The BBC reports that the "world's second largest offshore windfarm" has gained approval. It will be located 10 miles off the North Wales coast in the Irish Sea.
The key is, of course, in the numbers. When all 150 turbines are rotating and generating, the farm will provide electricity for 680,000 homes. When they are not generating electricity, those homes will rely on conventional electricity generation which has to be maintained on standby.
Although the Irish Sea is a windy place, it is not always windy and sometimes it may be too windy for safe operation of the turbines. Proof that this is so was seen when flying over the Furness area one sunny morning when not one of the existing wind turbines was rotating (you'll have to believe me on this as a "still" photo is hardly conclusive evidence!)