Technical and economic analysis of renewable energy systems with hydrogen-ammonia energy storage: A comparison of different ammonia synthesis methods

The environmentally friendly and mild plasma-catalyzed ammonia (NH3) synthesis process is emerging as one of the sustainable strategies. With the continuous decrease in the cost of solar and wind power generation and the promotion of carbon neutrality policy, low-cost, intermittent renewable electricity will provide a possibility for the vigorous development of plasma NH3 synthesis technology. In this study, we propose a renewable energy system based on combined hydrogen-ammonia energy storage, which is technically and economically evaluated based on hourly meteorological data. The novelty of this study lies in the comparative evaluation of the technical and economic feasibility of the Haber-Bosch process and plasma catalytic process for ammonia synthesis within a renewable energy system that integrates electricity, hydrogen, and ammonia. To leverage the economic potential of regions rich in renewable energy, ammonia is considered not only as an energy storage carrier but also as a valuable export product. The results show that the internal rate of return of the hydrogen-ammonia combined energy storage system is 19.6 % for the H-B method and 19.8 % for the plasma method. If the plasma-NH3 synthesis method achieves a large-scale conversion rate of 10 % at the best energy efficiency of 37.9 g center dot kWh- 1, the levelized cost of electricity will be 0.062 $center dot kWh- 1, which is lower than the Haber-Bosch method of 0.069 $center dot kWh- 1. It will also be lower than the local levelized cost of electricity of 0.064 $center dot kWh- 1. Furthermore, the sensitivity analysis indicates that, with future reductions in initial construction and operating costs, plasmabased NH3 synthesis technology is expected to become a more economically viable alternative to the HaberBosch process due to its lower initial investment cost. This also demonstrates the economic feasibility of plasma catalytic technology and its potential competitive advantage over traditional ammonia synthesis processes in the future.