In the past five years, some very inventive startup companies have made a technological leap creating unique urban wind systems that require no towers and fit in beautifully in urban and suburban settings.
Rising 50 stories above the
Arabian Gulf, the twin towers of the Bahrain World Trade Center offer a
spectacular view of three spinning wind turbines 29 meters in length, spanning
the open space between the two towers, gripping their sides, and holding them
upright. Activated in April 2008, the wind turbines provide about 15% of the
building’s electricity. The rest of the world will likely not be able to afford
such awesome wind systems, but, in the past five years, some very inventive
startup companies have made a technological leap creating unique urban wind
systems that require no towers and fit in beautifully in urban and suburban
settings. These urban wind systems rest nicely on the parapets of multi-storied
buildings, creating kinetic architecture while reducing occupants’ power costs.
We preview them here.
AeroVironment Wind Systems
The graceful metallic vultures
poised at the edge of the tall building will not take off and swoop down on
unsuspecting critters—they are actually AVX wind turbines manufactured by
AeroVironment Inc. (AV). They have already been installed at seven locations
across the US, but are not yet in full production, says Paul Glenney, the
director of the Clean Energy Technology Center for AV, based in Monrovia,
CA.
AV’s first wind turbine, a
rudimentary black box 4 feet by 4 feet, was installed in June 2004 at Pioneer
Electronics in Long Beach, CA, says Glenney. “The intention was to understand
the look and feel” of the 400-watt wind turbine and to quiz people about it,” he
says.
From there, AV installed a beta
system, this time a white box with a screen, at a Staples Fulfillment center in
Ontario, CA. Additional beta systems were installed on buildings at BMW and
Nestles, and also in southern California. “We had increasingly more ambitious
goals with each installation,” says Glenney.
In the case of the BMW
installation, the company had to get it permitted, a difficult job involving
several meetings with the city’s planning commission. In southern California,
some local regulations require rooftop equipment to be screened or hidden—making
a rooftop wind turbine installation impossible.
The next step was a logical one.
“We wanted to make it kinetic architecture,” says Glenney. The current design,
which AV has named “Architectural Wind,” was created with the help of BMW’s
DesignworksUSA. In 2007, it won two international design awards. Since then, AV
has improved the turbine. The AVX400 was a three-blade, 400-watt unit, but it
created a lot of noise and was not cost effective. At 400 watts, it would
require 75 units to be installed on a building to get to 30 kW. Installation
costs alone made it prohibitive to commercialize. Back at the drawing boards, AV
added two blades and pushed it to 1,000 watts. Thus, to get to 30 kW, only 30
units need to be installed. The five-blade model also solved the noise problem.
All the sites have now been retrofitted with the 1,000-watt systems.
Glenney explains that the lowest
speed most wind turbines spin at is five miles per hour. The blades are made of
molded thermoplastic with carbon fibers. With the three-blade unit, they would
start fluttering, making a loud clacking noise when the breaking device went
into action at about 27 miles per hour. The new five-blade AVX1000 turbine not
only spins at low revolutions per minute (RPM), it takes a very high wind speed
to make it flutter.
AV has continued to work on the
aerodynamics of its turbine, says Glenney, in wind tunnels at California
Institute of Technology and Oregon State University. This wind turbine is
designed to take advantage of the chimney effect of rapidly rising wind or
“accelerated wind zone movement” coming over the top of a building at strength
40% greater than the prevailing wind flow, he explains. Knowing the vector flow,
the turbine can be positioned at the edge of a building to catch that faster
wind.
Glenney says AV might decide as
soon as the third quarter, 2008, to go into production, or it may decide to stay
in low production for another six months. It will depend on adoption by
customers, and whether the company can reduce manufacturing costs, he says. The
company wants to retain the aesthetic design, but to reduce the price 30%, it
may look at smoothing out blade curves, or it may be able to leverage economies
of scale, he says. The current high commodity costs could impact manufacturing
costs, but not at the current low-rate of production, says Glenney.
The public is experiencing
tremendous interest in AV’s turbines. Glenney says the company does have orders,
and if it can create aggressive cost reductions, it may move forward. Visit the
company’s Web site at www.avinc.com for news and more details.
AV Wind Turbines Attract
Attention
Tom Romundstad, St. Louis County,
MN, property manager in Duluth, can attest to the popularity of AV’s wind
turbine. Six 1-kW units were installed on the roof of the Government Services
Center in Duluth early in 2008. Since then, Romundstad has received calls from
Montana, Alaska, Wisconsin, and many other municipalities inquiring about the
units, following local press coverage. And the local National Guard wants to
install some on its building.
Romundstad explains that St. Louis
County bought the 1980s era building from the State in 2002. It was in poor
shape and used a lot of energy. Since then, the county has completed a large
number of retrofits including lighting, and the rebates awarded for the energy
conservation work were reinvested in solar photovoltaic systems on three
buildings including this one. The turbines complement the solar, he says. The
system, which is scalable, currently powers the building’s hallway and stairwell
lights.
