Readers may recall the little ding-dong between Gordon Hughes and David Mackay over the rate of decline in performance of wind turbines as they age. Hughes thought that this happened much faster than Mackay.
Mackay has been looking at the subject again today, analysing how newer windfarms have performed against older ones. His intention was to look at how technological improvements have shown up in the load factors of the turbines, but it's possible that he has inadvertently shown that Hughes was right.
The reason for this is that the rate of improvement in load factor is no greater than would be expected from the fact that the turbines are newer. So you can draw one of two conclusions:
Either way, wind turbines look just a bit more like a dead end than they did yesterday.