There are 3 choices in the UK, fossil fuels, nuclear and hydro. With the closure of coal fired stations, and the imminent closure of the older nuclear stations this situation will get worse.

 

[geoffk]

The problem with wind and solar power is that they are not always on, you need other technology to provide a base load and to back up when when they are not available. There are 3 choices in the UK, fossil fuels, nuclear and hydro. With the closure of coal fired stations, and the imminent closure of the older nuclear stations this situation will get worse.

So really you are saying we have barely enough, or insufficient, generating capacity because so many coal-fired stations have closed.

 

[Shaw S Hunter]

So really you are saying we have barely enough, or insufficient, generating capacity because so many coal-fired stations have closed.

Various parties have been warning just this for a little while now. The difficulties with progressing any additional nuclear capacity haven't helped in terms of long-term planning but as long as the French continue to have a reasonable surplus most of the time there seems to be an acceptance that we can carry on more or less as we are. Given just how many people have been affected by this incident you would expect there to be political noises next week but we live in rather unusual times so I'm not sure that anything will change as a result of it.

 

[PG]

Various parties have been warning just this for a little while now. The difficulties with progressing any additional nuclear capacity haven't helped in terms of long-term planning but as long as the French continue to have a reasonable surplus most of the time there seems to be an acceptance that we can carry on more or less as we are. Given just how many people have been affected by this incident you would expect there to be political noises next week but we live in rather unusual times so I'm not sure that anything will change as a result of it.

I seem to recall a C4 documentary cira 2014 predicting that the lights would go out with increasing regularity fron this year.
Can't help thinking of https://hooktube.com/watch?v=y1T1dS-bh4s
Mysterious times by Sash... and thats going back 20 odd years!

 

[AM9]

Aside from the class 700 'told you so' posts from all the usual suspects, the origins of the problems yesterday lie in the drive to 'sweat the assets' and maximise profits on the National Grid. This shows just how the mantra of privatisation can get dangerous when the one-eyed monster of 'profit at any cost'* grips the Conservative administration.
The subject of network breakdowns is described in this 2014 document that proposed and agreed to relax the maximum rate of frequency change on the nominally 50Hz supply.
https://www.nationalgrideso.com/document/10771/download
It acknowledged that there was an increased risk both of generator failure owing to frequency changes outside their designed limits and subsequent the creation of 'island networks' that a) because of their disconnection from the national network would be less tolerant of demand fluctuations and crucially, b) much more difficult to reconnect owing to synchronisation issues. The goal was of course profit, £33m at 2014 ECs.
Interestingly, the class 700s (and some other recently introduced rolling stock) probably have electrical distribution systems designed before this change to the UK network was ratified. In the same timframe, EMUs have followed a the drive of more efficient power usage, particularly in respect of energy return to the supply. Like most western European countries, the UK supply has traditionally had astable 50Hz supply which has allowed transformers and conversion electronics to employ higher performance narrow-band operation. Thus when repeated out of specification excursions occur, the management systems recognises something more serious than a simple dewirement or local power cut, which are fundamental realities of OLE. I would imagine that the frequency yesterday was potentially all over the place both at the time when the initial two sources dropped out, but also when areas were being shut down creating islands and even when reconnections were inititlly being attempted. Through that period, drivers were attempting to return their trains to service unaware that the system was seeing a totally different situation to a conventional power cut.
Clearly if this is to become more than a once in a decade event, the protection mechanisms might need readdressing, although just desensitising them runs the risk of actual hardware damage rather than inconvenient shutdowns.
* - provided that it is at somebody else's cost of course

 

[Failed Unit]

Aside from the class 700 'told you so' posts from all the usual suspects, the origins of the problems yesterday lie in the drive to 'sweat the assets' and maximise profits on the National Grid. This shows just how the mantra of privatisation can get dangerous when the one-eyed monster of 'profit at any cost'* grips the Conservative administration.
The subject of network breakdowns is described in this 2014 document that proposed and agreed to relax the maximum rate of frequency change on the nominally 50Hz supply.
https://www.nationalgrideso.com/document/10771/download
It acknowledged that there was an increased risk both of generator failure owing to frequency changes outside their designed limits and subsequent the creation of 'island networks' that a) because of their disconnection from the national network would be less tolerant of demand fluctuations and crucially, b) much more difficult to reconnect owing to synchronisation issues. The goal was of course profit, £33m at 2014 ECs.
Interestingly, the class 700s (and some other recently introduced rolling stock) probably have electrical distribution systems designed before this change to the UK network was ratified. In the same timframe, EMUs have followed a the drive of more efficient power usage, particularly in respect of energy return to the supply. Like most western European countries, the UK supply has traditionally had astable 50Hz supply which has allowed transformers and conversion electronics to employ higher performance narrow-band operation. Thus when repeated out of specification excursions occur, the management systems recognises something more serious than a simple dewirement or local power cut, which are fundamental realities of OLE. I would imagine that the frequency yesterday was potentially all over the place both at the time when the initial two sources dropped out, but also when areas were being shut down creating islands and even when reconnections were inititlly being attempted. Through that period, drivers were attempting to return their trains to service unaware that the system was seeing a totally different situation to a conventional power cut.
Clearly if this is to become more than a once in a decade event, the protection mechanisms might need readdressing, although just desensitising them runs the risk of actual hardware damage rather than inconvenient shutdowns.
* - provided that it is at somebody else's cost of course

