Prior to any efficiency modifications, more than 75% of the fleet — bulkers, tankers and containerships — will not be compliant with the Energy Efficiency Existing Index (EEXI) that will enter into force in 2023, according to Joey Daly, Cargo Analyst at VesselsValue.
In 2021 the International Maritime Organization (IMO) adopted two new energy efficiency requirements — EEXI and the Carbon Intensity Indicator (CII). These were part of global measures to reduce the level of shipping’s greenhouse gas (GHG).
EEXI measures CO2 emissions per transport work. It is the sibling of the Energy Efficiency Design Index (EEDI), which has been in force since 2013. While EEXI and EEDI in practice measure the same thing, EEDI is applied to new ships while EEXI applies to vessels that might not have been built at a time when sustainability and energy efficiency was a priority.
VesselsValue divided the non-compliant vessels into three groups, based on the difference between the attained and required index, plus the efficacy of technological improvements.
The first group consisted of vessels that can be made compliant using energy-saving devices retrofitted to the main structure.
The second group consisted of vessels for which an engine power limitation procedure was the most likely option.
The third and final group included those vessels that would struggle to remain compliant without drastically reducing speed and fuel consumption. These might be favourites for a trip to the breaker’s beach.
The vessels in group 1 would need to be fitted with energy-saving devices (ESDs) – of which there is a wide choice from which to choose – to become compliant with IMO regulations. ESDs can do alter the EEXI equation in a variety of ways, e.g., by reducing the main engine power required to maintain the same speed through improvements in hydrodynamics and alterations to the propeller. Propulsion improving devices, hull air lubrication systems and sails are other possibilities.
Vessels in group 2 would not be helped sufficiently by the use of ESDs. For these an engine power limitation (EPL), or a shaft power limitation (ShaPoLi) would be required. EPLs limit the maximum engine power achievable by a marine engine, while ShaPoLis limit the power transmitted by the shaft to the vessel’s propellers. Either of these procedures would directly reduce a vessel’s maximum continuous rating (MCR), which is a key component of the EEXI equation.
However, since these moves would in effect turn into mandatory slow-steaming, the average operational speed would drop, meaning that more ships would be required to move the same amount of goods per year.
Finally, for Group 3 the option would be to operate outside regulations, or to be demolished.
VesselsValue said that, if EEDI/EEXI is to be successful in its authors’ aims, the level at which it becomes unprofitable for a non-compliant vessel to operate commercially would need to be set low and in line with the EEXI calculation.
It was noted that, in order to achieve global decarbonization targets, a move to alternative fuels was the only sustainable, long-term option.