Greenhouse gas emissions’ reduction goals of a 50% reduction by 2050 were established by the IMO. As a first step to achieve this reduction already by 2030 this project uncovers how much of the CO₂ emissions it is possible to reduce by combining the available state of the art technology.
The reduction of CO₂ emissions is done in two steps. The first step consists in reducing the power demand in terms of auxiliary and propulsion systems. After that, cleaner power supply alternatives are considered to further reduce the emissions.
In terms of auxiliary power, heavy consumers such the air conditioning, the lighting or water systems are considered. The reduction of auxiliary power is not only achieved with the introduction of more efficient equipment but also by the introduction of passive design strategies that enhance savings by reducing the loading on the systems. Altogether it is possible to reduce the auxiliary power demand by 33% in comparison with the benchmark design. The reduction of auxiliary power demand has a significant impact on the yearly consumption due to the significant percentage of operational time spent at anchorage.
In terms of propulsion power demand, the reductions achieved are even more significant, 51% and 70% power demand reductions are possible at cruising and maximum speed, respectively. The introduction of the Van Oossanen’s Fast Displacement Hull Form (FDHF), the reduction of displacement by making an aluminium hull and the application of the patented Hull Vane® are the main reasons for such a significant propulsion power demand.
Finally, the switch in power plant arrangement of the yacht results in further 10% reduction. In this case, simply the change from diesel direct arrangement to a hybrid arrangement leads to yearly savings, mainly because emissions at cruising are reduced due to the power take-off operational mode of the power plant, saving generator set emissions.
All in all, it is possible to already achieve a reduction of approximately 41% of the yearly CO₂ emissions on a 50 m motor yacht. One of the most important conclusions to be taken is that all these reductions are possible when finding the optimal interaction between components, from auxiliaries to power plant arrangement. Mainly, the CO₂ emissions reduction followed from a fuel consumption reduction, not yet introducing power supply from renewable energies nor alternative fuels which despite being the way to the future are not yet fully mature and suitable for this specific case.