July-August 2009

Architectural Wind

Logan Airport and Maui Ocean Center find small and beautiful energy where tall and functional doesn't fit.

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A new category of wind turbines has turned all the rules of onsite wind power upside down. Welcome to the world of “architectural wind,” where tall mounting poles are out, slick design is in, and making a publicly visible aesthetic element is just as important as energy output.

Architectural wind is the new contender in the renewable energy arena. It’s based upon small, modular wind turbines designed to take advantage of a building’s aerodynamics, while contributing a visually aesthetic “designed-to-be-green” statement. In terms of qualifying as distributed energy, their integration with a building makes it hard to find a better example. If installations such as AeroVironment’s project at Logan Airport are any indication, the marketplace for small wind is ready for some solid growth.

In June 2008, AeroVironment commissioned a group of 20 turbines at Boston’s Logan International Airport Office Center as part of a project for the Massachusetts Port Authority (Massport). The project represents one of the highest profile examples of this new trend and garnered top positions in articles published by the New York Times and USA Today, and many more local media outlets.

The Look Is Definitely a Plus
Curiosity from visitors and other airports is just as strong, according to Terry Civic, manager of utilities for the Massport, which includes Logan International Airport and the Port of Boston. “There’s more interest than we had anticipated, and the response we’ve been hearing is overwhelmingly positive from both the community and others in the energy industry and airport management,” says Civic.

Photo: Courtesy of Massachusetts Port Authority AeroVironment commissioned a group of 20 turbines at Boston’s Logan International Airport Office Center

Not surprisingly, much of the enthusiasm comes from the turbine’s appearance. “I think the look is definitely a plus,” says Civic. “For this kind of urban application, neighbors want to see a positive investment in the environment and want to see us moving in that direction.”

Professor Richard Wlezien, chair of Tufts School of Engineering’s mechanical engineering department agrees. Wlezien teaches a course on wind energy and is developing a project with students at Tufts that looks at wind turbine design. “I think the time is coming for artists and architects to get involved when you start thinking of things that really fit into the urban environment,” he says. “It’s a holistic approach, and though it’s just the beginning stages, there’s a big difference between having the first turbine in a city and having one on every building.”

Wlezien predicts that city ordinances will have a strong impact. “I have a home in Southern Virginia, and they have very strict requirements,” he explains. “For example, the city requires that home air conditioning units have to be hidden from the street, and it won't be long before we start getting such rules in wind energy. If we’re proactive about it as a community and start solving the problem before it becomes an issue, we won’t have to end up fighting with restrictive rules.”

Civic describes Logan’s installation as something aesthetic and “…much different than a giant 40-foot pole in somebody’s backyard.”

But actually, it’s more like 20, 8-foot fans tipping, in what looks to be a precarious angle, on the edge of the building. That angle and the patented design of the system on a building are responsible for a surprisingly high degree of performance. With proper placement and tilt, the turbines capture the acceleration in wind speed caused by the building’s aerodynamic properties. AeroVironment’s turbines use the accelerated wind to bolster electrical power generation by more than 50%, as compared to the power generation from systems located outside of the acceleration zone.

According to Paul Glenney, director of AeroVironment’s clean energy technology center, Logan’s Airport Office Center has the right proportions and the right location for a rooftop wind system. “These low-profile big box buildings have a lot more surface area,” says Glenney. “But if you look at a high-rise building, the energy density [and demand] in that footprint is very high and putting wind turbines on top of tall buildings will create some energy, but you need to do a lot more. The low-profile buildings are great, because not only can you find a parapet or wall with room for lots of wind turbines, but you can add photovoltaics or some other complementary renewable energy.”

Airports Seeking Energy Efficiency Answers
The turbines create a lively pattern of movement on Logan’s building, but attractive wind power wasn’t at the top of Massport’s list when Civic and the team went looking for ways to reduce their greenhouse gas footprint. There was an interest in renewable energy as one of the methods, but tall wind poles at an airport didn’t make sense, so the obvious options appeared to be solar or fuel cells, until the team attended a demonstration of the AeroVironment technology in California. “We were intrigued by their design,” recalls Civic. “Because of the airport’s circumstances the rooftop turbines were a great fit. But what was important was that airports like Logan are very concerned with the environment and keeping operations well managed in that area.”

