Flying wind turbines.
Now there's an idea.
But I must have missed something.... or perhaps helicopter was the wrong term? Did they mean autogyro? But no, they specifically report that these things helicpter up to their target altitude using the rotors to lift the device. So, where does the energy come from to lift them? The wind? and still enough left to drive a dynamo and generate 20MW of electricity!.
OK, I can concieve of the idea that you inpout energy to generate lift and could even buy that once at altitude, the things now flys more like an autogyro since wind speed across the rotors will generate lift autogyro fashion, and then the rotors drive dynamos. Fine, but are the gear box configurations the same? Does this mean Hillier style rotor heads? or because we have four rotors, presumably each pair rotating counter to the others, we could have simpler heads. But still, that's a lot of generator and gear box.

Currently we seem to be at around 2.5MW for land based and trying for 5MW offshore turbines.
These flying beasties appear to be 20MW. I guess because 20MW sounds better and thus we only need 43 fields of 600 FEGs to generate enough for the US energy needs.
How much bigger or smaller are the inventors claiming this 20MW hardware will be than the 2.5 and 5 MW land and offshore based turbines? They don't say.
Hmmm.

Alec Evans kindly posted this link in an earlier thread which suggested that the integrity even of the land based turbines is less than we were lead to believe:
www.spiegel.de/international/germany/0,1518,500902,00.html
Take a look at the pictures.

Now tell me who wants 20MW of generator plus gear box plus the various bits and pieces shredding itself in the skys above our heads and showering down around and upon us?

Crashes are inevitable. They say:
"Statistically, however, FEGs should be just as reliable as commercial airliners, whose safety records are incredibly good.

"And FEGs don't take off or land at airports teeming with people in and around them."

Yes, but aircraft have continuous maintenance programs and because, when one crashes, it does the aviation industry no good at all, they do tend to be quite rigorous about maintenance (except occasionally when we discover the cause of the crash is some maintenance deficiency due to cost cutting). But here we have an unammned device with no-one (near enough) on the ground to worry about... even if they do crash, they will land on unpopulated areas.. and gievn the maintenance problems (are they going to winch engineers up to them or winch them down.. with lost production and no revenue) or will they become blase about maintenance. OK, maybe the flying integrity could be pretty good but what about the generators and gearboxes? Again, see the link and pictures. Plus the cable. Aircraft aren't tethered.

(incidentally, one major aircraft manufacturer discovered the rather alarming information that something like 80% of failures are due to maintenance. Hence one reason to move away from routine preventative maintenance)

Actually, I have an image of a cable breaking or some other failure (and for some reason failures often seem to be due to multiple faults) and the device retaining enough flying capability to autogyro its way to ground.... like a flying strimmer, cutting the cables of other device or drifting into more populated areas before finally coming to grief. Oh, I'm sure they'll claim that the GPS system will be behind a pre-programmed decent mechanism that will attempt to bring the whole thing down safely.... but will it?

Besides, how far apart will these things be tethered? Surely, if they are going to be flying at around 15000 feet, then presumably the ground stations must be a similar distance apart to prevent an ascending *** being in a different wind layer running in an opposed direction to an adjacent *** and accidentally encountering its cable. That's what, 12-13000 square kilometers per field of 600? Or should we allow more or less space between ground stations? Suppose 20MW proves illusory and they have to settle for 10 or even 5?

By the way, wasn't there an Arthur C Clarke story about a geosynchrous satellite tethered to the earth with some super cable with elevators running up and down it?