Dual fuel-based Multi-Energy system for Australian renewable energy zones at country scale

• Optimized an off-/on-grid multi-energy system for eight renewable energy zones. • Dual-fuel hydrogen production and blended natural gas optimization are analysed. • The optimum on-grid system has LCE of 0.1003 $/kWh and NPC of $0.219 million. • Optimum system emits 569 kg/yr of carbon, far less than diesel, oil, or gas systems. This paper aims to optimize dual-fuel facilitated off-/on-grid multi-energy systems (MESs) for different renewable energy zones (REZs) in Australia. The main objective is to develop a novel MES with the main feature of green hydrogen production and blended natural gas utilization for remote households. The proposed optimal system produces green hydrogen of 5343 kg/yr via proton exchange membrane (PEM) electrolyzer and blends it with natural gas. It involves 20 % hydrogen and 80 % natural gas in the overall volume of the blending process. This study contributes by performing optimal sizing of the components, economic-energy-environmental, and performance analyses to examine the most feasible solution for each REZ. The results indicate that the optimal system in North Queensland REZ has the lowest levelized cost of energy (LCE) of 1.28 A$/kWh and 0.1003 A$/kWh, and the net present cost (NPC) of A$0.311 million and A$0.219 million for off-grid and on-grid configurations. The optimal on-grid system has 95.27 % less carbon emissions than the natural gas-fueled combustion energy system.