Another sad, unqualified statement

I was reading about the Thanet offshore windfarm, the largest in the UK and read one of those classic unhelpful statements, "The Thanet offshore wind farm will create enough renewable energy to power 240,000 homes."
The problem with that statement is it doesn't say 1) Whether this takes into account the fact that wind turbines might only run at about 10% installed capacity (a 2GW turbine only produces an average 200MW over a year) 2) Whether it is the best case scenario i.e. at 100% of operating output (I doubt it, that wouldn't sound very impressive) and 3) what other allowances it might take into account such as the number of turbines that might be disabled for maintenance at any one point.
The sad fact is 240,000 homes is not a great number, it is only a 3rd of Kent's homes (assuming they are 'average' in size) and bearing in mind that, particularly in winter, the farm could produce nothing for days at a time, the 40 year lifespan and the £780M cost, it is hard to determine whether this is really value for money.
Sadly these things all sound great, they are "renewable" but we must look beyond the warm feeling we get by not burning fuel and consider the inconvenience of variable output electrical plants and work out the real economics. I for one would not like to see electricity increase by 10 times the price just to pay for these "green" energies when compared to other methods.