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heights</title></head><body>
<div><br></div>
<div>Dan,</div>
<div><br></div>
<div>You said it so well. I'll only add that it has given the small
wind industry a HUGE black eye to have major manufacturers pushing
short towers. It will take us decades to overcome. On a weekly basis,
I deal with the fallout from this, from Home Power readers, workshop
students, clients, authorities, the general public, etc.</div>
<div><br></div>
<div>Too many manufacturers do not even sell a tower for the NW, since
sites where it's appropriate to have towers shorter than 100 feet are
quite rare here, and 140-plus is more typical if you are serious about
kWh, not just stuff that spins, in this land of very tall trees.</div>
<div><br></div>
<div>I would love to see manufacturers saying "we don't sell a
tower shorter than..." instead of "we don't sell a tower
taller than..."</div>
<div><br></div>
<div>Thanks,</div>
<div><br></div>
<div>Ian</div>
<div><br></div>
<div>PS -- If I lived underground on the tundra, I'd buy a 60-foot
tower, at least... ;-)</div>
<div><br></div>
<div>PPS -- I hope to see a bunch of wrenches at the
<http://www.smallwindconference.com> in June.</div>
<div><br></div>
<div><br></div>
<div><br></div>
<div>At 9:44 PM -0600 4/28/12, Dan Fink wrote:</div>
<blockquote type="cite" cite>Ross;</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>The Skystream has a reputation now of a
reliable performer at a good price point, and your SWWP monopole
towers are attractive and sexy as long as a concrete truck can get to
the site. But we couldn't recommend a Skystream on a 34 foot monopole
to anyone anywhere -- violates the 30 foot rule. The 45 ft monopole
would be OK assuming the site has nothing taller than a wooden cow
fence anywhere within 500 feet. That's a pretty rare
situation.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>Single story building heights of 30 feet
are the norm in most places, as are tree heights of 40-60 feet. The
price on your 60 foot monopole is jaw-dropping for most of our
clients.....but they need to buy your tower to get a warranty. We are
usually recommending towers of 80-100 feet. This excludes your
products from our recommendations in all but very rare, clear
sites.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>All I can say further
is........</blockquote>
<blockquote type="cite" cite>V = V0 x (H/H0)^alpha</blockquote>
<blockquote type="cite" cite>and that alpha exponent is really a
bitch. Even experienced, highly qualified small wind experts
underestimate it much of the time I think -- I've seen some amazing
wind conference presentations of site photos compared to MET tower
alpha measurements on this topic. And then we have turbulence
intensity...yet another factor.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>I have a great slide show we use for all
of our wind power intro classes (the class is called "Wind Power
Reality") It's photo after photo of "Good turbine, bad
site." Skystreams on short monopoles are 80% of the photos. We
have our students estimate alpha exponent, and de-rate the skystream
energy curve of kWh per month. I wish we could get real data to
see how our estimates come out....but it's ugly.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>We just cannot, in good faith, try to
tell a Client to fly a wind turbine on a tower that's too short. They
will blame *US* for the lack of production, not the wind turbine
manufacturer. And 74 feet is WAY too short in most of the cases we
see.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>No offense intended, we see how client's
jaws drop when they see monopole tower prices....that gives some
unscrupulous dealers an incentive to be deceptive and fudge the data.
But it's way cheaper to increase the height of a tilt-up or guyed
lattice tower from 40 to 80 or 100 feet, compared to doing that with a
monopole.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>*It's all $ / kWh, on the grid or
off.*</blockquote>
<blockquote type="cite" cite>And wind speed pays back 8:1 on your
bet...or overestimating it sets you back 1:8, with an angry customer
too.</blockquote>
<blockquote type="cite" cite>But in Vegas, there's a pit boss. In
Small Wind, it's the wild wild west, it seems.</blockquote>
<blockquote type="cite" cite>-- <br>
Dan Fink,<br>
Executive Director;<br>
Otherpower<br>
Buckville Energy Consulting<br>
Buckville Publications LLC<br>
NABCEP / IREC accredited Continuing Education Providers<br>
970.672.4342 (voicemail)</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>On Sat, Apr 28, 2012 at 7:51 PM, Ross
Taylor <<a
href="mailto:ross.taylor@windenergy.com">ross.taylor@windenergy.com</a
>> wrote:<br>
<blockquote>Hi Bob, I'm not sure if this was a question or a
good-natured (I hope) jab. But, since you asked, I think it's
appropriate to answer. We sell mono-pole towers for the
Skystream in heights ranging from 34' to 70' and we also have guyed
towers to 70' as well. Our most popular tower is the 45 foot and
we actually discontinued the 34 foot tower. But, in places where
that tower works just fine (coastal installations, the plains, etc)
our dealers complained very loudly and requested that we re-instate
it. So, we did and we do still sell those.</blockquote>
<blockquote><br></blockquote>
<blockquote>I don't want to derail the original thread and I'm happy
to discuss tower heights with you, perhaps offline, but I would
respectfully submit that the right height for a wind turbine (ours or
anyone else's) is that height which puts the turbine's rotor in clear
air. That height will depend upon the terrain, vegetation,
structures, and the wind conditions/speed. By better training
our dealers, we're hoping that they will select the right tower for
that site and the conditions which exist there. And this has,
indeed, led to better installations. So, this is the reason the
OP won't find a direct sales channel.</blockquote>
<blockquote><br></blockquote>
<blockquote>Respectfully,</blockquote>
<blockquote><br></blockquote>
<blockquote>Ross</blockquote>
<blockquote><br></blockquote>
</blockquote>
<div><br></div>
<div><br></div>
<x-sigsep><pre>--
</pre></x-sigsep>
<div>Ian Woofenden <ian.woofenden@homepower.com>, Senior Editor,
Home Power magazine<br>
Subscriptions: $14.95 per year PO Box 520, Ashland, OR 97520 USA
800-707-6585 (US), 541-512-0220<br>
or download free sample issue at
<http://www.homepower.com></div>
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