Shipping’s journey to decarbonisation: Engine Retrofitting of Vessels for Alternative Fuels 

In the face of global environmental concerns, the maritime industry is undergoing a profound transformation to decarbonise and reach the International Maritime Organization’s (IMO) ambitious net-zero emissions target by 2050. Low or zero-carbon fuels to propel the world’s fleet are fundamental to meeting this target. However, existing vessels will require retrofits to be able to safely switch from fossil fuels (diesel and LNG) to low or  zero-carbon alternatives.
  
Engine retrofitting is a complex process that involves cutting-edge technologies, coupled with skilful engineering and the consideration of compliance frameworks as well as business and community perception. Therefore, providing a thorough, annual guide to engine retrofitting is a key requirement for the maritime industry to be  ready to embark on this journey of applying alternative fuels to existing ships. 
To this end, Lloyd’s Register (LR), a global leader in maritime safety and risk management, has unveiled its inaugural Engine Retrofit Report, a comprehensive guide for the shipping industry as it embarks on the transformative journey towards decarbonisation.

The report delves into the intricacies of engine retrofits, exploring the technical, economic, and regulatory considerations that shipowners must consider when evaluating and implementing these solutions. With a focus on methanol and ammonia as promising alternative fuels, the report provides valuable insights into the readiness of the industry to embrace these technologies.

Fleet and technology readiness
The retrofitting journey begins with a comprehensive assessment of the state of the fleet and the technology available, as retrofit readiness is not a one-size-fits all concept. Both methanol and ammonia have been extensively studied as emerging alternative fuel providers, but technological readiness levels for engine conversion varies between vessels. In turn, no specific timeline has been set on the development of technology availability for retrofitting, but there have been many promising advancements already, especially regarding methanol engine conversions. 

Data published in May 2023 suggests there  are approximately  477  vessels which could be retrofitted to  run on low or zero carbon emissions  fuels, like methanol and ammonia.
‘Fuel-ready’ class notations issued by class societies like LR, provide assurance that these vessels are able to operate using the fuel specified. When looking at the world fleet and vessels’ readiness to adopt new fuels, vessel design, implementation of new equipment, and associated costs, must also be factored in to fully appreciate the extent the work ahead. 

Subsequently, a Zero Ready framework has been developed to offer more clarity on fleet readiness and help stakeholders plan retrofits more effectively. 

Regulation and System Integration Challenges
While engine technology readiness is a crucial factor in ship conversions for low or zero-emissions fuels, the larger issue lies in integrating the wider fuel system and related supporting systems onto existing vessels. Since methanol is a liquid fuel at room temperature and pressure, retrofitting it is easier than other fuels. However, existing vessel arrangements must still be considered due to factors like energy content, fuel-specific properties, and safety system requirements. Consequently, the applications of these alternative fuel types require thorough regulation to be deemed safe for use by commercial vessels and pose significant challenges in successful integration. 

Yard Capacity and Capability
Addressing the practical side of retrofitting, the capacity and capability of shipyards to meet the growing demand for engine retrofitting should be a prerequisite in this process. This is because the lack of both capability and capacity  could potentially compromise the maritime industry’s retrofit ambitions to apply new  fuel technologies to the existing fleet.

Human Factors
Recognising the importance of human factors in this process is crucial. The emphasis must be  on the need for skilled crew members to operate and maintain the retrofitted engine, as well as suitably qualified  engineers  to retrofit the engine in the first place. This requires training, and maintaining high safety standards of  occupational health for those that live and work alongside the new fuels, those members on board, and is a crucial part of the holistic nature of engine retrofitting. 

Economic influences
Incorporating renewable methanol or ammonia into maritime operations is anticipated to exert a notable upward pressure on fuel expenditures, potentially resulting in a more than twofold cost escalation for vessels across diverse segments, as shown by the techno-economic modelling data unveiled in the Report. From a business standpoint, navigating this cost challenge becomes imperative. However, a promising prospect emerges in a scenario where alternative fuel costs decrease, coupled with an increase in carbon pricing, potentially tilting the economic balance in favour of these new  fuels. Therefore, balancing the economic considerations within the broader context of sustainable business practices in reducing carbon emissions becomes a crucial aspect for key stakeholders in the maritime industry.

Overall, according to the Engine Retrofit Report, the maritime energy transition might be accelerated significantly by retrofitting a sizeable portion of the 9,000–12,900 large merchant vessels that are projected to be in the world’s fleet by 2030.
 
For this to be a reality,  it is important  to address  fleet readiness, technological considerations, regulatory drivers, practical aspects like shipyard capacity for retrofitting and importantly, human factors.

The Engine Retrofit Report offers guidance to industry stakeholders to make informed decisions in their pursuit of reducing carbon emissions and reaching the IMO’s net-zero emissions target by 2050. As the maritime sector navigates this transformative journey towards decarbonisation, engine retrofitting will become a key element in the mix to enable the maritime industry to move towards a more sustainable future. 

Find out more and read the full report ‘Engine Retrofit Report 2023: Applying Alternative Fuels to Existing Ships’ here.