The Port of Seattle is moving to make Seattle-Tacoma International Airport more sustainable with a proposal to become the first U.S. airport heated entirely by renewable natural gas.
Last month the Port issued a request for proposals seeking renewable natural gas service for the airport’s boilers and its bus fueling system. Those two uses account for more than 80 percent of the Port’s natural gas emissions. If implemented, the project would replace all fossil natural gas currently used for those systems with renewable natural gas.
Renewable natural gas, also called biomethane, is produced when organic material decomposes. Common sources include landfills, wastewater treatment facilities, and digesters that process food or agricultural waste. By capturing and upgrading that methane, renewable natural gas provides a low-carbon alternative to conventional natural gas.
“The Port can play a major role in creating a renewable natural gas market because we offer a stable, long-term use of gas,” said Arlyn Purcell, director of aviation environment and sustainability at the Port of Seattle. “If we can attract a project developer to supply the airport, this will spur more opportunities to feed the current gas pipeline with RNG rather than have landfills or digesters flare the gas on-site or allow their methane emissions to escape into the air.”
Switching to renewable natural gas would reduce the airport’s greenhouse gas footprint by addressing a large portion of its on-site emissions. Using RNG for heating and transit fueling also supports broader climate and air-quality goals by displacing fossil fuel use and making productive use of organic waste streams.
The Port is evaluating proposals and expects to award a contract by late 2019. If successful, the project could serve as a model for other airports and large facilities seeking to decarbonize building heat and vehicle fleets without waiting for full electrification.