Remote ammonia production for the future energy demand of Belgium: Techno-economic optimization of local and remote ammonia production under uncertainty

Abstract

Regions with abundantly available renewable energy are not necessarily the same as those with a high population density and high energy consumption. Therefore, renewable energy can be produced in optimal climate conditions with a remote renewable hub and transported to these population-dense regions. To establish this energy transport, ammonia provides a flexible, easy-to-handle energy carrier, which already showed a viable option for transporting energy from Australia to Japan. However, current literature rarely considers the impact of techno-economic uncertainty (variable energy consumption or uncertain capital and operational expenses) on the feasibility of this transport. Using those uncertainties, we performed a robust design optimization on the levelized cost of ammonia and the power-to-ammonia efficiency to compare the local (Belgium) and remote (Morocco) ammonia production and transport for Belgium. This paper provides the robust designs (i.e. least sensitive to uncertainty) for local and remote renewable ammonia production and the advantages of both approaches on the levelized cost and power-to-ammonia energy efficiency. The results confirm that ammonia production in regions with high solar irradiance followed by the transport of ammonia is cost-effective and robust (790 euro/tonneNH3 in mean and 128 euro/tonneNH3 in standard deviation) over local production (1334 euro/tonneNH3 in mean and 249 euro/tonneNH3 in standard deviation). However, local ammonia production provides for more efficient and less sensitive power-to-ammonia plant designs (53.6% in mean and 0.1% in standard deviation), while the remote production is less efficient and more sensitive to uncertainties (47.9% in mean and 1.53% in standard deviation). Both objectives are highly influenced by the capacity of the photovoltaic arrays and the electrolyzers, wherein in the case of Morroco, the backup capacity plays a significant role in the system’s efficiency. Future work aims to perform a techno-economic environmental evaluation of this robust design optimization, including environmental indicators like recycling of composite materials and depletion of rare materials