Unthreaded
Entropic Man
According to Weather Spark
The wind in Belfast
Over the course of the year typical wind speeds vary from 1 m/s to 9 m/s (light air to fresh breeze), rarely exceeding 14 m/s (strong breeze).The highest average wind speed of 6 m/s (moderate breeze) occurs around January 12, at which time the average daily maximum wind speed is 9 m/s (fresh breeze).
The lowest average wind speed of 4 m/s (gentle breeze) occurs around August 5, at which time the average daily maximum wind speed is 6 m/s (moderate breeze).
I'm not sure how this applies to 'your' turbines situation but it doesn't look like turbines around Belfast are going to achieve optimum that often.

golf charlie
That sounds "exciting".

In the interests of science, I delved into bin and retrieved newspaper.
Paper published in Ocean and Coastal Management (to which I have no access) but the publication date is given as September 2016. Lead author C.Zheng.
Data used from weather stations and satellites, over period 1989-2011.
Suggests gales more frequent and stronger.
Effect on seabirds a separate study "just published by the Royal Society".
Study linked to work by Australian scientists using 20 years of satellite data showing steady increase in wave height and incidence of very large waves in the open ocean (no details given).

SandyS Absolutely! The beauty and simplicity of the Beaufort Scale, was that it was 'as observed, on that ship, at that time'.
A major cause of yotties getting into worse situations, especially when relying on anemometers etc is 'Apparent Wind', which pilots are familiar with.
If sailing downwind at 8 knots, with 16 knots of wind behind you, the Apparent Wind on deck, or at mast level is 8 knots. If you alter course, and sail at 45 degrees to the wind at 7 knots, the Apparent Wind suddenly jumps to about 22 knots. The waves and motion of the boat will change dramatically as the wind apparently increases in strength from F3 to F6, when actually the wind hasn't changed at all.
The concept of sailing into the wind was not a factor for consideration with square rigged ships in use at the time of Beaufort. I prefer to use Beaufort, and shipping forecasts are still given in Beaufort.
My worst storm at sea under sail was F9, gusting F10, based on Beaufort observations. We had lost the engine and electrical power, so no instruments were working! Local media subsequently stated F12 gusts, but I had no means or desire or motive to challenge that. My observations, memories, experience etc were F9 gusting F10. It was 15 years ago, in the Med, in September.
Nobody blamed Global Warming. It was nothing out of the ordinary.

SandyS. Original article on windspeed increase now consigned to bin (not retrievable) and google search unsuccessful. But recall mention of using satellite data to estimate winds (is this possible?) and a link with measured increased wave heights. Interesting that my initial results from google search were items bemoaning decreased wind speeds and its implications for offshore wind turbines.

IDAU/EM
I should have added that for the Vestas turbine there is an output chart which indicates maximum output at about 11/12m/s

golf charlie
Couple of issues with 19th century wind speeds, firstly measuring wind speed on a moving ship must be a bit tricky, a similar problem to air/ground speed in aircraft. Secondly shipping lanes cover a very small part of the ocean, usually the quickest routes from A to B. This is still the case as shown by lost fishermen and round the world sailors. Using what little data is a available to calculate a "global average" is a bit like using windspeeds measured at Heathrow to give data for Sumburgh.

IDAU/EM
Rated power for wind turbines not reached until 1bout 13m/s minimum wind sweeps, I don't think manufacturers would lie about it?
Performance data from Siemens SWT-2.3-101
Cut-in wind speed 3-4 m/s
Rated power at 12-13 m/s
Cut-out wind speed 25 m/s
Maximum 3 s gust 55 m/s (standard version)
60 m/s (IEC version)
Vestas V110-2.0 MW
Rated power 2,000 kW
Cut-in wind speed 3 m/s
Cut-out wind speed 20 m/s
Re cut-in wind speed 18 m/s
Wind class IEC IIIA
Operating temperature range standard turbine -20˚C to 40˚C
Operating temperature range low temperature turbine
-30˚C to 40˚C

Oh Sandy,
The turbines will achieve optimum results for its investors in reaping in as much of that subsidy loving as they can.
Now, if you are talking about energy production...well then most likely no so good at doing that?
Mailman