They may not be skyscrapers for light, but the new patches of rooftops in major airports across the country are starting to look like a green alternative to shrinking parking lots.
But there’s a catch: The shade helps protect our planes from light pollution, especially high-powered sunlight in winter when the sun only shines through the thick walls of aircraft shelters. Some of the sunscreens are listed under the Federal Aviation Administration’s standards for preventing light pollution, but while they appear safe, they can still interfere with cockpit instruments.
To deal with the problem, new and small airports across the U.S. are dipping into their general aviation budgets to build hundreds of solar-powered installations — called “solar gardens” in airport jargon — on top of passenger terminal roofs.
Relying on utilities rather than municipalities to provide power is a key difference between solar gardens at airports and rooftop panels already installed on private homes: They’re free of operating costs and don’t require local officials to pick up the tab.
However, that could change if lawmakers pass a bill recently introduced in Congress. The measure would require the Federal Aviation Administration to support an effort by the nation’s cities to create a single federal standard for solar gardens.
“This legislation moves us closer to the sort of interstate highways for power that we see for electricity,” said Rep. Pete King, a Republican from New York who introduced the bill last month.
The bill would only allow solar gardens at airports that are at least 150 feet from an airport’s perimeter.
Why airports? According to King, who has pushed for the project since 2012, airports offer valuable real estate and an easily accessible location for the community-minded project.
“If you got a lot of commercial airline passenger flights at an airport in the northeast, you could have over 100 megawatts of solar panels over the entire terminal,” he said. “That’s a big investment in terms of a general aviation airport.”
The news comes at a time when airport operators are looking for ways to improve business. Nearly 30 percent of the 135 airports in the U.S. saw traffic drop last year compared to 2011, a recent report by the Airports Council International-North America found.
There’s also a growing demand from commercial landlords who view solar gardens as a valuable source of energy. Alexandria Development Corp., a commercial real estate developer headquartered in McLean, Va., has applied for federal permitting for its 14,500-square-foot solar farm, expected to be complete by the end of the year.
Across the country, there are more than 100 solar gardens at airports, including a 100-panel array recently installed on the roof of the Heathrow Airport’s Terminal 5, a mile from the runway, according to Genscape, an energy and resource consultancy.
It took a little work to get the Heathrow permit. Part of it was drafting an FAA-approved waiver that the airport used when constructing its new terminal and additional flights that relocated in 2010. That meant the tower operations team had to download software built by Genscape on an iPad.
In the end, the plane could see through the veil of darkness on the roof. But the thermometer didn’t read zero, Genscape’s Ephrem Sabet said.
“The roofs will retain a healthy amount of solar radiation,” Sabet said. “The terminal facilities team will be able to harvest the solar energy to meet their needs.”