A fleet of miniature wind turbines at Boston Logan International Airport have perhaps the best view of the city, overlooking the downtown skyline across the expansive harbor as commercial jets descend overhead.
Each 6-foot-tall turbine, placed at the edge of the rooftop of the airport's headquarters, is affixed at a unique angle to capture the winds that gust through Boston Harbor and climb the building's walls.
The 20 turbines, installed in July, are expected to generate about 100,000 kilowatt-hours annually, equal to 3% of the building's energy needs.
"There's a clean flow of air coming off the harbor toward the building," says Steven Gitlin, a marketing executive at AeroVironment, a California company that worked on the $140,000 project. "The turbines are uniquely created for the urban environment. And it makes a lot of sense for airports that want to reduce their carbon footprint."
Logan's turbines are one of the most visible examples of the environmentally friendly initiatives being embraced by major U.S. airports. From low-flush toilets and hybrid taxis to solar panels and recycled coffee grounds, some of the largest airports are aggressively implementing green measures to save on energy costs and to generate favorable impressions among travelers.
Airports have always had to comply with certain environmental regulations arising out of their operations, as local governments require impact studies on new construction projects and soundproofing nearby homes. Landings and takeoffs, as well as the diesel shuttles that circle the terminal roads, leave thousands of tons of toxic emissions in a compact area of the city. And for years, many airports have been slow to adopt measures that go beyond the minimum requirements, says Steve Howards of consulting firm Clean Airport Partnership.
U.S. airlines emitted about 418 billion pounds of carbon dioxide in 2007, according to the Air Transport Association, the airline industry trade group.
"Airports have been spending hundreds of millions in terminal facilities that are aesthetically pleasing but aren't designed to conserve energy," he says. "Because of the precarious situation in airlines, airports require quick return on investment. Sometimes the return on investment on these (environmental) projects is not quick enough for the airport."
But like many other industries, airports are embracing the green zeitgeist, triggered partly by better social awareness and improving technology, and made more urgent by rising fuel prices. "If you're watching oil prices, it gives you more incentive for somebody like us to look at pilot programs for energy savings," says Sam Sleiman, Boston Logan's director of capital programs and environmental affairs. "The perception is that airports are pollutants, and we wanted to change the perception."
Some efforts aren't new
Some green efforts have been around for years. On-site compressed natural gas fueling stations, glass walls for more natural light, electrical connections at aircraft gates, lower-wattage bulbs, recycled building materials and water-conserving vegetation are standard environmental practices at many airports.
The more progressive airports are eagerly taking on other experimental and innovative green projects. Some projects, such as switching to more efficient light bulbs, require little or no investment. Others — such as efficient HVAC systems and installing electrification systems at gates — are costly projects that are funded with their own operations budgets, government grants or as part of new construction costs.
Here's a closer look at some:
Some airports have large plots of land that they are devoting to experiment with alternative energy. Denver International and Fresno Yosemite recently installed solar panels in their backyards in hopes of generating enough energy to save on their electricity bills.
In Denver's case, it's 9,200 panels, each equipped with sensors and measuring 3 feet by 5 feet. Each rotates on an axis as it follows the sun. The panels will generate about 3 million kilowatt hours of electricity a year, the equivalent of about half the energy used to run the airport's people-mover rail system, says Matt Cheney, CEO of MMA Renewable Ventures, which owns and operates the panels.
The airport didn't have to chip in for the $15 million cost, but its land contribution entitled it to energy credits with a local utility company.
Fresno Yosemite's 11,700 solar panels, installed in July, could provide up to 40% of the airport facilities' daily electrical needs, the airport says.
Boston officials' initial plans to experiment with wind power were stymied by the difficulty finding turbines that were small enough to fit on its lots, Sleiman says. It eventually turned to Monrovia, Calif.-based AeroVironment, which has been installing rooftop turbines on commercial buildings and was eager to deploy them at a large airport.
Since introducing its product at Logan, AeroVironment has received expressions of interest from other large airports, Gitlin says.
Some green measures require little capital investment and are aimed more at changing business practices. Seattle-Tacoma, the home airport for Starbucks' headquarters, requires all coffee grounds served by concessions, about 143 tons a year, to be recycled and trucked to a local facility for composting. "None of us imagined that it'd be of this magnitude," says Elizabeth Leavitt, the airport's director of environmental programs.
The airport also will install garbage and recycling compactors later in the fall and will begin weighing trash and charging concessionaires by the pound for removal. The airport will not charge for hauling recycled waste.
Denver, which will begin a composting trial in January for biodegradable wastes, already has 22 streams of trash collection and recycling. Last year, it collected more than 104,000 pounds of cooking oil that was reused for biodiesel fuel and manufacturing pet foods.
Denver has also found a way to reuse its bountiful snow and de-icing fluid used on aircraft during harsh winter conditions. The airport collected about 70% of the 1.8 million gallons of de-icing fluids used last year and mixed some of it with melted snow. The mixed fluid, which is piped to an on-site collection pond, is then reused as antifreeze or flushing fluids in toilets.
Minneapolis-St. Paul has spent $150 million in storm water management and de-icing-fluid recycling, including five large de-icing pads that are about 15 acres each.
Prodded by rules and financial incentives, a growing number of airports are banning diesel shuttles and urging taxi companies to buy more alternative-fuel vehicles.
Mineta San Jose says it has fully converted all of its 34 shuttles to run on compressed natural gas and has eliminated the use of more than 1.3 million gallons of diesel fuel since 2003.
Boston also encourages cleaner driving for passengers by providing preferred parking to those who drive to the airport in hybrid cars. It also doles out front-of-the-line privileges up to two times a day for taxis with cleaner fuel, a program modeled after one at San Francisco International.
"There are too many rental-car or hotel shuttles at airports with just two or three passengers in them," Howards says. "They're traveling billboards."
Green practices are also seeping into the airfield. Boston Logan will be the first U.S. airport to reduce toxic emissions by using runway asphalt heated at a lower temperature — 250 to 275 degrees, up to 75 degrees lower than is required for traditional "hot mix" asphalt.
Logan's Sleiman says warm mix uses 20% less energy to make, produces 20% fewer greenhouse emissions when applied and lets the airport use a higher percentage of recycled asphalt pavement in the final product. If the asphalt performs as expected, the airport will use it for future paving projects, he says.
Meanwhile, gate electrification is becoming an industry standard practice. Each gate is equipped with a 400-hertz electrical connection that allows parked aircraft to shut off the engine, thus saving jet fuel, and still run lighting and other avionics. Another practice of saving jet fuel at gates that is growing in popularity is to pump in preconditioned air from the terminal to the aircraft. Large tubes extend from the terminal to the aircraft belly, delivering air conditioning to passengers so that the aircraft's air conditioning systems can be turned off.
Boston Logan has the first LEED-certified terminal in the USA, a recognition awarded by the U.S. Green Building Council for constructions that follow its criteria of energy-saving measures. About 20% of the materials used to build Terminal A in 2001 were locally manufactured. It also features sensors that turn off lights at unoccupied gates, large and airy glass walls that reduce the need for lighting and heating, low-flush toilets and a roof that was painted in white to better reflect the sunlight.
Atlanta's Hartsfield-Jackson is also in the midst of a restroom upgrade aimed at conserving water. It's installing new toilets that use 1.28 gallons of water per flush vs. 1.6 gallons used by the current units. It also recently completed refitting men's urinals to use just half a gallon per flush, compared with one gallon in previous models.
Airport authorities estimate the changes will save 44 million gallons of water a year, a reduction of 13% in airport water usage. They had considered waterless urinals, but found that they might not be popular with travelers. They smelled.