Major UK power cut, 09/08/2019.

[PS_RalphW]

Reports of widespread power cuts across UK, particularly affecting transport infrastructure. Appears to have been caused by grid instability causing areas to trip out. Wind is unusually strong for summer, at 9Gw or 26% of demand. Not sure if this is a factor.

No cuts here in Cambridge

[adam2]

News report here
https://www.bbc.co.uk/news/uk-49300025

[adam2]

Later reports suggest that this was caused by the near simultaneous failure of two generators.

The national grid are required to be prepared for the loss of the largest single generating unit that is in use at the time.
If however TWO units fail at the same time, or within a few minutes of each other, then the frequency drops precipitously.
The frequency drop triggers the automatic starting of OCGT plant and calls for increased output from other plant, so far as possible.

If this does not relieve matters, then large areas are automatically blacked out by frequency relays.
This is a quick acting and fully automatic process with no question of any warning, exceptions, or consultations.
It seems likely that this is what happened today, that is however my supposition.
This has happened before, but not for many years.

[raspberry-blower]

UK Power twitter

Reporting now that they believe all power has been restored

[BritDownUnder]

Two units failing near simultaneously seems like they are related in some way. Perhaps the protection settings of one tripped when the first one failed.

Interestingly there will be a court case in Australia soon related to apportioning of blame for the 2016 Great South Australian blackout.

I am awaiting more news about the UK incident.

[adam2]

It would appear that two large scale losses of generation occurred in a very short time.
One was a CCGT plant and the other was an offshore wind farm. I am not aware of any plausible fault that would directly affect the actual wind turbines, so it seems probable that the windfarm substation or the cables thereto failed.

The national grid are able to cope with the largest plausible SINGLE loss of generating capacity, but not with TWO such failures.
It appears that the automatic frequency relays worked correctly in cutting off significant load and preventing a total collapse.

This has happened before, but is an infrequent event. IIRC it is over 10 years since the last somewhat similar event.

[raspberry-blower]

Interesting view on the recent power outage:

Tim Watkins: The Shape of Things To Come

[adam2]

Some interesting points of view linked to in the previous post.
Not certain that I agree with them though.

I suspect that the reports published so far are more or less accurate and that the power cut resulted from the near simultaneous failure of two power stations.
This has happened before, but not for over ten years IIRC.
I do however predict that the next such failure will be in a lot less than 10 years.

The chaos resulting from this widespread but fairly brief power cut was a bit worrying.

[woodburner]

According to a spokesman from one of the “renewable� power companies, (since no other companies’ representatives were “available�, Little Barford station tripped out, and it was 45 minutes before the wind generators bit the dust. 45 minutes is hardly “near simultaneous� according to the spaoesman.

[BritDownUnder]

Interesting view on the recent power outage:

Tim Watkins: The Shape of Things To Come

Quite an interesting blog that was. A good read.

I remember having to generate some frequency and system voltage values when there was a grid trip on a remote Indonesian island a few years back. Such data should be readily available and not hidden. Perhaps as the blog says the powers that be are covering asses.

Being more realistic though the official explanation is probably the most plausible and I agree with Adam that with the reduction in synchronous generation and spinning 'inertia' on the system with more solar and wind there will be more incidents like this in the future.

Little Barford was a GE plant and knowing a bit about those probably some of the protection settings were not correct. The same could be said about the protection settings for the wind farm. Problems with wind farm 'ride through' settings (whatever they are) were implicated in the Australian blackout. I would put some hacker activity as an outside possibility and with the increasing centralisation and remote control of power stations this is an increasing possibility.

Woodburner - could you please list the name of the 'spokesperson' (let's be gender neutral in 2019) or even an article or media outlet where it came from. I'd love to know.

[BritDownUnder]

Can’t find anything on the web. But it was a spokesman. He was not gender neutral or any other snowflake liberal wishy-washy pc term.

The FT is now saying that the wind farm tripped first (FT is behind a paywall but if you googerel "National Grid electricity blackout report points to failure at wind farm" you can find it). Perhaps we can have an it's a knockout style competition of the spokesmen, spokeswomen and even gender neutral spokespersons to find out the real cause of this mysterious blackout. Maybe Mr Putin can be on the panel of judges.

[fuzzy]

Presumably wind farms use inverters to generate the HV AC for the grid - they are not synchronous generators. The load vs frequency drop does not apply to renewables - only to mechanically regulated turbine driven generators. Wind farms are either synchronised to their local distribution, or a central reference via radio, or they are not able to connect.

[Initiation]

Preliminary Ofgem report here


https://www.ofgem.gov.uk/system/files/d ... 7Th7S88Urg

[fuzzy]

Interesting report and depressing.
In August, 30% of our electricity is from burning precious gas that we will die without, from hypothermia, when it becomes scarce. I suppose capitalists are going to extract it fast anyway like all resources, so we might as well have some of it.

[cubes]

I've been hearing a lot of complaints online that some hospitals were cut off. I understood things to be that hospitals weren't protected from blackouts such as these are were expected to have their own backup facilities. Is this correct? If it is, why has nobody actually pointed this out?