That would depend on government pressure and support (£) for the renewables, wheather they are whole life environmetally friendly or not.

I remember reading an article in an environmetal magazine (not available in shops), that one of the scandinavian countries had taken down several wind farms that were erected 10 yrs or so ago due the the ineffectiveness and unreliability.
It's is a fact that the coldest days of the year usually fall when there is little or NO wind. Maximum power requirement by the nation and NO generation by wind turbines, just doesn't make sense to me.

Don't get me wrong i'm all for saving the planet, but selection of the correct technologies to do it. Eg tidal, can't see a day when the tide will decide not to come in or out.