Wind farms justify their costs
by being - you know - cheaper than anything else. Especially offshore.
Even Exxon say so in their medium term predictions.
The 'won't work without backup' line is political spin, and practical nonsense. Coal and gas supplies aren't immune to interruption and even parliamentary reports have realised that there's an imminent gas peak due 2020-2030:
So good luck getting gas generation to work affordably - or at all - thirty years from now.
As for nukes - when you include clean-up and reprocessing costs and traditional nuke underperformance, and exclude subsidy, nukes are seriously expensive. Clean-up costs are estimated at £76bn, and keep doubling with worrying regularity. And there's still no long-term solution for waste storage.
And guess who pays for that? (Clue - we do.)
Sp yes - building something that's going to cost £100bn or more to clean up (let's be realistic), has a history of being run by irresponsible chancers and wide boys, with a low but non-zero chance of making large parts of the UK uninhabitable (totally unthinkable - just like Fukushima) is a *genius* plan, when you can spend the same money on a mix of renewables (q.v. tidal, etc) which have negligible clean-up costs, aren't any less reliable in practice than current alternatives, and never run out.
Or is that too obvious for people who can't be arsed to think independently and prefer to parrot talking points and rhetoric from dodgy lobby groups?