The Future of Power Generation in Great Britain
Discussion
Gary C said:
LongQ said:
It occurred to me as I was considering the previous post that most emergency generators probably have very poor" prepare and test" plans (to save unnecessary CO2 emissions?) and that checking the fuel, other than the gauge that indicates whether there is anything in the tank(s), is probably an overhead too far.
Given the nature of the different recipes produced for various fuels depending on the season a rarely used system is very likely to be somewhat challenged in terms of achieving anything vaguely close to an instant "on sudden demand" start up - which is what most of them are supposed to offer as soon as power supply anomalies are detected if they are to be fit for purpose.
Our eight backup emergency diesel generators are given a three hour test run every 15 weeks at minimum 80% load, with a 12 hour run once a year.Given the nature of the different recipes produced for various fuels depending on the season a rarely used system is very likely to be somewhat challenged in terms of achieving anything vaguely close to an instant "on sudden demand" start up - which is what most of them are supposed to offer as soon as power supply anomalies are detected if they are to be fit for purpose.
We always fill our tanks with winter grade diesel.
I would like to think that it is but some past events relating to the installation and testing of new backup generators by clients I was working with at the time (nothing to do with the backup generator projects other than that they were to support systems that included the systems I was helping to implement or supporting) suggested that not all pre-planned activities work out as planned and the potential for unplanned requirements to fail to achieve objectives must be quite high.
LongQ said:
Gary, would you say your regime is typical of the way other types of organisations with emergency backup facilities operate?
I would like to think that it is but some past events relating to the installation and testing of new backup generators by clients I was working with at the time (nothing to do with the backup generator projects other than that they were to support systems that included the systems I was helping to implement or supporting) suggested that not all pre-planned activities work out as planned and the potential for unplanned requirements to fail to achieve objectives must be quite high.
We have a maintenance schedule furnished to our regulator and we have to keep to it or face prosecution I would like to think that it is but some past events relating to the installation and testing of new backup generators by clients I was working with at the time (nothing to do with the backup generator projects other than that they were to support systems that included the systems I was helping to implement or supporting) suggested that not all pre-planned activities work out as planned and the potential for unplanned requirements to fail to achieve objectives must be quite high.
Gary C said:
LongQ said:
Gary, would you say your regime is typical of the way other types of organisations with emergency backup facilities operate?
I would like to think that it is but some past events relating to the installation and testing of new backup generators by clients I was working with at the time (nothing to do with the backup generator projects other than that they were to support systems that included the systems I was helping to implement or supporting) suggested that not all pre-planned activities work out as planned and the potential for unplanned requirements to fail to achieve objectives must be quite high.
We have a maintenance schedule furnished to our regulator and we have to keep to it or face prosecution I would like to think that it is but some past events relating to the installation and testing of new backup generators by clients I was working with at the time (nothing to do with the backup generator projects other than that they were to support systems that included the systems I was helping to implement or supporting) suggested that not all pre-planned activities work out as planned and the potential for unplanned requirements to fail to achieve objectives must be quite high.
However for others things may not be so well organised and managed.
Some years ago one of my clients, a well know multi-national name at the time operating in a high tech environment, decided to introduce on site generation backup via generators and UPS.
They decided to test this new installation on a Friday afternoon as operators were busy loading base data for imminent live operation.
It failed and the systems went down.
As they were in data load mode (manual keying back then) it was not so bad as it would have for live operation - except that 4 days (x many operators) of data load was lost because the client, using their own systems hardware, had specific so much RAM memory that 4 days worth of keyboard activity was all contained in the RAM and had not been synchronised to disk.
The only benefit of the exercise was that they realised they should look at the systems settings and revise their choices for synchronising when data was written to disk.
Since this was to be a 24/7 operation there were limited options for future testing that could be planned and executed without causing certain disruption to operations.
That is not the only example of which I have some personal experience of being around when backup generators have been tested and failed. It makes one wonder about all such processes and how well the plans might be matched to requirements - especially when trying to plan to contain a moving target like an electricity distribution grid.
Condi said:
Much of the line of enquiry will be around Hornsea's protection systems, and did they trip in response to the unusually low frequency following Little Barford disconnecting.
Presumably also considering what to do to prevent such an abnormally low frequency occurring (if possible) and what additional steps and facilities might need to be included in the system (maybe already planned but not implemented?) to avoid the problem in the future?I might be misremembering but the somewhat similar (though differently caused) South Australia problem in 2016 was reported as having a rather short elapsed time between the initial drop out and the failed attempts to recover frequency stability. Seconds rather than minutes?
Either way it will no doubt be an informative investigation over all.
