Low grid frequency or dodgy data

[adam2]

According to the dynamic demand website, the UK grid frequency has been low and unstable for at least the last 40 minutes.
http://www.dynamicdemand.co.uk/grid.htm

The indicated frequency has routinely fallen below the normal operating limit of 49-8 cycles, and has briefly dropped to below the legal limit of 49-5. cycles.

This seems rather surprising under the prevailing circumstances of;
Modest load
No unusual frequency disturbances shown on the national grid site, though that has a lower resolution.
No OCGT plant running, according to gridwatch.
No unusual percentage of renewable generation.

I therefore wonder if the dynamic demand site is in error. A local power failure might have occurred, and we are might therefore be seeing the frequency of local standby generator rather than the grid.

OTOH, I have found no report of a power cut at the physical address of gridwatch.

All very odd, anyone know more ?

[adam2]

UPDATE
The indicated grid frequency from gridwatch is still low and variable, after nearly 3 hours.
Must be dodgy data.
No way would the national grid allow the actual frequency to remain that low for so long.

[Mr. Fox]

The DD meter is bouncing around all over the show.

It doesn't tally with my own (measured) logs or the data on Gridwatch and there's nothing significant on BMReports.

I guess DD need to get their soldering iron out again (or learn how to use the BMR API).

How the meter works

We soldered together a simple circuit to measure the AC grid frequency. It does this using a low-cost microprocessor to time the interval between each change in direction of electric current from a normal power socket.

The circuit is connected via an interface board to a web-linked computer which takes a reading of the grid frequency every second. The computer passes this value to a script on our web server where it is then saved.

http://www.dynamicdemand.co.uk/grid.htm#

[adam2]

I have contacted Dynamic demand and they have confirmed that the frequency meter is not working as it should.
Hopefully they will soon fix it.

[adam2]

Now fixed.

[adam2]

But now broken again.
The frequency meter on the dynamic demand website is now stuck at 50.015 cycles. An entirely plausible figure, but remaining at exactly the same figure, no way. Now fixed

[adam2]

There is some dodgy data on the gridwatch site at present. Over the last 24 hours, there have been numerous almost instantaneous changes in total demand and an input from different sources.

Such rapid changes are most improbable and suggest dodgy data. A sudden drop in demand of say 10% implies that 10% of the nation was blacked out.
Nothing on the news or indeed on this website, so dodgy data.

The gridwatch site is IMHO most interesting, but dont forget to apply the "commonsense test"

[adam2]

Some dodgy data today on gridwatch.
PV production shown as zero all day, impossible ! PV is very limited at this time of year, but NEVER zero.

[adam2]

Dodgy data on the Gridwatch site at present.
Wind power, CCGT, and nuclear showing as unchanged for the last 36 hours. Virtually impossible.

The Gridwatch site can be an interesting/useful source of data, but don't forget to apply the common-sense test to any unexpected figures.

[adam2]

Still the same after nearly two weeks.
Wind, nuclear, and CCGT output showing as completely unchanged since the beginning of the month.
Gridwatch used to do better than this !
I have emailed them without result, anyone else want to try ? in case action is related to the number of emails received.

[Ralphw2]

the MyGridGB site lost its data feed at the same time. It restarted a few days ago. Obviously the data feed changed in some way. I indirectly know the author of gridwatch, I might be able to pass on a message.

[adam2]

the MyGridGB site lost its data feed at the same time. It restarted a few days ago. Obviously the data feed changed in some way. I indirectly know the author of gridwatch, I might be able to pass on a message.

It would IMO be helpful if you can contact them, I find viewing the Gridwatch site interesting and cant be the only person interested in such things.

[Ralphw2]

The author of Gridwatch has been in hospital an is convalescing alone in a remote house. I will pass on the message when he is in better shape.

[adam2]

Thanks for that.

[adam2]

Still not working, after more than a month.
Does Ralph, or anyone else, have any news regarding the health of the author ?