King County Metro announced plans to purchase up to 73 all-electric battery buses from Proterra at a cost of up to $55 million, starting with 20 buses totaling $15.12 million. Charging stations to support the initial orders of those buses will range from $5.5 million to $6.6 million.

The 40-foot battery buses have an estimated range of about 25 miles, with a quick charging time of just 10 minutes. Maintenance costs of all-electric buses are expected to decline versus hybrid-diesels, primarily because they have fewer moving parts, according to the agency.

Eight of the buses are slated to go into service this year; 12 more in 2019. Up to eight of the new 40-foot battery buses will likely operate on Metro Routes 226 and 241 in Bellevue, Wash. As part of a pilot project last year, Metro began running three all-electric buses on these routes, which serve some of the county’s densest job centers, including the Microsoft campus and downtown Bellevue.

As part of today’s announcement, Metro will acquire up to nine long-range electric buses from different manufacturers to test the battery technology with a range of about 140 miles. With this approximately $7 million acquisition, Metro is challenging the industry to produce buses that can travel farther. The agency also is calling on the industry to develop 60-foot long buses, better able to replace the articulated buses that make up 55% of its fleet.

King County Metro was the first transit agency to adopt diesel-electric hybrids, and it currently operates more than 170 electric trolley buses. By committing to replacing its current fleet with clean vehicles, Metro is influencing the development and expansion of the all-electric bus market.

In conjunction with this battery bus order, Metro is conducting a comprehensive analysis of the best approach for achieving a zero-emissions fleet. A Battery Bus stakeholder group is advising on the approach and priorities for achieving a zero emissions fleet.