A new type of bus is coming to D.C. streets, and unlike with traditional buses, there won’t be any diesel fumes to smell or noisy engine to hear. D.C. now has 14 of these buses – the largest electric fleet on the East Coast. They’ll be spread out on the six Circulator routes, starting operation May 1. Three were recently unveiled downtown, where Mayor Muriel Bowser went on an inaugural ride.

“Oh, it was fantastic,” said the mayor, stepping off the bus in front of the Wilson Building. “Quiet, clean. I know people will appreciate that we’re making this investment in sustainability.”

The buses plus charging technology cost $16 million, but are expected to save the city $6 million over the lifetime of the more efficient buses. The 14 electric buses will make up just about one fifth of the Circulator fleet, but they will have a big impact on the environment – saving 90 thousand gallons of diesel a year, and 125 tons of CO2 emissions.

Unlike the city’s diesel buses, diesel hybrids, or natural gas buses, these battery powered buses have no tailpipe.

“Figuratively and literally in the United States market, diesel buses stink,” said Ryan Popple, CEO of Proterra, the company that makes these electric buses. For the past 40 or 50 years, he said, bus technology in the United States has been stagnant.

“Our buses in the U.S. are basically metal boxes with truck engines stuck in the back of them.”

Popple said that adds up to a noisy, lurching ride. This lack of bus innovation is one reason many commuters choose other options if they can, and many cities overlook the lowly bus, dreaming instead of streetcars or light rail. Some environmentalists want the District Department of Transportation to go all-electric. Payton Chung is with the D.C. Chapter of the Sierra Club.

“What we’d like DDOT to consider is, as they replace buses, purchasing only electric buses,” he said. “This would improve air quality, especially on busy downtown streets. This would reduce our reliance on fossil fuels.”

He says it would also help make progress toward Mayor Bowser’s recent pledge to make the District “carbon neutral” by 2050.

D.C. isn’t the first in the region to try out electric buses. Metro has one solitary electric bus that has been quietly shuttling passengers around the city for about a year. And Howard County has been operating a few in Columbia, Maryland.

“We have three electric buses running in the county right now,” said David Cookson, a planning manager with the Howard County Department of Transportation. The buses are an experiment, funded entirely by a grant from the Federal Transit Administration.

“They’re working well, but we don’t anticipate going out and getting more in the near future,” said Cookson.

Electric buses save money on fuel and maintenance over the lifetime of the bus, but they’re more expensive upfront. And it’s still new technology – Cookson said changing your fleet over is a big decision, not taken lightly.

“Most vehicles have a lifespan of 12 years. So you really want to go for a tried and true product.”

Still, electric buses are catching on. Last year, a dozen cities around the world pledged to go all-electric, including Seattle and Los Angeles. As for making all of D.C.’s Circulator fleet electric, DDOT Director Jeff Marootian says it’s on the table.

“We’re excited to have these buses entering into service soon, and as we continue to expand our service, we’ll consider our options.”

But in terms of impact on the environment, any bus is already a lot better than a car. A noisy, stinky diesel bus carrying 40 passengers has 80 percent lower greenhouse gas emissions per person than a single-occupancy car.