PCM-Enhanced PV Panel

PCM-Enhanced PV Panel, ANSYS Fluent CFD Simulation

Description

Thermal management of photovoltaic (PV) systems presents a significant challenge in solar energy technology, since PV modules can experience temperature increases of up to 35°C above ambient conditions during peak sunlight exposure — a rise that substantially impacts performance, with power output declining by approximately -0.65% for every 1°C increase in temperature.

This project compares two configurations: a conventional PV panel without any cooling enhancement, and an enhanced system incorporating PCM-based passive cooling. The PV system was modeled as a multi-layer structure comprising a glass cover layer, an Ethylene-Vinyl-Acetate (EVA) layer, silicon solar cells, a second EVA layer, and a Tedlar back sheet, with the PCM-enhanced configuration additionally incorporating a layer of RT42 paraffin PCM.

The full 3D geometry, including both the conventional and PCM-enhanced configurations, was built in SpaceClaim, capturing all PV panel layers along with the PCM containment structure. The domain was meshed in ANSYS Meshing using a structured grid of approximately 1,000,000 elements, sized to adequately resolve thermal gradients while maintaining computational efficiency.

Methodology

The Solidification and Melting model was activated to capture the PCM's phase-change dynamics, while the Discrete Ordinates (DO) radiation model captured radiative heat transfer throughout the system. Solar ray tracing was enabled for precise solar load calculations, using location-specific parameters set to longitude -84.63°, latitude 13.65°, and UTC-5 time zone — eliminating the need for simplified radiation source terms and enabling more realistic solar irradiation modeling. Momentum equations were deliberately disabled, focusing computational resources specifically on the system's thermal behavior.

The simulation ran over a period of 19,500 seconds (approximately 5.4 hours) to evaluate thermal performance across both configurations.

Conclusion

The PCM-enhanced system achieved an average PV temperature of 313.25 K (40.1°C), compared to 315.06 K (41.91°C) for the conventional system — a difference of 1.81 K. The PCM-enhanced configuration also showed a notably more uniform temperature distribution across the panel, with temperature contours revealing effective heat absorption by the PCM layer and lower peak temperatures thanks to its thermal buffering effect; by contrast, the conventional system exhibited higher thermal gradients and less uniform distribution overall.

Liquid fraction contours reveal the PCM's phase transition progressing gradually from top to bottom, with liquid fraction values ranging from 0.122 to 0.267 — confirming a progressive, effective thermal energy storage process rather than an abrupt phase change. The PCM case also showed a broader overall temperature range (312–317 K) compared to the conventional case (312–315 K), reflecting the PCM's role in redistributing and moderating heat across the panel.

This 1.81 K temperature reduction translates to an estimated 1.18% improvement in electrical efficiency, based on the standard -0.65%/°C temperature coefficient for PV performance. Beyond the direct efficiency gain, the more stable operating temperature also suggests reduced thermal stress on PV components and improved long-term reliability — confirming that PCM-based passive cooling offers a measurable, meaningful improvement in PV thermal management under realistic solar loading conditions.