Can Green Ammonia Deliver on Its Double Promise?
Green ammonia is increasingly gaining attention for its potential to play a double role in the global energy transition: decarbonizing fertilizer production and enabling long-distance hydrogen transport. But can it truly live up to this promise?
1. Ammonia’s Vital Role in Food and Emissions
Ammonia is a cornerstone of global agriculture, with around 85% of its production used in nitrogen-based fertilizers, according to the International Renewable Energy Agency report “Decarbonizing Hard-to-Abate Sectors With Renewables” (p. 46). Ensuring stable ammonia supplies is essential to feeding a growing global population.
Yet, the production process is deeply carbon-intensive. As the IRENA noted, about 72% of ammonia is made from natural gas and 26% from coal. Ammonia production alone accounts for:
Its total emissions are comparable to those of South Africa’s entire energy sector, as the International Energy Agency (IEA) notes in its Ammonia Technology Roadmap (p. 8-9).
2. Green Ammonia: A Cleaner Alternative
Green ammonia offers a solution. It is produced by synthesizing green hydrogen (from renewable-powered electrolysis) with nitrogen extracted from the air. The technology is commercially available, and scaling up production could significantly reduce the sector’s fossil fuel dependency and emissions.
With global ammonia demand expected to rise—especially for food security—shifting toward green ammonia is not only viable but urgent.
3. Beyond Fertilizers: Ammonia as a Hydrogen Carrier
Green ammonia's second potential lies in its use as a carrier for green hydrogen, particularly for long-distance and overseas transport.
Transporting hydrogen in its gaseous form is inefficient due to its low energy density. Liquefying hydrogen increases its density but requires extreme cooling to –253°C, making the process energy-intensive and costly.
Ammonia, by contrast:
Liquefies at –33°C
Carries 1.7x more hydrogen per cubic meter than liquefied hydrogen
Uses existing global transport infrastructure
As the IEA's The Future of Hydrogen report (p. 78) notes, ammonia is more cost-effective than pipelines for distances over 1,500 km, particularly for transcontinental delivery.
4. The Challenges Holding Green Ammonia Back
Despite its promise, green ammonia faces several hurdles:
High production costs: Currently, renewable ammonia costs $720–$1400/tonne, while fossil-based ammonia ranges from $110–$340/tonne. IRENA (p. 48) estimates prices could fall to $310–$610/tonne by 2050.
Energy losses in transport: Converting hydrogen to ammonia, shipping it, and then reconverting it back consumes 7–18% of the hydrogen’s energy content at each step, as mentioned in the IEA's The Future of Hydrogen report (p. 76).
Infrastructure gaps: There is a need to build conversion and reconversion facilities at ports and terminals globally.
Safety and regulation: Ammonia is toxic, corrosive, and flammable, requiring stringent handling protocols and globally aligned regulatory standards.
5. How to Unlock Green Ammonia’s Potential
To overcome these barriers and scale green ammonia sustainably, a combination of strategies is required:
Close the cost gap:
Introduce subsidies, carbon pricing, and tax incentives to make green ammonia cost-competitive with fossil-based alternatives.
Mobilize investment:
Support large-scale green ammonia projects through public-private partnerships and international climate finance, especially in renewable-rich regions.
Boost innovation:
Increase R&D funding to improve the efficiency of ammonia synthesis and hydrogen reconversion, and reduce overall energy losses.
Build infrastructure:
Invest in conversion and reconversion facilities at key ports to support green hydrogen transport via ammonia.
Ensure safety:
Develop and enforce international safety standards for the handling, storage, and shipping of toxic and corrosive ammonia.
Establish global regulation:
Create a harmonized regulatory framework to enable safe, cross-border ammonia trade for hydrogen delivery.
Sources:
The IRENA report on Decarbonizing Hard-To-Abate Sector with Renewables
The IEA reports on the Ammonia Technology Roadmap, and the Future of Hydrogen