First blackout of the wind power heavy system

Martyn1981

mmmmikey wrote: »

Again, scratching my head and remebering back to O-Level physics ( which was some time ago now ) then I think the speed of rotation is more siginificant than the mass here - i.e. gas generators spin at 3000 rpm whereas wind turbines turn at a fraction of that speed.


Edit: so shouldn't we be discussing momentum as well as inertia? One for the scientists.....

Not a clue mate, not a clue! We exceeded my pay grade several posts ago.

zeupater

mmmmikey wrote: »

Again, scratching my head and remebering back to O-Level physics ( which was some time ago now ) then I think the speed of rotation is more siginificant than the mass here - i.e. gas generators spin at 3000 rpm whereas wind turbines turn at a fraction of that speed.


Edit: so shouldn't we be discussing momentum as well as inertia? One for the scientists.....

Hi

As none of the plethora of alleged scientists have yet responded, you'll probably find that Ek=1/2mv2 would probably do the job ...

Kinetic energy is the key and as you observed, velocity is relatively more important when doubled - however, what needs to be considered is that the radius of the spinning element in a gas generator weighing Xkg is far less than that of the blades in a wind turbine weighing Y tonnes. Additionally, rpm is effectively meaningless when comparing the energy available in the two technologies, it's simply the relative energy of the mass in motion, so a large mass rotating slowly in a large radius can easily store more kinetic energy than a small mass rotating quickly in a small radius ...

HTH
Z

Martyn1981

zeupater wrote: »

Hi

As none of the plethora of alleged scientists have yet responded, you'll probably find that Ek=1/2mv2 would probably do the job ...

Kinetic energy is the key and as you observed, velocity is relatively more important when doubled - however, what needs to be considered is that the radius of the spinning element in a gas generator weighing Xkg is far less than that of the blades in a wind turbine weighing Y tonnes. Additionally, rpm is effectively meaningless when comparing the energy available in the two technologies, it's simply the relative energy of the mass in motion, so a large mass rotating slowly in a large radius can easily store more kinetic energy than a small mass rotating quickly in a small radius ...

HTH
Z

So, in short, a 12MW WT with 165 tonnes of blade, and 60 tonnes of hub spinning round would take more than just me, a long pole and a net to stop?

zeupater

Martyn1981 wrote: »

So, in short, a 12MW WT with 165 tonnes of blade, and 60 tonnes of hub spinning round would take more than just me, a long pole and a net to stop?

Hi

Ever seen a trebuchet throw a car? ... you'd have acceleration to 200mph that would make a F1 car look like a snail ...

It's really the management of this kinetic energy that can allow the turbines to provide a short boost to the grid through providing more energy than would be normal to maintain rotation at a particular demand loading .... effectively overclocking the turbines for a while in the acceptance that tapping into the stored kinetic energy will act as a brake to slow the velocity over time, but better this to buy time for other assets to be brought on line than suffer a major frequency drop issue before those assets can react.

HTH
Z

GreatApe

zeupater wrote: »

Hi

Ever seen a trebuchet throw a car? ... you'd have acceleration to 200mph that would make a F1 car look like a snail ...

It's really the management of this kinetic energy that can allow the turbines to provide a short boost to the grid through providing more energy than would be normal to maintain rotation at a particular demand loading .... effectively overclocking the turbines for a while in the acceptance that tapping into the stored kinetic energy will act as a brake to slow the velocity over time, but better this to buy time for other assets to be brought on line than suffer a major frequency drop issue before those assets can react.

HTH
Z

As per common sense if you did this in a wind heavy system for anything other than a very short burst you'd screw yourself

You'd get a boost for a few seconds, the result being reducing the speed of the turbine blades so that after those few seconds the turbine itself now produces less energy

So you might have a wind turbine generating 10MW, you draw 15MW from it for 20 seconds but now when you let it be it's generating only 5MW as it has slowed down

Not a good solution

GreatApe

https://www.thetimes.co.uk/article/blackout-fears-over-national-grid-cables-from-the-continent-w5m2m0l6h



Okay it seems very much like this new grid we are entering is going to need short term battery storage and asap

Something like 2GW power 1GWh energy

joefizz

GreatApe wrote: »

https://www.thetimes.co.uk/article/blackout-fears-over-national-grid-cables-from-the-continent-w5m2m0l6h



Okay it seems very much like this new grid we are entering is going to need short term battery storage and asap

Something like 2GW power 1GWh energy

And before the 31st October.... ;-)

zeupater

zeupater wrote: »

Hi

In a nutshell, until the investigation is complete everything is pure speculation for anyone & everyone, including academics with far more relevant & impressive qualifications than anyone would be able to claim on this board ...

