Energy effectiveness of ocean-going cargo ship under various operating conditions

The increasing economic cost and environmental impact of maritime transportation necessitate the reduction of fossil fuel consumption of ocean-going cargo ships. Although fundamental ship propulsion system theory is well-known and is at a mature stage of development, there is still an enormous variety in the assessment methodology of (environmental) transport performance of ships. Furthermore, calibration of ship propulsion system model parameters with testbed, towing tank and full-scale measurement data is rare, as these measurements are both difficult and expensive. Finally, the effects of different power management strategies on the ultimate energy conversion effectiveness of typical cargo ships have rarely been investigated systematically. In this paper these three issues are discussed, addressed and solved for a representative benchmark chemical tanker. This ship was chosen to investigate the so-called energy conversion effectiveness under various propulsion control and electric power generation modes, as ample real ship data is available. The transport performance assessment of the ship's power plant is generalised for hybrid arrangements with either Power-Take-Off or Power-Take-In. The results show that an optimal combination of propulsion control, power management and voyage planning will further reduce the global fuel consumption and CO2 emissions produced by the shipping industry.