In late April 2018, Washington State Ferries (WSF), the operator of the largest fleet of ferries in the United States, announced plans to convert the three largest boats in its fleet to electric power. WSF uses 18 million gallons of diesel fuel each year, more than any other consumer in Washington state. Consequently, it is also the largest producer of greenhouse gases in the state’s transportation system, generating 73 percent of annual emissions.
Washington is the second most glaciated state in the US. One of the most common routes taken by the three ferries to be converted is between Seattle and Bainbridge Island, with the snowy peaks of Mount Baker and Mount Rainier visible to passengers on the route. Washington also has glaciers in the Olympic Mountains and the North Cascades.
WSF plans to swap two of four diesel engines in its Jumbo Mark II ferries for battery packs, which will power the motors needed for propulsion. The changes to the first boat will be largely funded with money from a federal settlement with Volkswagen as a result of its 2015 violation of the Clean Air Act.
The three Jumbo Mark II ferries, Puyallup, Tacoma, and Wenatchee, were chosen to be the first converted because they are the largest boats in the fleet and are responsible for 26 percent of WSF’s fuel consumption. The vessels each have a carrying capacity of 202 cars and 1,800 passengers. They are due for 20-year propulsion system replacements so the changes can be made with few impacts on ferry service. Additionally, the ferries are relatively young and can be used for another 30-40 years. The list goes on, including benefits like reducing engine noise to decrease disruptions to marine life, increasing engine reliability, and decreasing ferry operation costs.
Washington State Department of Transportation officials estimate that converting all three ferries will be equivalent to taking more than 10,000 cars off the road.
Until WSF can have charging infrastructure installed, the two remaining diesel engines will charge the batteries. The hybrid system will still reduce emissions. Ian Sterling, a spokesperson for the state ferries, told the Daily Herald that “It will take a long time to be all-electric, but that’s ultimately where we want to be.” Once charging stations are operational, charging times will only take about twenty minutes.
All of these benefits come with a learning curve; the batteries will need to be replaced every four to five years and crews will need to master the new technology. Nevertheless, WSF aims to have 22 of 26 vessels in its fleet operating as plug-in hybrids by 2040.