you see where i'm going with this?

kidding aside, this is visionary...

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

:)

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

The spinnaker sail is ballon-like in shape whereas the mail sail works like the wing of a plane.

By that, you mean shaking so violently that it seems almost certain to fall off?  Or is that a Delta-only thing?

Be nice to America. Or we'll bring democracy to your country.

How counter-intuitive.

Oh, wait ... I find it more likely that they don't know which one is the mainsail.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

Commenter Godfrey makes some good points over at the bd site:

Chetwood Associates’ sail-like ‘wind dam’ lands on Lake Lagoda - Building Design

Godfrey 15 November, 2007

Looks nice but unfortunately the idea is completely flawed and demonstrates a total lack of understanding in fluid dynamics (amongst other areas of physics). 'Dams' work because of the difference in potential between one side and the other. In a water dam, the differential is the gravitational potential energy of the water on one side vs the other. The size of the dam is unimportant for electricity generation, only the difference in altitudes. The energy harnessed is the potential energy lost moving water from higher altitude to low altitude. A wind turbine of the type here is exactly like the ones in the fields. What this 'sail' intends to do is increase the wind velocity over the blades and hence generate more power. However, as with water turbines, the power generated comes from a loss of potential energy. Here the potential is pressure. There must be a higher total air pressure on the inlet side of the turbine than at the outlet otherwise the air wouldn't flow. Sails are not used to generate pressure differentials, they are intended to generate force. The pressure difference on either side of a yacht sail is not much. But bigger sails deilver more motive force than smaller, because the small pressure differential is over a larger area. All a bigger sail will do in this design is create bigger forces, not larger flows through the turbine. And by the way, turbines (which are NOT propellers) work because air 'escapes' around them, not in spite of the fact. Sorry to party poop, but there are very good reasons why this hasn't been done before.