Hydrogen-to-Ammonia Green Fuel Production via Haber–Bosch Process in a Solar–Wind Poly-Generation System: Design, Intelligent Optimization, and 4E Analysis

Abstract

Hydrogen offers a pathway to deep decarbonization; however, its storage and transport remain significant barriers for large-scale renewable energy systems. This study proposes a novel hybrid solar-wind poly-generation architecture that couples a two-level thermal cascading structure (supercritical CO2 Brayton and transcritical CO2 Rankine cycles) with a continuously operated water electrolyzer–Haber–Bosch ammonia loop, enabling stable renewable-to-hydrogen-to-ammonia conversion without auxiliary heating. This framework provides a highdensity and safe long-term energy storage solution. A comprehensive 3E analysis, operational CO2 emission avoidance assessment, and multi-objective optimization were performed using an ANN-based surrogate method coupled with the NSGA-II algorithm. Exergy and economic analyses identified the solar field as the main source of irreversibility and cost, contributing to 48% and 60.1%, respectively. The surrogate-based optimization reduced computational time by 97.63% relative to direct simulation (≈38 hours to 54 minutes) while maintaining accuracy. Under optimized operating conditions (solar field area of 5624.32 m2, compressor pressure ratio of 1.93, solar irradiance of 411.29 W/m2, wind speed of 7.98 m/s, and regenerator effectiveness of 0.86), the system achieved an exergy efficiency of 35.86%, ammonia production of 1.09 kg/h, and a payback period of 5.07 years under the adopted economic assumptions. The environmental assessment indicates 167.5 kg/h of CO2 emissions avoided, corresponding to an emission reduction cost of 4.02 $/h. A Dubai-based case study demonstrated conceptual feasibility under steady-state conditions. The results highlight the system’s theoretical potential as an advanced renewable-to-ammonia platform for high-density energy storage and multi-product output, subject to further dynamic validation and detailed engineering.