Background: Partial shading is among the most common and operationally significant causes of energy yield loss in grid-connected solar photovoltaic (PV) systems, arising from obstructions such as clouds, vegetation, adjacent structures, and soiling, yet its impact varies considerably with array configuration.

Objective: This study evaluates the effect of increasing partial shading (0%, 25%, 50%, and 75% of array area) on the maximum power output of a grid-connected PV array, and compares power loss outcomes between Series-Parallel (SP) and Total-Cross-Tied (TCT) array configurations under identical shading scenarios.

Method: A simulated dataset, modelled on patterns reported in published experimental and simulation-based literature on partially shaded PV arrays, was used to evaluate maximum power point (MPP), fill factor, and percentage power loss across twenty-four simulated test runs (six replicates per shading level, two array configurations). Data were analysed using descriptive statistics and one-way analysis of variance (ANOVA) in MATLAB/Simulink and SPSS (version 27).

Key Results: Power output declined sharply with increasing shading in both configurations, with the SP configuration losing approximately 79.8% of unshaded output at 75% shading, compared to 71.2% for the TCT configuration. The TCT configuration consistently outperformed the SP configuration at every non-zero shading level, attributable to improved current redistribution across cross-tied connections. Partial shading was also found to introduce multiple local maxima on the power-voltage (P-V) curve, creating a risk of conventional maximum power point tracking (MPPT) algorithms converging on a suboptimal local peak.