National Grid is forecasting almost 100% wind generation at 8.30pm Thursday.

[ywindythesecond]

http://img3.imageshack.us/img3/757/ngforecast3678mw.jpg (http://imageshack.us/photo/my-images/3/ngforecast3678mw.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

[Rheghead]

Och away, you know that can't happen, they'll get shutdown and get compensated handsomely. Is there any explanation why they are forecasting a higher level than what they are metering?

[orkneycadian]

Whats the expectation on the amount of fossil fuel that will be burned at this time? Will it be more, less or the same as when the winds not blowing?

[Rheghead]

Just a quick calculation suggests that today, 45,000 tonnes of CO2 will have been prevented from going into the atmosphere because of UK's wind farms

[bekisman]

1.1 Spinning reserve
The intermittent and unpredictable nature of output from wind farms causes problems. In order to stabilise supply and demand, grid operators must maintain continuous spinning reserve backup ready to go on stream immediately in response to changing weather conditions. This spinning reserve is emitting CO2 even when not producing electricity.

1.2 Spinning reserve in Denmark and Germany
The more wind energy penetrates the grid system, the more spinning reserve becomes crucial in meeting demand. The 2003 West Danish Grid [ELTRA] System Report | identified Spinning Reserve capacity as between 300MW and 500MW per 1000MW of installed capacity which means that with a Danish load factor of about 20%, "backup" can be of greater capacity than realised generation.1 The power company E.ON said it would take 50 GW of renewable energy for the UK to meet EU targets, but this would require 90% backup from gas and coal plants to ensure supply when "intermittent renewable supplies" are not available.2


http://www.publications.parliament.uk/pa/ld200708/ldselect/ldeconaf/195/195we59.htm

[ywindythesecond]

Och away, you know that can't happen, they'll get shutdown and get compensated handsomely. Is there any explanation why they are forecasting a higher level than what they are metering?
Well spotted Reggy. They are currently forecasting 3742MW from a metered total of 3731MW. Probably the result of rounding up decimal points. I didn't know before now that they tweaked short-term forecasts, they didn't use to but they went on to half-hour forecasts about a month ago.

[Rheghead]

Well spotted Reggy. They are currently forecasting 3742MW from a metered total of 3731MW. Probably the result of rounding up decimal points. I didn't know before now that they tweaked short-term forecasts, they didn't use to but they went on to half-hour forecasts about a month ago.

Actually I don't think so, a couple of months ago they forecasted over 4000MW from ~3700MW what they were metering though actual performance fell much short of that.

[Rheghead]

1.1 Spinning reserve
The intermittent and unpredictable nature of output from wind farms causes problems. In order to stabilise supply and demand, grid operators must maintain continuous spinning reserve backup ready to go on stream immediately in response to changing weather conditions. This spinning reserve is emitting CO2 even when not producing electricity.

1.2 Spinning reserve in Denmark and Germany
The more wind energy penetrates the grid system, the more spinning reserve becomes crucial in meeting demand. The 2003 West Danish Grid [ELTRA] System Report | identified Spinning Reserve capacity as between 300MW and 500MW per 1000MW of installed capacity which means that with a Danish load factor of about 20%, "backup" can be of greater capacity than realised generation.1 The power company E.ON said it would take 50 GW of renewable energy for the UK to meet EU targets, but this would require 90% backup from gas and coal plants to ensure supply when "intermittent renewable supplies" are not available.2


http://www.publications.parliament.uk/pa/ld200708/ldselect/ldeconaf/195/195we59.htm


Mynydd Llansadwrn Action Group need to go back and look at their sums

[ywindythesecond]

Actually I don't think so, a couple of months ago they forecasted over 4000MW from ~3700MW what they were metering though actual performance fell much short of that.

I spotted a high forecast at the beginning of November and queried it through the bmreports service desk, and this was the outcome:

To BSC Service desk
Good morning
I note that the frequency of wind forecasting has increased to half-hourly for both initial and latest values. I also note that the latest forecast value for period 29 on 31st October is 4026MW when the “Total metered capacity” is stated as 3731MW. Can you please explain this apparent anomaly.
Regards
Stuart

From: Aitchison, Noel (noel.aitchison@logica.com)
To: asksyc@btconnect.com
Sent: Monday, October 31, 2011 10:24 AM
Subject: INC2365009 - Wind forecast data

Hi Stuart,

Looks like a question for National Grid. I’ve passed it on, so I’ll let you know what they say.

Thanks,

Noel.

From: Aitchison, Noel (noel.aitchison@logica.com)
To: Stuart Young (asksyc@btconnect.com)
Sent: Tuesday, November 01, 2011 10:13 AM
Subject: RE: INC2365009 - Wind forecast data

Hi Stuart,

We’ve had an update from National Grid about the error. It is a bug on their system. Their forecasting system was including predicted data from non metered sites.

They are installing a patch to correct the fault today, and at that point, the forecast values should drop.

Noel.

From: Aitchison, Noel (noel.aitchison@logica.com)
To: Stuart Young (asksyc@btconnect.com)
Sent: Tuesday, November 01, 2011 5:03 PM
Subject: RE: INC2365009 - Wind forecast data

The patch is now applied. So on the graph you’ll see a big drop on the Latest Forecast Values for period 43 today, and on the Initial Forecast Value for period 45 tomorrow.

Noel.

[Rheghead]

Thanks Ywindy for your dilligence, makes sense now, I'm sure it was the same incident that we saw, my scale of time is lacking.

[secrets in symmetry]

Mynydd Llansadwrn Action Group need to go back and look at their sumsLol! Indeed they do!

Having seen who posted the original, are you surprised? He has a habit of finding websites full of rubbish and copying them onto the forum without comment. He obviously doesn't "understand" any of it....

[bekisman]

Lol! Indeed they do!

Having seen who posted the original, are you surprised? He has a habit of finding websites full of rubbish and copying them onto the forum without comment. He obviously doesn't "understand" any of it....
Gosh, bit late tonight - just got off shift?

[ywindythesecond]

It has been quite a windy few days. This is how wind output has performed against National grid forecast for the last couple of days.

http://img687.imageshack.us/img687/1226/27nov2011output.jpg (http://imageshack.us/photo/my-images/687/27nov2011output.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

It looks to me either that the wind energy output has been too high to be accomodated on the Scotland/England interconnector and we have paid for it to be turned off, or the wind has been so strong that the turbines have been shut down for safety reasons. It is just possible that we have paid for turbines to be shut down because there is inadequate grid capacity when it was actually too windy for them to operate safely anyway.

[TAFKAL]

Shame they can't just increase the resistance so they spin more slowly rather than turning off...

[orkneycadian]

Is there any explanation why they are forecasting a higher level than what they are metering?

Erroneous data?