And still the power generation claims of the wind-power lobby get reported as fact

The Telegraph reports the breaking off a wind-turbine blade at a wind farm and ends the piece with this claim: 'The Whitelee windfarm... turbines can generate 322MW of electricity, enough to power 180,000 homes.'

Of course the key word there is 'can' because as well know windfarms rarely produce electricity at anything like capacity. Indeed The TimesM recently reported that:

'THE first detailed study of Britain’s onshore wind farms suggests some treasured landscapes may have been blighted for only small gains in green energy.

The analysis reveals that more than 20 wind farms produce less than a fifth of their potential maximum power output.

One site, at Blyth Harbour in Northumberland, is thought to be the worst in Britain, operating at just 7.9% of its maximum capacity. Another at Chelker reservoir in North Yorkshire operates at only 8.7% of capacity.

Both are relatively small and old, but larger and newer sites fared badly, too, according to analyses of data released by Ofgem, the energy regulator, for 2008.

Siddick wind farm in Cumbria, now operated by Eon, achieved only 15.8% of capacity, the figures suggest. The two turbines at High Volts 2, Co Durham, the largest and most powerful wind farm in Britain when it was commissioned in 2004, achieved 18.7%.

Turbine efficiency is calculated by comparing theoretical maximum output with what the farms actually generate. The best achieve about 50% efficiency and the norm is 25%-30%. '

I cannot find the generation figures for Whitelee but I doubt that it is more than 50% of the 322MW figure quoted in The Telegraph.


As an aside I have just looked at the always fascinating Neta site and see that for the last 24 hours this was the breakdown of power generation by type of power source:
Gas - 52.3%
Coal - 24.3%
Nuclear - 19.8%
Pumped Storage - 1.2%
Wind - 1.1%
Non pumped storage Hydro - 0.7%
Interconnect - 0.6%

That 1.1% is 12,206MWh; I wonder what the claimed capacity of UK Wind Farms is?

ChrisM reports in my comments that "Current capacity is 4122 MW with another 10,000 MW under construction". If this is true then wind farms were running at around 12.3% over the period I examined; impressive!