The National Aeronautics and Space Administration (NASA) has replaced two-thirds of its fleet with vehicles that run on cleaner fuels, including biofuels, electricity, and compressed natural gas (CNG). Its fleet greening is part of an effort by federal agencies to comply with President Obama’s sustainability goals.

This allowed the NASA fleet to reduce its petroleum fuel use by 62% since 2005 — down to 483,660 gallons in FY-15. The fleet’s alt-fuel use has nearly doubled in the same time frame — up to 283,592 gallons and gasoline gallons equivalent (GGEs), said Tim Currie, agency transportation manager.

The NASA fleet consists of 3,138 vehicles. Of these, there are 1,595 flex-fuel vehicles, 257 dedicated electric vehicles, 117 hybrids, 10 plug-in electric vehicles, and four compressed natural gas vehicles. The fleet is dispersed across 14 centers throughout the U.S., and also includes very small fleets in Moscow and Australia, Currie said.

With Obama’s Executive Order 13693 mandating that by the end of 2020, 20% of all new agency passenger vehicle acquisitions must be zero-emission or plug-in hybrid vehicles, the NASA fleet is moving toward electrification.

The vast majority of vehicles operate within campuses — the largest of which is 25 square miles — so Currie sees electric vehicles easily transitioning into the fleet.

“A 40-, 60-, or 80-mile driving range is more than enough to compensate for the day-to-day workload of NASA,” he said.

The problem is vehicle availability. More than 60% of the fleet consists of light- and medium-duty pickup trucks, but Currie will be limited to purchasing sedans to meet the mandate.

For now, however, Currie’s greening efforts have been recognized by the White House, which awarded him with a 2016 GreenGov Presidential Award in the Greening the Fleet category in September.

“It’s a combined effort of the transportation managers and the operators for recognizing the requirement and understanding their role in the behavior of change that it took for that to occur,” Currie said.

The federal government has tripled its consumption of alternative fuels since 2005, to 15.1 million gallons, surpassing the administration’s fleet alternative-fuel consumption goal by 50%, according to the White House. It further reported that the federal fleet had 4,337 electric vehicles and 22,863 hybrid electric vehicles in 2015.