The nature of wind output has been obscured by reliance on “average output” figures. Analysis of hard data from National Grid shows that wind behaves in a quite different manner from that suggested by study of average output derived from the Renewable Obligation Certificates (ROCs) record, or from wind speed records which in themselves are averaged. It is clear from this analysis that wind cannot be relied upon to provide any significant level of generation at any defined time in the future. There is an urgent need to re-evaluate the implications of reliance on wind for any significant proportion of our energy requirement.