K. Visser

Electrical energy storage for dynamic positiong operations: Investigation of three application case

In this paper we focus on integration of batteries with ship power systems for three application cases. Presented application cases include two platform supply vessels, one equipped with diesel engines and other with dual fuel engines, and a heavy lift crane vessel. Besides reducing the number of running engines and maintaining original dynamic positioning capabilities, we also demonstrate novel possibilities of battery usage, such as harvesting of waste energy, and implementation of dual fuel engines for dynamic positioning. In all application cases, results indicate significant fuel savings and reduction of running hours due to spinning reserve function of batteries.

A quantitative comparison of hybrid diesel-electric and gas-turbine-electric propulsion for future frigates

Future frigates need to reduce fuel consumption and emissions, while improving effectiveness. This paper quantitatively compares top speed, fuel consumption, emissions, acceleration performance and engine loading of hybrid diesel-electric and gas-turbine-electric propulsion, using validated models and introducing sequential turbocharging and power take-off. This simulation study demonstrates hybrid diesel-electric propulsion can reduce fuel consumption and CO2 emissions by 10% to 25% compared to gas-turbine-electric propulsion, while reducing top speed by 3 kts. Moreover, hybrid diesel-electric propulsion is found to provide good acceleration without thermally overloading the engine when speed control is employed for the electric drive in combination with torque control for the diesel engine.