packagePVT_UN
Information
This package contains validation models for the PVT_UN collector
(referred to as PVT2 in Meertens et al., 2026),
an uncovered and uninsulated PVT collector,
based on experimental data from a long-term outdoor test campaign in Austria (Veynandt et al., 2023).
The full dataset spans 58 consecutive summer days with 5-second resolution, capturing a wide range of operating conditions. Notably, the test period includes days with several hours of very high wind speeds, reaching up to 10–12 m/s, which significantly affect convective heat losses.
The full dataset was split into 8 weeks to limit the file size per dataset.
The validation models allow to change the week via the parameter week.
The user can also merge the files together into one dataset and
change the fileName parameter in the meaDat block
to simulate the all 58 summer days in one run.
The package includes two models:
- Thermal: Validates thermal output using the quasi-dynamic ISO 9806:2017 formulation.
- Electrical: Validates electrical output using the PVWatts V5 formulation.
Model limitations
Overall, the validation of the PVT_UN model shows good agreement under operating conditions that are representative for unglazed, non-insulated PVT collectors. However, several limitations arise from characteristics of the experimental setup rather than the model itself. Because the collector has no rear insulation, heat losses remain high, and the circulation pump was operated continuously, even during periods with negative thermal output. This operating mode is not representative of real-world installations, where flow would typically be stopped when thermal gains fall below losses. In addition, the imposed temperature differences between the heat transfer fluid and the ambient air were significantly higher than what would normally occur in practical PVT operation, further amplifying thermal losses and exposing the collector to an extreme regime outside the datasheet parameter range. These conditions can lead to discrepancies between simulated and measured performance, but they do not reflect typical system behavior. When the analysis is restricted to periods with positive thermal output, the model exhibits good thermal performance.
Validation results
The complete validation methodology, covering the model formulation, datasheet-based thermal–electrical coupling, and performance metrics, is documented in Meertens et al. (2026). The same paper reports the detailed results, including MAE and RMSE values and the energy deviations for each day type.
References
- Meertens, L.; Jansen, J.; Helsen, L. (2026). Development and Experimental Validation of an Open-Source Photovoltaic‑Thermal Collector Modelica Model that Only Needs Datasheet Parameters. Submitted to Mathematical and Computer Modelling of Dynamical Systems, Special Issue on Modelica, FMI, and Open Standards.
- Veynandt, François, Franz Inschlag, et al. Measurement data from real operation of a hybrid photovoltaic‑thermal solar collectors, used for the development of a data‑driven model. Data in Brief 49 (2023): 109417. DOI: 10.1016/j.dib.2023.109417
- Veynandt, François, Peter Klanatsky, et al. Hybrid photovoltaic‑thermal solar collector modelling with parameter identification using operation data. Energy and Buildings. 295 (2023): 113277. DOI: 10.1016/j.enbuild.2023.113277
Contents
| Name | Description |
|---|---|
| PVTCollectorValidation | Validation model of a photovoltaic–thermal (PVT) collector using the ISO 9806:2017 thermal method with integrated electrical coupling |
| PVT_UN_Electrical | Validation model for an unglazed rear-non-insulated PVT Collector |
| PVT_UN_Thermal | Validation model for an unglazed rear-non-insulated PVT Collector |
| BaseClasses |