At 10:37 pm +0300 6/3/02, <monolit@...> wrote:
>
>The following are why the VAWT is good:
>
>NO Aircraft style blades.

high speed vawts need airfoil section blades.

>NO Yaw dampening.

No yaw. This seems like a good idea until you find out that the
blades are yawing once per revolution and this puts incredible stress
on them

>NO Pitch control or control box.

you need some controls on a wind turbine if you want it to last.
VAWTs are much harder to control than HAWTs but this is not an
advantage.

>NO Tip brakes.

I have seen them used (without much success).

>NO "Furling" for excessive or gusty winds.

so what do you do to prevent overspeed? Use a big brake I suppose.

>NO Weather vane or tail vane.

sure but you pay a big price for that.

>NO Dangerous high RPMs.

please explain.

>
>
>Could anybody explain me in same simple plain manner, why VAWT is bad?

Because the wind comes at the blades from one side and then the other
each revolution, until they fall off.

Low speed VAWTs of the savonius type are different but they are too
slow and inefficient to be worth considering for most applications.

--
Hugh

on the way down to Wales to teach the CAT windpower course.
http://www.scoraigwind.co.uk/