As for the once in a decade. I guess you read a lot of the reports about how we are at the limits of generation capacity. Some experts predict this will be a frequent event after the failure of successive governments to tackle it. We will see.

 

[AM9]

... As for the once in a decade. I guess you read a lot of the reports about how we are at the limits of generation capacity. Some experts predict this will be a frequent event after the failure of successive governments to tackle it. We will see.

In the febrile atmosphere of privatised utilities decisions take a very long time to come to anything so I doubt that any significant reduction in risk of such collapses will be coming soon. I do however hope that any daft suggestions to re-instate outgoing fossil burning generation plant as a quick fix are firmly put down. The forthcoming impact of climate change is much more of a threat to life than inconvenient power network failures.

 

[Failed Unit]

In the febrile atmosphere of privatised utilities decisions take a very long time to come to anything so I doubt that any significant reduction in risk of such collapses will be coming soon. I do however hope that any daft suggestions to re-instate outgoing fossil burning generation plant as a quick fix are firmly put down. The forthcoming impact of climate change is much more of a threat to life than inconvenient power network failures.

I read too much private eye. . The IET are a little less pessimistic. Both agree that inactivity back to Blair / Brown has got us in a mess and the recent 2 governments have dithered as well.

I don’t think any power solution is perfect. Nuclear = no carbon. But has other very well known issues. Wind = unreliability in the cold. Fossil fuels = lots of carbon.

It is what’s your poison. But that is for another thread I guess.

 

[Howardh]

I don’t think anyone will dispute that but do you think that taking over 6 hours to move trains is acceptable for a modern railway? Yes the route cause was national grid and many experts in the power industry could see it coming. But Siemens product let us down badly for service recovery? I am sure all the public facing communications will blame the initial fault - but I suspect Siemen’s staff will be looking into why their product messed up the network because of its inability to be reset.

As for the once in a decade. I guess you read a lot of the reports about how we are at the limits of generation capacity. Some experts predict this will be a frequent event after the failure of successive governments to tackle it. We will see.

Without wishing to bring politics into this, I think we import a lot of power from the EU when we are short. If we leave without a deal, do we know if those extra supplies will still be available?

 

[Sleepy]

I read too much private eye. . The IET are a little less pessimistic. Both agree that inactivity back to Blair / Brown has got us in a mess and the recent 2 governments have dithered as well.

I don’t think any power solution is perfect. Nuclear = no carbon. But has other very well known issues. Wind = unreliability in the cold. Fossil fuels = lots of carbon.

It is what’s your poison. But that is for another thread I guess.

But as long as they install lots of smart meters everything will be rosy !

 

[Bald Rick]

Without wishing to bring politics into this, I think we import a lot of power from the EU when we are short. If we leave without a deal, do we know if those extra supplies will still be available?

We import up to around 10% of our power from France, Belgium, Holland and Ireland, although this is offset by the amount we export. We do this because it’s cheaper than generating our own. I can’t imagine that the impacts of a ‘no deal’ would lead to the juice being cut off, but if it did we would just burn more gas or coal. Or ask the politicians to spout more hot air in the vicinity of a wind farm.

 

[Class 170101]

Various parties have been warning just this for a little while now. The difficulties with progressing any additional nuclear capacity haven't helped in terms of long-term planning but as long as the French continue to have a reasonable surplus most of the time there seems to be an acceptance that we can carry on more or less as we are. Given just how many people have been affected by this incident you would expect there to be political noises next week but we live in rather unusual times so I'm not sure that anything will change as a result of it.

Without wishing to bring politics into this, I think we import a lot of power from the EU when we are short. If we leave without a deal, do we know if those extra supplies will still be available?

I'm not sure that we can carry on as we are, relying on outside countries post our exit from the EU. Whilst it makes financial sense for the EU nations to carry on supplying us power - does it politically?

Additionally I would note that this is summer where demand I would expect to be lower but come the winter do we have enough???

 

[Mathew S]

Without wishing to bring politics into this, I think we import a lot of power from the EU when we are short. If we leave without a deal, do we know if those extra supplies will still be available?

