Assumption of identical cell parameters
SunSolve assumes that all cells within a module share the same intrinsic electrical properties — specifically, identical values of recombination current density (J0), series resistance (Rs), and shunt resistance (Rsh). As a result, any module-level mismatch that occurs in a simulation is driven purely by variations in illumination intensity, rather than by differences in intrinsic cell characteristics.
This simplification aligns with the findings of several studies demonstrating that cell-to-cell performance variance in modern manufacturing is negligible. Across multiple production datasets, the worst-case loss due to such variance was found to be below 0.05% [Evans2015, Evans2018].
“In the case of classifying cells into modules, it has been shown that mismatch loss will remain below 0.1% even for the case where no cell sorting whatsoever is done. When even rudimentary cell sorting is used, loss should be well below 0.05% in all cases.” — Evans2015
“Historically, this is a well-studied and documented effect but in a modern photovoltaic module the effects is so small it is virtually un-measurable [Forniés2013, Evans2015], due to low variance in the cell performance in mass production.” — Evans2018
“For the total loss, group A (single bin, no sorting) is the worst of all even though the total loss is less than 0.04%.” — Evans2018
“When the losses associated with mismatch are assessed holistically, it can be seen that installation-related issues are a much more significant area of loss than those that can be influenced with decisions made in manufacturing.” — Evans2018
In summary, the assumption of identical cell parameters is justified for high-efficiency crystalline silicon modules, where cell-to-cell variability is practically negligible compared to optical, thermal, or installation-induced mismatch effects.