Sorry, I know I ask all sorts of really dumb layman's questions on this thread, but the level of knowledge here is excellent, so here goes:
As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
LongQ said:
Presumably also considering what to do to prevent such an abnormally low frequency occurring (if possible) and what additional steps and facilities might need to be included in the system (maybe already planned but not implemented?) to avoid the problem in the future?
Yes and no. Gary mentioned earlier (way back) what freq the transmission connected generation is designed to work down to - from memory something like 47.5Hz. You'll never stop unexpected trips completely, hence why it should all operate at far below normal frequencies until the grid has had a chance to recover. alangla said:
Sorry, I know I ask all sorts of really dumb layman's questions on this thread, but the level of knowledge here is excellent, so here goes:
As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
A couple of questions in there.... As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
When something unexpected happens all the contracted Frequency Response kit will kick in - batteries, thermal stations providing frequency services etc and this happens automatically. Then the guys in the control room will dispatch additional generation - more batteries and hydro (both traditional and pumped storage) are the quickest to dispatch, followed by things like open cycle gas and reciprocating engines. This is usually enough to replace the lost generation, along with turning up any large scale thermal plant. On Friday you could see that happening - the frequency dropped then started to recover, before Hornsea also tripped.
In the case of a total blackout then several stations around the UK have blackstart capabilities on site (ie diesel generators), and places like Dinorwig can also provide blackstart energy, but the process of restarting the grid would be slow and complicated. You can't simply turn everything back on, it has to be energised in sectors so all the parts are synchronised together.
This is quite a good piece from Aurora on what happened;
https://www.auroraer.com/wp-content/uploads/2019/0...
alangla said:
Sorry, I know I ask all sorts of really dumb layman's questions on this thread, but the level of knowledge here is excellent, so here goes:
As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
Try this 2017 document.As I understand it, pumped storage stations like Dinorwig & Cruachan provide a "black start" capability to the grid, i.e. provide enough energy that other stations can get themselves running & synchronised. I assume that's meant to be from a situation where the grid is effectively at 0Hz, i.e. stopped.
In the situation we saw last week, where frequency is out of tolerance, but the grid is still active, would it be expected that, along with load shedding, you could throw in a load of hydro/pumped (and presumably wind) energy to attempt to bring the frequency back into tolerance?
Am I right in saying that the big question from last week was why Hornsea tripped - I take it it would be expected to continue to produce as frequency fell & contribute to a grid restart if required?
Again - apologies for the dumb questions.
https://www.drax.com/energy-policy/need-whole-coun...
It's from Drax so of course has a partisan element to it but in general if you were to read the reports about, for example, the great South Australia blackout in 2016 you would see the same issues being discussed.
The Grid needs to be able to 'self heal' some aspects of its operations in the event of some sort of unplanned catastrophic disruption.
Part of that is related to managing frequency and that needs to be done very rapidly before safety systems around the grid start to respond in order to protect the local grid and ultimately the entire grid from serious damage.
The UK nominal grid frequency is 50Hz and the operation target range seems to be between 49.9 and 50.1 Hz with a slight margin acceptable either side of those values.
NG's operational licence requires them to maintain 50Hz +/- 1%. So if I read that correctly that's a required range in worst case of 49.5 to 50.5 Hz.
From the publicly available records of Grid Frequency (recorded every 15 seconds) one can see that there is a sudden drop from 50.003Hz to 49.248Hz and the numbers stay below the worst case expected frequency for the best part of 4 minutes. (According to the values reported at 15 seconds intervals.)
2019-08-09 15:52:30 50.003
2019-08-09 15:52:45 49.248
2019-08-09 15:53:00 49.104
2019-08-09 15:53:15 49.23
2019-08-09 15:53:30 49.202
2019-08-09 15:53:45 48.889
2019-08-09 15:54:00 48.914
2019-08-09 15:54:15 49.001
2019-08-09 15:54:30 49.084
2019-08-09 15:54:45 49.273
2019-08-09 15:55:00 49.5
2019-08-09 15:55:15 49.601
2019-08-09 15:55:30 49.676
2019-08-09 15:55:45 49.7
2019-08-09 15:56:00 49.724
2019-08-09 15:56:15 49.761
2019-08-09 15:56:30 49.867
2019-08-09 15:56:45 49.954
2019-08-09 15:57:00 49.958
2019-08-09 15:57:15 49.999
2019-08-09 15:57:30 50.034
During that time demand was greater than supply but as the Grid systems shut down a lot of demand would have go evaporated and so, presumably, the network could return to frequency balance relatively quickly - probably more quickly than could be achieved (on a distributed grid) by turning on more generation and synchronising it.
The old solution was to avoid the problem by having enough spinning reserve to be able to ramp up supplies over a few minutes and rely on the spinning mass of generators to maintain the rotation that was used to establish the frequency. The effects of a failure could be buffered well enough for long enough (in most cases) to allow supplies to be maintained.to at least the level of criticality required at the time.
