According to the latest annual report on ship engine retrofitting titled "Engine Retrofit Report: Applying alternative fuels to existing ships" released by Lloyd's Register of Shipping, due to the large number of ships requiring on-site retrofitting, there may be insufficient production capacity in shipyards in the future.

In order to achieve the decarbonization goal of the shipping industry by 2050, the development of ship technology often focuses on newly built ships. However, given the long service life of ships, it is evident that many old ships using fossil fuels will continue to be used before 2050, and it is predicted that these ships account for about 20% of the global fleet.

Transforming the existing fleet is the key to energy transformation

Therefore, renovating these ships is a key factor in the energy transformation of the shipping industry. One solution is to retrofit ships to use carbon neutral or zero carbon fuels, which may require modifications to the ship's engines, tanks, pipelines, systems, and structures.

Claudene Sharp Patel, Technical Director of Lloyd's Register of Shipping (LR), said, "The decarbonization of existing fleets is crucial for reducing greenhouse gas emissions in the shipping industry. It is expected that by 2030, there will be 9000 to 12900 large commercial ships in the global fleet that need to be modified to varying degrees to have zero carbon emission capabilities. Modifying more of these ships can quickly accelerate the transformation of maritime energy.".

Requires a large amount of shipyard production capacity

However, the 2023 Engine Renovation Report released by Lloyd's Register of Shipping found that a lack of shipyards with sufficient renovation experience may hinder the progress of existing fleets in adopting alternative fuel technologies. Currently, the number of shipyards capable of such renovations is limited, and it is likely that only a small number of ships will be retrofitted, as renovating old ships (over ten years) and small ships is very challenging.

This report identifies key factors that affect market size and timing of retrofitting, including the date when the shipping industry begins building zero emission ships, the age of ships retrofitted by shipowners or operators, and appropriate engine types and cylinder bore sizes.

The study clearly points out that research on the technical status, integration and compliance of alternative fuels used in existing ships, as well as commercial cases of ship modification, has found that shipyard capacity and production capacity issues may hinder the application of alternative fuel technology on existing ships.

Fuel retrofitting is more complex than most projects in shipyards, which may jeopardize the decarbonization goals already set. Another factor to consider is the availability of shipyard berths. According to LR, the shipyard's maintenance capabilities are currently limited, and there are other limitations in the supply chain, namely the need to balance the demand for new shipbuilding with the growing demand for modified engines.

The main challenges of engine modification

This study analyzed the demand, capability, and adoption of engine modification, and also pointed out that if the shipping industry wants to use modification as an effective path to reduce carbon emissions, it needs to master new skills in ship construction, electrical engineering, and fuel processing. One of the main challenges identified in the report for the renovation is system integration, and the key issues can be summarized as:

1. Storage tank: Fuel with lower energy density requires a larger storage tank capacity. Finding a suitable location to place the storage tank is challenging, as it not only meets safety requirements but also minimizes the impact on structural integrity and cargo capacity.

2. Fuel preparation. Some existing ship designs find it difficult to install fuel pumps and valve groups near the engine compartment.

3. Pipeline: The cost and size of double-layer fuel pipelines have increased, and there is also a need to minimize interference with ship structures when planning ship modification pipeline routes.

4. Safety: Exhaust, blowing, ventilation, and fire/gas leak detection and prevention all increase the complexity of the renovation. In addition, designers need to always pay attention to safety issues and minimize opportunities for crew members to come into contact with toxic and flammable fuels.

Human factors cannot be ignored

The impact of new fuel on crew members cannot be ignored when existing ships are equipped with alternative fuels. Working, operating, and maintaining new equipment on ships using these fuels will bring new risks.

The evaluation of human factors not only includes working conditions and schedules, but also includes checking design and safety procedures to ensure that these risks are minimized. For example, ensuring that the design of the ship meets the abilities and limitations of the crew under different operating environment conditions.

The limiting factors of shipyard renovation capacity

The complexity of ship modification means that the number of shipyards initially able to implement such projects is very limited. Fuel modification is more complex than most projects carried out by repair shops, and modifying the engine itself is a relatively simple process that only requires the installation of prefabricated engine components. However, considering completely different fuel uses in the design is quite challenging because traditionally, repair shops focus on repairing ships based on the original design.

Fuel modification requires professional skills, which fundamentally limits the application of alternative fuels in ships. The ship designers surveyed by LR emphasized three important areas:

1. Ship structure: Careful consideration should be given to the design and location of system components such as storage tanks, fuel preparation rooms, and pipelines to meet safety requirements, especially for ventilation and hazardous areas. Furthermore, it is crucial to evaluate the impact of each component on the strength and stability of the ship's structure.

2. Electrical engineering: Strengthening monitoring (leak and fire detection), automatic mitigation systems (including purification, fire protection, exhaust, and ventilation), and more complex fuel chain supervision pose new requirements for ship electrical and automation infrastructure, requiring shipyards to have higher electrical engineering skills to install new systems when necessary.

3. Fuel treatment: Especially during the commissioning and testing phase of renovation projects, shipyards need to have the ability to handle alternative fuels. At present, the number of ships using alternative fuels is limited, and the introduction time of these ships is relatively short, which limits the opportunities for repair shops to access these ships. These requirements mean that the number of repair shops initially capable of fuel modification is very limited. A key indicator for measuring shipyard capabilities is the type of work they have previously engaged in. For example, repair shops with experience in complex offshore projects are likely to possess the required design and electrical engineering skills, while shipyards that have converted ships into floating production and storage facilities also possess similar capabilities. Another limiting factor is that there are too few experienced engineers. Although some designers suggest that shipyards lacking expertise in certain areas (such as stainless steel welding) can directly hire new teams, in reality, this is difficult to achieve. As a designer pointed out, all industries are undergoing green transformation, not just in the maritime sector. Everyone wants the experts we need