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Photo: AeroVironment
AeroVironment's Architectural Wind turbine installation at the Aquarium in Camden, NJ. |
The turbines were installed on the
east edge of the rooftop to catch winds coming off the north shore of Lake
Superior. A support I-beam was lifted to the roof on which the turbines were
mounted. This will allow the roof to be re-roofed later on, explains Romundstad.
The turbines can turn 35 degrees in each direction to catch the wind. He says AV
now has turbines with 360-degree access to the wind.
The county did not need permits to
install the wind turbines, but Romundstad had protective guards placed on top of
the turbines in case falcons, which nest in downtown Duluth, come by to visit.
Since the system was installed, the area has experienced a lot of west winds.
“We’re in the period now when northeasterly winds pick up,” he says, explaining
one of the reasons why the turbines have produced just 400 kWh since
installation.
The major reason for the lack of
production, however, was the shorting out of two generator-housing seals shortly
after installation last February that reduced power production on the 6-kW
system by 2 kW. The lack of production was not noticed for several weeks. As
soon as AV was notified, a repairman was dispatched from California, and he took
all six turbines apart, checked all the seals, and replaced the destroyed
ones.
In addition to St. Louis County,
20 Architectural Wind systems were installed in March 2008 at Boston Logan
International Airport, MA, on the roof of the Logan Office Center. The wind
turbines are expected to provide about 2% of the building’s monthly energy use,
or $13,000 annually.
Other locations include Laughlin
Air Force Base in Texas, where six wind turbines were installed on the roof of
the Laughlin flight simulator between summer 2006 and December 2007. A series of
wind turbines were installed at Arizona State University, in Tempe, AZ, on the
edge of the building housing the School of Sustainability, in early 2008. And a
4.8-kW wind turbine system was installed on the roof of the Adventure Aquarium
in Camden, NJ, in September 2007. Finally, Kettle Foods installed 18
Architectural Wind systems on the roof of its new 73,000-square-foot potato chip
manufacturing facility in Beloit, WI, in mid-2007 as part of the company’s
effort to build sustainably. Kettle achieved gold level certification for
Leadership in Energy and Environmental Design (LEED) from the US Green Building
Council. AV reported the 18 1-kW wind turbines are projected to generate
approximately 28,000 kWh annually—enough to produce 56,000 bags of potato chips,
according to Kettle.
Broadstar Wind Systems
Likening the AeroCam to a mini
ferris wheel, the small wind turbine could generate electricity in an urban
setting like a shopping mall and become an architectural attraction, says Steve
Else, president and one of the founders of Dallas, TX-based BroadStar Wind
Systems. He believes the AeroCam can easily be installed in almost any
environment to create distributed power generation sources.
“I think this
market will explode,” he says.
Broadstar started up in 2004.
Following years with Oracle and Ariba as a manufacturing systems engineer, Else
started an oil and gas investment company in 2002 and is using the profits to
fund this company. Tom Stephens, the company’s chief engineer, is the inventor
of the AeroCam. The AeroCam is still in the testing phase, so Broadstar will
seek financing starting in summer 2009 once beta testing is concluded, around
the time when the company will go for general deployment of the wind
turbine.
“We won’t go to general release
until we iron out all the issues,” says Else. “It’s very important to us that
customers are happy and the product is reliable.”
Beta testing with 10-kW and 250-kW
prototypes is beginning in at least five different environments. Two are at
Fortune 100 company locations at an industrial complex and in a one million
square foot distribution center. Else says the second beta test will begin at
Texas A&M University, in July. Another will take place in the United Kingdom
on an eastern shoreline, to determine how the blades deal with salt blast and
corrosion. He is looking for a test site in Canada to check out how the AeroCam
handles icy conditions.
The patented design features 10,
12, or 14 blades on each module, depending on the size. The blades use the natural flow of air
to create lift, and an offset cam that allows the blades to continually adjust
for optimal pitch throughout a 360-degree rotation of the turbine. The AeroCam
is about 30% smaller than a conventional horizontal axis wind turbine yet
generates the same amount of power. The original module produces 10 kW at 30
miles per hour wind speed. The company is designing 100-kW, 250-kW, and 500-kW
models in parallel. In each of the models, as wind speeds increase, delivered
power also increases. For example, the power curve on the company’s Web site,
www.broadstarwindsystems.com, indicates the 500-kW AeroCam IV will
produce 800 kW at 35 miles per hour.
The AeroCam will fit in
environments where big turbines won’t fit, says Else. In the urban setting, the
roof edge of a tall building is a perfect place for a small wind turbine, he
argues, given that the focus of the wind is at the building’s parapet.