In the absence of a 'deal' then the strict answer is no, we don't know that the energy supplies - or anything else for that matter - will still be available. The reality, though, is that I think it's highly unlikely that the countries involved would turn anything off unless the situation deteriorated massively.

 

[LNW-GW Joint]

We import up to around 10% of our power from France, Belgium, Holland and Ireland, although this is offset by the amount we export. We do this because it’s cheaper than generating our own. I can’t imagine that the impacts of a ‘no deal’ would lead to the juice being cut off, but if it did we would just burn more gas or coal. Or ask the politicians to spout more hot air in the vicinity of a wind farm.

There are at least 2 new links with the continental power system under construction, one of them through the channel tunnel.
I think these are just commercial deals and won't be affected by Brexit (unless new tariffs are applied).
EDF (Électricité de France) is one of the main players and is a nuclear generator in France, and has big contracts in the UK (including with Network Rail).

 

[Mathew S]

There are at least 2 new links with the continental power system under construction, one of them through the channel tunnel.
I think these are just commercial deals and won't be affected by Brexit (unless new tariffs are applied).
EDF (Électricité de France) is one of the main players and is a nuclear generator in France, and has big contracts in the UK (including with Network Rail).

Electricity (and gas) is considered goods, just like cars, tulips, or wine, for the purposes of international trade. So, tariffs could be applied. Whether they would be, between the UK and the EU, in the event of a no-deal Brexit is, of course, another thing that we simply don't know.

 

[Bald Rick]

I'm not sure that we can carry on as we are, relying on outside countries post our exit from the EU. Whilst it makes financial sense for the EU nations to carry on supplying us power - does it politically?

A good part of Central Europe, and even Germany, gets a fair proportion of its gas from Russia. Politics doesn’t really come into it. If the price is right...

 

[Bald Rick]

There are at least 2 new links with the continental power system under construction, one of them through the channel tunnel.
I think these are just commercial deals and won't be affected by Brexit (unless new tariffs are applied).
EDF (Électricité de France) is one of the main players and is a nuclear generator in France, and has big contracts in the UK (including with Network Rail).

I think the one through the tunnel is in use now.

There’s another one coming across from Norway.

 

[hwl]

I think the one through the tunnel is in use now.

There’s another one coming across from Norway.

And 2 from Ireland as well.

None of the contracts will be affected by Brexit.

 

[Bald Rick]

And 2 from Ireland as well.

None of the contracts will be affected by Brexit.

Indeed. I meant that the Norway one was under construction; that is due for completion in 2021. I need to correct myself, the HVDC link through the tunnel (1GW) is due to be energised early next year. All told, by 2021 will have about 7.5GW of capacity with our friends in Europe. Most of it will be nuclear or renewable.

 

[HSTEd]

In the febrile atmosphere of privatised utilities decisions take a very long time to come to anything so I doubt that any significant reduction in risk of such collapses will be coming soon. I do however hope that any daft suggestions to re-instate outgoing fossil burning generation plant as a quick fix are firmly put down. The forthcoming impact of climate change is much more of a threat to life than inconvenient power network failures.

In a post-carbon all-electric world, grid collapse is a matter of life and death.
If this had escalated further we could have been looking at mass blackouts for hours whilst they ran the Black Start procedure.

If that happened in mid-winter, people would have died. Potentially thousands.

And the carbon emissions for spinning reserve is relatively minor.

 

[Intellectual98]

2GW of loss is somewhat worrying because a single large PWR like the ones at Hinkly Point C is ~1600MWe......

Totally agree. But I'm not sure the exact expected failure of a nuclear plant. I know they cannot be shut off fast, and each individual reactor has redundancy in its construction. Would all 1.6GW stop immediately, or would it usually taper off as reactor output drops. Could a failure of a single item on such a large reactor or the distribution /generation side of it result in an immediate loss of all capacity. If 1.6GW of steam generation immediately fails what would the backup cooling be for the reactor. All questions that I'm sure were asked in the design of the reactor and facilities, and I'm sure a highly qualified engineer produced a nice risk assessment somewhere.

 

[Oxfordblues]

13 June 2019: Unite union spokesman "The closure of Fiddlers Ferry Power Station increases the likelihood of possible future power cuts"

9 August 2019: massive power cuts!

 

[AndrewE]

Totally agree. But I'm not sure the exact expected failure of a nuclear plant. I know they cannot be shut off fast, and each individual reactor has redundancy in its construction. Would all 1.6GW stop immediately, or would it usually taper off as reactor output drops. Could a failure of a single item on such a large reactor or the distribution /generation side of it result in an immediate loss of all capacity. If 1.6GW of steam generation immediately fails what would the backup cooling be for the reactor. All questions that I'm sure were asked in the design of the reactor and facilities, and I'm sure a highly qualified engineer produced a nice risk assessment somewhere.

