Navigating Sustainability: Ammonia's Potential for Maritime Shipping

Amogy is retrofitting a 1957-built diesel-electric tug with its ammonia-to-power system (Amogy)

Published Oct 17, 2023 8:00 AM by Seonghoon Woo, CEO of Amogy

With maritime shipping responsible for a substantial 90 percent of global trade by volume and contributing to approximately three percent of the world's carbon emissions, the need for decarbonization is paramount. Amidst the mounting public and private sector pressure for the industry to reduce its carbon footprint and transition to more sustainable energy solutions, ammonia has emerged as a promising fuel for a wide range of vessel types. What follows is an overview of ammonia’s advantages as a fuel, the policy and regulatory landscape, and the strategies necessary for safe implementation for maritime shipping.

The Potential of Ammonia

Ammonia (NH3), the second most widely produced chemical in the world, is most commonly associated with fertilizers and household cleaning products. However, its potential as a carbon-free energy solution is gaining global recognition from governments, the private sector, and other stakeholders, particularly for hard-to-abate sectors like maritime shipping. Ammonia boasts several key advantages as a fuel:

1) High Energy Density: Ammonia has an impressive energy density, surpassing that of compressed hydrogen by nearly threefold. This makes it an ideal candidate for large-scale energy storage and long-distance transportation.

2) Ease of Storage and Transportation: Unlike hydrogen, ammonia can be stored as a liquid, making it convenient to handle, transport, and integrate into existing infrastructure. More than 200 gas carriers capable of shipping ammonia and 150-200 ports are equipped with terminals for unloading and storing traded ammonia. There are over 3,000 miles of existing ammonia pipeline in the U.S.

3) Carbon-Neutral Potential: Notably, ammonia can be produced using low-carbon methods like wind, solar, and carbon capture, aligning seamlessly with decarbonization goals. The growth of these methods is expected to add over 9 million tons of low-carbon ammonia production capacity annually by 2025.

These diverse advantages position ammonia as a promising candidate in the transition towards cleaner and more sustainable energy systems. The maritime industry is actively pursuing pilot and demonstration projects to evaluate ammonia engines and power systems across different vessel classes.

As an example, slated to sail in early 2024, Amogy is currently retrofitting a 1957-built tugboat that previously ran on diesel generators and electric motors with its innovative 1MW ammonia-to-power system. Amogy’s technology converts ammonia into a clean energy source by using a unique catalyst to crack ammonia into hydrogen for direct integration into a fuel cell. This power system, referred to as a “powerpack” is both scalable and modular, providing large-scale power for heavy-duty applications.

Policy and Regulatory Landscape

The International Maritime Organization (IMO) has made significant progress in promoting global shipping decarbonization, and there has been growing support for decarbonizing across the value chain. Worldwide support and collaboration are evident in various policy developments and industry initiatives.

For example, the Clydebank Declaration and the Green Shipping Challenge, aim to create green shipping corridors and accelerate the adoption of low-carbon fuels and technologies. Various industry initiatives, including the Getting to Zero Coalition and Cargo Owners for Zero Emission Vessels, support aggressive decarbonization targets.

Norway has taken the lead in incentivizing green shipping. In August 2023, the government launched a loan program to support environmental investments in the shipping industry with the goal of reducing emissions by 50 percent by 2030. Furthermore, Enova, the Norwegian government non-profit, launched new support programs for the use of hydrogen and ammonia power systems in vessels. The program will help establish the first profitable value chain for hydrogen and ammonia at sea by stimulating the demand side.

In North America, the U.S. is focused on research, innovation, and grants for sustainable fuel production, and clean energy technologies. With the passage of the Inflation Reduction Act in 2022, the U.S. has leap-frogged many countries in the scale of incentives for decarbonization efforts. Those efforts are expected to have a significant impact on the development of blue and green ammonia suppliers.

In Europe, initiatives like the EU Emissions Trading System and FuelEU Maritime aim to enforce economic penalties on carbon-intensive fuels and promote the use of low-carbon fuels. In the Asian Pacific, countries like Singapore, China, Japan, and South Korea are actively exploring ammonia as a maritime fuel, and Singapore plans to conduct an ammonia bunkering pilot by 2027.

Green shipping corridors have played a pivotal role in ammonia's development as a  maritime fuel. These corridors, including routes like the Hamburg-Halifax Atlantic Corridor and the Australia-Asia Iron Ore Green Corridor, are driving progress.

As the technology progresses, overcoming cost barriers and achieving effective regulatory guidelines remain essential for the widespread adoption of ammonia as a green marine fuel.

Safe Implementation

Like other fuel sources, safety is paramount when considering ammonia's usage as a fuel, as it is a toxic chemical. Fortunately, established safety frameworks, refined over a century of use in industrial and agricultural settings, exist to guide its production, storage, transportation, and use.

Ammonia’s strong odor allows for easy detection at low concentrations, contributing to enhanced safety management. Moreover, its gaseous form rapidly dissipates, minimizing the risk of containment or fire in case of a leak. Globally recognized safety regulations and standards are in place, with organizations like OSHA providing guidelines and training materials. Additionally, institutions like the International Maritime Organization and industry associations, including the Ammonia Energy Association and the Ammonia Safety Training Institute, actively work to codify safety regulations for maritime ammonia use, focusing on both onshore and sea bunkering.

By emphasizing proper handling, training, and technological solutions, associated risks can be mitigated. The establishment and enforcement of stringent safety standards will be integral to the safe and sustainable use of ammonia in maritime operations.


The path to sustainability is intricate and continually evolving, but ammonia's potential as an energy source is too substantial to ignore. With the right policies, investments, and safety measures, ammonia could soon become a staple in the fuel tanks of vessels worldwide, propelling us toward a more environmentally responsible and sustainable maritime future.

Seonghoon Woo is CEO of Amogy.

For more information, see Amogy's latest white paper, "Ammonia as a Clean Energy Solution for Maritime Use."

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.