Decarbonisation Round Table flags biofuel as opportunity for older ships; doubts over shore power

These three takeaways were identified by a Decarbonisation Round Table featuring Maikel Arts (head of cruise, Wärtsilä), Linden Coppell (VP sustainability & ESG, MSC Cruises), Rael Harris (CCO, Ocean Technologies Group), Valeria Mangiarotti (technical environmental solutions director, Sardinian Ports), Javier R. Sanchez (regional director West Med & Asia Global Ports Holding and md of Barcelona Cruise Port) and Liina Vahala, (project manager NEcOLEAP at Meyer Turku).

The group also voiced slight doubts about the true potential of shore power in light of the massive investments required and the length of time projects take to be realised.

Net-zero cruise ship ready by 2030

The resounding clear (and not surprising) message is LNG and methanol are going to be the most relevant alternative fuels for the next generation cruise ship, while hydrogen is not expected to play any significant role, and ammonia is not considered to be an option for cruise ships at all.

Vahala left no doubt that Meyer Turku is ready for this newbuild journey, having the ambition to have a methanol concept ready to work by the end of next year.

Meyer Turku recently delivered Mein Schiff 7 to TUI Cruises in a methanol-ready state with the exception of adaptations necessary to the main engines, and TUI CEO Wybcke Meier earlier communicated it hopes to have the ship operating on methanol by 2026.

Along with methanol, LNG will retain and most probably increase its relevance, not least as new engine technology helps to reduce methane slip massively. MSC's Coppell believes in the potential of LNG, saying it continues to have ‘very strong attention and potential to take the cruise industry a long way down the renewable journey’. At the same time, however, Coppell and other round table experts also stressed the strong relevance of design flexibility for new cruise ships. 

Upgrades and retrofits provide a perspective for older ships

Existing cruise ships need more diversified approaches on the road towards climate neutral cruising. As Wärtsilä's Arts illustrated, interesting opportunities do exist - but their financial viability depends much on the age of a vessel or a fleet. In general, retrofits to LNG are technically possible but very complex and in practice hardly an option.

Methanol retrofits however - while constituting a very significant investment - can be an option, though mostly just for younger ships below about ten years of age. The engine part is not the most complex and costly part of such a transformation - in contrast, elements such as the total modification of tanks, ventilation, etc consume most of the investment, he shared.

The tank space mostly needs to be doubled, the engine room layout will be totally altered with lots of additional equipment added, and accommodation also may be impacted due to additional ventilation and the creation of safe spaces. While the total investment is very significant, the achieved lifetime extension is likewise high.

For ships between ten and 20 years of age, a methanol retrofit is usually not justified, but a moderate lifetime extension is still viable, including for example, engine efficiency upgrades, modifications to propellers or hull (including the addition of a ducktail or bulbous bow) or even the addition of hull air lubrication.

For ships in the 20 to 25 year age range such technology upgrades are financially too much, although every ship obviously needs to be investigated as a single case. But as a rule, vessels above the age of 20/25 years are merely best off with no upgrades but a transfer to an gradual increased use of biofuel for emission compliance.

Minimising energy consumption

A focus on operational efficiency, good housekeeping and optimised maintenance can still help to bring the energy consumption down - and to keep the ship in (commercially viable) operation for a number of further years. Overall, Arts suggested to set focus on minimising energy consumption, on flexibility and on a structured lifecycle management approach (including the choice of suitable partners) to keep existing ships on track on the road towards decarbonisation.

Wärtsilä, for its part, helps cruise ship owners by means of its new Wärtsilä Decarbonisation Model, a computer tool that builds - based on detailed input comprising among others operational data, design data, etc - a 'digital twin' of the existing ship. In a next step this digital model is converted and optimised in order to verify the impact of different measures. Once the model has been successfully upgraded, the specific planning of the upgrade or retrofit of the 'real' vessels can start.

Innovative propulsion requires new crew skills

The round table also determined that the issues to be considered in the context of innovative fuels and propulsions do not end with regulatory compliance and financial viability - crew competence is another highly relevant issue. In that context, they voiced that seafarer education needs to be reviewed in order to prepare prospective deck and engine crew, as well as officers, for alternative fuels. A message sent in that context was that the approach to learning needs a fundamental change, and that the traditional approach that seafarers trained future seafarers needs to be complemented with other elements.

Ports play a key role - but is shore power really the right way forward?

Synergies between ships and ports are vital on the road towards climate-neutral cruising, and ports play an essential role to facilitate the use of alternative fuels. Mangiarotti, who is also a MedCruise director and President of ESPO's Cruise and Ferry Port Network, left no doubt that the Mediterranean ports stand ready to take their role: According to a MedCruise survey, 27% of member ports have already implemented LNG bunkering and 81% are willing to provide this service, while 29% offer shore power and 94% aim to do so by 2030.

On the other hand, shore power failed to gain real enthusiasm by the experts with the massive investment needed and the time it takes to implement fuelling doubt, as well as the question if it really is the right solution for the future – or even the present?

This question illustrates that there are still a lot of uncertainty along the road towards decarbonisation, despite the fact that net-zero cruise ships are on the horizon by 2030.