For a large cruise ship, for example, up to 6% (or up to 2,000 tons of fuel) of annual savings can be achieved by engine speed optimisation.
The concept has been created with a simple configuration of electrical system using existing ABB components. The concept is new to the commercial maritime industry.
‘No matter what bunker costs are now, ship owners look to the long term and always want ways to maximise fuel efficiency,’ says Juha Koskela, managing director of ABB’s Marine and Ports business.
DAC adjusts the rotational speed of the diesel generating sets, allowing the system frequency to vary within the specified range. Currently, many ships still run with their generators at a set speed, regardless of the power requirement, creating a surplus of wasted energy.
The medium voltage power system in the ship is specially engineered for variable frequency, including component design and system integration. Distribution for the auxiliary and hotel loads is provided by frequency converters or directly from the variable frequency system.