The global shipping industry is responsible for nearly 3% of worldwide greenhouse gas emissions, a figure that continues to rise as global trade expands. With international regulations tightening under the International Maritime Organisation (IMO) to achieve net-zero emissions by 2050, the need for clean fuels has never been greater. Among the most promising alternatives is green ammonia, a carbon-free fuel with the potential to transform maritime transport.
This article explores the role of green ammonia in decarbonising shipping, its advantages, challenges, and future prospects.
Why the Shipping Industry Needs Green Fuels
Traditional shipping relies on heavy fuel oil, a carbon-intensive energy source that releases high levels of carbon dioxide, sulphur oxides, and nitrogen oxides. While measures such as energy efficiency improvements and LNG adoption provide temporary relief, they do not deliver the deep decarbonisation required to meet IMO’s ambitious goals.
This is where green ammonia uses in shipping become highly relevant. Produced using renewable energy, green ammonia offers a sustainable ammonia-based solution that is scalable, storable, and versatile.
What Makes Green Ammonia Suitable for Shipping?
Green ammonia has several characteristics that make it an attractive marine fuel:
- Carbon-free combustion: Unlike fossil fuels, green ammonia does not emit carbon dioxide when used as a fuel.
- High energy density: It provides higher energy per unit volume compared to hydrogen, making it more practical for long voyages.
- Proven transport and storage systems: Ammonia already has an established global network of pipelines, terminals, and green ammonia transporters.
- Versatility: It can be used directly in ammonia-powered engines or cracked into hydrogen for fuel cells.
Comparison: Green Ammonia vs. Conventional Marine Fuels
Below is a comparison of green ammonia with conventional shipping fuels:
| Aspect | Green Ammonia | Conventional Marine Fuels (HFO, LNG) |
|---|---|---|
| Carbon Emissions | Zero direct CO2 emissions | High CO2 and sulphur emissions |
| Energy Density | High, better suited than hydrogen for long-distance shipping | Moderate to high, but reliant on fossil resources |
| Infrastructure | Global ammonia supply chains already exist | Well-established but fossil fuel dependent |
| Environmental Impact | Renewable, sustainable, and future-ready | Unsustainable with high emissions |
| Future Potential | Key role in decarbonising shipping and achieving IMO targets | Limited; transitional but not long-term viable |
Green Ammonia Initiatives in Shipping
Several global projects are exploring renewable ammonia as a marine fuel:
- Demonstration vessels: Companies in Europe and Asia are developing ammonia-powered ships expected to be operational by the late 2020s.
- Fuel cell integration: Research is underway to combine green ammonia benefits with hydrogen fuel cells for higher efficiency.
- India’s role: With abundant renewable energy, green ammonia in India is being developed not just for agriculture and power but also for maritime exports. India’s ports are gearing up to handle sustainable ammonia storage and transport, making it a strategic hub for the shipping sector.
Challenges and Considerations
While green ammonia offers immense promise, there are challenges that must be addressed:
- Toxicity: Ammonia is hazardous to humans, requiring strict safety measures during storage and handling.
- Engine development: Marine engines compatible with green ammonia are still under testing and need commercial scale-up.
- High production costs: Electrolysis-based ammonia production is currently more expensive than conventional fuels, though costs are expected to decline with technology improvements.
Future Prospects
Despite these challenges, the future of sustainable ammonia in shipping looks highly encouraging. As the cost of renewable electricity falls and large-scale electrolyser projects are deployed, green ammonia will become more competitive.
The IMO’s decarbonisation goals, coupled with strong government support, are accelerating investment in green ammonia transporters, bunkering facilities, and demonstration projects. By the 2030s, the industry is likely to see widespread adoption of green ammonia uses in shipping, paving the way for a zero-emission maritime sector.
Conclusion
The shipping industry is at a crossroads: it can either continue relying on fossil fuels or embrace green ammonia as a transformative solution. While challenges exist, the benefits—ranging from zero carbon emissions to established transport infrastructure—position green ammonia as one of the most viable marine fuels of the future.
As governments, shipping companies, and technology providers work together, the adoption of renewable ammonia will not only decarbonise maritime transport but also help create a more sustainable global trade system.
