## 4 Conclusions  
In this work, PCM panels for PV applications were successfully prepared and compared. EG vacuum impregnation is confirmed as a suitable process for the shape stabilization of organic PCMs, either paraffin (RT35 and RT44) or a fatty acid mixture (MPA). EG is particularly effective in avoiding MPA leakage, probably due to the stronger polar interaction and the planar shape of the crystals. Panels with a fixed geometry can be obtained via a cold compaction process, additionally conferring a low void fraction to the composites. Consequently, the graphitic network enhances the thermal conductivity from 7 to 16 times with respect to the neat PCMs, with and the maximum reached value of 6 W/m\(\cdot\)K was approached by RT44/EG14 at 25 \({}^{\circ}\)C. The high melting enthalpy of the thermal management systems was maintained thanks to the low EG fraction (14 phr), guaranteeing 3.3-4.4 MJ/m\({}^{2}\) of thermal management ability. The intervals in which the cooling action can be exploited are 30-39 \({}^{\circ}\)C for RT35/EG14, 40-47 \({}^{\circ}\)C for RT44/EG14, and  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**TMS** & \(\rho\) & \(\lambda_{\text{2S}}\) & \(\Delta T\) \({}^{+}\) & \(\Delta T\) \({}^{-}\) & \(\Delta H_{m}\) & \(\Delta H_{m}\)\({}^{*}\) & **SD** & _TMA_ & \(t\) & _TEC_ \\
**Panels** & **[g/cm\({}^{3}\)]** & **[W/(m\(\cdot\)K)]** & **[\({}^{\circ}\)C]** & **[\({}^{\circ}\)C]** & **[J/g]** & **[J/cm\({}^{3}\)]** & **[kg/m\({}^{2}\)]** & **[MJ/m\({}^{2}\)]** & **[mm]** & **[kg/Unit]** \\ \hline RT35/EG14 & 0.94 & 4.03 & 30–39 & 37–30 & 206 & 194 & 18.8 & 3.9 & 19.4 & 14.4 \\ RT44/EG14 & 0.99 & 5.95 & 40–47 & 45–35 & 220 & 218 & 19.8 & 4.4 & 18.4 & 15.4 \\ MPA/EG14 & 1.05 & 4.66 & 45–51 & 48–42 & 159 & 167 & 21.0 & 3.3 & 17.3 & 11.7 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Specifics of realized thermal management systems.  
45-51 \({}^{\circ}\)C for MPA/EG14. Outdoor tests with the thermal management panels coupled to silicon PV cells will be necessary to make conclusions regarding the effectiveness of improving the PV conversion efficiency, which will depend not only on the material properties but also on the environmental conditions at a specific latitude and season. Thereby, a rank of the investigated systems cannot be drafted a priori and all of the passive cooling systems developed in this study can be considered good candidates in PV applications. The obtained PCM-based panels were attached to the rear of the polycrystalline silicon cells, whose efficiency improvement was quantified under exposure to sunlight conditions during the summer of 2024 at a latitude of 46\({}^{\circ}\) N. The results of the PV tests by using the selected PCM/EG panels will be presented in a forthcoming paper.  
Conceptualization, S.S., F.V., L.F. and R.P.; methodology, S.S., F.V., L.F., M.G. and R.P.; validation, S.S., R.P. and L.F.; formal analysis, S.S.; investigation, S.S.; resources, L.F.; data curation, S.S.; writing--original draft preparation, S.S; writing--review and editing, F.V. and L.F.; supervision, F.V., R.P. and L.F.; project administration, R.P. and L.F. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
We kindly acknowledge [PERSON] for her help in material preparation.  
The authors [PERSON] and [PERSON] were employed by the company Eni S.p.A. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.