On Thu, 12 Feb 2009 21:51:03 +0000, Arthur2 wrote:
If instead of blades they had the things you see on some wid speed
measurement devices
that have 3 or more cup shaped receptacles on horizontal bars fixed to a
vertical axis.
The wind can hit these assemblies at any angle it chooses with no difference
to the efficiency
of the 'machine'.

I suspect it's a bit harder to 'feather' those sorts of designs so they
don't self-destruct during really high winds. Other than that though, not
sure...

Related note: aren't the "egg beater" vertical turbines supposed to be
more efficient than horizontal-axis ones, and will also (like the
anemometer) work happily with wind blowing from any direction?