Analytic $I_{\text{sc}}$–$V_{\text{oc}}$ Method and Power Loss Modes From Outdoor Time-Series $I$–$V$ Curves

Utilizing large-scale outdoor I-V data streams, the authors demonstrated a feasible, repeatable method to construct outdoor time-series I
_sc
-V
_oc
curves. Resulting Analytic I
_sc
-V
_oc
curves are validated with laboratory Suns-V
_oc
measurements. Comparing I
_sc
-V
_oc
with real I-V curves, power loss modes including uniform current loss, recombination loss, series resistance loss, and current mismatch loss can be quantified in units of watts or percent nominal power, making them directly comparable. Above power loss modes are calculated for long-term I-V data from fielded modules in different climate zones, and dominant power loss modes were determined from the resulting time series. This method has been published as an open source package in R programming language.