A Comparative Analysis of EEDI Versus Lifetime CO2 Emissions

Abstract

The Energy Efficiency Design Index (EEDI) was introduced as a regulatory tool employed at the ship design phase to reduce the carbon dioxide (CO2) emissions and increase the vessel’s operational efficiency. Although it stimulated the greening of the shipping operations, its effectiveness is considerably criticised from various shipping industry stakeholders. The aim of this study is to investigate the EEDI effectiveness on accurately representing the environmental performance of the next-generation ships power plants for two representative ship types, in specific, an ocean-going tanker and a cruise ship. The performance of the optimal power plant solutions identified in previous studies is analysed according to the existing EEDI regulatory framework and compared with the lifetime CO2 emissions estimated based on an actual operating profile for each ship. The results indicate that the EEDI underestimates the effect of technologies for reducing carbon emissions in all the investigated cases. In this respect, it is concluded that EEDI is classified as a conservative metric, which however can be used as an approximation to compare alternative solutions early in the design phase.

Emphasis on Occupancy Rates in Carbon Emission Comparison for Maritime and Road Passenger Transportation Modes

“…Fuel consumption F c (kg) for each vessel operation is calculated based on the IMO model presented in [6] and as mentioned in [64,65]:…”

The Rise of Ultra Large Container Vessels: Implications for Seaport Systems and Environmental Considerations

“…At that time, when the so-called Maersk Cclass (LOA 1 345 m, Beam 42.8 m, Draught 14.5 m, Capacity 8650 TEU) was the largest container ship ever built (CRSL 2021a), there were concepts for ships with up to 12,500 TEU where the term ULCV or Ultra Large Container Ship (ULCS) was already in use (van Ham 2005, p. 89). Albeit ships with more than 18,000 TEU seemed feasible from a shipbuilding point of view (Wijnolst et al 1999, p. 74), it was assumed that the limitations, in particular port limitations, associated with their size would prevent widespread acceptance of such vessels (van Ham 2005). The units of up to 24,000 TEU that are in service today falsified this assumption.…”

“…While the EEDI only aims at improving the efficiency of new built ships, MEPC adopted a similar index for the existing fleet, the Energy Efficiency Existing Ship Index (EEXI) in 2021 to be applied after 2022 (IMO 2021). Both indices, however, have been criticized to only make small contributions towards IMO's decarbonization goals (Trivyza et al 2020;Rutherford et al 2020;Psaraftis and Kontovas 2021). EEDI and EEXI are accompanied by a so-called Ship Energy Efficiency Management Plan (SEEMP) and the Carbon Intensity Indicator (CII).…”

Energy Optimization of Marine Drive Systems with Permanent Magnet Synchronous Motors

“…The IMO determined a time sequence for tightening global regulations in terms of EEDI [9] (Figure 1), posing huge challenges to designers and engineers due to technological limitations (e.g., the possibility of increasing the efficiency of the ship's main propulsion engines). As presented in many works [11][12][13][14][15], the effectiveness of the determined EEDI is not fully adequate for an improvement in the ship's carbon footprint. However, it is certain that a real increase in the energy efficiency of ship systems (by reducing losses) will reduce the emission of air pollution by ships while improving the economic effect.…”