may be required, explains Gilchrist.
If the roof isn’t an option, freestanding models can be located on an unused patch of your property. These turbines
can be comparable in size to a standard area light pole or
between 100-150 feet. This is still substantially smaller than
utility-scale turbines, which are typically over 300 feet tall
when measuring ground to blade tip.
Whether rotating overhead or gracing the edge of your
parking lot, these vertical axis turbines are sure to stand
out. Considering that solar panels may be obscured by
parapet walls and geothermal is hidden underground, vertical axis turbines are an eye-catching way to position your
company as an environmental leader.
“Companies looking to make a visual statement about
their sustainability initiatives can attract positive attention
with these turbines,” Gilchrist says.
As an additional benefit, VAWTs are quieter because
their RPMs are lower than utility models, he adds. This
means less vibration is carried through the building as well.
“These turbines can also contribute to bird safety.
Because the blades don’t spin as fast and their arms are
shorter than a large turbine, they are easier for birds to see
and avoid,” explains Gilchrist.
Lastly, access is far easier with VAWTs. Critical components such as the gearbox are often at ground level so no
scaffolding or safety harnesses are needed to perform routine maintenance and inspections, says Schneider. Maintenance is similar to larger models with lubrication changes
and blade cleaning. Some manufacturers also offer service
contracts, notes Gilchrist.
Ensure your warranty, which is typically two to five
years, covers routine failures as these turbines are designed
to move continuously, Schneider adds.
Quantify Your Wind Resource
As with any renewable, you need to have a firm projection of how much energy your site is capable of producing.
For turbines, you should calculate your wind resource
in order to capture as much of it as possible. The forceful winds on top of your building should produce enough
torque to generate a suitable amount of electricity, but it’s
best to confirm this before installation.
“We use a CFD (computational fluid dynamics) analysis
to measure turbulence,” Gilchrist explains. “This helps us
to model the building and take into account surrounding
structures. What you want is laminar air, which will reli-
ably spin the turbine.”
“Wind speeds can also be established by consulting wind
maps or taking measurements with anemometers,” adds
Schneider. Either way, you need this data to right-size your
turbine and optimize its location.
A Collaborative Technology
Owners who want to significantly supplement a portion of their energy needs are unlikely to hit the mark with
these diminutive turbines alone – this solution is best to
implement when you want to diversify your renewable
“Wind and solar go hand in hand,” Schneider says. “Sun
is great during the day and in the summer months, but it’s
also windier at night and during the winter season. These
technologies are complementary and one can pick up the
slack when the other is less available.”
“The combination of wind and solar can also address
specific site conditions,” Gilchrist adds. “Say you have a tall
building in a northern latitude where sunshine is incon-
sistent. The height of the building contributes to the wind
siting and can pick up the slack for power generation when
there’s cloud coverage.”
Look for Financing Options
To help recoup a portion of your capital expenses, make
sure to apply for the Federal Investor Tax Credit. Small
wind turbines under 100 kilowatts that have been in service
since December 2008 qualify. The credit is equal to 30% of
expenditures and will be available to owners through 2016.
Already common with solar, PPAs (power purchase
agreements) are also gaining traction with wind installations,
Hilton Worldwide wanted to at- tract green-minded customers to its resorts for personal lodging and events. Taking advantage of
Fort Lauderdale’s strong coastal winds
and the building’s 26-story height, the
hotel installed six building-integrated
turbines on its roof.
The 4 k W turbines stand approximately 52 feet tall and are
strategically positioned on each corner and the center of the
hotel’s rooftop to capture maximum wind velocity. The VAWTs are
projected to produce 24,000 k Wh, which supplements 5-10% of
the resort’s energy needs.
At an investment cost of over $500,000, annual savings will be
between $25,000-$50,000 with a payback of 10-20 years. The
turbines are also expected to offset 70,000 pounds of carbon annually. Plans are underway to combine the installation with solar.
“The turbines will help us visualize the hotel as a place to be
conscious of energy use. They will help to highlight the importance of conserving electricity and start dialogue,” says Randy
Gaines, vice president of engineering for Hilton Worldwide.
INFORMATION COUR TESY OF UGE AND HILTON FOR T LAUDERDALE BEACH RESOR T;
IMAGE PROVIDED BY UGE
HILTON FORT LAUDERDALE BEACH RESORT
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