Clean Energy Meets Agriculture: The Role of SMRs in Low-Emission Ammonia

Ammonia, a chemical compound with the formula NH₃, is a cornerstone of modern agriculture and a critical input to global food production. Today, nearly half of the world’s population depends on crops grown using ammonia-based fertilizers. Yet the scale and importance of ammonia come with a significant environmental cost: conventional production methods are highly energy-intensive and among the largest sources of industrial carbon dioxide emissions worldwide. As governments and industry look to decarbonize essential commodities, ammonia has emerged as both a priority and a challenge.

While global interest in low-emissions hydrogen and ammonia remains strong, the market is currently experiencing a period of recalibration. Many previously announced projects have been delayed or cancelled as developers confront challenges related to cost, infrastructure readiness, financing, and long-term offtake certainty. These headwinds highlight a critical reality: decarbonizing ammonia at scale requires solutions that prioritize reliability, high utilization, and robust long-term economics, not just low-carbon credentials.

The Environmental Challenge of Ammonia Production

In 2024, the world produced 200 million tonnes (Mt) of ammonia. As around 2.4 kilograms of carbon dioxide (CO₂) are released to the atmosphere per kilogram of ammonia produced, this resulted in a staggering 480 Mt of direct CO₂ emissions in 2024 alone. Moreover, ammonia continues to be a growing industry, potentially exceeding 300 Mt by 2040 if including the emerging market for ammonia as a low-carbon alternative fuel.

Why does this matter? About 70% of all ammonia produced is used to create nitrogen fertilizers and nearly half the world’s food production depends on it. While ammonia is vital for feeding the planet, the environmental cost of its production cannot be ignored.

How Ammonia is Made (and Why It’s a Problem)

Ammonia is created by combining hydrogen gas (H₂) with nitrogen gas (N₂) in a process called the Haber-Bosch reaction.

• Hydrogen production is the largest contributor to ammonia’s carbon footprint. Currently, nearly all hydrogen is made through a process called steam methane reforming, which relies on fossil fuels like natural gas or coal for both high-temperature process heating (>800°C) and as a direct feedstock. The hydrogen production step alone accounts for about 90% of an ammonia plant’s energy demand and generates more than 90% of the CO₂ emissions linked to ammonia plants. This concentration of energy demand also means that hydrogen production economics, particularly power availability, cost, and reliability, are often the decisive factors in whether low-emissions ammonia projects can advance beyond the planning stage.
• Nitrogen production is achieved through air separation, a process that removes nitrogen from oxygen in the air. At large commercial scale, this is typically accomplished using cryogenic separation technology, which requires electricity that is often generated using fossil fuels.
• The Haber-Bosch reaction (N₂ + 3H₂ <-> 2NH₃) commercially operates at high temperatures (350–550°C) and pressures (100-300 bar) and has low equilibrium conversion, requiring a large recycle stream. In addition, ammonia is often stored as a refrigerated liquid, requiring additional energy to power compressors and refrigeration systems.

A Cleaner Way Forward: The Role of NuScale

What if we could make ammonia without releasing CO₂? Producing hydrogen using water electrolysis makes it possible, and commercial-scale electrolysis technology is available today. Water electrolyzers use electricity to split water into H₂ and O₂, essentially a hydrogen fuel cell run in reverse. Converting this hydrogen to ammonia with a Haber-Bosch process neatly addresses challenges with storage and transport of hydrogen. The overall process to produce ammonia can then become fully electrified and, when powered with renewable or low-emissions energy, eliminates the need for fossil fuels both as a feedstock and as an energy source.

There are three main types of electrolysis systems:

• Alkaline: A mature and durable technology that is widely used, but fairly inefficient. It also requires the water to be dissolved in a corrosive alkaline solution.
• Proton Exchange Membranes (PEM): A newly commercialized technology that has a similar efficiency to alkaline but uses pure water. This technology is better suited to fluctuating power supplies, but requires platinum and iridium.
• Solid Oxide: An up-and-coming technology that uses high-temperature steam, which significantly improves the electrolyzer efficiency. The efficiency can be even higher if external steam supply is available. They require no scarce metals to produce, but the high temperatures make the process more challenging to operate.

Several demonstration and commercial-scale electrolyzer-based ammonia plants are being built worldwide, including the NEOM Green Hydrogen project, which uses 3.8 GW of solar and wind power to produce 1.2 Mt of ammonia per year.

While projects like NEOM demonstrate the technical feasibility of producing low-emissions ammonia at scale, replicating this model broadly requires power solutions that can deliver consistent output, high utilization, and predictable economics across diverse geographies and market conditions. While current projects rely primarily on renewable energy sources, nuclear energy remains a viable but under-recognized option. Powering ammonia production with small modular reactors (SMRs), like the NuScale Power Module™, offers several key advantages:

• Made-to-fit flexibility with 4, 6, or 12 modules for desired ammonia plant capacities that are in line with existing ammonia plants
• With >95% online time, all components of the hydrogen and ammonia production plant can be optimally sized using standard operating conditions
• No daily ramping up and down of the hydrogen and ammonia process to match the intermittent electricity supply, which introduces reliability and capability risks
• No need to build cost-intensive storage for excess electricity or hydrogen
• Can be co-located with the hydrogen and ammonia plants, reducing transmission losses
• Small overall site footprint
• Long reactor lifetime of >60 years
• Has capability for both electricity and steam supply, which would be beneficial for solid oxide electrolysis
• Could also power a continuous desalination plant if freshwater availability is limited

For production of ammonia, like most chemical commodities, high utilization and consistent production rates are key priorities. A nuclear power plant using NuScale Power Modules has the flexibility to be a reliable and low-carbon source of electricity and/or process heat to meet a variety of downstream needs.

Coupling nuclear energy with electrolyzer technology to produce hydrogen and ammonia is a key pathway to reducing the CO₂ emissions from this industry and towards achieving decarbonization goals.

Why This Matters

Decarbonizing ammonia production remains an essential goal, not only for reducing industrial emissions, but for safeguarding global food security in a carbon-constrained world. However, recent market developments have made clear that success will depend less on ambition alone and more on disciplined project design, reliable energy supply, and long-term economic viability.

For ammonia production, where continuous operation and high utilization are paramount, dependable sources of low-emissions electricity and process heat will be critical. By coupling proven electrolyzer technologies with nuclear energy solutions such as NuScale Power Modules, developers have a pathway to address many of the challenges currently slowing project deployment.

As the hydrogen and ammonia markets mature, solutions that emphasize reliability, scalability, and durability will be best positioned to support meaningful emissions reductions and long-term industry transformation.