Not sure, it appeared to be the time that the two generator systems failed / went off line almost at the same time.
Given the frequency prior to this situation was above 50Hz tends to suggest the national network was not stressed.
Looking at the graphs I can’t see any noticeable significant peak normally at around 4pm… but you never know…
Yesterday’s and last week’s demand looked like this
Sunday morning is low demand, 25GW typically & a time they always hit the ‘impressive’ numbers.
Good to see we are making progress. Nice to see we are selling to the EU for once when the wind blows. So much more to come with the new offshore wind that will be on-line in the near future. It’ll be even better to see the nuclear generators sorted, we have close to 8GW available, but with what looks like maintenance events we look to be about 2GW down.
I can’t see any data with real time detail that shows the ‘pumped hydro’ generators on-line on Friday.
We have 4 of these with capacity totals of 2.78GW.
They are designed specifically to provide practically instant power for just such events as this & are able to come on-line in less than a minute - 16 seconds at Dinorwig to go from 0 to 1.8GW.
The data I have only shows hourly averages, but even so I can only see a max of 0.824GW at 17:00 on 09/08/19
I would love to know what effect they had on the Friday failure. .
Counting is something I am conditioned to do without thinking when there is a storm! I think it is from when I was a child and first learnt that 5 seconds means a mike away.
If I hadn’t already disconnected I’d be rushing to if the nearest lightning was only a mile away, not wait for closer because you have no idea how close the next one could be, and a strike on electricity or telephone distribution systems anywhere in the area could be significant.
Wasn’t London affected? If so, then “huge swathes of the country” would fit, because London is the main part of the country, the rest is pretty much irrelevant.
Intriguing yes, but looking at the math its actually more intriguing.
Total UK pumped hydro capacity is 2.78GW & if we look at the potential capacity loss of Hornsea offshore & Little Barford CCTG, the math does not add up.
Hornsea has only Project 1 on-line since February 2019
But its only part completed & will not be at full capacity until Q1 2020 when its potential output will be 1.2GW
Wikipedia shows that 28 of 174 turbines have been installed as of 3rd May 2019, so assuming they now have 50% of the 174 installed, 0.6GW going off-line is not actually that much of a loss.
Little Barford (CCGT) is only 0.74GW (740MW)
Same again. less than 1GW going off-line
The math does not make sense or my data is all wrong
The maths might not add up… however to my mind what we don’t know is the effect of sudden unplanned loss to the grid with respect to the protection circuitry. Therefore it might not be a linear type relationship with respect to drop in supply and the speed at which it happens and the number of generators going off line… I guess the maths might be a little more involved… or you could be on the money of course …
Some of my university friends worked on the design of Foyers and it’s construction in the early 70’s. I will be interested in the findings of any inquiry into this incident, especially if the pumped storage facilities failed in any way. My guess is that they should have been readily available at 16:00 for the inevitable evening peak demands, even though the reservoirs are probably only full in the early morning.
The 1.8GW Dinorwig station is the largest in UK & can provide power for up to 6 hours. Topping up the NG demand is done by progressively bringing each of the 6x 0.3GW (300MW) turbine/alternator sets.
A semi side issue news story: The last three Didcot cooling towers came down this morning.
At almost the same time (07:00) the Didcot & surrounding area lost power, a power cable fire was the cause. Obviously unrelated you might say, just a coincidence - but not so it seems, it looks like it was the dust cloud from the demolition drifted across & caused a flash-over, but maybe not; watch the 1st video it looks like the shock wave from the explosions caused the power cables running across the field to start swinging around, the 2nd video shows the cables still moving & the flashing & the start of the fire
Now if I am right these are relatively low voltage distribution power lines at 33kV. Imagine what would have happened if it was the national grid at 275 or 400 kV … sobering thought, though admittedly those pylons are made from steel, and the spacing is far larger.
Indeed, these cooling towers were the left overs from the old coal fired station.
The new plant is a 1.36 GW CCGT & links into the 400kV north-south NG line that runs adjacent to the power station. So a lot of 400kV to damage
Revised … watch the 1st video, a second or so after the explosion you can see a short flash to the left of the picture. This was debris from one of the explosives scoring a detect hit on the power line. That started the power cables swaying around
This video shows it all … https://www.thesun.co.uk/news/9728904/didcot-power-outages-tower-demolition/
Another ‘semi side issue’ for you…we live close to Dinorwig power station, and power cuts and surges used to be quite common, coinciding with them ‘pulling the plug’ and firing up the turbines. Fortunately, this was sorted out, apparently at considerable expense, and we no longer have these problems, although they are still almost contantly digging holes in the ground to fix the buried cable that links the station to the grid.