UK research supports this: Moreover, Graham Sinden of Oxford University analysed over 30 years of wind data from 66 sites spread out over the UK and found low wind speed events affecting more than 90 per cent of the UK had an average recurrence rate of only one hour per year.
Re-definition needed: They argue that large-scale wind power is more appropriately described as "variable”, while the variability associated with breakdowns of conventional power stations is better described as “intermittent".
Wind not condemned to the margins: Wind power can therefore replace base-load power stations with the same annual energy generation. For example, 2600MW of wind turbines, with an annual average power output of about 850MW, can replace a 1000MW coal-fired power station with the same annual average power.
A little extra peaking insurance needed: To maintain reliability of the generating system at the pre-wind level, a little additional peak-load plant (for example, gas turbine) has to be installed.
The Australian Financial Review, 19/8/2006, p. 63