Abstract: The integrated energy production unit (IEPU) based on power to ammonia (P2A) technology couples green hydrogen production from renewable electricity and the Haber-Bosch ammonia synthesis process. This system provides green ammonia for various sectors, including agriculture, industry, and manufacturing. Its significance lies in advancing the integration of renewable energy sources and the storage and transportation of hydrogen. To quantitatively assess the energy efficiency, techno-economic feasibility, and carbon reduction potential of the IEPU, this study employs Aspen Plus to establish process models for key operations such as electrolytic hydrogen production, ammonia synthesis, and heat exchange networks. The IEPU is subject to comprehensive system simulation, facilitating quantitative evaluations of energy flows, exergy flows, carbon footprints, and the levelized cost of green ammonia production among various equipment components. Thermal-economic performance evaluation reveals that the overall energy efficiency of the IEPU system under design conditions is 39.47%, with an exergy efficiency of 26.51%. Techno-economic assessment indicates that with a renewable energy electricity price of 0.204 RMB/kWh and an annual utilization of 6000 hours, the cost of green ammonia produced by the IEPU system is approximately 1.5 times that of the traditional coal-based ammonia production process. Results from the life cycle carbon footprint assessment, based on water, nuclear, wind, and photovoltaic energy-driven IEPU systems, demonstrate carbon footprints ranging from 0.20 to 2.39 kg CO_2.eq/kg NH₃. These findings provide valuable insights for the planning and design of ammonia-based IEPU systems.