The optimal design of central-station photovoltaic (PV) systems depends, among other factors, on the field layout of PV arrays, PV array geometry, tracking constraints, and intermodule electrical connections. We illustrate the sensitivity of yearly PV system energy delivery losses that stem from inter-array shading as a function of key field, tracker, and array-related variables for flat-plates. The results turn out, to an excellent approximation, to be independent of site. We quantitatively assess the magnitude of series/parallel module connections, and bypass diode placement within arrays, on energy losses attributable to inter-array shading. The sensitivity to key design parameters is also found to be predicted accurately by calculations of collectible energy only. As such, the calculations are of general value for rapid yet accurate PV system analysis and optimization.