Integrated Modelling and Enhanced Utilization of Power-to-Ammonia for High Renewable Penetrated Multi-Energy Systems

Abstract

This paper proposes an integrated model of power-to-ammonia (P2A) to exploit the inherent operational dispatchability of nitrogen-ammonia (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) cycles for high-renewable multi-energy systems. In this model, the steady-state electrolytic process is mathematically formulated into a thermodynamic system based on thermo-electrochemical effects, and the long-term degradation process of P2A is transformed as the short-term degradation cost to characterize its cost-efficiency. Furthermore, the enhanced utilization of P2A is explored to form a renewable energy hub for coupled multi-energy supplies, and a coupling matrix is formulated for the optimal synergies of electrical, ammonia and thermal energy carriers. An iterative solution approach is further developed to schedule the hub-internal multi-energy conversion and storage devices for high-efficiency utilization of available hybrid solar-wind renewables. Numerical studies on a stand-alone microgrid over a 24-hour scheduling periods are presented to confirm the effectiveness and superiority of the proposed methodology over regular battery and power-to-gas (P2G) storages on system operational economy and renewable energy accommodation.