Theoretical review of series resistance determination methods for solar cells

Using a systematic approach, a collection of expressions for the series resistance of a solar cell are derived from the diode model. Many published series resistance determination methods are among them, or are slight variations on them. Some expressions have not yet been described in the literature. Representation of the methods in a two-dimensional array allows for easy comparison and reveals that many of the previously published methods are more alike than might appear at first sight. From a discussion of the various methods, on the basis of the two-dimensional array arrangement, an overview of the required approximations and assumptions for each method is assembled. Taking the effect of these approximations and assumptions into account, it is expected that the method of Wolf & Rauschenbach will provide the most accurate value for the series resistance of a solar cell.