ABS’ Energy Efficiency Design Index (EEDI) Phase 3 Compliance Debrief for Large Bulk Carriers and Tankers has been published, providing insight into current EEDI regulations, the compliance landscape, technical measures for large ships to achieve compliance, and energy efficiency technologies.
The IMO’s EEDI is a key component to reduce greenhouse gas emissions by 2030 and 2050 and sets minimum energy efficiency design requirements for different ship types and sizes.
According to ABS, while design efficiency is improving slowly across different DWT segments of bulk carriers and tankers, compliance with Phase 2 and 3 is expected to be challenging. For large Capesize bulk carriers (200k – 300k DWT), the number of delivered hulls meeting EEDI Phase 2 appears to be increasing between years 2016 – 2019 with vessels showing improved average achieved efficiency. In a similar manner, Suezmax tankers (125k – 200k DWT) built in 2016-2019 show increasing compliance margins against EEDI Phase 2. No vessel in either of these categories though has achieved 30 per cent reduction compared to the baseline yet.
A small number of VLCC tankers (DWT >300k) have achieved EEDI Phase 2 criteria though no VLOC bulker (DWT > 300k) has reported compliance. No vessel in either of these categories has achieved a 30 per cnt reduction compared to the baseline yet.
Smaller DWT segments such as Panamax bulk carriers (55k – 80k DWT) and Aframax tankers (80k – 120k DWT) appear to meet Phase 2 criteria more comfortably when compared to larger capacity peers. However, these better performers have marginal compliance with Phase 3 by only a few vessels.
ABS says that proposals to strengthen EEDI compliance criteria need to be carefully examined by the IMO MEPC with consideration of the 2013 interim guidelines on minimum propulsion power.
One problem the industry faces is the lack of innovative technology uptake by bulk carriers and tankers. This has been discussed at MEPC meetings, but ABS notes that the innovative technology applications fitted on a few VLCC tankers delivered between 2017- 2019 and reported to the IMO GISIS are 4th term. The most common 4th term innovative technologies fitted on commercial cargo vessels are waste heat recovery systems (WHS) for electric power generation. A direct comparison with the same capacity VLCC tankers with identical main parameters, EEDI power (PME) and reference speed (VREF), shows that efficiency benefits can range between 1.9 – 2.7 per cent.
ABS also states in its guidelines that the IMO EEDI database provides no reference for comparison of energy saving devices (ESD). These technologies (e.g. pre-swirl stators, rudder bulbs) together with optimised propeller/rudder configurations are commonly found on newer bulk carrier and tanker vessels. Their efficiency benefits though cannot be separated from the overall performance of the vessel as they are accounted for in the EEDI reference speed (Vref) during model tests and speed trials.
The experimental case studies reviewed at MEPC 72 (IMO, 2018b) suggest that with practical energy saving devices applied, the latest bulkers and tankers are likely to achieve approximately 25 per cent EEDI reduction rate but only few can meet a 30 per cent reduction. In order for these ships to meet EEDI Phase 3 criteria, it is necessary to use lower main engine MCR. This conclusion iterates back to the need to finalise the minimum propulsion power requirements.
According to ABS, substantial improvement of a vessel’s attained EEDI can be achieved through the use of gas fuels and dual fuel engine installations. Even though a number of ships have been fitted with such engines and verified for EEDI, the IMO GISIS currently provides no reference for comparison.
Click here to read the full debrief by ABS.