Another day, another wind farm scandal

Another day, another wind farm scandal – Telegraph Blogs:
"..... the National Grid has been secretly forking out millions on diesel-generated power in order to stop the lights going out.
And why does the National Grid need this hugely expensive, dirty energy available on standby? 
For all those occasions when the wind isn't blowing, is why. 
The greater the proportion of our total energy capacity taken up by wind, the more unstable our grid becomes.
But rather than admit the scale of the problem (already causing havoc in places like Germany), the Coalition has had to persist in the charade that renewables are an essential part of our energy mix.
So rather than scrap all wind projects – the only really sensible option – we instead have to go through the nonsense of having even more expensive energy in reserve (ie diesel generators) driving up our bills by another 5 per cent."