Snohomish County, Washington, expands use of electric vehicles at transfer stations

As part of its ongoing efforts to maintain an environmentally sustainable and cost-saving infrastructure system, the Snohomish County Public Works Solid Waste Division in Washington is currently in the process of replacing diesel powered terminal tractors with electric-powered units.

Three of five terminal tractors will be replaced at the Airport Road Recycling and Transfer Station (ARTS) and the Southwest Recycling and Transfer Station (SWRTS), with plans to replace the remaining two units within the two years.

According to an Oct. 6 release, the division has been pleased with the performance of this electric unit—especially noting reduced with mechanical issues.

“We were looking for a better performing vehicle that also had some cost savings as we replaced aging equipment, but we also are able to achieve environmental benefits with these electric yard goats.” said Kevin Kelly, solid waste division director. “We look forward to the continued reductions of carbon emissions, lifetime cost savings, and reduced maintenance these electric vehicles offer for many years to come.”

Terminal tractors are the most commonly used, heavy-duty vehicles for moving trailers on county property. Staff uses them to move 53-foot intermodal trailers onsite at the division’s three transfer stations. Each container is filled with approximately 59,000 pounds of compacted refuse for transport via rail to the county’s landfill.

Savings generated from use of electric vehicles:

• Operating cost comparison: Average hourly operating cost (fuel, parts, and labor) for a diesel terminal tractor is $36.10 per hour; electric terminal tractor is $11.33 per hour (not including cost of electricity). This electric vehicle was used 890 hours in 2020, equating to a savings of over $22,000 in operating costs for the year.
• Initial cost of equipment: $240,000 for electric vs. $120,000 for a diesel vehicle. A 10-year life is expected, generating operating and fuel savings which will more than make up the difference of the initial cost.
• Fuel savings (diesel vs. electric): Annual fuel consumption for one diesel terminal tractor is 1,002 gallons of diesel fuel vs. 0 gallons for electric.
• Reduced maintenance time/cost for electric vs. diesel: Maintenance time for a diesel unit is 169 labor hours and $27,147 annually; 82 labor hours and $10,080 annually for an electric unit.
• Tons of CO2 emissions avoided: 10 tons avoided annually through the use of one electric terminal tractor. Therefore, 30 tons will be saved annually for the three new tractors.