It isn't about if we have wind or not it is about whether we have the right intensity of wind to make the wind farms efficient, and we don't; or rarely don't in England at least. Only the upper part of Scotland is any good for this and perhaps parts of Wales.
You can tailor your turbines to suit the wind - the problem we have in the UK is the variability of the wind. That said, they're still a viable contributor to the grid, particularly the smaller, domestic units. Personally I don't have a problem with the larger ones, but I know that there's a strong movement against them on aesthetic grounds.
Turning the other sources of energy up and down to cater for this is costly and inefficient, and nuclear plants take a long time to build etc.
Whether or not it's costly to vary the output of other plants is largely dependent upon whether they were built to be variable supplies or consistent - most are built to be consistent, because we don't have a well-planned method for approving and commissioning suppliers.
Nuclear plants do take longer to build, yes, but they also have a much longer productive lifespan, are off-line significantly less and are immeasurably less polluting (which is the major issue, at the moment, in energy production).
Yet we are pulling down viable gas fired plants that do a good enough job!!!
The environmental costs of continuing to utilise fossil fuels, though, is considerable - if it weren't, we wouldn't be having a discussion at all, we'd continue with coal, gas and oil.
O.