Why hydrogen lies at the heart of future fuels

When you talk about decarbonising shipping and transitioning towards future fuels, it is important to note that most of these fuels, except biofuels, are made from hydrogen. As such, it does not matter which direction shipping takes as it moves away from heavy fuel oil, it is inevitable that the sector will create a huge future demand for low-carbon hydrogen.

This means that as a prime user of this fuel source, our sector has to do its homework and determine how best to provide sufficient clean hydrogen at an affordable price, which at present remains a conundrum. To achieve this goal, we need to co-operate closely as a sector, factoring in all elements, from vessels to ports, so that we can provide the technology for the shipowners and operators and develop the bunker infrastructure in line with the ports.

This is a remarkable task, but we are not starting from scratch: we have already done a lot of work in this area, starting five or six years ago with smaller auxiliary power units. Progressive developments mean that we are now at a point where we can start to develop multi-megawatt-power ships using fuel cells running on pure hydrogen or ammonia. Earlier this year, the Fuel Cell and Hydrogen Joint Undertaking, of which we are partners, announced a call for a project for a liquid hydrogen, multi-megawatt vessel and it quickly became one of the most fiercely competitive calls of all the topics, so the interest is there.

“To decarbonise shipping by 2050 we need to start launching hydrogen vessels soon”

But there is another key question that needs to be addressed: which of those fuels based on hydrogen will be the one that becomes the mainstream option in the future? 

We are all aware that ships have a long lifetime and those that are being built today, or within the next few years, are still going to be in service in 2050. If we want to decarbonise shipping by 2050, we need to start launching those vessels that are going to contribute to this process over the next few years.

To tackle this uncertainty over the choice of future fuels, we developed a hydrogen fuel comparison tool. It factors in the whole value chain, including cost of fuel production; combustion; liquefaction; it also considers the cost of fuel; transportation; storage; and the cost of onboard equipment among other things. We even looked at any potential loss of revenues from the uptake of such fuels; for example, we acknowledged that alternative fuels have worse energy density properties than diesel and that cargo space might be compromised by fuel storage.

The results show us that those fuels which require the least additional transformation of hydrogens are always going to be the most cost-effective option: hydrogen is always going to be cheaper than liquid hydrogen, which in turn is going to be cheaper than synthetic fuels because it does not require additional processing. Ammonia is going to be cheaper than the more refined synthetic fuels because it does not require the carbon molecule. 

However, as the almost exact opposite progression applies to the energy density of the fuels, with the cheapest fuels having the worst density properties, the choice of fuels becomes a question of finding the right balance between the fuel costs and impact on cargo space.

Our findings, which consider over 40 different ship types, show there is a small place for compressed hydrogen, mostly for ships that can be bunkered often. When you only need 200 nautical miles of range, for example, losing some cargo space because of extra fuel volume has less impact. Further distances make liquid hydrogen a far more viable option. And then at some point for deepsea shipping applications, synthetic fuels start to make the most sense, with ammonia clearly leading the way in terms of cost.

Grzegorz Pawelec is research, innovation and funding manager at Hydrogen Europe