In a 2018 paper, decarbonizing intraregional freight systems with a focus on modal shift, a team of researchers led by EPP Ph.D. student Lynn Kaack recommended improving the efficiency of individual vehicles, measured in grams of CO2 per tonne-km. The most cost-effective way to do this, Kaack et al determined, is “Shifting as much freight as possible from road transportation to rail and water is one of the most important means for decarbonizing the freight sector.”
Shipping carries more than 90% of world trade and has continued to do so during the covid pandemic, yet is still far and away the least polluting of the world’s transport industries. Even in a world where containers are being carried across multiple landmasses over the course of a single truck journey, shipping’s exemption from the Paris climate accord has not prevented the industry from taking action. Despite its image problem in the mainstream press, shipping is arguably going beyond the call of duty to clean up its act, limiting emissions and imposing penalties on itself comparable with those levied in other transport modes.
One of these initiatives is the Energy Efficiency Design Index (EEDI), which has been successful in improving the efficiency of newbuilds. At its Marine Environment Protection Committee (MEPC) 75 in November, the IMO made three big decisions relating to the EEDI with major implications for shipping’s greenhouse gas emissions. Crucially, one of them introduces a new efficiency measure not applied in any other industry.
EEDI Phase 3 brought forward
The first major change was to bring forward what were set to be newbuild EEDI specifications come January 2025 – ‘Phase 3’ – to April 2022, instead. The move affects a large number of ship types including gas carriers, general cargo vessels and LNG carriers.
Container ships, meanwhile, must raise their game significantly.
Newly-built vessels of 200,000dwt and over will need to cut emissions by 50% over baseline levels – a particularly tough task. For the rest of the fleet, a scaled efficiency improvement – from 30% for ships of 15,000dwt to 45% for vessels between 120,000 and 200,000dwt.
EEXI – EEDI for existing ships
Recently the number of newbuilds has fallen, but the emissions from shipping have increased – in excess of the IMO’s 2050 target of a 50% reduction in CO2 emissions. Apparently in response to this, the IMO has implemented another change – the Energy Efficiency Existing Ship Index (EEXI).
This initiative would extend EEDI by applying it to vessels in the existing fleet, regardless of the year they were built, and grant each of them an Energy Efficiency Certificate and ranking. The certificate will be issued up until the first yearly International Air Pollution Prevention (IAPP) survey after January 2023.
The industry faces a problem, however, in that in order to perform the EEXI calculation, owners of existing vessels will be required to revisit each vessel’s sea trial documentation as it relates to speed and power – which for older vessels, could be rather complex.
In a recent interview with The Motorship, Lars Robert Pedersen, BIMCO Deputy Secretary General, commented that de-rating engines would be the most likely strategy for bringing older vessels up to code with EEXI requirements – something which could cause mechanical issues if performed incorrectly.
CII – above and beyond
Another new concept being introduced is the Carbon Intensity Indicator (CII), one that has not been attempted in other industries. For this, the metric to be used is yet to be decided, and is due to be discussed in May 2021. It will be a case either of as well as grams of CO2 per dwt-mile (AER) or CO2 per cargo ton-mile (EEOI), similar to the metric Kaack et al. use in their study.
Unfortunately, in the latter case several years’ data collection effort would be needed before a cargo mass baseline could be assembled for each ship. “The IMO Data Collection System (DSC) does not hold data on cargo mass carried,” said Pedersen in his interview. “This means several years will need to be spent collecting this data before baselines can be calculated.”
The EEOI measure would, however, be a dramatically more effective way to measure carbon emissions on a ship-by-ship basis; and crucially, seeing the figures laid out in this way would provide an unimpeachable justification for a modal shift toward shipping and away from other, far more polluting transport modes.