King County Metro Zero Emission Fleet 20 Years Away — Here's Why

SEATTLE, WA — If you drive down East Marginal Way in Tukwila past King County Metro's South Base, you'll see crews tearing down an old office building. If all goes according to plan, that space will soon make room for all-electric buses and their complementary charging stations.

It might not seem like much today, but it's one step on the way to Metro's goal of having a zero-emissions fleet by 2040. And the reason the goal will take about 20 more years to reach is because Metro has so much work to do to prepare for buses that run only on batteries or overhead wires.

Metro officials last week updated the King County Council's Regional Transit Committee on the status of the zero-emission fleet goal.

Today, about 12 percent of the approximately 1,600-vehicle Metro fleet are zero emission buses. A majority of those — 174 — are electric trolleys that run on overhead wires. Just 11 are battery-powered buses that run on two Eastside routes, the 226 and 241. The rest of the fleet consists mainly of hybrid diesel buses that use Prius-like regenerative braking to reduce emissions.

But the buses that could change Metro's fleet don't technically exist yet — at least not in a way that's proven in Puget Sound's hilly, rainy, congested environment.

Metro is testing long-range articulated buses that run completely on batteries. The buses are supposed to have a range of 140 miles (the buses in operation on the Eastside have a 25-mile range), but the reliability of that is under review. No transit agencies in the U.S. have successfully used long-range battery buses on a large scale.

The city of Albuquerque bought 15 60-foot battery-powered buses from a Chinese manufacturer for a rapid-transit project. But the city had to cancel the program citing insurmountable technical problems, including brake failures.

There are other impediments besides technology. Diane Carlson, Metro's capital projects manager, pointed out that the agency will have to hire or retrain mechanics to be able to work on battery buses.

Metro also needs much more room to store buses and charging stations, she said. The South Base annex in Tukwila will be complete by 2021. It won't be until about 2030 that Metro will be able to build new bases to handle a larger battery-powered fleet and charging stations.

One milestone to look forward to is the elimination of the all-diesel 30-foot buses. Those are the smallest buses in Metro's fleet, and typically operate on routes with tight turns. Danny Ilioiu, Metro's zero-emission fleet planning manager, said they could all be replaced within a few years by 35-foot diesel hybrid buses.

You might see Metro testing the new, 60-foot long-range battery buses on streets around the county. Once proven to work, the buses will be used first in South King County as part of a focus on reducing harmful emissions there.

"We need to understand what these buses do before making the change," Ilioiu said.