The heavyweight battle for shipping’s future fuels

Delivering jabs for different fuel types, serving up hooks to keep their energy source in the fight, Maersk, Lloyd’s Register, CORE Power and Shell duked it out for a big stake in shipping’s future. 

In the first corner, representing methanol, was Maria Strandesen, Head of Future Fuels at A.P. Moller - Maersk. Touting the benefits of green methanol as a contender with mature engine technology and low toxicity, she claimed it is a great candidate for large container ships. With Maersk having already baptised their first green methanol container vessel, it’s certainly a serious proposition.  

Strandesen said: “In large container ships we do see green methanol as one of the really good options and the reason being that, first of all, the engine technology is quite mature. 

“It has low toxicity both towards the human side and the aquatic organisms. It's easy to handle. It's liquid at ambient temperatures. And you can produce it in a variety of ways.” 

Scalability is the key, she added, as Maersk has 24 more container ships designed to run on green methanol on order. 

“Around 2026-ish point we would need to burn about 750,000 tons of green methanol which is a significant amount,” she said. 

But Maersk is encouraged by the growing number of orders for methanol container ships worldwide, currently at 125. “That's great because that creates a really significant demand signal that will help the chicken and egg dilemma that we face. We are confident and we do see a growing number of green methanol suppliers in our pipeline.” 

Welcoming ammonia to the ring 

In the second corner, fighting for ammonia, was Mark Darley, Global Marine and Offshore Director at Lloyd’s Register. 

Ammonia enters the ring with its advantages: near-zero emissions when generated from renewables, a relatively high energy density, and an existing global infrastructure. However, ammonia's toxicity is an issue, making safety the paramount concern.  

The other disadvantages are that there's still a lot of work to do to really understand what happens when you put ammonia in engines, and that seafarers must be upskilled to handle ammonia, and regulations need to catch up with its use. 

“About a million seafarers will have to be upskilled to support the use of transportation of ammonia alone,” Darley confirmed. Plus, IMO’s International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk doesn't currently permit the burning of toxic cargoes. 

Hydrogen may be the go-to-gen 

Sitting in the third corner was Stephen Brown, Shell’s Manager of Technology, taking up the mantle of hydrogen. 

Hydrogen boasts abundance, high energy per weight unit, and potential for emission-free consumption. 

“As a molecule it's the most abundant molecule element in the universe: 75% of all matter. In terms of its energy per weight unit, it's the highest. It's very, very light. It can be produced from renewable sources. And when it is burned, consumed, or converted there are zero emissions on the water, potentially,” Brown enthused. 

However, this lightweight contender brings flammability challenges, demanding innovative ship designs and safety measures. 

Brown emphasised that new fuels can't simply be plugged into old systems; radical design changes are needed. 

“The work we've been doing over the last few years has been to understand hydrogen and with that understanding, we can then design for it. The hazards presented by these new fuels are considerably more challenging,” he concluded. 

Going nuclear in the ring 

In the final corner was Mikal Bøe, Chairman and CEO of CORE Power, supporting nuclear energy. 

Bøe argued that with shipping's massive energy consumption, alternatives like ammonia and methanol - derived mainly from natural gas - won't be climate saviours, despite the hype. 

Instead, Bøe presented new nuclear as the only true zero-emission technology and fuel for a ship's lifetime. His argument centred on economics, highlighting the transportability challenges of other fuels like hydrogen. 

“Shipping consumes 350 million tonnes of heavy fuel and we generate four billion megawatt hours of energy. Moving transport and global trade away from fossil fuels actually presents an almost insurmountable challenge of scale,” Bøe lamented. “The alternative fuels that are mostly discussed are ammonia and methanol, fuels that will function in conventional engines. But if we produce those fuels as we do today, which is almost entirely from natural gas, we will go from 3% of the global emissions up by a factor of five to around 15%. I don't think that's really a solution.  

“So, we recognise that actually nuclear, love it or hate it, is the only true zero technology and fuel for the lifetime of a ship. And no other energy source for power system will give us really a true zero emission footprint, and that's an important thing to recognise.” 

It is, Bøe added, economics that win out at the end of the day. “If you can go faster for less money, and you can deliver on time, without stopping for refuelling, and you can provide benefits to the ports you call at, you're changing the contract to the public.” 

The winner on points is… all of them 

Bøe finished by urging for a return to first principles: a cubic metre of liquid hydrogen is 71 kgs; a cubic metre of bunker fuel is 991 kgs. Therefore the same weight of liquid hydrogen requires 14 times the volume and will have many technical challenges. The largest VLCC on the water today would theoretically carry 17,000 tons, he outlined.

“If we're going to produce millions and millions and millions of tonnes of the stuff, we actually have to do it where we need it because of the transportability. Practically speaking, that scale isn’t there. So, if we're going to use hydrogen as the base feedstock for ammonia, methanol for sustainable aviation fuel, we have to make it where we need it.” 

As the debate intensified, Brown countered with a discussion about energy density, explaining that higher efficiency ship designs are needed to mitigate some of hydrogen’s energy density challenges. 

“Our work is already suggesting that we'll be able to carry more cargo in the same hull dimensions with more of that volume on board. It is preying on the properties of the product and actually using the hull effectively for those future fuels,” he closed.