When Christina Cassotis, the chief executive of Pittsburgh International Airport, heard about the power outage that forced London’s Heathrow Airport to suspend operations last week, she thought of the workers who were frantically trying to manage the chaos.
But when an outage hits closer to home, she has a more restrained response: Keep calm and carry on.
For almost four years, her airport has been powered by a mix of on-site natural gas generators and solar panels. The airport estimates that the stand-alone system, known as a microgrid, has saved it about $1 million a year on its energy costs and allowed it to use the electric grid as a backup, Ms. Cassotis said.
“We did it because we wanted resiliency and redundancy,” she said. “Airports are critical transportation infrastructure. We should be able to operate no matter what.”
That level of energy independence is rare, especially among larger airports.
Many airports have backup generators to help them maintain critical functions like air traffic control and lighting during power outages. But those standard emergency measures have limitations. They may require refueling if an outage lasts for many hours or days, for example. That’s why most airports remain heavily reliant on external power to keep passengers and planes moving.
But U.S. airports are increasingly experimenting with generating and storing electricity on site — typically with solar power and batteries — to curb carbon emissions, prepare for future electricity needs, and manage rising disruptions caused by climate change and aging infrastructure.
Denver International Airport has multiple connections to the grid in case one fails, but it recently also put in place a solar-powered battery storage system to keep its underground trains running in an emergency. At New York’s Kennedy International Airport, a $19 billion overhaul includes plans to install thousands of solar panels and batteries to cut emissions and keep its new Terminal 1, which is expected to open in 2026, running during outages that can be very disruptive and costly for airports and everyone who relies on them.
“If you have a reliable, effective airport, you’re helping to support economic resiliency,” said Joey Cathcart, a sustainable aviation expert at RMI, a sustainability nonprofit in Colorado previously known as the Rocky Mountain Institute. He and his colleagues have helped to develop a federally funded guide for airports interested in microgrids like the one in Pittsburgh.
Power outages at airports are more common than many officials would like. A 2023 Government Accountability Office report identified 321 outages that lasted at least five minutes at two dozen U.S. airports from 2015 to 2022. Airports and other infrastructure, such as the electric grid itself, are also increasingly under threat by natural disasters, many of which are linked to climate change. The number of storms and other weather events that caused at least $1 billion in damage has steadily risen in recent decades, from five in 2000 to 27 last year, according to the National Centers for Environmental Information, a part of the U.S. Commerce Department.
In late 2017, an electrical fire caused a power outage at Hartsfield-Jackson Atlanta International Airport, disrupting flights nationwide and costing Delta Air Lines, the largest airline at the airport, tens of millions of dollars. That and other outages prompted Ms. Cassotis to ask her team to look into microgrids.
“We basically just started the process of investigating,” she said. “Can we even have one?”
The airport, which sits on the natural gas deposits of the Marcellus Shale, solicited proposals to design, build and operate a microgrid at no upfront cost to the airport. By July 2021, the microgrid was up and running. Today, it produces 23 megawatts of energy: three from a solar array on top of an old landfill and the rest from five natural gas generators. At peak demand, the airport, which served nearly 10 million passengers last year, only uses about 14 megawatts, selling the excess to the grid.
Establishing the microgrid, which is owned by two energy companies, has already paid off for the airport, which locked in low electricity rates for years and has cut carbon emissions by more than six million pounds annually, Ms. Cassotis said.
It has also spared the airport from disruptions. Heathrow’s closure on March 21 disrupted global travel, leading to more than 1,000 canceled flights and stranding thousands of passengers. It began with a fire at an electric substation and, weeks earlier, something similar happened near Pittsburgh’s airport, according to Ms. Cassotis. Fires near substations had disrupted some of the power feeds to the airport. The airport disconnected those feeds to prevent problems from spreading to its microgrid and continued operating as usual.
“There’s an actual tangible value in terms of dollars saved,” Ms. Cassotis said. “And then there is the peace of mind.”
Resilience isn’t the only reason that airports might want to generate and store electricity on site.
Aviation accounts for 2 to 3 percent of global emissions and is a particularly difficult industry to decarbonize because there are few emission-free alternatives for jet fuel. Setting up arrays of solar panels, like the thousands that the Denver airport has already installed or those coming to J.F.K., can help reduce an airport’s carbon footprint. They can also help to supplement rising energy needs as airport vehicles, shuttles, rental cars and, eventually, small aircraft shift to battery power.
Denver’s airport is served by two dedicated electric substations, each of which can power the whole facility, providing redundancy in an emergency, according to Scott Morrissey, senior vice president of sustainability at the airport. The airport also has backup generators.
“Once we have all of these sources electrified, we want to make sure that that electricity supply is as reliable and resilient as it can be,” he said.
The Port Authority of New York and New Jersey, which oversees J.F.K and the other two large airports serving the New York region, is also pairing sustainability with resilience. At Kennedy, which also has redundant power sources and generators, Terminal 1 will include a massive array of rooftop solar panels, fuel cells and batteries.
“To not have to deal with that disruption is obviously very advantageous from a business continuity perspective,” said Jessica Forse, the lead project manager overseeing a broader airport overhaul, which includes the terminal revamp. “In a large, international airport — Heathrow, J.F.K. — those disruptions are seen everywhere. They ripple broadly across the airspace, domestically and internationally.”
For now, such ambitious projects are limited, but interest is rising. The Federal Aviation Administration has provided airports grants to explore such options. Airport officials have also been seeking advice from Ms. Cassotis and others who were early in adopting solar panels and microgrids.
“As this market has developed over time, there’s a range of options that should work for different types and sizes of airports,” said Lauren Shwisberg, who leads research and projects aimed at switching to less carbon-intensive electricity at RMI.
