Wind problems

Readers letters

As economic activity has accelerated our carbon emissions have increased by several percent

The opposing views about wind turbines presented in the last issue illustrate the contrasting positions very eloquently. The proponent was a salesman from Renewables UK, who take no responsibility for the under-performance of their equipment in freezing weather. In contrast, the sceptic was Derek Birkett, with decades of experience balancing our electricity supplies to maintain power quality and grid frequency.

Further evidence to endorse his opposition was released earlier in April, when it was revealed that, as economic activity has accelerated, our carbon emissions have increased by several percent (partly due to the long outage at Sizewell B).

This development was compounded by two other valuable data sets. Firstly, the announcement from DECC that, despite building ever more turbines, wind farm load factors had declined to only 21% in 2010. Secondly the release of the study by the John Muir Trust that had found that turbines were producing below 10% of capacity for more than a third of the time. Unfortunately, the coincidence of low wind speeds and maximum demand (due to low temperatures) occurs every winter. With temperatures around -10C, our nuclear plants were often producing 50 times the output of wind farms, although they have only twice the installed megawattage.