Here's a link to what the a number of those experts think may be the issue ... expert reaction to the major UK power failure .... not really much to go on and, as mentioned, plenty of speculation, have a read & make your own mind up if you need to jump the gun ...

As it played out it's quite possible that the headlines wouldn't have been so sensationalised by the press if the trains had a push button reset/start button when the power was restored and hospital contingency measures were tested regularly, in which case the very act of raising the profile of such things may actually be a bonus ... trains need an engineering review & contingency measures need better & formalised maintenance & test schedules (UPS, standby generators, recovery plans etc) ...

Whatever the final report says the root cause was, it's likely that the explanation would involve a combination of balancing supply to demand at a time of day where demand is normally volatile anyway, grid failure event(s), rapid changes to ~48.8Hz (/out-of-specification) frequency conditions (related automated connectivity issues!?) and potentially even timescale sensitive human or procedural errors at the grid management centre ...

... additionally, I've no idea what the weather was like in the area at the time, but it was alternating between periods of hammering down with rain with the occasional rumble of thunder in the distance and blue sky where we were at around the time it happened, so add the potential of shorting & spiking tripping relays into the mix and there's something else to consider & write a report section on ....

The issue that needs to be recognised is that even while ongoing cause & effect analysis is looking for the root cause and associated event sequence, it's important that focus is turned to 'lessons learned' by affected sectors with appropriate actions being implemented ....

HTH
Z

Hi All

Further to the above & relating to the previous salient point ... "what combination of events broke the network as that's where the issue manifests ... chances are it could have happened to any form of generation feeding into the grid, including the growing reliance on inter-connectors! "

The interim report is no longer confidential & available to all!

Our preliminary findings based on analysis to date are:

• Two almost simultaneous unexpected power losses at Hornsea and Little Barford occurred independently of one another - but each associated with the lightning strike. As generation would not be expected to trip off or de-load in response to a lightning strike, this appears to represent an extremely rare and unexpected event.
• This was one of many lightning strikes that hit the electricity grid on the day, but this was the only one to have a significant impact; lightning strikes are routinely managed as part of normal system operations.
• The protection systems on the transmission system operated correctly to clear the lightning strike and the associated voltage disturbance was in line with what was expected
• The lightning strike also initiated the operation of Loss of Mains (LoM) protection on embedded generation in the area and added to the overall power loss experienced. This is a situation that is planned for and managed by the ESO and the loss was in line ESO forecasts for such an event.
• These events resulted in an exceptional cumulative level of power loss greater than the level required to be secured by the Security Standards and as such a large frequency drop outside the normal range occurred.
• The Low Frequency Demand Disconnection (LFDD) system worked largely as expected.
• The Distribution Network Operators quickly restored supplies within 31minutes once the system was returned to a stable position.
• Several critical loads were affected for a number of hours by the action of their own systems, in particularly rail services.

Whatever the final report says, the interim one is certainly fully in line with expectations referenced above ... now to the detail, lessons learned stage and implementation of event mitigation ...

Interim report ... Ofgem 2019/08 incident report (pdf) ... if anyone's actually interested! ...

HTH
Z

silverwhistle

I didn't realise the issue with the trains was an engineering one, and seems a remarkably short-sighted design .


Last year I was on a Southern third-rail train that broke down and was treated to the sight of the driver trotting through the front coach with a girt big wooden paddle, I think designed to try and get the pick up to make contact again with the third rail. This was unsuccessful on this occasion and we had to have another train brought up behind us which then reversed back to the nearest junction. But at least the principal was there of restarting without the intervention of external help.


In that case there was no issue with loss of supply to signalling, but I don't know the situation with regard to the recent incident.

zaax

What happened to electric mountain which is supposed to be able to power Britain for 8 hours at a moments notice