In this study, a novel hybrid thermal energy storage and ammonia fuel cell system is developed and investigated for a solar tower based power plant. An annual analysis of the developed system is performed by considering the monthly average days. Also, the actual power demands as well as the solar intensity changes are taken into account. Thermodynamic approaches of energy and exergy analyses are utilized for system analysis. The energetic efficiency of the proposed power plant varies between 5.3% and 37% while the exergy efficiency ranges between 5.7% and 39%, depending on the corresponding power demands as well as available solar energy. The system simulation results for each month are also described in terms of the specific exergies and enthalpies at the turbine inlets. Furthermore, energy efficiency of the direct ammonia fuel cell is evaluated to be 37% and the exergy efficiency is found to be 34% at the peak power density. At a temperature of 500 degrees C, a specific thermal energy storage capacity of 266 kJ kg(-1) is determined for the hybrid system. (C) 2019 Elsevier Ltd. All rights reserved.