Seattle's King County launches first 3 Proterra electric buses

King County Executive Dow Constantine launched King County Metro Transit's first all-electric battery-powered buses in Bellevue, Wash.

"We're taking advantage of the latest clean-energy technology to achieve our goal of an all-electric and hybrid fleet in three years," said Executive Constantine. "Riders on the Eastside will have the opportunity to try out our all-electric, zero-emission buses that demonstrate our commitment to reducing fuel costs and carbon emissions."

The Proterra all-electric bus is the first of three that Metro will test this year. Constantine set a goal for Metro to increase transit service through 2020 with no net increase in greenhouse gas emissions.

Metro's three battery buses will operate on Bellevue routes 226 and 241, serving some of the county's densest job centers, including the Microsoft Corporate Campus and downtown Bellevue. The routes, which also serve the Bellevue Transit Center, start and end at the Eastgate Park-and-Ride, where the battery charging station is located.

The 38-seat prototype buses have a composite body and can travel 23 miles or more between charges. Batteries take 10 minutes or less to charge. The prototype buses are expected to get the equivalent of 15 miles per gallon more than a regular hybrid bus.

The automated, state-of-the-art charging station at Eastgate requires minimal work by the driver. Sophisticated software helps position the bus below a charging head that transmits electricity wirelessly. Recharging the battery takes 10 minutes or less, and when complete the driver is alerted and drives away.

According to data collected by other transit agencies operating the Proterra bus, the battery-powered vehicles generate a cost savings of 49% per mile compared to a hybrid bus, and a 40% savings over a diesel bus.

Metro will test the performance and efficiency of the new technology for up to a year on local streets and roads to determine whether battery-electric buses can be a future replacement option for its remaining diesel-powered coaches.

The three battery buses were paid for in part with a $4.7 million federal grant. Metro is pursuing $3.3 million in additional grants to buy six more battery buses and a second charging station, which would enable Metro to completely convert the two Eastside bus routes to 100% electricity.