Yellow School Buses Go Green, With Natural Gas
A $5-million stimulus will soon color the nation’s yellow school buses a shade greener. By next October, 175 aging diesel buses will be outfitted with compressed-natural-gas engines (CNG), says Michael Martin, executive director of the National Association for Pupil Transportation.
CNG emits about 30% fewer greenhouse gases than diesel engines, according to Stewart Kennedy, president of NGV Fleet Partners, a firm that converts buses to CNG. Engine conversions double buses' lifespans, granting vehicles that are scheduled to soon be replaced 7 to 10 more years of runtime, Martin says.
A conversion costs about $50,000, and the federal program will cover about $16,000 to $18,000. To compare, a new diesel bus costs about $160,000.
School districts switching from diesel to CNG will save about $1 per gallon.The new engines also reduce maintenance costs because they require oil changes less frequently.
Thanks to state grants, the Los Angeles Unified School District has been running CNG buses since the early 1990s. Enrique Boull’t, LAUSD's director of transportation, says that its benefits to students are obvious: “There’s no black smoke coming out of the tailpipe . . . and [the ride] is quieter.” By the end of the year, nearly a third of the district’s 1,300 buses will be CNG-powered.
Boull’t hopes to green all of his district’s vehicles within three years. With a chuckle, he adds, “I wish we had done it by yesterday.”