The production of hydrogen from photovoltaics (PV) has gained attention due to its potential as an energy vector. In this context, there are two basic configurations for electrically coupling PV to hydrogen electrolyzers: direct and indirect. The direct configuration operates variably based on meteorological conditions but has simplicity as an advantage. The indirect configuration involves a power stage (PS) with a maximum power point tracker and a DC-DC converter, maintaining an optimal power transfer from PV to electrolyzers but incurs losses at the PS. The direct configuration avoids these losses but requires a specific design of the PV generator to achieve high electrical transfer. The comparative analysis of hydrogen production between these two approaches indicates that the indirect paradigm yields a 37.5% higher hydrogen output throughout a typical meteorological year compared to the optimized direct configuration. This increase enhances the overall sunlight-to-hydrogen efficiency, elevating it from 5.0% in the direct case to 6.9% in the indirect one. Furthermore, the direct setup, sensitive to PV power fluctuations, suffers an 18% reduction in hydrogen production with just a 5% reduction in photogenerated power. Under optimal performance, the direct coupling produces less hydrogen unless the DC-DC converter efficiency drops 17% below commercial standards.

中文翻译：

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优化氢气生产：光伏发电与电解槽之间直接和间接耦合的比较研究


利用光伏发电（PV）生产氢气因其作为能源载体的潜力而受到关注。在这种情况下，将光伏电耦合到氢电解器有两种基本配置：直接和间接。直接配置的操作根据气象条件而变化，但具有简单的优点。间接配置涉及带有最大功率点跟踪器和 DC-DC 转换器的功率级 (PS)，可维持从光伏到电解槽的最佳功率传输，但会在 PS 处产生损耗。直接配置避免了这些损失，但需要对光伏发电机进行特定设计才能实现高电力传输。这两种方法之间的氢气产量比较分析表明，与优化的直接配置相比，间接范例在整个典型气象年的氢气产量高出 37.5%。这一提高提高了太阳光转化为氢气的整体效率，从直接情况下的 5.0% 提高到间接情况下的 6.9%。此外，直接装置对光伏发电波动敏感，氢气产量减少了 18%，而光生发电仅减少了 5%。在最佳性能下，直接耦合产生的氢气较少，除非 DC-DC 转换器效率下降到商业标准以下 17%。