On 25/09/2012 16:55, harry wrote:
There will be a backup, gas turbine eg
http://en.wikipedia.org/wiki/Pembroke_Power_Station
http://en.wikipedia.org/wiki/Connah%..._Power_Station
Can be quickly started and high turndown ratio.

Those open cycle gas turbines are way less efficient than the ones that
feed a steam boiler from the hot exhaust.

There's a trade-off; run an intermittent source with open cycle
turbines, or run a combined cycle station at double the efficiency, and
forget the windmills.

Andy