Trend of Temperature Coefficients of c-Si Module Technologies from the past 15 Years

The temperature dependence of PV module power is a key parameter for energy yield calculations, especially for hot climates. Project yield assessments typically rely on datasheet values where temperature coefficients (TCs) are often reported optimistically and seldom verified. A representative selection of crystalline silicon (c-Si) modules with various cell technologies produced over the past 15 years was screened. The dataset covers Al-BSF, PERC, TOPCon, HJT and back contact (BC) designs with varying cell sizes (5”, M0, M3, M6, M10), module circuitries (60 cells in series, 144 cells with 2x72cells as series-parallel interconnection) and module sizes (168x97cm² vs 228x114cm²). A long-pulse flash method to determine TCs consistently across three irradiance levels was applied. A clear trend towards lower TCs for maximum power  with newer cell technologies was observed. Additionally, module design and cell cutting quality can impact absolute values. The TC irradiance dependence for Isc , Voc  and Pmpp  showed similar patterns across all technologies. The presented data support industry trends and helps to further improve energy rating according to IEC 61853-series. The presented results can also serve as base for benchmarks where new concepts are checked versus older modules where long term field experience exists.