Here is a reply I gave to someone suggesting there was some potential in wind turbines. I may add figures later.
The wind output is complicated to work out but starting with the initial cost, new grid and installation that is the financial hole which needs to be filled first. Assuming, like solar panels, they produced a little power, then solar for instance may never pay themselves back simply as the amount they need to return to cover the initial £8000 or so may never be completed as they wear out before that point, even with subsidies which technically do not count as they are money not power.
There is a daily power input for wind turbines which must be subtracted from their output, brakes, heating if icy, and motor to turn and sometimes I hear to start up at all. Then there are the power stations which run in tandem constantly and their costs pretty much cover anything produced per day by the turbines as they cost the same whether drawing the power or not. Maintenance is incredible, especially for offshore which are the highest for anything including oil rigs, and a good deal of the random power they produce daily is lost as it comes at times of low demand. Also they need a member of staff to constantly monitor the peaks as if they don't turn them down they will spike and blow the system which is only a feature of wind and no other forms of generation.
All these factors are a direct consequence of their physical nature so impossible to overcome, besides vastly expensive battery arrays which could hold the meagre amount produced at low demand points for later, but a drop in the ocean. There is absolutely no way round these issues and it is physically impossible to generate constant power or even useful power, while the little generated by offshore costs 12 times the cost of coal.