"Wind Lenses" could triple the output of a turbine

[murpen]

This looks promising: Japanese breakthrough will make wind power cheaper than nuclear

[emordnilap]

But it's already cheaper than nuclear.

It's just that nuclear isn't costed correctly.

[UndercoverElephant]

This looks promising: Japanese breakthrough will make wind power cheaper than nuclear

I can't understand why nobody has figured this out before now.

[emordnilap]

This looks promising: Japanese breakthrough will make wind power cheaper than nuclear

I can't understand why nobody has figured this out before now.

Maybe they have and it's not worth it? We need better information.

Anyone on here with a small turbine could try it out and let us know what happens.

[murpen]

I can't understand why nobody has figured this out before now.

The best ideas are ones that seem obvious in hindsight.

[ujoni08]

Brilliant! This principle (a low pressure zone created by an aerofoil or diffuser) is what gives aeroplane wings lift. Low pressure also allows venturis to draw liquids or gases through holes.
I wonder how the NIMBYs will take to the new look
ujoni08

[Snail]

I see the solway windfarm every day, and while indvidual turbines look great, the pattern they create from the shore do make the view an eye-shore. And I have to say, these look like monstrosities.

Anway, won't placing a load of these on agricultural land simply be the same as bio-fuel, taking away land useful for food. And would such number of turbines not create temperature differences on a larger scale than what wind farms do now, and so influence climate change?

Maybe they have and it's not worth it? We need better information.

We don't need just more information, we need An Inspector Calls.

[ujoni08]

As I understand it, the trick is in the flared surround. Wind flows through the centre, and spins the turbine as normal, but wind that flows over the surround is forced to take a longer route, and when it goes past the edge of the surround, it causes an area of low pressure behind the turbine. That low pressure draws wind through the centre faster than the actual wind speed, spinning the turbine faster and generating more power than a standard turbine.

[Snail]

Thanks ujoni08 for explaining. I didn't understand how it increases the energy so much, it seems too much like getting a free lunch from nothing. Something thermodynamics doesn't allow.

[emordnilap]

Maybe they have and it's not worth it? We need better information.

We don't need just more information, we need An Inspector Calls.

And you need a smack.

[kenneal - lagger]

Thanks ujoni08 for explaining. I didn't understand how it increases the energy so much, it seems too much like getting a free lunch from nothing. Something thermodynamics doesn't allow.

But aero dynamics does. As Jon says, it's the same principle as the aircraft wing or even lorries driving close behind each other on the motorway. The vortices behind the front lorry create a low pressure zone which draws the vehicle behind along with it using less fuel, slipstreaming. I've never worked out or seen anything about whether the first lorry uses more fuel though.

[An Inspector Calls]

They're converting them to be ducted turbines. The same concepts already exist for hydro turbines: compare non ducted tidal turbines such as Stranford Lough to ducted turbines such as Kaplans or Francis. But I wonder what the duct length to blade diameter ratio has got to be?

http://oxfordoceanics.co.uk/ewtec.pdf

http://www.wind-works.org/SmallTurbines ... bines.html

[Yves75]

I guess the major problem with this thing is that you cannot really "depower" it when very heavy winds ( like putting the turbine wings "wind ahead")

Really doubt that it wasn't considered before if overall advantages

[An Inspector Calls]

No, all you have to do is feather the blades, just as you do with a conventional windmill.

The difficulties with this idea are

• difficulty of constructing the duct,
  requirement for larger base construction (unless the duct arrangement can be perched on top of a windmill tower),
  large increase in capital cost - at least double I would think,
  turning the machine into wind will require more power, again increasing capital and revenue costs.

[Yves75]

No, all you have to do is feather the blades, just as you do with a conventional windmill.

Yes but you can't feather the duct (the round thing)