Comparative Analysis of Hydrogen Production and Economic Feasibility: Direct versus Indirect Coupling of Photovoltaic Systems with Electrolyzers

Hydrogen production using photovoltaics (PV) is essential for decarbonizing many sectors of the economy. The integration of PV and hydrogen electrolyzers is actively debated, with focus on direct versus indirect configurations and the option of storage. Direct configuration connects PV directly to the electrolyzer, offering simplicity and reduced installation costs but depends on the weather for efficient power transfer. Indirect configuration adds a power stage, increasing complexity and losses, but enabling maximum power tracking. Adding batteries allows storage of excess PV energy, extending hydrogen production. This study optimizes a PV generator to maximize annual hydrogen production in the direct configuration, then uses the same PV array for indirect configurations with and without batteries for a fair comparison. Results show that the indirect configuration with a battery yields 78% more hydrogen annually than without a battery and 109% more than the direct configuration. The indirect configuration with a battery uses 86.9% of PV energy for hydrogen production, yielding the highest profit at 2.53 € ⋅ W−1 (euros per watt-peak of PV), compared to the direct and indirect configurations without a battery, which use 41.9% and 44.6% of PV energy and generate 1.49 and 1.83 € ⋅ W−1, respectively.