Technoeconomic evaluation of offshore green ammonia production using tidal and wind energy: a case study

Abstract

The climate crisis is driving policy makers, energy companies and chemical industries to accelerate the transition from conventional high-carbon ammonia to low-carbon and zero-carbon (green) ammonia. Ammonia is produced on a vast scale globally and is predominantly used for fertilizers but has a potential use as an energy vector. Utilizing variable renewable energy (typically solar or wind) for green ammonia production requires expensive energy storage. Tidal stream energy is a novel energy source for green ammonia production and could be an ideal energy source given its high resource availability and predictability. The objective of this paper is to determine if tidal stream energy is a useful energy resource (technically and economically) for offshore green ammonia production. This idea is presented through a case study on the Pentland Firth, a globally excellent tidal stream location. Using 30 years of hourly wind and tidal data, the addition of tidal stream capacity to wind capacity is shown to decrease the hydrogen storage requirement by 96% and eliminate the fuel cell requirement and thus reduce the levelized cost of ammonia (LCOA) by 12%.