Windmills

Wind power is already pretty cheap.

Bret Cahill

Sure. What you're talking about is basically an overgrown version of a chairlift support tower with a pivot.

Probably not. It depends on how much of the cost of the energy is taken up by the windmill structure...my guess is, not much. Putting two windmills on one tower may reduce your structural cost (not necessarily, it depends on how much the horizontal beam costs compared to another tower), but it won't reduce your blade/generator cost or your land cost (you still need to maintain the same windmill spacing).

Tom.

The Betz Limit is based on continuity; the air slowed by the extraction of kinetic energy must be dispersed and this only allows a 59% max efficiency. Single disk blades are already over 40%.

Two disks might not be a cost effective improvement.

What I'ld like to see in a generalized Betz Law that covers ALL wind turbines, not just disk rotors.

Bret Cahill

Can be done, and has been done:

then "Faktablade" from the menu top right, and select 2a from the menu on the new page - windmills with double sets of sails dating from

1900-1910.

Looks like a fairly complicated structure. Why would it reduce cost at all ?

Timo

Tower stuctures are around 60% of the costs of a windmill. This is what this design is aiming at-reducing this cost along with the grid connection costs

Your double windmill has however some features that will raise the cost as well:

- the loads on the tower will increase, so will the cost of the tower

- you will need a heavy bearing at the top

- you will need structure for your arms

From a structural point of view I can't believe you will gain anything.

I don't know much about the grid connection, but then in your system you need a swivel and some electronics to separate the two alternators.

Timo