Meeting IMO’s climate goals for 2050

Abstract

The global temperature is rising as a consequence of the climate change. In order to stop the further increase of the global temperature, the international community has decided to aim at reducing global greenhouse gas (GHG) emissions in the near future. To achieve this ambition, various alternatives in shipping need to be explored including sailing on alternative fuels.
This study investigates the consequences of sailing on alternative fuels. It is investigated which problems might occur when sailing on alternative fuels, which rules are mandatory when sailing on alternative fuels and as a consequence what the effects are on the cargo transport costs.
The problems occurring when sailing on alternative fuels are caused by the lower energy densities of these fuels, the rules and requirements with regard to the storage of some of these fuels and the shape of the storage tanks for some specific fuels. The shape and requirements regarding the fuel storage tanks can make it necessary to replace cargo for storage tanks, which will result in increased transports costs. Furthermore, the lower energy density of alternative fuels result in more fuel weight, or volume as compared to conventional fuels. In order to transport the same amount of cargo, an extra bunker stop, or taking less fuel and reducing the sailing speed, can be an option. Another option to compensate for the increased weight, or volume of the alternative fuels, is to reduce the cargo taken on board. All options will result in higher transports costs as compared to sailing on conventional fuels. To investigate how these extra costs are composed a main question has been formulated: "In a situation where the transport costs are minimized, how do the transport costs compare when sailing on various fuels with different energy densities than conventional fuels?".
To answer this main question, a model was developed. The model is suitable to calculate the transport costs in various situations. For this research, three vessel types on three operations, using seven fuel types have been analyzed.
The analyzed vessels were a container vessel, an oil tanker and an ore carrier. The chosen voyages are common voyages. The analyzed fuels are fuels which are able to achieve the goal of reducing the CO2 emission with 70% per transport work in 2050 as compared to 2008. Heavy fuel oil was used as benchmark. Based on the simulations used in the developed model it was found that: the costs of alternative fuels are higher than those of conventional fuels. Batteries are too heavy, too large and too expensive to be considered as an option, for the researched vessels and operations. The capital costs of fuel cells make that the use of fuels in combination with a fuel cell is currently expensive at higher speeds. High fuel storage costs make hydrogen currently not competitive with conventional fuels. The transport using an oil tanker are the lowest for hydrotreated vegetable oil, second lowest for ammonia in combination with an internal combustion engine and the highest for battery electric.