Just passing this along for the Optimism Department:
Water from wind
...Max Whisson has come up with a brilliant and very simple idea.
It involves getting water out of the air. And he's not talking about cloud-seeding for rain. Indeed, he just might have come up with a way of ending our ancient dependence on rain, that increasingly unreliable source.
And that's not all. As well as the apparently empty air providing us with limitless supplies of water, Max has devised a way of making the same 'empty' air provide the power for the process...
There's a lot of water in the air. It rises from the surface of the oceans to a height of almost 100 kilometres. You feel it in high humidity, but there's almost as much invisible moisture in the air above the Sahara or the Nullarbor as there is in the steamy tropics. The water that pools beneath an air-conditioned car, or in the tray under an old fridge, demonstrates the principle: cool the air and you get water. And no matter how much water we might take from the air, we'd never run out. Because the oceans would immediately replace it.
Trouble is, refrigerating air is a very costly business. Except when you do it Max's way, with the Whisson windmill...
...Usually a windmill has three blades facing into the wind. But Whisson's design has many blades, each as aerodynamic as an aircraft wing, and each employing "lift" to get the device spinning. I've watched them whirr into action in Whisson's wind tunnel at the most minimal settings. They start spinning long, long before a conventional windmill would begin to respond. I saw them come alive when a colleague opened an internal door.
...They don't face into the wind like a conventional windmill; they're arranged vertically, within an elegant column, and take the wind from any direction.
The secret of Max's design is how his windmills, whirring away in the merest hint of a wind, cool the air as it passes by...
With three or four of Max's magical machines on hills at our farm we could fill the tanks and troughs, and weather the drought. One small Whisson windmill on the roof of a suburban house could keep your taps flowing. Biggies on office buildings, whoppers on skyscrapers, could give independence from the city's water supply. And plonk a few hundred in marginal outback land - specifically to water tree-lots - and you could start to improve local rainfall.