DC wiring losses and mismatch affects how the module I-V curves are combined into an array. Series strings of modules all must carry the same current and parallel strings must operate at the same voltage. This fact means that any combined value of current and voltage may not equal the maximum power point (MPP) for all modules in the array. When mismatch is present, either due to inherent performance differences between modules, heterogeneous irradiance or temperature on the array, or even differential wiring losses across the array, the ideal performance (MPP) is never fully realized. This step aims to calculate the magnitude of this loss.