I think it is the turbines and the steam circuits that are most likely to require (or cause) immediate shutdowns on nuclear power stations, and probably in most other thermal stations too.

 

[Intellectual98]

In a post-carbon all-electric world, grid collapse is a matter of life and death.
If this had escalated further we could have been looking at mass blackouts for hours whilst they ran the Black Start procedure.

If that happened in mid-winter, people would have died. Potentially thousands.

And the carbon emissions for spinning reserve is relatively minor.

I don't think any fossil plant can react to a loss of nearly 2GW in a matter of minutes. It still takes time to get relatively fast reacting gas generators up to speed. Load shedding (preferably intelligent*) and battery backups have by far the fastest reaction times. Fast reaction is the best way to prevent a runaway grid collapse.

As we move to more electric cars, solar generation etc it's essential we have intelligent load shedding, and systems to return stored power like V2G. More and more people have battery storage on their solar systems, and the increasing uptake of electric cars means there will be a huge untapped potential source of energy.

Intelligent load shedding would mean less critical systems would shut off first. As grid frequency is a great indicator of grid health and is easily measured by devices surely they could be designed to decrease power consumption when the grid frequency is low. The important thing would be not to have all devices reacting instantaneously, with variable time delays or different trigger points for frequency. Otherwise there would be a risk of overreaction.

 

[ashkeba]

Indeed. I meant that the Norway one was under construction; that is due for completion in 2021. I need to correct myself, the HVDC link through the tunnel (1GW) is due to be energised early next year. All told, by 2021 will have about 7.5MW of capacity with our friends in Europe. Most of it will be nuclear or renewable.

MW or GW?

 

[ashkeba]

I'm not sure that we can carry on as we are, relying on outside countries post our exit from the EU. Whilst it makes financial sense for the EU nations to carry on supplying us power - does it politically?

Yes. At the moment, there's enough attempts to blame other countries for the acts of self harm by UK politicians. Imagine if foreign companies actually did something!

 

[cjmillsnun]

Without wishing to bring politics into this, I think we import a lot of power from the EU when we are short. If we leave without a deal, do we know if those extra supplies will still be available?

Potentially not. And yes I'm being serious. The EU has published their No deal plans. We would be treated like any other non EU member.

 

[cjmillsnun]

950MW of wind disappeared, as well as around 500MW of gas and solar each according to gridwatch. Thats 2 GW of loss in a few minutes. That's fairly substantial. It also happened at roughly peak demand, meaning there was a lot less spare capacity in the system as backup.


No, most wind turbines will feather at a certain speed to stop them spinning. This is usually a wind speed of 20-30 mph on more domestic units, 50-60mph on large scale installs.. Problem is, if they keep spinning too fast they tend to either catch fire in the generators, or start throwing blades, which is not an ideal situation.


Regarding electric cars as some have stated adding additional demand. It wouldn't be hard to program the latest smart chargers to start reducing output as the grid frequency changes. Maybe a gradual reduction to 49hz and any lower would completely stop charging. Most utility companies are also offering an E7 style or more flexible tariff that means most people would be avoiding charging at 1700 because the cost of electricity is just too high. Vehicle to Grid is still a way off, but if introduced would be an excellent way of providing a large amount of aggregate electric back to the grid to stabilise the situation before large scale rolling blackouts are even needed.

V2G is starting. I know of a few people who have had their chargers converted.

 

[HSTEd]

Totally agree. But I'm not sure the exact expected failure of a nuclear plant. I know they cannot be shut off fast, and each individual reactor has redundancy in its construction. Would all 1.6GW stop immediately, or would it usually taper off as reactor output drops. Could a failure of a single item on such a large reactor or the distribution /generation side of it result in an immediate loss of all capacity. If 1.6GW of steam generation immediately fails what would the backup cooling be for the reactor. All questions that I'm sure were asked in the design of the reactor and facilities, and I'm sure a highly qualified engineer produced a nice risk assessment somewhere.

That depends on the fault.
A fire in the electrical switchyard or similar could result in the circuit breakers openly instantenously with little warning.
Or an emergency scram.

Or if there is a fault that needs a shutdown the operators might have a few minutes to phone the grid operator and tell them they are about to trip before it happens.

EDIT:
An example of the latter was the time when they started ingesting astronomical quantities of jellyfish into the condenser system

 

[AM9]

13 June 2019: Unite union spokesman "The closure of Fiddlers Ferry Power Station increases the likelihood of possible future power cuts"

9 August 2019: massive power cuts!

How many members does/did Unite have at Fiddlers Ferry?