Roger (K8RI) k8ri at rogerhalstead.com
Tue Oct 6 15:07:46 PDT 2009

Peter Laws wrote:
> On Tue, Oct 6, 2009 at 13:21, Roger (K8RI) <k8ri at rogerhalstead.com> wrote:
>> 40' is very low.  Around here (flat land farming country-Lower Michigan)
> Not for home-scale wind power.  As long as you are well above the
> treetops (to get away from the dynamics caused by friction), 40' would
> work.
Around here it takes about 80' to get level with the tops of most trees. 
In our yard it's heavily wooded to the N and W with the neighbors to the 
S having a number of large trees.  I've had to move my satellite dish to 
about the 30' level on the tower and that's a good 100' from their lot 
line and about 130-150' from the one big willow tree.
But, getting back to the wind powered generator, it'd have to be high 
enough for the blades to be out of the turbulence caused by the trees, 
with with 80' trees (occasionally higher) I'd need at least 100' which 
is the height of the only two small, conventional generators I know of 
in the area.  As you get higher the winds are not only more consistent, 
but reach useful levels much more often.  The S-rotors work just fine 
much lower if the wind can get to then and they don't seem to be 
bothered much by the turbulence. They also produce useful power at much 
lower wind velocities.   

Compared to commercial generators the small ones with say a 6' blade 
circle are much less efficient.
> I think the "test" in the OPs text referred to a test of the local
> government.  As is often the case with renewable energy -- wind, PV,
> solar hot water -- they have no idea what to make of it or how to
> regulate it (though they are certain they should tax it).
Ain't it da truth!
> I'd start by finding out the make of the inverter/charge controller.
Some of the inverters are terrible while others make nary a whisper.
I wonder what part of the country this test is in.


Roger (K8RI)

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