In fact, airports are something of a high-profile case in terms of carbon emissions. According to the Air Transport Association, US airlines emitted about 418 million pounds of carbon dioxide in 2007. Moreover, a study released by the Clean Airport Partnership revealed that just the sheer volume of airports represents huge opportunities for energy efficiency improvements. Nationally, commercial airports own or manage millions of square feet of building space.

So, it’s not surprising that the installation of the turbines at Logan Airport is just one of the many initiatives targeted at exceeding national standards for energy efficiency. In fact, Logan International made history as the nation’s first airport terminal awarded Gold Level certification for Leadership in Energy and Environmental Design (LEED) by the US Green Building Council.

That status, plus the visual statement made by the turbines, was just as important as the economics of the system. Nonetheless, the project had to make sense financially. In May and June, the turbines generated just 1,430 kWh, but Massport’s plan doesn’t anticipate a high volume of power generation until the winter months, because the turbines are positioned to catch the prevailing winds on the north side of the building. Those winds are at their highest from October to April. “The turbines have been fairly quiet in the summer,” says Civic. “But we weren’t expecting summer to be a highly productive time. We were hoping at the high end to see just under 100,000 kWh per year, and the low end would be about 60,000 kWh per year, over a range of 10 to 15 years.”

Photo: Courtesy of Massachusetts Port Authority AeroVironment’s turbines use the accelerated wind to bolster electrical power generation by more than 50%, as compared to the power generation from systems located outside the acceleration zone.

The building consumes about 2.6 million kWh, and that was before a new data server room was completed. At a production rate of 100,000 kWh annually, the turbines would supply about 3% of the building’s energy needs. Cost of the project was estimated at $140,000 by AeroVironment management.

“The cost was a consideration and ran about $6,500 to $7,500 per turbine, but that’s not an outrageous sum for a demonstration project,” says Civic. In reality, all 10 of AeroVironment’s installations could be referred to as demonstration projects.

State Data Requirements Affect Rebates
Glenney notes that the company is in a low rate of initial production on its turbines and is considering another dozen installation in the next few months. “The biggest decision point for the business is in the process of generating data to qualify for rebates with energy commissions in states such as California, New York, and New Jersey,” he explains. “They all require a year’s worth of records, and we just started our data gathering in February. So, by March of next year, we will have enough performance data to make a decision.”

The measured pace has created somewhat of an exclusive position for AeroVironment’s demonstration sites that include: the new Kettle Foods potato chip factory in Beloit, WI; Laughlin Air Force Base near Del Rio, TX; the St. Louis County Government Service Center; and the newest addition to the group—the Maui Ocean Center Wind Turbine Project.

Like most of the AeroVironment installations, the Maui Ocean Center has some creative funding behind it. In this case, it’s a partnership between Maui Ocean Center, AeroVironment, and Maui Electric Company, with the support of the County of Maui.

According to Kate Zolezzi, general manager of the Maui Ocean Center, AeroVironment provided the shipping and installation, and Maui Electric Company contributed funds just to see if the technology could find a high level of adoption on the island.

Zolezzi was more than grateful for the funding, because she had been looking for a renewable energy resource for several years. Maui has both abundant sun and wind, but the center’s buildings would require modifications to support rooftop photovoltaic panels, and the center has pumps and other mechanical systems that run all the time, so solar wouldn’t be as efficient as the winds that can also run constantly.

Working Around Height Restrictions
Another consideration was the center’s location in a designated “special management area” and “shoreline view corridor.” “We have to take into account our county codes and height restrictions,” says Zolezzi. “AeroVironment’s turbines moved to the forefront, because even with their canopies they are only about eight-and-a-half-feet tall. So, we have the perfect location and the units allowed us to stay within our height requirement.”

As for their appearance and quiet operation (50 decibels of wind noise), Zolezzi shares the same enthusiasm as Civic. “They enhance the building, and the curb appeal was certainly one of the reasons we chose AeroVironment," she says. "They do add to the look of what is basically a block wall.”

