WSF will contract to replace the four existing direct current (DC) diesel generators in the Hyak with four new alternating current (AC) diesel generators, as well as replacing the two main DC propulsion motors. Two new ship's service generators and a new ship’s service switchboard will be installed. A power management system and battery bank will also be installed to enable the most efficient use of power.
Why is WSDOT
converting the Hyak to hybrid power?
The Hyak propulsion plant is the only original power plant left among the Super class vessels. The Elwha, Yakima and Kaleetan have had major revisions over their service lives. The Hyak needs a revision to continue to serve until 2031, when it is projected for retirement.
The power load on the Hyak typically goes from 60 percent for a 20-50 minute crossing to 5-10 percent while loading/offloading at a dock for 10-30 minutes. Because of these large and regular fluctuations in propulsion power load, a hybrid power management system using variable speed AC generators will allow for the most efficient use of diesel engine power.
The End Result
The Hyak will have a reliable and efficient propulsion system with cutting-edge hybrid technology, saving fuel and reducing emissions.
The Hyak currently burns an average of 1.34 million gallons of fuel per year, and we’ll save 20 percent of that after the conversion. Fuel savings will total about $21.5 million over the remaining life of the vessel.
The conversion will also reduce emissions. Reduction in carbon dioxide will be 2,674 metric tons per year; particulates will be reduced by nearly 1 metric ton per year, and nitrous oxide will be reduced by 17 metric tons per year.
It will also save on engine wear and tear. Maintenance savings will be about $1.2 million over the remaining life of the vessel.
What is the project timeline?
- February-April 2013: Request for proposals by potential contractors
- June 2013: Award contract
- October 2014-May 2015: Conversion work
- June 2015: Sea trials
- Fall 2015: Hyak back in service as hybrid
The Hyak conversion will cost about $22 million.
Other hybrid ferries around the world
Construction and use of hybrid ferries has increased world-wide in recent years. Below are some examples.
How can I get more information?
WSF Communications Manager
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