The message
from "Clot" contains these words:

We do experience periods when anticyclonic weather affects large
parts of the UK at one time.

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Winter anticyclones

These, it is alleged, frequently becalm the whole country and cause
problems for the system operator, due to the absence of any wind
power, especially at periods of peak demand. The capacity credit, it
is argued, is therefore zero. However, the Environmental Change
Institute at the University of Oxford was quite clear when appearing
before a House of Lords Select Committee [12]:

"We have looked at that [stationary anticyclones in the middle of
winter over the British Isles] occurring in the wind data and the
wind data does not show it."

Several authors, including National Wind Power, have also found that
peak demand periods actually tend to coincide with above-average
wind plant output [13]. The reason for this is that wind output will
tend to be correlated to periods of high peak demand, as one of the
key factors in determining the load on the electricity system is
wind speed. Cold, windy days will lead to increased demand for
heating.

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http://www.sd-commission.org.uk/pages/230505.html Full report,
Annex B.

I'm surprised at this. I wonder how the stats were pulled together.

Now who was it who said there were lies, damned lies and statistics?

Disinterested information in this area is hard to come by and may not
even exist.

Sinden has an Agenda but I can't trace the original report to see if the
inserted "[stationary anticyclones in the middle of winter over the
British Isles]" above genuinely reflects his views or is a gross
distortion of the gross distortion in the paragraph above.

Anyone who takes much notice of our weather must know we do from time to
time have high pressure centred over the British Isles and some of these
occur in winter. So how to get round acknowledging it.

"Middle of winter" - 5th Feb or whatever particular day you chose for
middle of winter might just have escaped during the year(s) covered by
the data.

"stationary anticyclones" - scope here for being ruled out either for
being only one in a year or more likely by a pedantic view of
stationary. Weather is dynamic and even blocking highs are never totally
stationary.

"occurring in the wind data" - a single years data chosen on the basis
of, exceptionally, no blocking high.

The first paragraph quoted above by Hansen is a classic, full of strawmen.

Alleged - nothing like casting a little doubt

Frequently - well if nothing else get them on numbers

Becalm the whole country - From Scilly to Shetland, Channel Isles to
Northern Ireland. I would be surprised if a windless high ever came
close to that huge area.

Capacity credit not zero - possibly not but not very much at all is
still not zero.

--
Roger Chapman