If PV source circuits have different orientations, what affects the current of the string?

When photovoltaic (PV) source circuits have different orientations, the current of the string is primarily influenced by the worst orientation among the panels. This is because all panels in a series string must produce the same amount of current for the system to operate effectively.

In a series configuration, the current is determined by the panel that generates the least amount of current due to shading, differences in orientation, or other factors. If one panel is oriented poorly—meaning it receives less sunlight compared to others—it will restrict the overall current flowing through the entire string to match that panel's output. This results in a bottleneck effect where the panel with the worst performance governs the total current.

Understanding this is crucial for designing and optimizing solar panel installations. When evaluating a system with multiple orientations, installers need to ensure that the panels with the least favorable conditions, such as shading or incorrect angle positioning, are accounted for, as they greatly affect system performance.