US Firm Uses Solar Energy to Make Sustainable Nitrogen Fertiliser

California-based Nitricity has created an experimental reactor that produces economical and ecological nitrogen fertilizers using solar energy. Their on-site fertilizer production eliminates the emissions of fertilizer transport and provides a sustainable alternative to the Haber-Bosch process, which uses fossil fuels to fix nitrogen.

The nitrogen extracted from the air enables Nitricity to produce nitric acid, the most essential nutrient in fertilizers that plants use to grow all of our food.

In October 2021, the company began commercial operations with an installation of 144 solar panels. On its official website, Nitricity then provided the results of an experimental study on its pilot project in Fresno, California. The starting solar system was a complex of 16 ground panels producing 75-85V and a maximum power of 2.4kW.

The plant was connected directly to an underground irrigation system, used to fertilize a tomato crop. The study shows the success of the experiment, with tomatoes in quantity and quality comparable to those obtained by the control system (ie a normal fertilizer with nitrogen produced in series).

Nitricty claims their technology will appeal to a broad range of customers. The system is readily available, allowing farmers who are far from fertilizer production centers to benefit from the innovation. The Nitricity process challenges the industrial production of ammonia, a process that directly creates more CO2 than any other human-driven chemical process on earth. The main raw material for modern nitrogen fixation is natural gas, and its conversion into ammonia generates heavy pollution.

Nitricity’s distributed and localized nitrogen solution also avoids transport emissions. The process of distributing fossil-based nitrogen fertilizers can cause market inefficiencies, resulting in the cost of fertilizer for a farmer two to five times higher than what would be available from a factory. Due to their direct link with natural gas, the production costs of fossil-based fertilizers are also unpredictable and fall on costs.

A practical example of the application of Nitricity technology, with the case of a wheat producer:

• 1 hectare of wheat needs about 112 kg of nitrogen.
• 112 kg of nitrogen (via ammonia or urea) is now produced in a coal or NG factory, which emits around 136 kg of CO2.
• With the current process, then, 300 grams of N2O are emitted per hectare. This means that one hectare emits around 200kg of CO2 due to N2O emissions into the soil.
• In total, 1 hectare of wheat can emit up to 340kg of CO2 emissions from the production and application of fertilizers.

Nitricity’s technology seems to mitigate nearly 100% of these emissions. If these fertilization systems are paired with solar-powered greenhouses and other sustainable land management methods, solar energy will likely be needed for our food supply in the future.