A common belief among shipping professionals is that zero-carbon fuels are required to significantly reduce greenhouse gas emissions from maritime transport for the long run.

Garry Noonan is Ardmore Shipping’s head of transition technologies. Photo: Ardmore Shipping

With such fuels expected to take years or even decades to develop, some experts believe shipowners should adopt existing technologies to kick-start decarbonisation efforts, rather than wait for the new energy sources.

“Sometimes we can get hung up on zero-carbon fuels,” said Garry Noonan, head of transition technologies at product tanker owner Ardmore Shipping.

“I mean, it’s an energy transition. Zero-carbon fuels aren’t going to [emerge] overnight.”

Slow development of new fuel technologies and infrastructure come as the industry's debate over future fuels continues to drag on.

LNG has emerged as the most popular alternative fuel, due to its mature propulsion technology and sufficient supply, but most researchers believe its climate benefits are too limited to decarbonise shipping in the long term.

In contrast, renewable hydrogen, ammonia and methanol as marine fuels can help achieve zero-emission shipping, but their associated technologies remain under development and commercial viability is in doubt.

“What will be the future fuel? That's the million-dollar question, which I don't think anyone really has an answer to,” said Mikko Kuosa, chief executive of Finnish software provider NAPA.

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“It will still take a little bit [of] time, because the fact is that all these alternative technologies are not fully mature.”

Kuosa suggested that for now, shipowners can focus on achieving just-in-time arrival and reducing port waiting times with route optimisation, which can cut fuel consumption and carbon emissions.

“This is a rather easy area for the industry to find efficiencies and improvements by using more sophisticated ways of weather routing,” he said.

Norsepower chief executive Tuomas Riski believes energy-saving devices can be compounded with digital routing technology to enhance decarbonisation effects.

His company has installed rotor sails on six vessels across the tanker, dry bulk, ro-ro and passenger sectors. The auxiliary, wind-based sails are mechanical cylinders that spin to help propel a vessel forward, thereby reducing fuel consumption.

“We are openly collaborating with providers of [route optimisation] software … We can deliver them data of the performance of our rotor sails,” Riski said.

“Let’s say typically it’s 5% [fuel] saving. Maybe it can be increased to 6% or 7% with route optimisation.”

Tapping into existing technologies can kick-start decarbonisation and benefit shipowners in the long run, Riski said, as new, zero-carbon fuels are expected to cost more.

“Those fuels, they are so expensive that even a small saving makes a lot of sense,” he added.