Hi friends,

We just released our latest video, ORN#7 Vertical Axis Wind Turbines,
http://www.youtube.com/watch?v=kp522phTgBc



While coming through Detroit we stopped in to visit Enviro-Energies, a
company that makes a very different kind of wind turbine. Vertical
axis wind turbines are more commonly mounted on rooftops and spin,
well, vertically instead of horiztonally. Think about a
merry-go-round with sails, and that’s a lot like what we saw on our
visit. Nothing like what we’re used to a wind turbine looking like.
Carrick chatted with Ken Johnson, President of Enviro-Energies about
vertical axis wind turbines, or VAWTs.

So why use a VAWT instead of the traditional propeller-type wind
turbine? WARNING: long answer to follow. From how I see it, they are
different products for different applications. Traditional horizontal
wind turbines are mounted on towers or poles – generally, the higher
you place the turbine the more consistent wind speed you’ll see.
They’re not meant to mount on a rooftop, not only because of the lower
elevation but also because the sloping roofs produce a lot of
turbulence in the airflow. The Enviro-Energies turbine actually
takes advantage of air turbulence from sloped roofs and is better able
to handle shifting wind direction.

For homeowners, putting up a wind turbine can be a tricky situation.
In our town in Massachusetts, the policy states that any pole or tower
would have to fall on my property in ANY direction, so if I have a
75-foot tower I’d better have a good amount of land. I don’t have
many acres of land so that wouldn’t work for me. Because VAWTs are
roof-mounted, this isn’t a problem for getting town approval.

VAWTs are marketed touting a number of benefits, some of which I will
take issue with. They are sold as being silent and harmless to birds
(suggesting those are problems with traditional propeller-types).
These claims play to many people’s mistaken impressions that wind
turbines are loud and a big threat to birds, which I and many other
people spend a lot of time refuting. In my experience, small
residential wind turbines do make noise when they’re really moving,
and larger commercial-sized wind turbines (newer ones anyway) do not.
The Enviro-Energies turbines they are silent at any size and speed.
Wind studies have shown that on average, wind turbines kill 2 birds
per year – again, cats, windshields, plate glass windows, etc., are
responsible for more birds killed annually than wind turbines.

What is really intriguing about the Enviro-Energies wind turbine is
that they have developed large-scale turbines that could be put on
tall buildings in cities. This is an application where traditional
horizontal turbines would not work. Usually wind power is generated
in rural areas with transmission to cities, but designs like this
could bring wind power to the cities themselves. The largest model
they can produce at Enviro-Energies is 200 feet wide, with bladders
filled with helium to significantly reduce the weight of the turbine.

Now, Enviro-Energies is not the only company out there making vertical
axis wind turbines. Actually, if you mention VAWTs to most wind
energy enthusiasts they will usually groan and roll their eyes. VAWTs
are relatively new to the game and there are a lot of new companies
making wind turbines that look neat, but haven’t been thoroughly
tested and usually produce much less energy than they are marketed
for. Just do a search online for vertical axis wind turbines and you
will see an amazing variety of designs, and a lot of amazing claims
with how much electricity they can produce at lower wind speeds.
During the interview, Ken talked about their approach to design and
how much the sails of the Enviro-Energies turbine catch wind more
efficiently at low wind speeds.

Another interesting feature of the Enviro-Energies turbines is that
they use magnetic levitation, which greatly reduces the friction while
turning. In the video you can see Carrick very easily turning a
20-foot turbine. That’s one way to get Carrick to burn off some
energy! Also, Ken mentioned that company logos and advertisements can
be added to the sails which make large and unique billboard, while
sending a green message.

So check out the video and enjoy – this visit was definitely one of
the best examples of being able to visit and report on something that
most people have never seen or heard of. I’m grateful that we had the
opportunity!

Be well,
Colin
--
Our Renewable Nation, A Cross-Country Eco-Video Adventure
www.OurRenewableNation.org