February 20, 2020. Austin-Bergstrom International Airport (ABIA) began its transition to renewable natural gas for its shuttle bus fleet on January 1, 2020, with the help of Clean Energy Fuels Corp., the leading provider of natural gas fuel for transportation in North America and a longtime partner with ABIA. This partnership calls for Clean Energy to provide the airport with its Redeem™ brand of renewable natural gas, the first commercially available vehicle fuel made entirely from 100% organic waste.