1 million gallons of biodiesel fuels WSDOT on road to greener, more sustainable transportation

By Noel Brady

Our fleet of trucks and ferries recently realized a seven-digit milestone on the road to sustainability. For the first time, the agency’s fuel purchases in 2013 included more than 1 million gallons of biodiesel for ferries and mid-to-large-size trucks and equipment.

That means a net savings of more than 1 million gallons of regular diesel, including 687,741 gallons used for ferries and 318,775 purchased by the land fleet to fuel work trucks and other heavy equipment. It’s big news for Washington, where transportation ranks the largest source of greenhouse gas emissions. And it’s the latest green thumbs up for WSDOT’s award-winning fleet.


According to the U.S. Environmental Protection Agency (pdf 753 kb), substituting biodiesel, which is derived from vegetable oils and animal fat-based oils, for petroleum-based diesel can reduce smog-forming emissions from particulate matter by 10 percent, hydrocarbons by 21 percent and carbon monoxide by 11 percent for highway vehicles. Hydrocarbons are greenhouse gases that contribute to climate change.

WSF’s fleet of vessels each use up
to 5 percent biodiesel. Soon WFS
will launch a pilot project to study
the feasibility of using up to 10 percent
biodiesel to fuel ferries.
Increasing the use of biofuels, such as biodiesel, is a widely accepted strategy for slowing climate change. Since biodiesel is derived from plant matter, it is not a fossil fuel, so it’s renewable. Biofuels come from plants and trees, which need CO2 to grow. Using biofuels doesn’t add as much CO2 to the atmosphere; it recycles it.

Considering these factors and others, a 2006 study published in the scientific journal Proceedings of the National Academy of Sciences (PNAS) found that biodiesel can reduce greenhouse gas emissions by 41 percent.

The benefits of biodiesel are clear, and we plan to continue
growing its use as an alternative fuel, said WSDOT Energy Policy Manager Tim Sexton. Washington State Ferries uses biodiesel made primarily from recycled canola oils. WSF is preparing for a pilot project to evaluate increasing the percentage of biodiesel it uses to fuel vessels.

Into the green fleet first

Since 2009, use of biodiesel and other alternative fuels, such as propane and electricity, has helped WSDOT’s  fleet cut greenhouse gas emissions by 263 metric tons of CO2 equivalent. Since 2008 WSDOT also:
  • Reduced employee travel by 2.2 million miles
  • Cut fuel consumption by 10 percent or about 400,000 gallons
  • Purchased plug-in hybrids, all-electric vehicles and charging stations

Source: Washington State GHGEmissions Inventory 2009-2010