Development and experimental validation of an open-source photovoltaic-thermal collector modelica model that only needs datasheet parameters

This work introduces the first validated, user‑friendly, open‑source photovoltaic–thermal (PVT) collector model in Modelica for system‑level simulation. Existing open‑source approaches typically combine a solar‑thermal collector with a separate PV module model, resulting in steady‑state formulations that miss dynamic thermal behavior and thermal–electrical coupling. The developed PVT model follows the ISO 9806:2017 quasi‑dynamic thermal standard, includes a dedicated electrical formulation, and relies solely on manufacturer datasheet parameters, avoiding measurement‑based calibration. Validation against two unglazed PVT collectors shows strong agreement across diverse operating and weather conditions. A systematic coefficient‑conversion procedure enables consistent use of datasheet parameters originating from ISO 9806:2013, ISO 9806:2017 or ISO 9806:2025. A quantitative comparison with the state‑of‑the‑art PVT representation used in Modelica demonstrates that neglecting wind‑dependent heat losses, long‑wave radiative exchange, and thermal–electrical coupling leads to substantial thermal power overestimation and noticeable electrical power deviations. Together, these contributions deliver a transparent and robust tool for PVT system simulation within the IDEAS library.