In fact, Zolezzi is already anticipating how another six of the turbines would look, and how their power output could further reduce the center’s dependence upon Maui Electric. “The utility is allowed to pass through 100% of fuel oil adjustments and fuel oil is used to generate electricity here in Hawaii. Our monthly bill could be as much as $80,000, and it’s not uncommon for more than half of it to be attributed to a fuel oil adjustment charge.”

Based on AeroVironment’s site analysis, the company estimated an optimal production of 48,800 kWh per year, but Zolezzi says the center is staying conservative and estimating about half of that. The center is located in a valley between two large mountains that make for a tendency to funnel and accelerate the wind. With the inverter connected directly to the center’s grid, all of that wind power is consumed by support operations. “We would love to take advantage of net metering, but this site isn’t big enough,” she explains.

Payback As Low As Three to Four Years
Nonetheless, Zolezzi considers the investment and estimated payback of three to four years (depending on the rise and fall of utility rates) as very good, especially when compared to photovoltaic systems that didn’t match the turbines’ economics, even with tax rebates and credits. “Based upon the performance, we could envision what another six would look like lined up around the parapet of a building or wall,” she says. “I would like to think that we would get at least one more set of six as, we are testing this product and the company for their ability to maintain and service the product over quite a distance.”

Photo: Courtesy of Massachusetts Port Authority Customers, such as Massport and the Maui Ocean Center, are enjoying the renewable energy benefits and the publicity that the turbines generate regarding their carbon reduction efforts.

As in the case of Logan Airport, AeroVironment provided a monitoring system for the turbines and for the center. It’s a touch screen kiosk installed at one of exhibit areas. Visitors can monitor the turbines and the weather conditions to see temperature and humidity, plus, the current power output or past performance. “We really wanted the educational component,” says Zolezzi. “We have a lot of visitors with a lot of questions, so this makes it easy to disseminate accurate information.” Not surprisingly, the information leans to the green by highlighting the impact of a kilowatt-hour upon carbon emissions and the equivalent number of cars that the renewable energy can displace.

Such benefits have made Zolezzi so enthusiastic, that she has lobbied AeroVironment to build a higher output turbine. But Glenney doesn’t see a higher output product in the near future.

“There is no plan for producing over one kilowatt right now, because, in the early days, we traveled all over the country and in the UK and looked at buildings, and the shape and scale that can work with architects and green building specialists,” recalls Glenney. “We really felt that a wind turbine couldn’t be much bigger than this, and be on the building and still look right. So, for now, we are set on the size, but the important question is how to install it cheaper and reduce the
overall cost.”

Photos: Courtesy of Maui Ocean Center Maui has both abundant sun and wind, but the center’s buildings required modifications to support rooftop photovoltaic panels.

Visitors can monitor the turbines and the weather conditions to see temperature and humidity, plus the current power output or past performance.

At a cost of roughly $6,500 to $7,500 per unit, AeroVironment’s architectural wind product would seem to sit comfortably with comparable options in the market. But Glenney remains cautious about predictions of the category truly going mainstream. “There’s a lot of issues to qualifying a wind site, and, regarding the payback, we think we can do a lot of business with early adopters who may overlook a quick return, because a longer payback is adequate for an early technology demonstrator.”

But beyond the early adopters, AeroVironment’s ultimate target is the mass market, and Glenney expects more research and development to fine-tune their economic value proposition.

Fine-tuning doesn’t seem to detour customers such as Massport and the Maui Ocean Center, and they are more than just enjoying the renewable energy benefits and the publicity the turbines generate regarding their carbon reduction efforts. These organizations have demonstrated that there is a solid market for doing a lot of business with early adopters that don’t demand a quick return. But will their business be enough to carry the category into mainstream status?

Wlezien sees one point of evidence to support the marketplace. “We’re seeing a tremendous amount of excitement in universities,” notes Wlezien. “I’m teaching a graduate course in wind engineering, and such a course at Tufts would typically have about 10 students, yet I have 37 signed up for my course. So the demand and excitement is huge and the time is right for this kind of growth.”      

Author's Bio: Ed Ritchie is a writer specializing in energy, transportation, and communication technologies.