Double-Encapsulated Phase Change Material Microcapsules with Paraffin Shell for PV Cooling: Experimental and Performance Analysis

Energy is indispensable in modern society. Solar Photovoltaic (PV) technology has gained increasing popularity due to its notable power generation advantages. However, PV modules face a critical “temperature-efficiency” contradiction during energy conversion: only about 20% of solar radiation is converted into electricity, while the remaining energy accumulates as heat, leading to significant performance degradation. To address this issue, our experiment employs a novel cooling technology-phase-change microcapsule cooling. By utilizing the heat absorption and release during the phase transition of the microcapsules, the temperature of PV modules is effectively regulated. Furthermore, the phase-change microcapsules designed in this work innovatively introduce paraffin as a secondary shell material, which improves thermal cycling stability. After 200 thermal cycles, the enthalpy loss remains negligible, with a retained enthalpy of 188.8 J/g. The microcapsules were applied to the back of PV modules, and field tests were conducted in Lhasa (91°06′ E, 29°36′ N). The results show a maximum temperature reduction of 16 °C (average: 4.66 °C) on the front side and 15 °C (average: 4.33 °C) on the back side, along with an increase in Pmax (P max ) of up to 11.11% (average: 4.55%). This study not only advances the development of bio-inspired encapsulation techniques for novel phase-change microcapsules, but also provides an innovative thermal-management solution for PV modules operating in extreme environments.