New, stronger batteries to boost King County Metro’s trolley bus fleet

Editor’s note: Metro’s agreement with Kiepe was finalized in Sept. 2024

Electric trolleys are Metro’s original zero-emission fleet. Our 174 “trackless trolleys” are preparing to get a power boost that will increase their ability to travel farther off wire and prepare them for continued service to the region.

Kiepe Electric and Metro have reached a $26 million agreement for Kiepe to supply new, improved battery packs for our trolley fleet. Metro’s current fleet of 174 trolley buses went into service in 2015 through 2017. The fleet had off wire capabilities that were state of the art for the time, allowing buses to detour around incidents and construction for short distances.

It’s now time to replace the batteries that power the trolleys and to simultaneously take advantage of the stronger batteries now available. In addition to being selected to provide the new batteries, Kiepe Electric is also the manufacturer of the original propulsion systems for Metro’s trolley fleet.

Nearly triple the power

The new battery packs will provide 72 kwh to each trolley – nearly triple the energy capacity of the current battery packs. This is expected to extend the range of operation off wire for when there are incidents blocking the trolley route, or nearby construction activity that requires deenergizing the overhead wires that power the system. Currently, these types of larger disruptions meant that Metro had to temporarily replace affected trolleys with diesel hybrid buses. However, the new  extended range will allow the electric trolleys to continue to operate, helping Metro reduce our emissions.

The batteries are charged while traveling “in-motion,” so no other infrastructure upgrades are needed outside of the bus batteries and charging components. The new batteries were tested in four of our trolleys – two 40-foot trolleys and two 60-foot trolleys – for over 1,000 miles. The tests confirmed the new battery systems provide substantially more off wire range than the battery systems on the existing trolley fleet.

These new batteries will ensure the trolleys will keep rolling into the next generation. As Metro continues its transition to a zero-emission future, our electric trolleys—which have been part of Seattle’s transit system for over 80 years—will continue to be an important part of our fleet!