The King County Council voted Feb. 4 to speed up converting all county vehicles, including public transit buses, to electric.
The legislation, approved in January by a council committee (CU No. 1937 [9.3]), moves the deadline for King County Metro having a zero-emission bus fleet from 2040 to 2035.
The unanimous council vote came five days after Metro announced its first big order of electric-battery buses—40, 60-foot-long articulated buses from New Flyer for delivery in 2021. At about $1.3 million apiece, the total is around $53 million.
The county plans to spend about $81 million on an order later this year for another 80 buses—20 more 60-foot models and 60 that are 40-feet-long at $925,000 each—arriving in fall 2022.
Metro selected New Flyer's Xcelsior CHARGE model after months of field tests with 10 electric-battery buses leased from three different manufacturers. The test buses use a variety of lithium-ion batteries. Metro tested them in different conditions to evaluate range and recharge rates. The Xcelsior CHARGE models have batteries with a capacity of 466 kWh.
"They had quite a bit of seasonal variation" between the different buses, Danny Ilioiu, Metro's zero-emissions program manager, told Clearing Up.
After conducting engineering tests—the buses shadowed in-service coaches—Metro put the buses to work carrying passengers in late 2019. Based on field tests, an electric-battery bus uses roughly 2 kWh per mile, Ilioiu said.
Before the first bus is delivered, Metro will install chargers at its base in Tukwila, south of Seattle. Buses will charge overnight and, when possible, during midday breaks. A bus will pull into a parking spot and plug into a charger hanging from a gantry overhead, said Jeffrey Arbuckle, Metro's capital planning supervisor.
Installing chargers should cost a bit more than $300,000 for each bus, Arbuckle said.
In all, Metro expects to spend as much as $60 million on construction and electrification infrastructure at its Tukwila base, according to a King County press release.
By staggering bus charging during the night, the base's peak demand should not top 7 MW, which should be manageable with the existing infrastructure, Arbuckle said.
Metro plans to buy another 250 battery-electric buses to be delivered in 2025.