Currently, there are no standards, and no permits are required for the 10-kW
AeroCam, which has a 10-foot diameter. Else says this model may fall within the
category of rooftop accessory requirements.
Ideally, the AeroCam lends itself
to being integrated into the design of a new building. Else predicted that in 10
years, all new buildings will integrate solar, wind, and a ground loop to cool
liquid underground for air-conditioning. “Sensibly designed buildings should
have all three,” he says. Else says the urban sites won’t be the biggest market
initially. He predicts it will take four to eight years to achieve a large urban
market, and must be done in collaboration with others in the industry. Other
applications, including micro-wind farms, require less real estate than
traditional wind systems since they can be installed on poles as low as 30 feet.
Small communities or rural cooperatives could install a series of modules at the
edge of a park and interconnect with the local utility. The AeroCam requires no
special equipment or cranes, making it easier and less expensive to install and
maintain over the long term.
The AeroCam can also be installed
as infill in large fuel storage sites or in existing wind farms to create
greater overall power generation. There is plenty of wasted land in between big
wind turbines, which must be placed three diameters apart hundreds of feet above
the ground to operate in smooth airflows, Else points out. The AeroCam can
withstand turbulent environments because of its lower hub height and small
footprint, and capture surface-wind energy without disrupting the airflows that
the larger turbines need to operate effectively.
Else says cost modeling indicates
the company will be able to manufacture the AeroCam at $1 per watt, allowing a
customer to buy a 250-kW unit for $250,000. He says the turbines would be
manufactured in the United Kingdom while sourcing components from Asia and
China. The small, modular size of the AeroCam will allow the company to ship it
anywhere in the world for $4,000, he says.
Aerotecture Wind Systems
Aerotecture International’s unique
and patented wind turbine design resembles a giant squirrel cage, except for the
blades whirling silently inside. The cage can be installed either horizontally
or vertically. It is small enough that two men can carry a unit and tip it up
for vertical installation. This can be seen in a documentary on the company’s
Web site, www.aerotecture.com. Bill Becker, the coinventor and CEO of
the company, talks while leaning against an horizontally mounted installation as
the blades whirl.
A company representative was not
available to talk about its wind turbine system, communicating that they were
overwhelmed with media inquiries and work, but information is available on the
Web site. Also, two owners of systems describe their experiences below.
The Aerotecture wind turbine comes
in two models: The 510V is rated at 1 kW in 32-miles-per-hour winds; the 520H is
rated at 1.8 kW. The newest model is a hybrid, using solar panels in tandem with
the 510V model. The company recommends the units be installed at least 40 feet
above the ground to take advantage of strong winds, and that they be above or
away from surrounding trees and other obstructions, and in an area where the
average wind speeds are at least 10 miles per hour.
Vertical Aerotecture wind turbines
operate in winds coming from all directions, but horizontal systems require a
dominant wind direction for maximum efficiency. The rotational axis must be
oriented perpendicular to the dominant wind direction. The corkscrew design of
the polycarbonate foils tipped with aluminum blades shields the turbine and
helps it start at very low wind speeds of two miles per hour.
This feature also protects birds.
At the Randall Museum in San Francisco, CA, where an Aerotecture wind turbine
was installed in June 2005 to power an exhibit for the United Nations World
Environment Day, there was not a single bird killed. There are 100 bird species
on the hill where the museum is located. “We watch birds fly around it, like red
tail hawks,” says museum director Chris Boettcher. Apparently, they see the
glint of the foils that reflect light 360 degrees, he says.
All Aerotecture turbines are
commercially available, and are designed and custom-built to fit the
architecture of the building. The electricity generated by the wind turbine
system can be sent to a battery bank or to the utility grid. The 510V model
costs about $15,000, and the 520H model costs $21,000. Currently, the wind
systems are only being sold in San Francisco; Chicago, IL; Paterson, NJ; and
upstate New York where the company has dealerships. Aerotecture is currently
focusing on grid-connected systems where utilities provide net metering,
according to information on its Web site. It is working to set up mass
manufacturing and dealerships in other areas of the US and worldwide.
The first Aerotecture turbine was
installed on the roof of Becker’s cousin’s law office in Round Lake, IL, in
October 2003, where it operated as the test site. Becker’s cousin, Jim Magee is
the senior partner of Magee Negele & Associates, and the Round Lake village
attorney. In that role, he was able to expedite the city permits for the
installation on top of the one-story office building.
“In fairness to truth, there’s
been so much experimentation,” says Magee. Primarily, this has involved
upgrading the alternators. The first was a converted automobile alternator and
the newest one is a much-improved technology, he says.
The greatest benefit, Magee says,
is the backup power it provided the two times the utility power failed. The
turbine’s generated power is fed into the back office and powers computers and
lights through batteries. There was no flicker in the seconds after the power
failure—“It was dramatic and wonderful,” he says.
