Navigating Green Waters: Propulsion and Engine Optimization for EEXI Compliance

The maritime industry is at the helm of significant change as it sails toward a more sustainable future. With the Energy Efficiency Existing Ship Index (EEXI) regulation coming into effect in 2024, vessel owners and operators are tasked with optimizing propulsion systems and engines to reduce greenhouse gas emissions. If you want to read more about EEXI please follow THIS LINK.

In this article, we’ll dive into the challenges, available technology, and what marine engineers need to do to navigate this sea of change successfully.

Challenges on the Horizon

Complying with the EEXI regulation presents several challenges, primarily centered around improving energy efficiency while minimizing emissions. Some of the key challenges include:

  1. Evaluating Existing Systems: Vessel owners must assess their current propulsion and engine systems to determine their energy efficiency and EEXI compliance. This often requires complex calculations and data analysis.

  2. Investment Costs: Upgrading propulsion systems and engines can be a significant investment. Owners need to balance these costs with the long-term benefits of improved efficiency and compliance.

  3. Technology Integration: Implementing new technologies and optimizing engines can be a complex process. Ensuring these systems work seamlessly with existing onboard systems is crucial.

  4. Regulatory Compliance: Meeting EEXI requirements necessitates compliance with stringent emissions standards. Staying up to date with evolving regulations is an ongoing challenge.

Technology on the Market

To address these challenges, a range of innovative technologies and solutions are emerging in the maritime sector:

  1. Fuel-Efficient Engines: Modern, fuel-efficient engines with advanced combustion technologies and improved design are becoming more widely available.

  2. Exhaust Gas Cleaning Systems: Technologies like scrubbers and selective catalytic reduction (SCR) systems help reduce emissions from engines, aligning with EEXI standards. More about this if you follow THIS LINK.

  3. Alternative Fuels: The adoption of alternative fuels such as LNG, hydrogen, and ammonia can significantly reduce greenhouse gas emissions.

  4. Energy Recovery Systems: Systems that recover and reuse waste energy from the engine, such as waste heat recovery systems, contribute to greater efficiency.

  5. Propulsion Efficiency Solutions: Upgrading propulsion systems with modern propellers and thrusters designed for efficiency can reduce fuel consumption.

    Source and Credit: MOL

    One of the most common methods to improve the attained EEXI is to limit the engine power or shaft power of the ship. This can be done by re-setting the fuel index by limiting the fuel rack using either mechanical stop or setting the control system in combination with an approved override functionality as defined in the IMO guidelines. This method is called Engine Power Limitation (EPL) or Shaft Power Limitation (ShaPoLi). To read more about this, please follow THIS LINK.

    However, this method also poses some challenges and risks for the ship operation, such as reduced maneuverability, increased fuel consumption, increased maintenance costs, and potential safety issues.

    Therefore, ship operators need to consider other measures to optimize the propulsion and engine performance of their ships, such as installing energy saving devices, using alternative fuels, or upgrading the propulsion system. Some of the available technologies on the market that can help achieve this are:

    • FuelOpt: This is a propulsion optimization system developed by Yara Marine Technologies that provides an integrated ShaPoLi feature that complies with the EEXI framework. The system enhances vessel efficiency while minimizing the impact of engine or shaft power limitations on daily operations. FuelOpt can also reduce fuel consumption and emissions by controlling the propeller pitch and engine load in real time.
    • Rotating sails: These are vertical cylinders that rotate around their axis and use the Magnus effect to create a forward thrust. They can be installed on existing ships as an auxiliary propulsion system that can reduce fuel consumption and emissions by up to 20%. Some examples of rotating sails are Flettner rotors and Norsepower rotor sails .
    • Bulbous bow: This is a protruding bulb at the bow of a ship that modifies the water flow around the hull and reduces the drag. It can improve the hydrodynamic efficiency of a ship and reduce fuel consumption and emissions by up to 15%. However, it requires careful design and optimization for different ship types and speeds.
    • Propeller fins: These are appendages attached to the propeller blades that increase the thrust and efficiency of the propeller. They can reduce fuel consumption and emissions by up to 5%. Some examples of propeller fins are Becker Mewis Ducts and Propeller Boss Cap Fins .
    • Alternative fuels: These are fuels that have lower carbon intensity than conventional marine fuels, such as liquefied natural gas (LNG), biofuels, hydrogen, ammonia, or methanol. They can reduce greenhouse gas emissions from ships by up to 100%, depending on their production and use. However, they also require new infrastructure, storage, handling, and safety measures.
    • Propulsion systems: These are systems that convert energy into propulsive force, such as diesel engines, electric motors, gas turbines, or fuel cells. They can be upgraded or replaced with more efficient or low-carbon technologies that can reduce fuel consumption and emissions. Some examples of propulsion systems are hybrid propulsion, diesel-electric propulsion, or hydrogen fuel cell propulsion .

What Marine Engineers Need to Do

Marine engineers play a pivotal role in ensuring vessels comply with EEXI regulations and optimizing propulsion and engine systems. Here’s what they should consider:

  1. Data Analysis: Conduct detailed data analysis to determine the current energy efficiency of propulsion and engine systems. This forms the foundation for improvement strategies.

  2. Collaboration: Collaborate with naval architects, designers, and technology providers to select the most suitable propulsion and engine optimization solutions.

  3. Regular Maintenance: Implement a rigorous maintenance schedule to keep engines and propulsion systems in optimal working condition, reducing energy wastage.

  4. Training: Stay up to date with the latest technologies and best practices through continuous education and training programs.

  5. Monitoring and Reporting: Implement systems for real-time monitoring of engine and propulsion system performance. Regularly report on energy efficiency improvements and emissions reductions.

  6. Documentation: Maintain comprehensive records of all upgrades, modifications, and maintenance activities related to propulsion and engines for compliance verification.

The EEXI regulation is expected to have a significant impact on the shipping industry in 2024 and beyond. As the maritime industry charts a course towards greater sustainability, marine engineers are the navigators guiding vessels through these uncharted waters. By leveraging the available technology and adhering to best practices, marine engineers can help vessel owners and operators meet the challenges of EEXI compliance while contributing to a cleaner, greener future for the maritime world.

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