The nation's biggest ferry system is aiming to convert some of its fleet from diesel to natural gas propulsion.
This month, Washington State Ferries formally asked the U.S. Coast Guard to review the proposed changeover. It's another example of fleet operators in the Northwest taking a hard look at cheaper fuel.
After three years of study, the Wash. State Department of Transportation has determined it is technically and financially feasible to convert six mid-sized car ferries to run on cleaner burning liquefied natural gas.
Assistant secretary David Moseley told lawmakers that moving away from diesel could save 40-50 percent at today’s pricing.
"One reason for looking at this is cost... Can we reduce the cost of our fastest growing operating expense? And secondly, can we reduce the amount of emissions that we put into the environment?" said Moseley.
State budget documents project annual fuel savings of $1.1 million per vessel. That yields a payback period of around 12 years on an estimated cost of $12-15 million per ferry to convert to LNG fuel.
Washington is not alone on this. BC Ferries is leaning toward natural gas fuel for three new ferries it is about to order. And earlier this year, the freight line TOTE commissioned designs for the LNG conversion of two cargo ships that sail between Tacoma and Alaska.
With U.S. Coast Guard approval and funding from the state legislature, Washington State Ferries could begin converting its first ferry to LNG propulsion in 2016.
The six car ferries WSF has identified as most suitable for conversion are the M/V Issaquah, M/V Kittitas, M/V Chelan, M/V Kitsap, M/V Cathlamet and M/V Sealth. The Issaquah Class ferries all carry 124 cars, except for the Sealth which has a 90-car capacity.