Parametric and distribution-based definition of climatic zones for photovoltaics

The definition of climatic zones for photovoltaics (PV) is critical for improving resource simulation, energy forecasting, and performance evaluation. Existing classifications provide valuable frameworks, but suffer from limitations in integrating relevant PV parameters into the classification pipeline and remaining technology-agnostic. This paper addresses these shortcomings by introducing a classification tailored to key PV performance metrics: the PV array energy yield ( ) and module performance ratio ( ), using the annual irradiation ( ) and a novel irradiation-weighted module temperature ( ) as core climatic parameters. These parameters ensure a technology-independent yet performance-relevant classification for the two most widely used parameters in the PV community. The classification is backed by high-resolution climatic data ( ) and recent advancements in PV simulations and data science. Additionally, we explore a distribution-based approach to account for the increasing importance of variability in PV generation. Applying the theory of optimal transport to the distribution of daily irradiation, we devise a novel classification concept that groups locations with similar daily generation characteristics. This method is better suited for applications where the variability of the generation, rather than annual averages, is the main feature of interest, such as firm power generation. We apply our framework to a global and pan-European classification to illustrate the effectiveness of our methodology.