Oakland International Airport added five zero-emission electric buses as part of its long-term plan to fully electrify its vehicle fleet in the next decade, the Port of Oakland announced on Friday.

The K9MD RIDE buses were manufactured in Lancaster, Calif., by the electric vehicle company RIDE, the American arm of the Chinese automotive and technology company BYD. The new buses will replace the airport’s current fleet of renewable natural gas-powered vehicles.

“We look forward to continuing our path towards an all-electric bus fleet in the coming years,” said Port of Oakland Director of Aviation Craig Simon. “Passengers and employees that utilize the new state-of-the-art buses can enjoy quiet, spacious, comfortable, and modern vehicle interiors without emissions.”

The new buses and associated charging infrastructure cost $5.5 million in total. Three different California grant programs provided $2.7 million of that funding, according to port officials.

With a range of up to 208 miles, the buses are an example of the “forward-thinking approach to environmental stewardship” while maintaining efficient transportation service, the Port of Oakland stated.

“We applaud Oakland Airport and their commitment to electrifying its fleet,” said Jason Yan, RIDE Vice President of Sales, West Region and National Account, in a Port of Oakland statement. “RIDE is thrilled to partner with OAK to offer sustainable transportation solutions that benefit both the environment and the community.”