• 2022-10-21
  • 2 min read

Amid growing global momentum for a carbon-neutral society, the EEXI/CII regulations will go into effect in January 2023. By applying CO2 emissions controls to ships, these regulations are expected to significantly reduce CO2 emissions in international shipping. This article explores the effectiveness of fuel efficiency improvements in ships, focusing on turbocharger: the prime example of energy-saving modifications in ships.

EEXI/CII Regulations and the shipping industry

In 2012, the total CO2 emissions of all international shipping amounted to approximately 800 million tons per year, rivaling the total emissions of Germany, and making up roughly 2.2% of global emissions. With the goal of decarbonizing the shipping industry, the International Maritime Organization (IMO) has set the targets of reducing CO2 emissions from ships by at least 40% by 2030 and 70% by 2050. To achieve these targets, the Marine Environment Protection Committee (MEPC) – a member of IMO – adopted the EEXI (Energy Efficiency Existing Ship Index) and CII (Carbon Intensity Indicator) regulations in June 2021, to come into force in January 2023.

Energy origin (from fuel combustion) CO2 emissions
Energy origin (from fuel combustion) CO2 emissions

Source: “CO2 emissions from international shipping” (Ministry of Land, Infrastructure, Transportation and Tourism) Created by processing

What is EEXI? What is CII?
EEXI is a framework for evaluating the fuel efficiency of existing ships that exceed 400 GT. Ships that fail to meet the standards for their ship type must achieve the same level of fuel efficiency as newly built ships through engine output restrictions and energy-saving modifications. CII is a framework for rating the actual fuel efficiency achieved by existing ships over one year, according to five levels. By requiring ships with a low rating to submit improvement plans and receive approval from the competent authorities, it promotes continuously energy-efficient operations.

Three ways that MET Turbocharger improve fuel efficiency

Three ways that MET Turbocharger improve fuel efficiency
Three ways that MET Turbocharger improve fuel efficiency

The primary measures available to ships that do not meet the EEXI/CII regulations are 1) restricting engine output, 2) energy-saving modifications, and 3) replacement with newly built ships. The relationship between low-speed operation and CO2 emissions reduction is a well-known fact, making “1) restricting engine output” an extremely effective way to save energy due to its high effectiveness and immediate impact. However, it also results in slower ship speeds, leading to concerns such as the reduced speed of logistics and the need to reorganize fleets. With these factors in mind, we would like to present various ways to implement option 2) energy-saving modifications, that can be applied to engines equipped with MET Turbocharger.

1. Turning off turbocharger to improve efficiency by approx. 2.5%

Large ships with multiple turbocharger can cut off one of their turbochargers so that the remainder operate more efficiently, improving fuel efficiency by an estimated 2.5%. See below for details.

2. Installing a VTI to improve fuel efficiency by approx. 3%

Installing a VTI (Variable Turbine Inlet) in a MET Turbocharger exhaust-gas inlet turbine sides provides an optimized turbine capacity suitable for partial loads. Doing so optimizes turbocharger efficiency during operation, resulting in an estimated fuel efficiency improvement of 3%.* See below for details. *In the case of MET66MA

3. Installing an internal EGB to improve fuel efficiency by approx. 2.5%

Installing an integrated EGB (Exhaust Gas Bypass) casing in a MET Turbocharger enables the bypassing exhaust gas during high load operation, and also making it possible to match the turning with low load operation. Doing so can improve fuel efficiency by an estimated 2.5%. Se below for details.

Balancing sustainable fuel efficiency and efficient ship operations

As the global economy continues to grow, so does demand for maritime logistics. Reducing environmental impact is a social obligation, but so is the pursuit of stable, efficient maritime transportation. Mitsubishi Heavy Industries Marine Machinery & Equipment will continue to offer proven technology and solutions to meet the diversifying needs of customers and respond to decarbonization and other changes in the market environment, thereby aiding the shipping industry to achieve its targets.

Mitsubishi Heavy Industries Marine Machinery and Equipment Co., Ltd. is a wholly-owned operating company of Mitsubishi Heavy Industries, Ltd., provides varied marine machineries and solution services.