Washington State Ferries had looked at using hybrid or liquid natural-gas-powered vessels as far back as around 2012, said Sterling, but found the technology wasn’t mature enough. Now, improvements in battery technology coming out of the automotive sector are prompting a second look.
The ferry operator’s electrification program will start with the most polluting vessels, three Jumbo Mark II ferries, which consume 5 million gallons of fuel a year between them and are soon due to have midlife propulsion system upgrades. As part of the upgrades, each vessel will have two of its four diesel generators and locomotive engines replaced with battery systems supplied by Siemens.
Switching the three Jumbo Mark IIs to fully electric operations would cut emissions by an estimated 48,000 metric tons of carbon dioxide a year, the equivalent of taking 10,000 cars off the road.
Washington State Ferries consumes as much fuel as a midsized airline.