Techno-Economic design and sizing of a grid-connected solar-wind-storage system for green hydrogen production

In this paper, we present an economic optimization and sizing study of a hybrid solar-wind system integrated with energy storage and grid connection for green hydrogen production. The proposed model used nonlinear constrained optimization to determine the optimal capacities of photovoltaic panels, wind turbines, storage devices, and electrolyzers to maximize the net present value (NPV) of the investment. The system operation was simulated over a multi-year horizon accounting for intermittent renewable generation profiles, electricity market prices, and operational constraints. The optimization yielded an optimal configuration with 85.95 kW of solar PV, 59.87 kW of wind power, 64.18 kW/100 kWh of battery storage, and 100 kW of electrolyzer capacity, achieving a cumulative hydrogen production of 318,545 kg over 20 years. The system achieved a NPV of 524,720 USD with a Levelized Cost of Hydrogen of 3.35 USD/kg. Sensitivity analyses revealed that NPV varied from approximately 60,000 USD to 180,000 USD as the discount rate increased from 2% to 16% and showed a strong positive correlation with hydrogen selling prices. The results demonstrated the techno-economic feasibility of hybrid renewable systems for sustainable hydrogen production, highlighting the trade-offs between capital expenditure and operational revenues.