  Green ammonia is poised to be a key part in the hydrogen economy. This paper
discusses green ammonia supply chains from a higher-level industry perspective
with a focus on market structures. The architecture of upstream and downstream
supply chains are explored. Potential ways to accelerate market emergence are
discussed. Market structure is explored based on transaction cost economics and
lessons from the oil and gas industry. Three market structure prototypes are
developed for different phases. In the infancy, a highly vertically integrated
structure is proposed to reduce risks and ensure capital recovery. A
restructuring towards a disintegrated structure is necessary in the next stage
to improve the efficiency. In the late stage, a competitive structure
characterized by a separation between asset ownership and production activities
and further development of short-term and spot markets is proposed towards a
market-driven industry. Finally, a multi-linear regression model is developed
to evaluate the developed structures using a case in the gas industry. Results
indicate that high asset specificity and uncertainty and low frequency lead to
a more disintegrated market structure, and vice versa, thus supporting the
structures designed. We assume the findings and results contribute to
developing green ammonia supply chains and the hydrogen economy.
