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 reliably 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.
Lincoln Financial Field
Lincoln Financial Field, home of the Philadelphia Eagles, is the first professional stadium in the U.S. capable of generating all of its electricity on-site.
The combination of 14 turbines and solar panels is projected to produce about six times the amount of power used during all Eagles home games on an annual basis. On non-game days, both renewables will offset 100% of all energy use, and any excess power can be fed back into the grid.
Located at opposing ends of the field, the turbines were strategically placed to provide “a visual representation of our commitment to sustainable efforts,” says Eagles president Don Smolenski. The system was also designed so that it doesn’t interfere with the fan experience. A custom braking system will ensure immediate stoppage if ever necessary.
INFORMATION AND IMAGES COURTESY OF UGE
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 portfolio.
“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 inconsistent. The height of the building contributes to the wind siting and can pick up the slack for power generation when there’s cloud coverage.”
YMCA Storer Camps
The serene setting of the YMCA Storer Camps will soon be home to a vertical axis turbine.
Located in Jackson, MI, the rural campus is composed of a large dining hall, lodges and cabins, a nature center, and various outbuildings. Plans are underway to turn the camp into a net-zero site. A vertical axis turbine was specified for its quiet operation, safety for wildlife, and low profile.
The power purchase agreement (PPA) for the equipment eliminates upfront, installation, and maintenance costs. The YMCA will save on operating costs from day one, only purchasing the electricity generated at a discount from what it currently pays the utility.
“When we’re done with our vision, we’ll have a 450-bed campus that uses less energy than is generated on-site,” says Glen King, chief development officer for YMCA. “By having renewable sources like wind, geothermal, solar, and biomass at our camp, we will provide a total immersion learning environment to show real-world examples of environmental stewardship and sustainable energy.”
INFORMATION AND IMAGE COURTESY OF CGE ENERGY
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, says Schneider. These contracts allow property managers to avoid buying a turbine outright and simply pay for the electricity it generates.
Also ask your utility about net metering, an option that gives your facility credits when you have excess clean energy you can put back onto the grid. Otherwise any power you can use will go to waste or you’ll pay an avoided rate that eats into your ROI. Not every provider allows this type of arrangement, notes Gilchrist, and you may need to upgrade your connections to enable this functionality.
So is a vertical axis turbine a match for your facility? As performance data can be hard to verify given the limited amount of commercial applications, risk-averse FMs may not feel comfortable with this option. It’s worth noting that the Small Wind Certification Council, an independent accreditation body, has not yet certified any building-integrated turbines. The organization verifies energy output, rated power, sound level, durability, and safety according to industry standards set by the American Wind Energy Association. The good news is that several VAWT models have pending applications, showing promise that the technology is edging forward.
If a traditional wind turbine is out of the question, vertical axis models remain your next best option to turn a stiff breeze into renewable energy. Their installation flexibility and small profile can adapt to urban locations where real estate is tight but wind is plentiful.
Pearson Square Court and Bridge Street Apartments
In Long Island City, Queens, three vertical-axis turbines grace the top of the Pearson Square Court apartment building. Installed in May 2014 and projected to generate 9.6 kWh, the turbines produce power that offsets the common areas in the building, including the lobby, hallways, gym, and roof lounge.
At the 388 Bridge Street apartment complex in downtown Brooklyn, two turbines can be seen spinning atop the building from the Long Island Expressway and surrounding streets.
Before these installations were set in motion, UGE conducted a site analysis to evaluate which renewable energy solutions would generate the optimal amount of electricity. The turbines’ helical structure was determined to be well suited to extract energy from winds in urban settings, which tend to come from many directions. Both projects have unobstructed locations for the turbines to gain maximum winds.
INFORMATION AND IMAGES COURTESY OF UGE
Jennie Morton email@example.com is senior editor of BUILDINGS.