This is an American site but it covers the profitability of wind farms.
http://www.awea.org/faq/wwt_costs.html
The problem with (almost) all renewable energy forms is that the supply is not controllable. You cannot suddenly whistle up a storm when it's half time at the cup final and everybody goes and puts on the kettle.
Storing energy is difficult - sure there are a couple of systems with reservoirs that pump water up and down but you lose 25% of the energy everytime and there are only so many Welsh lakes.
This is why we need a mixed energy generation strategy probably underpinned with nuclear