For the owner and operator, the notion of a future-proofed container ship is one that incorporates or has the structure to retrofit the fuels systems and technologies that ensure a commercially competitive lifecycle during the decarbonisation era
What are the demands on a future-proofed container ship? Starting with the fuel systems, ABS has produced a study on the likely decarbonisation pathway from 2020 to 2050. ABS director of sustainability, at its Global Sustainability Center in Copenhagen, Jan Otto de Kat* described the main points that came of the study.
“The largest contribution towards decarbonisation will come from fuels,” said Mr de Kat. “The three fuel pathways are light gas, heavy gas and bio synthetics.” He explained that light gas encompassed those with a low carbon to molecule content such as LNG, bio-derived methane and hydrogen. “Hydrogen has a high energy density, no carbon but has other challenges,” he said.
Heavy gas includes LPG, methanol, ethanol, with ammonia being the zero-carbon fuel in this category but with lower energy content. Bio synthetics are the derivatives of these fuels and come with a cost factor.
“Will one fuel fit the bill for all?” asked Mr de Kat. “No, we can expect a mix of these.” He noted that the whole power requirement of a container ship should be assessed for decarbonisation, including reefer plugs, hotel and accommodation energy requirements.
The future fuel mix is opaque: in a poll, nearly half (43%) of respondents reported the likely fuel mix for container ships in 2050 was too difficult to decide today, and over a third (36%) thought the fuel mix would be a combination of LNG, bio-sourced fuel oil and ammonia. However, the availability of low-carbon fuels would be a factor in deciding which fuel to choose for a newbuilding or a retrofit installation.
MAN Energy Solutions head of two-stroke promotion & sales Thomas Hansen said the engine builder had laid down a pathway to develop fuelling systems under different engine notations that can be retrofitted to burn different fuels, including ammonia in the near future:
“We have developed a number of technologies,” he said, “that allow us (MAN ES) to accommodate different fuels into the future.”
Given the options of fuel choice available now and fuels available soon, such as ammonia, a survey found that future retrofit possibilities was the number one (47%) criterion when deciding on a fuel for a container ship newbuilding today. A quarter of those polled considered operating cost was the main criterion and a similar amount judged the capital cost to be the main parameter.
LNG containment system designer GTT head of product line, LNG as fuel division, Alexandre Tocatlian noted GTT is working with MAN ES on a large-scale LNG-power retrofit with Hapag-Lloyd on a 15,000-TEU container ship. The containment system was built on the quayside and was lifted into the vessel and fixed in place. The operation took approximately a month, said Mr Tocatlian.
“GTT is working on a new concept of LNG conversion, via jumboisation,” said Mr Tocatlian. The aim is to add cargo capacity to compensate for the loss from the additional fuel tanks. The new block floated and welded in place has the LNG fuel tanks and additional container slots. “To give you a ball-park figure, instead of losing 300 TEU, the vessel gains 1,300 TEU,” he said. Like any other fuel tank, the GTT LNG fuel tank is designed for all fuel level situations and incorporates anti-sloshing features.
Would innovations like these be the driving force in the conversion of container ships to LNG power, or were other factors at play? In a poll, stronger regulation was the most popular reason (42%) to take the step toward LNG power. A lower capital cost and wider LNG availability and infrastructure were the second reasons given – both options polled 28%.
Newbuild or retrofit
Should owners retrofit or order new vessels? Mr de Kat noted that owners will consider if it is worthwhile undertaking a conversion. “But the tougher choice is what to do with a newbuild,” he said. “If you invest in LNG now, make the system flexible enough so that you can convert, for example, to ammonia.”
What does an engine retrofit entail? Mr Hansen said the engine itself is not the biggest problem, it is fitting another fuelling system. This is not as daunting as it sounds – a lot of the preparation work can be done at sea, with the cylinder covers replaced in the shipyard.
Mr Tocatlian noted that “the first retrofit is always the longest”, and the process will be optimised. GTT prefers to offer the jumboisation option, which provides other gains besides the lower carbon of LNG fuelling.
Taking the proposition one stage further, what three to five technologies would be incorporated today into a newbuild container ship for the main trade lanes and what would be added to allow retrofitting later? Mr Tocatlian would have LNG and with an ammonia-ready notation. He would also add innovations in propeller design, waste heat recovery and hull air lubrication.
Mr Hansen noted that nearly all container ships on order today are specified with fuel oil with the option of LNG. With the future uncertain, preparing for the possible use of alternate fuels is sensible. “Build your ship in such a way that there is accommodation for a second fuel,” he said, even if that alternate fuel has not been decided.
Mr de Kat took a slightly different approach and regarded having the ship as energy efficient as possible was the first requirement. “This means optimising the hull design, propeller, energy-saving devices, auxiliary power and optimisation software,” he said. Regarding future fuel and retrofits, the key would be to make installation as easy as possible.
Unless an owner orders a bespoke container ship, a future-proofed container ship rests on the designs offered by shipyards. This puts a lot of trust in the shipyards to define a future-proof design. In a poll, only 9% felt they could rely on the shipyard to define a future-proofed container ship. Consultants were chosen by 29% and class society by 31%. A third (34%) of those surveyed put their trust in defining the future-proofed container ship in engine makers.
*Adopted from the Riviera webinar The future-proofed container ship held on 9 February 2021.