PV module energy rating standard IEC 61853-3 intercomparison and best
practice guidelines for implementation and validation
Abstract
The IEC 61853 standard series aims to provide a standardized measure for
PV module energy rating, namely the Climate Specific Energy Rating
(CSER). For this purpose, it defines procedures for the experimental
determination of input data and algorithms for calculating the CSER.
However, some steps leave room for interpretation regarding the specific
implementation. To analyze the impact of these ambiguities, the
comparability of results and the clarity of the algorithm for
calculating the CSER in part 3 of the standard, an intercomparison is
performed among research organizations with 10 different implementations
of the algorithm. We share the same input data, obtained by measurement
of a commercial crystalline silicon PV module, among the participating
organizations. Each participant then uses their individual
implementations of the algorithm to calculate the resulting CSER values.
The initial blind comparison reveals differences of 0.133 (14.7%) in
CSER. After several comparison phases, a best practice approach is
defined, which reduces the difference by a factor of 210 to below 0.001
(0.1%) in CSER for two independent PV modules. The best practice
presented in this paper establishes clear guidelines for the numerical
treatment of the spectral correction and power matrix extrapolation,
where the methods in the standard are not clearly defined. Additionally,
we provide input data and results for the PV community to test their
implementations of the standard’s algorithm. To identify the source of
the deviations, we introduce a climate data diagnostic set. Based on our
experiences, we give recommendations for the future development of the
standard.