Well folks - wind power has one big advantage - it is available wherever the windmill is. If that is on a narrowboat then at least you get to top-up the battery and probably cover the residual on the TV or satellite reciever. Which could be switched off rather than hitting the remote but then non-techies mostly wouldn't.

The other top-ups are going to be mains (longgggggggggggggggg leads?) or engine. It is not a case of overall CO2 budget always, availability is sometimes paramount.

Repair instead of replace is a cheaper CO2 solution.

But if you really want to ballance the books think on this. All energy is solar (including wind) except nuclear! And if we insist on spending millions of years of insolation trapped in fossil fuels in a few hundred years, we is going to exhaust the bank ballance.

If solar energy falling on the earth NOW (of whatever kind) cannot supply all our needs then we, as a world, are most definitely raiding limited reserves. 50 years of oil is a mere blink in the history of just Homo Sapiens. It ain't rocket science - but it is communal responsibility - and we ain't got that much that these days.