These days it's a different game.
Others may have a more complete and comprehensive view of the reply to the question but hopefully this provides and answer of sorts for now.
ETA:
Condi's post above (posted whilst I was composing!) covers the subject in greater detail and seems to offer much the same general answer.
Expect to see a lot of Muskian "Big Batteries" installed rather quickly.
Edited by LongQ on Wednesday 14th August 15:45
LongQ said:
having enough spinning reserve to be able to ramp up supplies over a few minutes
Alongside that, concerning frequency, I read somewhere that the Drax frequency response was less than a second.Aye here it is.
https://www.drax.com/energy-policy/need-whole-coun...
turbobloke said:
LongQ said:
having enough spinning reserve to be able to ramp up supplies over a few minutes
Alongside that, concerning frequency, I read somewhere that the Drax frequency response was less than a second.Aye here it is.
https://www.drax.com/energy-policy/need-whole-coun...
"....the response starts less than a second from the initial frequency deviation."
But so long as that response is well located in the grid section needing support the result should be fine.
The South Australian Muskian battery can, apparently, respond in microseconds and keep supplying frequency support for several minutes if required.
So a few of those scattered around the country and replaced every few years might be enough to prevent problems most of the time. For now.
(I am assuming that the initial 'glowing' reports are real and still valid after a longer period of operation.)
LongQ said:
turbobloke said:
LongQ said:
having enough spinning reserve to be able to ramp up supplies over a few minutes
Alongside that, concerning frequency, I read somewhere that the Drax frequency response was less than a second.Aye here it is.
https://www.drax.com/energy-policy/need-whole-coun...
"....the response starts less than a second from the initial frequency deviation."
But so long as that response is well located in the grid section needing support the result should be fine.
The South Australian Muskian battery can, apparently, respond in microseconds and keep supplying frequency support for several minutes if required.
So a few of those scattered around the country and replaced every few years might be enough to prevent problems most of the time. For now.
(I am assuming that the initial 'glowing' reports are real and still valid after a longer period of operation.)
turbobloke said:
LongQ said:
turbobloke said:
LongQ said:
having enough spinning reserve to be able to ramp up supplies over a few minutes
Alongside that, concerning frequency, I read somewhere that the Drax frequency response was less than a second.Aye here it is.
https://www.drax.com/energy-policy/need-whole-coun...
"....the response starts less than a second from the initial frequency deviation."
But so long as that response is well located in the grid section needing support the result should be fine.
The South Australian Muskian battery can, apparently, respond in microseconds and keep supplying frequency support for several minutes if required.
So a few of those scattered around the country and replaced every few years might be enough to prevent problems most of the time. For now.
(I am assuming that the initial 'glowing' reports are real and still valid after a longer period of operation.)
Had they been able to claim that they could stabilise an unstable network frequency situation within a second I'm sure they would have written exactly that.
As written the statement is leading the reader to come to a conclusion about its meaning without actually specify exactly what it does mean.
Elon would take pride in having his methods for presenting 'facts' endorsed so diligently.
Interesting approach here - https://www.theguardian.com/business/2019/aug/11/a...
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
rscott said:
Interesting approach here - https://www.theguardian.com/business/2019/aug/11/a...
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
Surely that's not a "virtual battery" at all - it's just an agreement to be at the front of the queue for load shedding. Also, 10 minutes notice wouldn't, (I think) have helped last week.Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
If they allowed their store's UPS systems/generators to supply the grid on the other hand...
Condi -
What is to stop an operator / developer that thinks he may not get their project awarded a CFD this year throwing their toys out of the pram and developing their project independent of the CFD process (and regulation).
Would it still fall within the 6GW cap ? How would the Ofto and alike align in your thoughts ?
What is to stop an operator / developer that thinks he may not get their project awarded a CFD this year throwing their toys out of the pram and developing their project independent of the CFD process (and regulation).
Would it still fall within the 6GW cap ? How would the Ofto and alike align in your thoughts ?
alangla said:
rscott said:
Interesting approach here - https://www.theguardian.com/business/2019/aug/11/a...
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
Surely that's not a "virtual battery" at all - it's just an agreement to be at the front of the queue for load shedding. Also, 10 minutes notice wouldn't, (I think) have helped last week.Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
If they allowed their store's UPS systems/generators to supply the grid on the other hand...
What they seem to be saying is that they can turn off the freezers once a day and that means the energy they are not using is either available to be used elsewhere or they have a way of being paid for turning it off on demand.
So if they can work with the fridges being turned off 'on demand' they can not only save the cost of the electricity but also get paid for doing so.
