Long-Term Field Performance Degradation Analysis of Heterojunction Solar Modules Across Five Climate Zones in Asia and Europe

Abstract

Heterojunction (HJT) solar module field-performance characterization at the multi-year time horizon has been historically limited by the recency of large-scale HJT deployment. This study synthesizes monitoring records from 23 deployments totaling 187 megawatts of HJT capacity, commissioned between 2018 and 2022, across temperate-oceanic, humid-subtropical, semi-arid, alpine-cold, and tropical-monsoon climate zones in Asia and Europe. We extract per-string degradation rates after sample-bias correction and compare them to manufacturer warranty curves and to peer-reference deployments of PERC modules at adjacent sites. The analysis identifies climate-zone-conditional degradation patterns and discusses the implications for HJT-specific reliability protocols and warranty-design refinements.