The original battery set is still
operating, and, when they are full, the utility meter does run more slowly.
“They’ve been up there, virtually silent, except when huge winds produce a
slight sound,” says Magee.
He also says that there is no
vibration and no bird kills, even though the cage is open. It is noteworthy, he
says, that the turbine is not bolted or anchored to the roof. Six cinderblocks
are at the base, and the turbine could be picked up and moved, cinderblocks and
all.
The one disadvantage Magee
described is that it is only 12 feet off the ground. If it were over 30 feet it
would be better. Furthermore, trees are on two sides that block some wind.
“Higher and more open is desirable,” he says, which would produce more
consistent winds.
Larry McCarthy, regional vice
president of property management for Mercy Housing Lakefront, Denver, CO, says
the jury is still out on the eight 520H Aerotecture wind turbines that span the
front edge of the five-story, 96-unit Margot & Harold Schiff single-resident
housing development in Chicago. Grants from the city and state paid the $150,000
cost of the system and installation. The building is new and the wind turbines
are building-integrated. The architect, Murphy/John Architects, claims the
geometry and orientation of the building was designed especially to increase the
speed of the wind as it flows over the roof. The eight wind turbines were
installed on the edge of the roof in August 2006 and began operating in March
2007. It was the Aerotecture’s first battery-free installation.
McCarthy hadn’t yet arrived on the
job when they were installed, but he says the alternators have been
malfunctioning, and they are just now getting a meter to measure energy
use. These turbines were the first
to be installed horizontally. “We’re not getting movement when the winds don’t
blow in the right direction,” he says. “I would have standing turbines if we
were doing it again.”
McCarthy explains that the power
generated by the turbines goes directly into the building’s electric system. A
solar thermal system was installed at the same time and heats water used by the
residents. He says the company that was hired by Aerotecture to install the
turbines handles maintenance on the system. McCarthy’s advice to potential wind
turbine buyers: Do your homework and investigate the cost to maintain the
system.
The projected energy savings for
this system was $1,500 per year. At that, the payback is something like 50
years, he says. The new meter coming will either prove or disprove that.
Blue Green Pacific
Blue Green Pacific, based in San
Francisco, has designed a residential wind energy system that would also be
appropriate for small businesses and schools. Blue Green’s 500-Watt turbine is a
vertical helix design offering a small footprint, minimal noise, no threat to
wildlife, and is affordable. It can be viewed at the company Web site,
www.bluegreenpacific.com.
Tod Pelman, CEO of the company,
says development is still very early, at the alpha level. Beta level testing is
just beginning and will continue for six months. The company is also developing
a 1-kW model. Two units have been installed on residences (including his) in San
Francisco. Two other units have been installed on a commercial building and on a
school.
San Francisco is developing
permitting rules for urban wind systems, propelled in part by Blue Green’s
installations. It created an urban wind task force to look at whether or not a
particular environment is conducive for wind turbines, according to Johanna
Partin, renewable energy program manager for the city. The task force will work
with the Building Inspection and Planning Departments to develop the rules.
Partin says Blue Green’s three wind turbines installed on the two residences
were permitted on a one-year pilot basis, and they have to be Underwriters
Laboratory (UL) listed. She says all vertical axis turbines are in the process
of getting this listing.
Motorwind
Lucien Gambarota who invented and
developed motorwave technology and, more recently, the motorwind system, founded
Motorwave Group, based in Hong Kong. He did not provide an interview, and the
following information was developed from the company Web site,
www.motorwavegroup.com.
Motorwind microturbines look like
a grouping of children’s colored whirling pinwheels lined up on a post or along
a fence. Furthermore, they are truly renewable. The 25-centimeter, round compact
gearwheels with blades made of plastic can be arranged in a range of shapes and
sizes from two to thousands of square meters. Because the blades are
injection-molded from polypropylene, the microturbines can be recycled several
times. They are designed to be installed anywhere on any support in modules, and
they operate at low and high wind speeds ranging from two meters per second to
more than 10 meters per second.
The company is targeting
applications for homes, factories, companies, schools, and farms. The first
commercial installation was on the roof of the Hong Kong Sea School in January
2007. The 396 turbines were stacked six rows high in three sections and were
colored to spell out the name, “Sea School.” Each unit is rated at 125 Watts.
Average output was predicted to be in the 0.6 kW to 1.3 kW range with a daily
production of approximately 10 kWh to 30 kWh.
The company is recommending the
Motorwind microturbine produce power only for in-house use at this time.
Currently, it does not have the regulators necessary to interconnect with the
grid. Motorwind microturbines are available in an 8-turbine set for high wind
speeds and a 20-turbine set for low wind speeds.
Motorwave
does not have distributorships outside Hong Kong, but the microturbines can be
ordered from their Web site. The cost is approximately $4.00 per watt with a
minimum investment of $200.