Worldwide shipping contributed about one billion tonnes of carbon dioxide (CO2) and three percent of yearly global greenhouse gas (GHG) emissions, according to the International Maritime Organization’s (IMO) Fourth GHG study.
Therefore, in order for the maritime sector to achieve the goals of the Paris Agreement, emissions must be cut by 45 percent from 2010 levels in 2030 and reach zero by 2050. Batteries, fuel cells (FC), green hydrogen, green ammonia, e-methane, and carbon capture are a few options to decarbonize the industry. Still, a definite winner has yet to be found.
Fuel cells are highly supported to play a key role in this decarbonization mission in a new report from IDTechEx titled “Fuel Cell Boats & Ships 2023-2033.” There are several ways, including burning, to transform the chemical energy in green fuels into mechanical energy. Fuel cells are suggested by IDTechEx as a very effective option that can lead to zero emissions due to their tremendous potential.
According to Luke Gear, Principal Technology Analyst at IDTechEx, “generally, batteries and hydrogen and ammonia fuel cells have tremendous potential to develop long-term pathways to zero emissions.” “It is simple to picture a time in the future where hydrogen PEMFC and batteries are widely used in the mid-term and ammonia SOFC are widely used in the long-term. What is certain, though, is that massive financial support, policy support, and investment from both the public and private sectors will be required to continue reducing emissions in the maritime sector.”
The maritime industry currently has access to two feasible technologies: solid-oxide fuel cells and proton exchange membrane fuel cells (PEMFC) (SOFC). Since hydrogen has the highest volumetric energy density, it is the most widely used and the focus of most providers for PEMFCs. For ocean-going ships, liquid hydrogen needs a lot more storage space, and it takes a lot of energy to attain and maintain the necessary -253°C. However, the maritime PEMFC market is expanding quickly, especially in the inland and coastal regions.
Many of these problems are addressed by SOFCs. They are fuel-flexible and can run on ammonia, hydrogen, LNG, LPG, methanol, ethanol, and other fuels with combined heat and power (CHP) operations at efficiencies above 80%. Compared to conventional PEMFC and marine diesel engine efficiency of 55 and 45 percent, respectively, this is a significant improvement.
Gear continues, “The benefits of ammonia and ammonia-fed SOFC+CHP are naturally creating industry excitement. “A 2MW SOFC system from Alma Clean Power will be retrofitted onto the offshore supply vessel Viking Energy in 2023, making it the first ammonia-powered SOFC vessel in the world. Yara will provide green ammonia, enabling up to 70% of the power requirements to have zero emissions.”
Long start-up times and a subpar dynamic response are only two of the difficulties that SOFC still needs to overcome. However, it is believed that these issues can be managed in a marine environment when used in conjunction with a battery system. The main drawbacks are supply chain and infrastructure problems. Megawatt SOFCs and green ammonia are currently hard to come by.
