Benefits and challenges for renewable ammonia
• Ammonia is a versatile fuel for stationary power and heat and for maritime transport that can be used in internal combustion engines, gas turbines, industrial furnaces, generator sets and fuel cells. It can be stored as a liquid at 8 bar or above and at ambient temperature, or at atmospheric pressure at -33°C.
• Around 18-20  Mt of ammonia is shipped internationally per year. Substantial investments will be required to expand the shipping infrastructure and allow ammonia refuelling.
• Renewable ammonia can displace fossil fuels at scale in hard-to-abate areas of the power and transport sectors. However, the use of ammonia as a fuel could increase emissions of nitrogen oxides (NOX and nitrous oxide, N2O), which must be avoided.
• Most of the proposed renewable ammonia plants use variable solar photovoltaics (PV) and wind. A number of electrolysis technologies exist. Technological and operational innovations, in combination with careful site selection and project design, can facilitate the integration of high shares of solar and wind.
• The current global electrolyser production capacity of a reported 2.1 GW per year (in 2020) needs to scale up more than 20-fold to meet the renewable ammonia manufacturing objectives for 2050.
• Demonstrations, technology commercialisation and regulatory development will be required for the ammonia fuel market to take off