Wind turbines, radar and fuel out of thin air!

There is an article on the BBC news website today about the problem of wind turbines causing radar clutter.
This was something I hadn't thought about - although I once had a summer job at what was then Ferranti's Radar Systems Department where the issue of clutter was very much in the engineers' minds.  Apparently the problem has been delaying the deployment of significant amounts of wind based energy generation.  Qinetiq have come up with a coating for the blades to reduce the problem - although it's not going to completely solve it.  As they say, every deployment is different.  I imagine the defence industry with all the technology that has been developed to make planes invisible to radar will be in demand to help solve this particular issue.

If one was being cynical, then one might suggest that not flying planes is compatible with deploying new energy generation facilities - but that's unlikely to be popular and I suspect that some of the issue is to do with defence of the realm.

On a slightly different topic, I caught a bit of an edition of James May's big ideas on Dave last night.  One of the ideas he explored was the idea of creating fuel out of thin air.  There's a group in the desert of Mexico who are looking to use CO2 from the air combined with Hydrogen from the electrolysis of water to create fuel.  The program was rather short on science - either because they were dumbing it down or because the proponents have secrets that they don't wish to share.  The one thing they did share was that they need to split the CO2 into CO + O - which requires temperatures on the order of 2400 degrees centigrade.  They've built a solar furnace to help them do this - and demonstrated cooking sausages and rather more impressively melting steel with it.  A bit reminiscent of those science fiction death rays.  I'd have to find out more about this - it's not clear how far along the technology really is - but they seemed to suggest that hooking their furnace up to their machine for generating fuel would allow them to generate 2 to 3 (presumably US) gallons per day.
That's not a whole lot - but I wonder how it compares in terms of efficiency with making biofuels?  Given that one is trying to reverse an exothermic reaction which gives off a whole lot of energy (when one burns the fuel) - it would seem that it's going to take a whole lot of energy to do the recombination of hydrogen and carbon monoxide to create it in the first place.