When city commissioners in Tallahassee, Fla., passed a resolution in early 2019 to rely exclusively on renewable energy by 2050, one cornerstone was already in place: a 120-acre, 20-megawatt solar farm at Tallahassee International Airport.
The solar arrays had been installed just over a year earlier by a private developer in an effort to combat climate change and curtail emissions. An additional 330 acres producing 42 megawatts came online in late 2019, supplying solar power to more than 100 municipal buildings, including City Hall, the airport terminal and a sewage treatment plant.
“We were thinking we would do less, because land was limited,” said Reese Goad, the Tallahassee city manager. “It’s difficult to find land in an urban setting.” But the airport provided city officials with a parcel of undeveloped land that also allowed for connection to the grid.
As the country considers its carbon footprint and alternative energy sources, the nation’s airports are turning their unused land, roofs and parking garages into solar farms. Twenty percent of public airports have adopted solar power in the last decade, according to a study last year at the University of Colorado.
Despite the interest, challenges still remain: Adoption is limited and varies by location, and officials can encounter environmental and bureaucratic hurdles. But airports are required by law to be financially self-sufficient, and the prospect of earning extra revenue is a powerful draw for governments.
“It’s an addition to the power grid, a revenue generator and energy for the airport itself,” said Peter J. Kirsch, a lawyer at Kaplan, Kirsch & Rockwell in Denver whose practice focuses on regulation and transportation infrastructure. “Airports are enormous users of power, and any effort to rely on renewable energy sources in lieu of traditional carbon-based ones will create a positive community reaction.”
Community solar programs, which allow some utility customers to buy solar power instead of using traditional fossil fuel, are in place at airports in Tallahassee; Tampa, Fla.; and Austin, Texas, among others. At Kennedy International Airport, a planned solar array is expected to be the largest in New York State when it is completed next year. These efforts give renters and those with limited means the ability to shift to clean energy.
Some airports, like San Francisco’s, use municipal bonds to finance the installation of solar farms, but most typically enter into a power purchase agreement with a third-party energy provider, which owns and operates an energy system after it is installed on the airport’s property.
“The government incentivizes development of renewable energy, such as solar and wind, through the use of tax credits and accelerated depreciation,” said Miriam S. Wrobel, a senior managing director at FTI Consulting in San Francisco. “Often, public entities such as airports cannot utilize the tax benefits, so third parties own the assets and sell the energy generated to the airport.”
Prices are locked for 20 to 25 years, but the owner gets paid only when the energy is flowing.
The bid for the Tallahassee project was won by Origis Energy, a Miami firm that offers clean energy storage solutions. Johan Vanhee, Origis’s chief commercial officer, said the airport project was a departure for the company. “We are a wholesale generator of renewable energy,” he said. “Ninety-nine percent of our plants are not on airports.”
But experts say the decreasing price of solar modules and the Infrastructure Investment and Jobs Act allocating $25 billion to airports may alter the percentage.
A decade ago, a module alone cost around $2.50 per watt, and now an entire utility-scale photovoltaic system costs around $1 per watt, said David J. Feldman, a senior financial analyst in Washington for the National Renewable Energy Laboratory, a research center based in Golden, Colo., and funded by the Energy Department.
“Solar costs have come down significantly in the last decade,” said Alicen Kandt, senior engineer at the National Renewable Energy Lab. “It becomes appealing in areas that may seem less than ideal.”
One of those overlooked locations is Maine, where a solar project proposed for Augusta State Airport is expected to provide 7.5 megawatts of capacity, all of it returned to the grid.
“It’s open space, no hazard to anybody, the state owns it, and it helps taxpayers and the environment,” Paul Merrill, a spokesman for Maine’s Department of Transportation, said of the project, which is expected to save the state $6 million over 20 years.
But there is resistance. At a recent city meeting, several elected representatives expressed reservations about the impact the project would have on a city recreation area. Mr. Merrill said the state was working with the city to get approval for a local permit and easement.
And Evergy, the utility that serves Kansas City, Mo., scrapped plans last year for an airport solar array after an engineering study found design problems. A 5-megawatt array was proposed to be built atop a new parking garage, part of a terminal renovation costing $1.5 billion, but the garage is between the air traffic control tower and the runway, and at times glare obscured the view of air traffic controllers.
Now, Brian Platt, the city manager, has more ambitious plans. Approximately 5,000 acres of the 11,000-acre airport are undeveloped, and a feasibility study is underway to see how much can be used for solar arrays. “We’re looking to power the entire city,” he said.
The Federal Aviation Administration provides guidance for evaluating solar technology for airports. In May, the agency streamlined its process evaluating glint and glare, allowing airports to evaluate potential impact to a control tower.
Austin International Airport, which previously installed 84 kilowatts of solar power in the cargo area and 27 kilowatts in the taxi area, recently added more than 6,600 solar panels on a garage roof. Airport officials entered into a 25-year power purchase agreement with the North American subsidiary of the French multinational company Engie when they realized installing solar panels on the roof instead of steel would cost $2.7 million, saving the airport $1.5 million.
“Solar is cheaper than steel,” said Tim Harvey, a customer renewable solutions manager at Austin Energy, the city’s utility, which signed a power purchase agreement with Engie. A separate agreement between Austin Energy and the airport allocates 300 kilowatts’ worth of renewable energy credits to the airport.
Through a community program, the deal provides power for 425 Austin Energy customers, fewer than 1 percent of the utility’s base. But advocates say size may not be the point.
“Some of the solutions may not provide a large amount of energy but still show a responsibility by the airport to do what they can to mitigate the burning of fossil fuels if they install solar,” said Jorge Barrero, a regional design director in Chicago at HKS, a global design firm based in Dallas.