Ammonia is a critical chemical to fertilize plants and feed the world. Recently, a first of its kind renewable ammonia plant has been built in Morris, MN, powered by wind energy. A broader deployment of such renewable plants will require careful selection of location and unit sizing to keep costs low and optimize the entire ammonia supply chain. In this paper, a 48-h receding horizon optimization problem is developed to optimally schedule unit set points for the system in order to minimize annual operating costs. This optimization formulation is then used to examine how the optimal operating cost depends on the key design parameters of location and unit size. Using the results obtained, simple correlations are developed which capture the dependence of operating costs on ratios of unit capacities, properly scaled to remove the dependence on location. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.