Another possibility is that there is a price difference between what they pay for electricity and what the Grid would pay them to pass it on.
I hope their chilled and frozen food management teams are on the ball when it comes to deciding whether the contents of a chiller or freezer are still suitable for sale.
Using a short term power supply storage system like a correctly specified UPS as anything other than its intended purpose is, in my opinion, inherently stupid. Unless someone has grossly over specified it in the first place.
Using an on-site emergency generator is currently covered by various arrangements although, as I understand it, there is usually a minimum generating capacity required to qualify.
I could imagine that some sharp operators who see a may pf playing the market might attempt to present multiple sites as an aggregate supply that would be big enough to qualify for the payments from the scheme.
LongQ said:
alangla said:
rscott said:
Interesting approach here - https://www.theguardian.com/business/2019/aug/11/a...
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
Surely that's not a "virtual battery" at all - it's just an agreement to be at the front of the queue for load shedding. Also, 10 minutes notice wouldn't, (I think) have helped last week.Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
If they allowed their store's UPS systems/generators to supply the grid on the other hand...
What they seem to be saying is that they can turn off the freezers once a day and that means the energy they are not using is either available to be used elsewhere or they have a way of being paid for turning it off on demand.
So if they can work with the fridges being turned off 'on demand' they can not only save the cost of the electricity but also get paid for doing so.
Another possibility is that there is a price difference between what they pay for electricity and what the Grid would pay them to pass it on.
I hope their chilled and frozen food management teams are on the ball when it comes to deciding whether the contents of a chiller or freezer are still suitable for sale.
Using a short term power supply storage system like a correctly specified UPS as anything other than its intended purpose is, in my opinion, inherently stupid. Unless someone has grossly over specified it in the first place.
Using an on-site emergency generator is currently covered by various arrangements although, as I understand it, there is usually a minimum generating capacity required to qualify.
I could imagine that some sharp operators who see a may pf playing the market might attempt to present multiple sites as an aggregate supply that would be big enough to qualify for the payments from the scheme.
rscott said:
Interesting approach here - https://www.theguardian.com/business/2019/aug/11/a...
Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
Interesting approach. Isn't that what smart meters and fridges were being pitched at domestically?Asda using 318 of their sites to provide a virtual 13MW battery for the grid. It's suggested Tesco could provide 25-50MW too and if they can get Sainsbury on board, that might be another 20MW or so.
A Tesco store that opened about 15 years ago has mains gas and electricity, as well as onsite CHP generator and a few dozen kW of Solar panels. Whe. You consider the number available in the UK they really are a good option for short term demand.
But 10 minutes isn't exactly rapid response when you compare what the Australian gigabattery has been capable of.
rscott said:
I think they're trying to say they'll have the ability to massively decrease their power consumption for a brief period (<10 minutes) to help smooth out issues with the grid.
I don't think so. They're saying they can turn off the fridges with 10 mins notice, which is comparable to how long it would take to dispatch STOR engines anyway. Instead of NG having to turn up supply, they can turn down demand, which is the way things are going. No doubt on 'average' days when nothing special is happening Flextricity will turn them off at peak prices and save Asda money that way too. What it doesn't say is how long they can be off for. LongQ said:
Another possibility is that there is a price difference between what they pay for electricity and what the Grid would pay them to pass it on.
I hope their chilled and frozen food management teams are on the ball when it comes to deciding whether the contents of a chiller or freezer are still suitable for sale.
1) Exactly. Asda have already bought the power anyway, if they can reduce their demand and sell the excess back to the market at a profit it makes sense to do so. I hope their chilled and frozen food management teams are on the ball when it comes to deciding whether the contents of a chiller or freezer are still suitable for sale.
2) Article says fridges are turned off anyway every day, so its more re-optimising when they are turned off than changing what happens. There will be dynamics around how long they can be off for, and what the minimum time between periods of no use are etc.
The3rdDukeofB said:
Condi -
What is to stop an operator / developer that thinks he may not get their project awarded a CFD this year throwing their toys out of the pram and developing their project independent of the CFD process (and regulation).
Would it still fall within the 6GW cap ? How would the Ofto and alike align in your thoughts ?
No idea - not my area of expertise. AFAIK there is nothing to stop you building things without a CFD as long as you fulfil all other requirements. CFD only guarantees a price, if that price can be guaranteed a different way and it is economic then you can carry on. What regulation is attached to the CFD which is otherwise not applicable to non CFD plant? What is to stop an operator / developer that thinks he may not get their project awarded a CFD this year throwing their toys out of the pram and developing their project independent of the CFD process (and regulation).
Would it still fall within the 6GW cap ? How would the Ofto and alike align in your thoughts ?
Edited by Condi on Wednesday 14th August 18:09
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