OLYMPIA, Wash. – Washington State Ferries made a big move in its effort towards clean energy.

It announced last week that it is converting up to three of its largest ships into electric hybrids.

It is starting the process with its Jumbo Mark II ferries that contribute 26 percent of all ferries’ emissions.

WSF is the largest ferry network in the country and burns 19 million gallons of diesel fuel every year, the most greenhouse gas emissions of any Washington state agency.

The department says it will spend nearly $4 billion over the next 17 years in its journey to reach zero emissions by 2050.