Concept Design and Performance Evaluation of a Fossil-Free Operated Cargo Ship with Unlimited Range

Abstract

To meet the IMO goals of emissions reduction in shipping, drastic actions must be taken. Wind-assisted propulsion and renewable energy sources are today discussed frequently as realistic alternatives for future ship propulsion and energy production. This study presents a new and innovative concept of a fossil-free operated cargo ship aiming to achieve an unlimited range. The purpose of the study is to present the feasibility but also the limitations of a ship propelled and operated purely on renewable energy harnessed at sea, independent from shore-based energy sources. Aside from Flettner rotors for propulsion, the ship concept incorporates photovoltaic generators, wind turbines, and a dual-mode propeller to produce energy for the auxiliary systems and for the Flettner rotors, as well as batteries to balance the energy production and consumption. The dual-mode propeller can be used for energy generation and propulsion, thus levelling out any speed drops or peaks and thereby ensuring more reliable operation. The whole system is modelled numerically, and full ship voyages are simulated using the ship performance model ShipCLEAN. Results show feasible achieved speeds on a route with realistic weather conditions. However, negative energy balances limit the pure renewable sailing conditions. Further logistic and technical challenges are discussed.

The Pathway to Decarbonization: Flettner Rotor Application in Maritime Logistics

“…This section will compare the strength and weaknesses of the Flettner rotor with other WASP technologies. Compared to kites and soft sails, the Flettner rotor is the 'friendliest' technology that can perform in any direction and velocity of wind [7]. Furthermore, the dimension of the Flettner rotor is smaller than other technology.…”

“…We can still develop the best possible technology, wind-assisted ship propulsion (WASP), from these alternatives. It is very reasonable because of the availability of wind energy in the open sea [7].…”

“…Open sea has two potential sources of energy: solar and wind energy. By capturing and optimizing these energies, the ship can sail with unlimited range [7]. Using kites, rigid and soft sails technology will influence the vessel's speed and lifting force by the unpredicted wind angle.…”

Neural Network Modeling Based on the Bayesian Method for Evaluating Shipping Mitigation Measures

“…Here, a three-layer neural network topology in Figure 2 was simply drawn from MATLAB software to show the process of neural network forward propagation. The number of hidden layer neurons n h needs to be further determined by input layer neurons n i and output layer neurons n o , usually as shown in Equation (3). The constant α is 1 minus 10.…”

“…Shipping is becoming a significant contributor to global carbon emissions that affect climate change. The Marine Environment Protection Committee (MEPC 72), meeting at the International Maritime Organization (IMO), has published a preliminary strategy to reduce carbon emissions by half by 2050 [2,3]. To help achieve this goal, the IMO has proposed some indicators, such as the Energy Efficiency Design Index (EEDI), to improve ship energy efficiency [4].…”